Prediabetes as a risk factor for all-cause and cause-specific mortality: a prospective analysis of 115,919 adults without diabetes in Mexico City

BACKGROUND

Prediabetes has been associated with increased all-cause and cardiovascular mortality. However, no large-scale studies have been conducted in Mexico or Latin America examining these associations.

METHODS

We analyzed data from 115,919 adults without diabetes (diagnosed or undiagnosed) aged 35-84 years who participated in the Mexico City Prospective Study between 1998 and 2004. Participants were followed until January 1 st , 2021 for cause-specific mortality. We defined prediabetes according to the American Diabetes Association (ADA, HbA 1c 5.7% to 6.4%) and the International Expert Committee (IEC, HbA 1c 6.0-6.4%) definitions. Cox regression adjusted for confounders was used to estimate all-cause and cause-specific mortality rate ratios (RR) at ages 35-74 years associated with prediabetes.

FINDINGS

During 2,085,392 person-years of follow-up (median in survivors 19 years), there were 6,810 deaths at ages 35-74, including 1,742 from cardiovascular disease, 892 from renal disease and 108 from acute diabetic crises. Of 110,405 participants aged 35-74 years at recruitment, 28,852 (26%) had ADA-defined prediabetes and 7,203 (7%) had IEC-defined prediabetes. Compared with those without prediabetes, individuals with prediabetes had higher risk of all-cause mortality at ages 35-74 years (RR 1.13, 95% CI 1.07-1.19 for ADA-defined prediabetes and RR 1.28, 1.18-1.39 for IEC-defined prediabetes), as well as increased risk of cardiovascular mortality (RR 1.22 [1.10-1.35] and 1.42 [1.22-1.65], respectively), renal mortality (RR 1.35 [1.08-1.68] and 1.69 [1.24-2.31], respectively), and death from an acute diabetic crisis (RR 2.63 [1.76-3.94] and 3.43 [2.09-5.62], respectively). RRs were larger at younger than at older ages, and similar for men compared to women. The absolute excess risk associated with ADA and IEC-defined prediabetes at ages 35-74 accounted for6% and 3% of cardiovascular deaths respectively, 10% and 5% of renal deaths respectively, and 31% and 14% of acute diabetic deaths respectively.

INTERPRETATION

Prediabetes is a significant risk factor for all-cause, cardiovascular, renal, and acute diabetic deaths in Mexican adults. Identification and timely management of individuals with prediabetes for targeted risk reduction could contribute to reducing premature mortality from cardiometabolic causes in this population.

FUNDING

Wellcome Trust, the Mexican Health Ministry, the National Council of Science and Technology for Mexico, Cancer Research UK, British Heart Foundation, UK Medical Research Council. Instituto Nacional de Geriatría (Mexico City).

RESEARCH IN CONTEXT

Evidence before this study: We conducted a literature search in PubMed to identify articles published in English before February 27 th , 2024 that reported on prospective studies examining the association between prediabetes with all-cause or cause-specific mortality or progression to diabetes in a Mexican or Latin American population, using the terms ("prediabetes" OR "impaired fasting glucose" OR "impaired glucose tolerance") AND ("mortality" OR "death") AND ("Mexico" OR "Mexican" OR "Latin America" OR "Latin American"). There were no studies examining risk associated with prediabetes definitions and mortality among adults in Mexico. We identified one study from Peru that included 988 participants and investigated only all-cause mortality for impaired fasting glucose and HbA 1c -based definitions of prediabetes from ADA and IEC; this study reported increased mortality risk related to ADA-defined prediabetes based on HbA 1c measures. Generalizability of these findings to other Latin American countries and regions with distinct cardiometabolic profiles in unclear. Added value of this study: Our study included 115,919 participants without diabetes from Mexico City, of whom (26%) had ADA-defined prediabetes and 7,203 (7%) had IEC-defined prediabetes. We found that prediabetes is associated with higher risks of all-cause and cause-specific mortality (cardiovascular, renal, and acute diabetic causes) than among participants without prediabetes. We found RRs to be larger at younger than at older ages, and largely similar for men compared to women. Among those without previously diagnosed diabetes, we found that the excess risk associated with ADA- and IEC-defined prediabetes at ages 35-74 years accounted for 6% and 3% of cardiovascular deaths, 10% and 5% of renal deaths, and 31% and 14% of acute diabetic deaths, respectively. .Implications of all the available evidence: Our results show that prediabetes is a significant risk factor for cardiovascular, kidney, and acute diabetic deaths among Mexican adults and accounts for a notable fraction of such deaths. Identification of individuals with prediabetes should be prioritized for optimized management to improve cardiometabolic outcomes in Mexican adults.

Dimethyl fumarate in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

Dimethyl fumarate (DMF) inhibits inflammasome-mediated inflammation and has been proposed as a treatment for patients hospitalised with COVID-19. This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing multiple treatments in patients hospitalised for COVID-19 (NCT04381936, ISRCTN50189673). In this assessment of DMF performed at 27 UK hospitals, adults were randomly allocated (1:1) to either usual standard of care alone or usual standard of care plus DMF. The primary outcome was clinical status on day 5 measured on a seven-point ordinal scale. Secondary outcomes were time to sustained improvement in clinical status, time to discharge, day 5 peripheral blood oxygenation, day 5 C-reactive protein, and improvement in day 10 clinical status. Between 2 March 2021 and 18 November 2021, 713 patients were enroled in the DMF evaluation, of whom 356 were randomly allocated to receive usual care plus DMF, and 357 to usual care alone. 95% of patients received corticosteroids as part of routine care. There was no evidence of a beneficial effect of DMF on clinical status at day 5 (common odds ratio of unfavourable outcome 1.12; 95% CI 0.86-1.47; p = 0.40). There was no significant effect of DMF on any secondary outcome.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

2022 Joint ESC/EACTS review of the 2018 guideline recommendations on the revascularization of left main coronary artery disease in patients at low surgical risk and anatomy suitable for PCI or CABG

In October 2021, the European Society of Cardiology (ESC) and the European Association for Cardio-Thoracic Surgery (EACTS) jointly agreed to establish a Task Force (TF) to review recommendations of the 2018 ESC/EACTS Guidelines on myocardial revascularization as they apply to patients with left main (LM) disease with low-to-intermediate SYNTAX score (0-32). This followed the withdrawal of support by the EACTS in 2019 for the recommendations about the management of LM disease of the previous guideline. The TF was asked to review all new relevant data since the 2018 guidelines including updated aggregated data from the four randomized trials comparing percutaneous coronary intervention (PCI) with drug-eluting stents vs. coronary artery bypass grafting (CABG) in patients with LM disease. This document represents a summary of the work of the TF; suggested updated recommendations for the choice of revascularization modality in patients undergoing myocardial revascularization for LM disease are included. In stable patients with an indication for revascularization for LM disease, with coronary anatomy suitable for both procedures and a low predicted surgical mortality, the TF concludes that both treatment options are clinically reasonable based on patient preference, available expertise, and local operator volumes. The suggested recommendations for revascularization with CABG are Class I, Level of Evidence A. The recommendations for PCI are Class IIa, Level of Evidence A. The TF recognized several important gaps in knowledge related to revascularization in patients with LM disease and recognizes that aggregated data from the four randomized trials were still only large enough to exclude large differences in mortality.

Genotyping, sequencing and analysis of 140,000 adults from Mexico City

The Mexico City Prospective Study is a prospective cohort of more than 150,000 adults recruited two decades ago from the urban districts of Coyoacán and Iztapalapa in Mexico City1. Here we generated genotype and exome-sequencing data for all individuals and whole-genome sequencing data for 9,950 selected individuals. We describe high levels of relatedness and substantial heterogeneity in ancestry composition across individuals. Most sequenced individuals had admixed Indigenous American, European and African ancestry, with extensive admixture from Indigenous populations in central, southern and southeastern Mexico. Indigenous Mexican segments of the genome had lower levels of coding variation but an excess of homozygous loss-of-function variants compared with segments of African and European origin. We estimated ancestry-specific allele frequencies at 142 million genomic variants, with an effective sample size of 91,856 for Indigenous Mexican ancestry at exome variants, all available through a public browser. Using whole-genome sequencing, we developed an imputation reference panel that outperforms existing panels at common variants in individuals with high proportions of central, southern and southeastern Indigenous Mexican ancestry. Our work illustrates the value of genetic studies in diverse populations and provides foundational imputation and allele frequency resources for future genetic studies in Mexico and in the United States, where the Hispanic/Latino population is predominantly of Mexican descent.

Educational and social inequalities and cause-specific mortality in Mexico City: a prospective study

BACKGROUND

Social inequalities in adult mortality have been reported across diverse populations, but there is no large-scale prospective evidence from Mexico. We aimed to quantify social, including educational, inequalities in mortality among adults in Mexico City.

METHODS

The Mexico City Prospective Study recruited 150 000 adults aged 35 years and older from two districts of Mexico City between 1998 and 2004. Participants were followed up until Jan 1, 2021 for cause-specific mortality. Cox regression analysis yielded rate ratios (RRs) for death at ages 35-74 years associated with education and examined, in exploratory analyses, the mediating effects of lifestyle and related risk factors.

FINDINGS

Among 143 478 participants aged 35-74 years, there was a strong inverse association of education with premature death. Compared with participants with tertiary education, after adjustment for age and sex, those with no education had about twice the mortality rate (RR 1·84; 95% CI 1·71-1·98), equivalent to approximately 6 years lower life expectancy, with an RR of 1·78 (1·67-1·90) among participants with incomplete primary, 1·62 (1·53-1·72) with complete primary, and 1·34 (1·25-1·42) with secondary education. Education was most strongly associated with death from renal disease and acute diabetic crises (RR 3·65; 95% CI 3·05-4·38 for no education vs tertiary education) and from infectious diseases (2·67; 2·00-3·56), but there was an apparent higher rate of death from all specific causes studied with lower education, with the exception of cancer for which there was little association. Lifestyle factors (ie, smoking, alcohol drinking, and leisure time physical activity) and related physiological correlates (ie, adiposity, diabetes, and blood pressure) accounted for about four-fifths of the association of education with premature mortality.

INTERPRETATION

In this Mexican population there were marked educational inequalities in premature adult mortality, which appeared to largely be accounted for by lifestyle and related risk factors. Effective interventions to reduce these risk factors could reduce inequalities and have a major impact on premature mortality.

FUNDING

Wellcome Trust, the Mexican Health Ministry, the National Council of Science and Technology for Mexico, Cancer Research UK, British Heart Foundation, and the UK Medical Research Council Population Health Research Unit.

2022 Joint ESC/EACTS review of the 2018 guideline recommendations on the revascularization of left main coronary artery disease in patients at low surgical risk and anatomy suitable for PCI or CABG

Task Force structure and summary of clinical evidence of 2022 ESC/EACTS review of the 2018 guideline recommendations on the revascularization of left main coronary artery disease. CABG, coronary artery bypass grafting; PCI, percutaneous coronary intervention; LM, left main; SYNTAX, Synergy Between Percutaneous Coronary Intervention with TAXUS and Cardiac Surgery. a'Event' refers to the composite of death, myocardial infarction (according to Universal Definition of Myocardial Infarction if available, otherwise protocol defined) or stroke. In October 2021, the European Society of Cardiology (ESC) and the European Association for Cardio-Thoracic Surgery (EACTS) jointly agreed to establish a Task Force (TF) to review recommendations of the 2018 ESC/EACTS Guidelines on myocardial revascularization as they apply to patients with left main (LM) disease with low-to-intermediate SYNTAX score (0-32). This followed the withdrawal of support by the EACTS in 2019 for the recommendations about the management of LM disease of the previous guideline. The TF was asked to review all new relevant data since the 2018 guidelines including updated aggregated data from the four randomized trials comparing percutaneous coronary intervention (PCI) with drug-eluting stents vs. coronary artery bypass grafting (CABG) in patients with LM disease. This document represents a summary of the work of the TF; suggested updated recommendations for the choice of revascularization modality in patients undergoing myocardial revascularization for LM disease are included. In stable patients with an indication for revascularization for LM disease, with coronary anatomy suitable for both procedures and a low predicted surgical mortality, the TF concludes that both treatment options are clinically reasonable based on patient preference, available expertise, and local operator volumes. The suggested recommendations for revascularization with CABG are Class I, Level of Evidence A. The recommendations for PCI are Class IIa, Level of Evidence A. The TF recognized several important gaps in knowledge related to revascularization in patients with LM disease and recognizes that aggregated data from the four randomized trials were still only large enough to exclude large differences in mortality.

Impact of outcome adjudication in kidney disease trials: observations from the Study of Heart and Renal Protection (SHARP)

Introduction

We aimed to assess opportunities for trial streamlining and the scientific impact of adjudication on kidney and cardiovascular outcomes in CKD.

Methods

We analysed the effects of adjudication of ~2100 maintenance kidney replacement therapy (KRT) and ~1300 major atherosclerotic events (MAEs) recorded in SHARP. We first compared outcome classification before versus after adjudication, and then re-ran randomised comparisons using pre-adjudicated follow-up data.

Results

For maintenance KRT, adjudication had little impact with only 1% of events being refuted (28/2115). Consequently, randomised comparisons using pre-adjudication reports found almost identical results (pre-adjudication: simvastatin/ezetimibe 1038 vs placebo 1077; risk ratio [RR] 0.95, 95%CI 0.88-1.04; post-adjudicated: 1057 vs 1084; RR=0.97, 95%CI 0.89-1.05). For MAEs, about one-quarter of patient reports were refuted (324/1275 [25%]), and reviewing 3538 other potential vascular events and death reports identified only 194 additional MAEs. Nevertheless, randomised analyses using SHARP's pre-adjudicated data alone found similar results to analyses based on adjudicated outcomes (pre-adjudication: 573 vs 702; RR=0.80, 95%CI 0.72-0.89; adjudicated: 526 vs 619; RR=0.83, 95%CI 0.74- 0.94), and also suggested refuted MAEs were likely to represent atherosclerotic disease (RR for refuted MAEs=0.80, 95%CI 0.65-1.00).

Conclusions

These analyses provide three key insights. First, they provide a rationale for nephrology trials not to adjudicate maintenance KRT. Secondly, when an event that mimics an atherosclerotic outcome is not expected to be influenced by the treatment under study (e.g. heart failure), the aim of adjudicating atherosclerotic outcomes should be to remove such events. Lastly, restrictive definitions for the remaining suspected atherosclerotic outcomes may reduce statistical power.

Relationship between clinic and ambulatory blood pressure and mortality: an observational cohort study in 59 124 patients

BACKGROUND

Ambulatory blood pressure provides a more comprehensive assessment than clinic blood pressure, and has been reported to better predict health outcomes than clinic or home pressure. We aimed to examine associations of clinic and 24-h ambulatory blood pressure with all-cause and cardiovascular mortality in a large cohort of primary care patients referred for assessment of hypertension.

METHODS

We did an observational cohort study using clinic and ambulatory blood pressure data obtained from March 1, 2004, to Dec 31, 2014, from the Spanish Ambulatory Blood Pressure Registry. This registry included patients from 223 primary care centres from the Spanish National Health System in all 17 regions of Spain. Mortality data (date and cause) were ascertained by a computerised search of the vital registry of the Spanish National Institute of Statistics. Complete data were available for age, sex, all blood pressure measures, and BMI. For each study participant, follow-up was from the date of their recruitment to the date of death or Dec 31, 2019, whichever occurred first. Cox models were used to estimate associations between usual clinic or ambulatory blood pressure and mortality, adjusted for confounders and additionally for alternative measures of blood pressure. For each measure of blood pressure, we created five groups (ie, fifths) defined by quintiles of that measure among those who subsequently died.

FINDINGS

During a median follow-up of 9·7 years, 7174 (12·1%) of 59 124 patients died, including 2361 (4·0%) from cardiovascular causes. J-shaped associations were observed for several blood pressure measures. Among the top four baseline-defined fifths, 24-h systolic blood pressure was more strongly associated with all-cause death (hazard ratio [HR] 1·41 per 1 - SD increment [95% CI 1·36-1·47]) than clinic systolic blood pressure (1·18 [1·13-1·23]). After adjustment for clinic blood pressure, 24-h blood pressure remained strongly associated with all-cause deaths (HR 1·43 [95% CI 1·37-1·49]), but the association between clinic blood pressure and all-cause death was attenuated when adjusted for 24-h blood pressure (1·04 [1·00-1·09]). Compared with the informativeness of clinic systolic blood pressure (100%), night-time systolic blood pressure was most informative about risk of all-cause death (591%) and cardiovascular death (604%). Relative to blood pressure within the normal range, elevated all-cause mortality risks were observed for masked hypertension (HR 1·24 [95% CI 1·12-1·37]) and sustained hypertension (1·24 [1·15-1·32]), but not white-coat hypertension, and elevated cardiovascular mortality risks were observed for masked hypertension (1·37 [1·15-1·63]) and sustained hypertension (1·38 [1·22-1·55]), but not white-coat hypertension.

INTERPRETATION

Ambulatory blood pressure, particularly night-time blood pressure, was more informative about the risk of all-cause death and cardiovascular death than clinic blood pressure.

FUNDING

Spanish Society of Hypertension, Lacer Laboratories, UK Medical Research Council, Health Data Research UK, National Institute for Health and Care Research Biomedical Research Centres (Oxford and University College London Hospitals), and British Heart Foundation Centre for Research Excellence.

Diabetes and infectious disease mortality in Mexico City

INTRODUCTION

Although higher risks of infectious diseases among individuals with diabetes have long been recognized, the magnitude of these risks is poorly described, particularly in lower income settings. This study sought to assess the risk of death from infection associated with diabetes in Mexico.

RESEARCH DESIGN AND METHODS

Between 1998 and 2004, a total of 159 755 adults ≥35 years were recruited from Mexico City and followed up until January 2021 for cause-specific mortality. Cox regression yielded adjusted rate ratios (RR) for death due to infection associated with previously diagnosed and undiagnosed (HbA1c ≥6.5%) diabetes and, among participants with previously diagnosed diabetes, with duration of diabetes and with HbA1c.

RESULTS

Among 130 997 participants aged 35-74 and without other prior chronic diseases at recruitment, 12.3% had previously diagnosed diabetes, with a mean (SD) HbA1c of 9.1% (2.5%), and 4.9% had undiagnosed diabetes. During 2.1 million person-years of follow-up, 2030 deaths due to infectious causes were recorded at ages 35-74. Previously diagnosed diabetes was associated with an RR for death from infection of 4.48 (95% CI 4.05-4.95), compared with participants without diabetes, with notably strong associations with death from urinary tract (9.68 (7.07-13.3)) and skin, bone and connective tissue (9.19 (5.92-14.3)) infections and septicemia (8.37 (5.97-11.7)). In those with previously diagnosed diabetes, longer diabetes duration (1.03 (1.02-1.05) per 1 year) and higher HbA1c (1.12 (1.08-1.15) per 1.0%) were independently associated with higher risk of death due to infection. Even among participants with undiagnosed diabetes, the risk of death due to infection was nearly treble the risk of those without diabetes (2.69 (2.31-3.13)).

CONCLUSIONS

In this study of Mexican adults, diabetes was common, frequently poorly controlled, and associated with much higher risks of death due to infection than observed previously, accounting for approximately one-third of all premature mortality due to infection.

Body Composition and Risk of Vascular-Metabolic Mortality Risk in 113 000 Mexican Men and Women Without Prior Chronic Disease

Background Body-mass index is the sum of fat mass index (FMI) and lean mass index (LMI), which vary by age, sex, and impact on disease outcomes. We investigated the separate and joint relevance of FMI and LMI with vascular-metabolic causes of death in Mexican adults. Methods and Results A total of 113 025 adults aged 35 to 74 years and free from diabetes or other chronic diseases when recruited into the Mexico City Prospective Study were followed for 19 years. Cox models estimated sex-specific death rate ratios from vascular-metabolic causes after adjustment for confounders and exclusion of the first 5 years of follow-up. To account for the strong correlation between FMI and LMI, additional models estimated rate ratios associated with "residual FMI" and "residual LMI" (ie, the residuals from linear regression analyses of FMI on LMI, or vice versa). In both sexes, higher FMI and LMI were associated with higher risks of vascular-metabolic mortality. For a given (ie, fixed) level of LMI, the rate ratio (95% CI) for vascular-metabolic mortality per 1 kg/m2 higher residual FMI strengthened and was higher in women (1.52 [1.38-1.68]) than in men (1.19 [1.13-1.25]). By contrast, for a given level of FMI, higher residual LMI was inversely associated with vascular-metabolic mortality (rate ratio per 1 kg/m2 0.67 [0.56-0.80] in women and 0.94 [0.90-0.98] in men). Conclusions In this study, higher residual FMI was more strongly associated with vascular-metabolic mortality in women than in men. Conversely, higher residual LMI was inversely associated with vascular-metabolic mortality, particularly in women.

Empagliflozin in Patients with Chronic Kidney Disease

BACKGROUND

The effects of empagliflozin in patients with chronic kidney disease who are at risk for disease progression are not well understood. The EMPA-KIDNEY trial was designed to assess the effects of treatment with empagliflozin in a broad range of such patients.

METHODS

We enrolled patients with chronic kidney disease who had an estimated glomerular filtration rate (eGFR) of at least 20 but less than 45 ml per minute per 1.73 m² of body-surface area, or who had an eGFR of at least 45 but less than 90 ml per minute per 1.73 m² with a urinary albumin-to-creatinine ratio (with albumin measured in milligrams and creatinine measured in grams) of at least 200. Patients were randomly assigned to receive empagliflozin (10 mg once daily) or matching placebo. The primary outcome was a composite of progression of kidney disease (defined as end-stage kidney disease, a sustained decrease in eGFR to <10 ml per minute per 1.73 m², a sustained decrease in eGFR of ≥40% from baseline, or death from renal causes) or death from cardiovascular causes.

RESULTS

A total of 6609 patients underwent randomization. During a median of 2.0 years of follow-up, progression of kidney disease or death from cardiovascular causes occurred in 432 of 3304 patients (13.1%) in the empagliflozin group and in 558 of 3305 patients (16.9%) in the placebo group (hazard ratio, 0.72; 95% confidence interval [CI], 0.64 to 0.82; P<0.001). Results were consistent among patients with or without diabetes and across subgroups defined according to eGFR ranges. The rate of hospitalization from any cause was lower in the empagliflozin group than in the placebo group (hazard ratio, 0.86; 95% CI, 0.78 to 0.95; P = 0.003), but there were no significant between-group differences with respect to the composite outcome of hospitalization for heart failure or death from cardiovascular causes (which occurred in 4.0% in the empagliflozin group and 4.6% in the placebo group) or death from any cause (in 4.5% and 5.1%, respectively). The rates of serious adverse events were similar in the two groups.

CONCLUSIONS

Among a wide range of patients with chronic kidney disease who were at risk for disease progression, empagliflozin therapy led to a lower risk of progression of kidney disease or death from cardiovascular causes than placebo. (Funded by Boehringer Ingelheim and others; EMPA-KIDNEY ClinicalTrials.gov number, NCT03594110; EudraCT number, 2017-002971-24.).

Experiences of the Data Monitoring Committee for the RECOVERY trial, a large-scale adaptive platform randomised trial of treatments for patients hospitalised with COVID-19

AIM

To inform the oversight of future clinical trials during a pandemic, we summarise the experiences of the Data Monitoring Committee (DMC) for the Randomised Evaluation of COVID therapy trial (RECOVERY), a large-scale randomised adaptive platform clinical trial of treatments for hospitalised patients with COVID-19.

METHODS AND FINDINGS

During the first 24 months of the trial (March 2020 to February 2022), the DMC oversaw accumulating data for 14 treatments in adults (plus 10 in children) involving > 45,000 randomised patients. Five trial aspects key for the DMC in performing its role were: a large committee of members, including some with extensive DMC experience and others who had broad clinical expertise; clear strategic planning, communication, and responsiveness by the trial principal investigators; data collection and analysis systems able to cope with phases of very rapid recruitment and link to electronic health records; an ability to work constructively with regulators (and other DMCs) to address emerging concerns without the need to release unblinded mortality results; and the use of videoconferencing systems that enabled national and international members to meet at short notice and from home during the pandemic when physical meetings were impossible. Challenges included that the first four treatments introduced were effectively 'competing' for patients (increasing pressure to make rapid decisions on each one); balancing the global health imperative to report on findings with the need to maintain confidentiality until the results were sufficiently certain to appropriately inform treatment decisions; and reliably assessing safety, especially for newer agents introduced after the initial wave and in the small numbers of pregnant women and children included. We present a series of case vignettes to illustrate some of the issues and the DMC decision-making related to hydroxychloroquine, dexamethasone, casirivimab + imdevimab, and tocilizumab.

CONCLUSIONS

RECOVERY's streamlined adaptive platform design, linked to hospital-level and population-level health data, enabled the rapid and reliable assessment of multiple treatments for hospitalised patients with COVID-19. The later introduction of factorial assessments increased the trial's efficiency, without compromising the DMC's ability to assess safety and efficacy. Requests for the release of unblinded primary outcome data to regulators at points when data were not mature required significant efforts in communication with the regulators by the DMC to avoid inappropriate early trial termination.

Multiancestry exome sequencing reveals INHBE mutations associated with favorable fat distribution and protection from diabetes

Body fat distribution is a major, heritable risk factor for cardiometabolic disease, independent of overall adiposity. Using exome-sequencing in 618,375 individuals (including 160,058 non-Europeans) from the UK, Sweden and Mexico, we identify 16 genes associated with fat distribution at exome-wide significance. We show 6-fold larger effect for fat-distribution associated rare coding variants compared with fine-mapped common alleles, enrichment for genes expressed in adipose tissue and causal genes for partial lipodystrophies, and evidence of sex-dimorphism. We describe an association with favorable fat distribution (p = 1.8 × 10^-09), favorable metabolic profile and protection from type 2 diabetes (~28% lower odds; p = 0.004) for heterozygous protein-truncating mutations in INHBE, which encodes a circulating growth factor of the activin family, highly and specifically expressed in hepatocytes. Our results suggest that inhibin βE is a liver-expressed negative regulator of adipose storage whose blockade may be beneficial in fat distribution-associated metabolic disease.

Association of Kidney Function With NMR-Quantified Lipids, Lipoproteins, and Metabolic Measures in Mexican Adults

CONTEXT

Chronic kidney disease (CKD) and diabetes are associated with dyslipidemia, metabolic abnormalities, and atherosclerotic risk. Nuclear magnetic resonance (NMR) spectroscopy provides much more detail on lipoproteins than traditional assays.

METHODS

In about 38 000 participants from the Mexico City Prospective Study, aged 35 to 84 years and not using lipid-lowering medication, NMR spectroscopy quantified plasma concentrations of lipoprotein particles, their lipidic compositions, and other metabolic measures. Linear regression related low estimated glomerular filtration rate (eGFR; <60 mL/min/1.73 m2) to each NMR measure after adjustment for confounders and for multiplicity. Analyses were done separately for those with and without diabetes.

RESULTS

Among the 38 081 participants (mean age 52 years, 64% women), low eGFR was present for 4.8% (306/6403) of those with diabetes and 1.2% (365/31 678) of those without diabetes. Among both those with and without diabetes, low eGFR was significantly associated with higher levels of 58 NMR measures, including apolipoprotein B (Apo-B), the particle numbers of most Apo-B containing lipoproteins, the cholesterol and triglycerides carried in these lipoproteins, several fatty acids, total cholines and phosphatidylcholine, citrate, glutamine, phenylalanine, β-OH-butyrate, and the inflammatory measure glycoprotein-A, and significantly lower levels of 13 NMR measures, including medium and small high-density lipoprotein particle measures, very low-density lipoprotein particle size, the ratio of saturated:total fatty acids, valine, tyrosine, and aceto-acetate.

CONCLUSIONS

In this Mexican population with high levels of adiposity and diabetes, low kidney function was associated with widespread alterations in lipidic and metabolic profiles, both in those with and without diabetes. These alterations may help explain the higher atherosclerotic risk experienced by people with CKD.

Low-intensity daily smoking and cause-specific mortality in Mexico: prospective study of 150 000 adults

Background

Research is needed to determine the relevance of low-intensity daily smoking to mortality in countries such as Mexico, where such smoking habits are common.

Methods

Prospective study of 159 755 Mexican adults recruited from 1998–2004 and followed for cause-specific mortality to 1 January 2018. Participants were categorized according to baseline self-reported smoking status. Confounder-adjusted mortality rate ratios (RRs) at ages 35–89 were estimated using Cox regression, after excluding those with previous chronic disease (to avoid reverse causality).

Results

Among 42 416 men and 86 735 women aged 35–89 and without previous disease, 18 985 men (45%) and 18 072 women (21%) reported current smoking and 8866 men (21%) and 53 912 women (62%) reported never smoking. Smoking less than daily was common: 33% of male current smokers and 39% of female current smokers. During follow-up, the all-cause mortality RRs associated with the baseline smoking categories of <10 cigarettes per day (average during follow-up 4 per day) or ≥10 cigarettes per day (average during follow-up 10 per day), compared with never smoking, were 1.17 (95% confidence interval 1.10–1.25) and 1.54 (1.42–1.67), respectively. RRs were similar irrespective of age or sex. The diseases most strongly associated with daily smoking were respiratory cancers, chronic obstructive pulmonary disease and gastrointestinal and vascular diseases. Ex-daily smokers had substantially lower mortality rates than those who were current daily smokers at recruitment.

Conclusions

In this Mexican population, low-intensity daily smoking was associated with increased mortality. Of those smoking 10 cigarettes per day on average, about one-third were killed by their habit. Quitting substantially reduced these risks.

Sequencing of 640,000 exomes identifies GPR75 variants associated with protection from obesity

Large-scale human exome sequencing can identify rare protein-coding variants with a large impact on complex traits such as body adiposity. We sequenced the exomes of 645,626 individuals from the United Kingdom, the United States, and Mexico and estimated associations of rare coding variants with body mass index (BMI). We identified 16 genes with an exome-wide significant association with BMI, including those encoding five brain-expressed G protein-coupled receptors (CALCR, MC4R, GIPR, GPR151, and GPR75). Protein-truncating variants in GPR75 were observed in ~4/10,000 sequenced individuals and were associated with 1.8 kilograms per square meter lower BMI and 54% lower odds of obesity in the heterozygous state. Knock out of Gpr75 in mice resulted in resistance to weight gain and improved glycemic control in a high-fat diet model. Inhibition of GPR75 may provide a therapeutic strategy for obesity.

Changes in the Diagnosis and Management of Diabetes in Mexico City Between 1998-2004 and 2015-2019

OBJECTIVE

To investigate the trends in diabetes prevalence, diagnosis, and management among Mexican adults who were participants in a long-term prospective study.

RESEARCH DESIGN AND METHODS

From 1998 to 2004, 159,755 adults from Mexico City were recruited to a prospective study, and from 2015 to 2019, 10,144 survivors were resurveyed. Diabetes was defined as self-reported diagnosis, glucose-lowering medication use, or HbA1c ≥6.5%. Controlled diabetes was defined as HbA1c <7%. Prevalence estimates were uniformly standardized for age, sex, and residential district. Cox models explored the relevance of controlled and inadequately controlled diabetes to cause-specific mortality.

RESULTS

During 1998-2004 and 2015-2019, 99,623 and 8,986 participants were aged 45-84 years. Diabetes prevalence had increased from 26% in 1998-2004 to 35% by 2015-2019. Of those with diabetes, the proportion previously diagnosed had increased from 76% to 89%, and glucose-lowering medication use among them had increased from 80% to 94%. Median HbA1c among those with diabetes had decreased from 8.2% to 7.3%, and the proportion of participants with controlled diabetes had increased from 16% to 37%. Use of blood pressure-lowering medication among those with previously diagnosed diabetes had increased from 35% to 51%, and their use of lipid-lowering therapy had increased from 1% to 14%. The excess mortality risk associated with diabetes accounted for 34% of deaths at ages 35-74 years, of which 5% were attributable to controlled and 29% to inadequately controlled diabetes.

CONCLUSIONS

Inadequately controlled diabetes is a leading cause of premature adult death in Mexico. Improvements in diabetes management have increased diagnosis and control, but substantial opportunities remain to improve treatment, particularly with lipid-lowering therapy.

Abdominal and gluteo-femoral markers of adiposity and risk of vascular-metabolic mortality in a prospective study of 150 000 Mexican adults

Aims

Results of previous studies of abdominal adiposity and risk of vascular-metabolic mortality in Hispanic populations have been conflicting. We report results from a large prospective study of Mexican adults with high levels of abdominal adiposity.

Methods and results

A total of 159 755 adults aged ≥35 years from Mexico City were enrolled in a prospective study and followed for 16 years. Cox regression, adjusted for confounders, yielded mortality rate ratios (RRs) associated with three markers of abdominal adiposity (waist circumference, waist–hip ratio, and waist–height ratio) and one marker of gluteo-femoral adiposity (hip circumference) for cause-specific mortality before age 75 years. To reduce reverse causality, deaths in the first 5 years of follow-up and participants with diabetes or other prior chronic disease were excluded. Among 113 163 participants without prior disease and aged 35–74 years at recruitment, all adiposity markers were positively associated with vascular-metabolic mortality. Comparing the top versus bottom tenth of the sex-specific distributions, the vascular-metabolic mortality RRs at ages 40–74 years were 2.32 [95% confidence interval (CI) 1.84–2.94] for waist circumference, 2.22 (1.71–2.88) for the waist–hip ratio, 2.63 (2.06–3.36) for the waist–height ratio, and 1.58 (1.29–1.93) for hip circumference. The RRs corresponding to each standard deviation (SD) higher usual levels of these adiposity markers were 1.34 (95% CI 1.27–1.41), 1.31 (1.23–1.39), 1.38 (1.31–1.45), and 1.18 (1.13–1.24), respectively. For the markers of abdominal adiposity, the RRs did not change much after further adjustment for other adiposity markers, but for hip circumference the association was reversed; given body mass index and waist circumference, the RR for vascular-metabolic mortality for each one SD higher usual hip circumference was 0.80 (0.75–0.86).

Conclusions

In this study of Mexican adults, abdominal adiposity (and in particular the waist–height ratio) was strongly and positively associated with vascular-metabolic mortality. For a given amount of general and abdominal adiposity, however, higher hip circumference was associated with lower vascular-metabolic mortality.

Dexamethasone in Hospitalized Patients with Covid-19

BACKGROUND

Coronavirus disease 2019 (Covid-19) is associated with diffuse lung damage. Glucocorticoids may modulate inflammation-mediated lung injury and thereby reduce progression to respiratory failure and death.

METHODS

In this controlled, open-label trial comparing a range of possible treatments in patients who were hospitalized with Covid-19, we randomly assigned patients to receive oral or intravenous dexamethasone (at a dose of 6 mg once daily) for up to 10 days or to receive usual care alone. The primary outcome was 28-day mortality. Here, we report the final results of this assessment.

RESULTS

A total of 2104 patients were assigned to receive dexamethasone and 4321 to receive usual care. Overall, 482 patients (22.9%) in the dexamethasone group and 1110 patients (25.7%) in the usual care group died within 28 days after randomization (age-adjusted rate ratio, 0.83; 95% confidence interval [CI], 0.75 to 0.93; P<0.001). The proportional and absolute between-group differences in mortality varied considerably according to the level of respiratory support that the patients were receiving at the time of randomization. In the dexamethasone group, the incidence of death was lower than that in the usual care group among patients receiving invasive mechanical ventilation (29.3% vs. 41.4%; rate ratio, 0.64; 95% CI, 0.51 to 0.81) and among those receiving oxygen without invasive mechanical ventilation (23.3% vs. 26.2%; rate ratio, 0.82; 95% CI, 0.72 to 0.94) but not among those who were receiving no respiratory support at randomization (17.8% vs. 14.0%; rate ratio, 1.19; 95% CI, 0.92 to 1.55).

CONCLUSIONS

In patients hospitalized with Covid-19, the use of dexamethasone resulted in lower 28-day mortality among those who were receiving either invasive mechanical ventilation or oxygen alone at randomization but not among those receiving no respiratory support. (Funded by the Medical Research Council and National Institute for Health Research and others; RECOVERY ClinicalTrials.gov number, NCT04381936; ISRCTN number, 50189673.).

Dexamethasone in Hospitalized Patients with Covid-19

BACKGROUND

Coronavirus disease 2019 (Covid-19) is associated with diffuse lung damage. Glucocorticoids may modulate inflammation-mediated lung injury and thereby reduce progression to respiratory failure and death.

METHODS

In this controlled, open-label trial comparing a range of possible treatments in patients who were hospitalized with Covid-19, we randomly assigned patients to receive oral or intravenous dexamethasone (at a dose of 6 mg once daily) for up to 10 days or to receive usual care alone. The primary outcome was 28-day mortality. Here, we report the final results of this assessment.

RESULTS

A total of 2104 patients were assigned to receive dexamethasone and 4321 to receive usual care. Overall, 482 patients (22.9%) in the dexamethasone group and 1110 patients (25.7%) in the usual care group died within 28 days after randomization (age-adjusted rate ratio, 0.83; 95% confidence interval [CI], 0.75 to 0.93; P<0.001). The proportional and absolute between-group differences in mortality varied considerably according to the level of respiratory support that the patients were receiving at the time of randomization. In the dexamethasone group, the incidence of death was lower than that in the usual care group among patients receiving invasive mechanical ventilation (29.3% vs. 41.4%; rate ratio, 0.64; 95% CI, 0.51 to 0.81) and among those receiving oxygen without invasive mechanical ventilation (23.3% vs. 26.2%; rate ratio, 0.82; 95% CI, 0.72 to 0.94) but not among those who were receiving no respiratory support at randomization (17.8% vs. 14.0%; rate ratio, 1.19; 95% CI, 0.92 to 1.55).

CONCLUSIONS

In patients hospitalized with Covid-19, the use of dexamethasone resulted in lower 28-day mortality among those who were receiving either invasive mechanical ventilation or oxygen alone at randomization but not among those receiving no respiratory support. (Funded by the Medical Research Council and National Institute for Health Research and others; RECOVERY ClinicalTrials.gov number, NCT04381936; ISRCTN number, 50189673.).

Effect of Hydroxychloroquine in Hospitalized Patients with Covid-19

BACKGROUND

Hydroxychloroquine and chloroquine have been proposed as treatments for coronavirus disease 2019 (Covid-19) on the basis of in vitro activity and data from uncontrolled studies and small, randomized trials.

METHODS

In this randomized, controlled, open-label platform trial comparing a range of possible treatments with usual care in patients hospitalized with Covid-19, we randomly assigned 1561 patients to receive hydroxychloroquine and 3155 to receive usual care. The primary outcome was 28-day mortality.

RESULTS

The enrollment of patients in the hydroxychloroquine group was closed on June 5, 2020, after an interim analysis determined that there was a lack of efficacy. Death within 28 days occurred in 421 patients (27.0%) in the hydroxychloroquine group and in 790 (25.0%) in the usual-care group (rate ratio, 1.09; 95% confidence interval [CI], 0.97 to 1.23; P = 0.15). Consistent results were seen in all prespecified subgroups of patients. The results suggest that patients in the hydroxychloroquine group were less likely to be discharged from the hospital alive within 28 days than those in the usual-care group (59.6% vs. 62.9%; rate ratio, 0.90; 95% CI, 0.83 to 0.98). Among the patients who were not undergoing mechanical ventilation at baseline, those in the hydroxychloroquine group had a higher frequency of invasive mechanical ventilation or death (30.7% vs. 26.9%; risk ratio, 1.14; 95% CI, 1.03 to 1.27). There was a small numerical excess of cardiac deaths (0.4 percentage points) but no difference in the incidence of new major cardiac arrhythmia among the patients who received hydroxychloroquine.

CONCLUSIONS

Among patients hospitalized with Covid-19, those who received hydroxychloroquine did not have a lower incidence of death at 28 days than those who received usual care. (Funded by UK Research and Innovation and National Institute for Health Research and others; RECOVERY ISRCTN number, ISRCTN50189673; ClinicalTrials.gov number, NCT04381936.).

COVID-19 pandemic and admission rates for and management of acute coronary syndromes in England

BACKGROUND

Several countries affected by the COVID-19 pandemic have reported a substantial drop in the number of patients attending the emergency department with acute coronary syndromes and a reduced number of cardiac procedures. We aimed to understand the scale, nature, and duration of changes to admissions for different types of acute coronary syndrome in England and to evaluate whether in-hospital management of patients has been affected as a result of the COVID-19 pandemic.

METHODS

We analysed data on hospital admissions in England for types of acute coronary syndrome from Jan 1, 2019, to May 24, 2020, that were recorded in the Secondary Uses Service Admitted Patient Care database. Admissions were classified as ST-elevation myocardial infarction (STEMI), non-STEMI (NSTEMI), myocardial infarction of unknown type, or other acute coronary syndromes (including unstable angina). We identified revascularisation procedures undertaken during these admissions (ie, coronary angiography without percutaneous coronary intervention [PCI], PCI, and coronary artery bypass graft surgery). We calculated the numbers of weekly admissions and procedures undertaken; percentage reductions in weekly admissions and across subgroups were also calculated, with 95% CIs.

FINDINGS

Hospital admissions for acute coronary syndrome declined from mid-February, 2020, falling from a 2019 baseline rate of 3017 admissions per week to 1813 per week by the end of March, 2020, a reduction of 40% (95% CI 37-43). This decline was partly reversed during April and May, 2020, such that by the last week of May, 2020, there were 2522 admissions, representing a 16% (95% CI 13-20) reduction from baseline. During the period of declining admissions, there were reductions in the numbers of admissions for all types of acute coronary syndrome, including both STEMI and NSTEMI, but relative and absolute reductions were larger for NSTEMI, with 1267 admissions per week in 2019 and 733 per week by the end of March, 2020, a percent reduction of 42% (95% CI 38-46). In parallel, reductions were recorded in the number of PCI procedures for patients with both STEMI (438 PCI procedures per week in 2019 vs 346 by the end of March, 2020; percent reduction 21%, 95% CI 12-29) and NSTEMI (383 PCI procedures per week in 2019 vs 240 by the end of March, 2020; percent reduction 37%, 29-45). The median length of stay among patients with acute coronary syndrome fell from 4 days (IQR 2-9) in 2019 to 3 days (1-5) by the end of March, 2020.

INTERPRETATION

Compared with the weekly average in 2019, there was a substantial reduction in the weekly numbers of patients with acute coronary syndrome who were admitted to hospital in England by the end of March, 2020, which had been partly reversed by the end of May, 2020. The reduced number of admissions during this period is likely to have resulted in increases in out-of-hospital deaths and long-term complications of myocardial infarction and missed opportunities to offer secondary prevention treatment for patients with coronary heart disease. The full extent of the effect of COVID-19 on the management of patients with acute coronary syndrome will continue to be assessed by updating these analyses.

FUNDING

UK Medical Research Council, British Heart Foundation, Public Health England, Health Data Research UK, and the National Institute for Health Research Oxford Biomedical Research Centre.

General and Abdominal Adiposity and Mortality in Mexico City: A Prospective Study of 150 000 Adults

BACKGROUND

Some reports suggest that body mass index (BMI) is not strongly associated with mortality in Hispanic populations.

OBJECTIVE

To assess the causal relevance of adiposity to mortality in Mexican adults, avoiding reverse causality biases.

DESIGN

Prospective study.

SETTING

2 Mexico City districts.

PARTICIPANTS

159 755 adults aged 35 years and older at recruitment, followed for up to 14 years. Participants with a hemoglobin A1c level of 7% or greater, diabetes, or other chronic diseases were excluded.

MEASUREMENTS

BMI, waist-to-hip ratio, waist circumference, and cause-specific mortality. Cox regression, adjusted for confounders, yielded mortality hazard ratios (HRs) after at least 5 years of follow-up and before age 75 years.

RESULTS

Among 115 400 participants aged 35 to <75 years at recruitment, mean BMI was 28.0 kg/m2 (SD, 4.1 kg/m2) in men and 29.6 kg/m2 (SD, 5.1 kg/m2) in women. The association of BMI at recruitment with all-cause mortality was J-shaped, with the minimum at 25 to <27.5 kg/m2. Above 25 kg/m2, each 5-kg/m2 increase in BMI was associated with a 30% increase in all-cause mortality (HR, 1.30 [95% CI, 1.24 to 1.36]). This association was stronger at ages 40 to <60 years (HR, 1.40 [CI, 1.30 to 1.49]) than at ages 60 to <75 years (HR, 1.24 [CI, 1.17 to 1.31]) but was not materially affected by sex, smoking, or other confounders. The associations of mortality with BMI and waist-to-hip ratio were similarly strong, and each was weakened only slightly by adjustment for the other. Waist circumference was strongly related to mortality and remained so even after adjustment for BMI and hip circumference.

LIMITATION

Analyses were limited to mortality.

CONCLUSION

General, and particularly abdominal, adiposity were strongly associated with mortality in this Mexican population.

PRIMARY FUNDING SOURCE

Mexican Health Ministry, Mexican National Council of Science and Technology, Wellcome Trust, Medical Research Council, and Kidney Research UK.

Sex-specific relevance of diabetes to occlusive vascular and other mortality: a collaborative meta-analysis of individual data from 980 793 adults from 68 prospective studies

BACKGROUND

Several studies have shown that diabetes confers a higher relative risk of vascular mortality among women than among men, but whether this increased relative risk in women exists across age groups and within defined levels of other risk factors is uncertain. We aimed to determine whether differences in established risk factors, such as blood pressure, BMI, smoking, and cholesterol, explain the higher relative risks of vascular mortality among women than among men.

METHODS

In our meta-analysis, we obtained individual participant-level data from studies included in the Prospective Studies Collaboration and the Asia Pacific Cohort Studies Collaboration that had obtained baseline information on age, sex, diabetes, total cholesterol, blood pressure, tobacco use, height, and weight. Data on causes of death were obtained from medical death certificates. We used Cox regression models to assess the relevance of diabetes (any type) to occlusive vascular mortality (ischaemic heart disease, ischaemic stroke, or other atherosclerotic deaths) by age, sex, and other major vascular risk factors, and to assess whether the associations of blood pressure, total cholesterol, and body-mass index (BMI) to occlusive vascular mortality are modified by diabetes.

RESULTS

Individual participant-level data were analysed from 980 793 adults. During 9·8 million person-years of follow-up, among participants aged between 35 and 89 years, 19 686 (25·6%) of 76 965 deaths were attributed to occlusive vascular disease. After controlling for major vascular risk factors, diabetes roughly doubled occlusive vascular mortality risk among men (death rate ratio [RR] 2·10, 95% CI 1·97-2·24) and tripled risk among women (3·00, 2·71-3·33; χ2 test for heterogeneity p<0·0001). For both sexes combined, the occlusive vascular death RRs were higher in younger individuals (aged 35-59 years: 2·60, 2·30-2·94) than in older individuals (aged 70-89 years: 2·01, 1·85-2·19; p=0·0001 for trend across age groups), and, across age groups, the death RRs were higher among women than among men. Therefore, women aged 35-59 years had the highest death RR across all age and sex groups (5·55, 4·15-7·44). However, since underlying confounder-adjusted occlusive vascular mortality rates at any age were higher in men than in women, the adjusted absolute excess occlusive vascular mortality associated with diabetes was similar for men and women. At ages 35-59 years, the excess absolute risk was 0·05% (95% CI 0·03-0·07) per year in women compared with 0·08% (0·05-0·10) per year in men; the corresponding excess at ages 70-89 years was 1·08% (0·84-1·32) per year in women and 0·91% (0·77-1·05) per year in men. Total cholesterol, blood pressure, and BMI each showed continuous log-linear associations with occlusive vascular mortality that were similar among individuals with and without diabetes across both sexes.

INTERPRETATION

Independent of other major vascular risk factors, diabetes substantially increased vascular risk in both men and women. Lifestyle changes to reduce smoking and obesity and use of cost-effective drugs that target major vascular risks (eg, statins and antihypertensive drugs) are important in both men and women with diabetes, but might not reduce the relative excess risk of occlusive vascular disease in women with diabetes, which remains unexplained.

FUNDING

UK Medical Research Council, British Heart Foundation, Cancer Research UK, European Union BIOMED programme, and National Institute on Aging (US National Institutes of Health).

Effect of diabetes duration and glycaemic control on 14-year cause-specific mortality in Mexican adults: a blood-based prospective cohort study

BACKGROUND

Diabetes is a cause of at least a third of all deaths in Mexican adults aged 35-74 years, with the excess mortality due mainly to vascular disease, renal disease, infection, and acute diabetic crises. We aimed to analyse the effect of diabetes duration and glycaemic control on death rate ratios (RRs) for these causes and to assess the relevance to cause-specific mortality of undiagnosed diabetes.

METHODS

About 100 000 women and 50 000 men aged 35 years or older from Mexico City were recruited into a blood-based prospective study between April 14, 1998, and Sept 28, 2004, and followed up until Jan 1, 2016, for cause-specific mortality. Participants who, at recruitment, reported any chronic disease other than diabetes and those who had missing data for HbA1c or diabetes duration were excluded. We used Cox models to estimate the associations of undiagnosed or previously diagnosed diabetes (almost all type 2) with risk of mortality from vascular disease, renal disease, and infection, exploring among those with previously diagnosed diabetes the independent relevance of diabetes duration (<5 years, ≥5 to <10 years, or ≥10 years) and HbA1c (<9%, ≥9% to <11%, or ≥11%). We also estimated the association of HbA1c with mortality in participants without diabetes at recruitment.

FINDINGS

133 662 participants were aged 35-74 years and had complete data and no other chronic disease. 16 940 (13%) had previously diagnosed diabetes, 6541 (5%) had undiagnosed diabetes, and 110 181 (82%) had no diabetes. Among participants with previously diagnosed diabetes, glycaemic control was poor (median HbA1c 8·9% [IQR 7·0-10·9]), and was worse in those with longer duration of disease at recruitment. Compared with participants without diabetes, the death RRs at ages 35-74 years for the combination of vascular, renal, or infectious causes were 3·0 (95% CI 2·7-3·4) in those with undiagnosed diabetes, 4·5 (4·0-5·0) for the 5042 participants with a diabetes duration of less than 5 years, 6·6 (6·1-7·1) for the 7713 participants with a duration of 5 years to less than 10 years, and 11·7 (10·7-12·7) for the 4185 participants with a duration of at least 10 years. Similarly, the death RRs were 5·2 (4·8-5·7) for those with HbA1c less than 9%, 6·8 (6·2-7·4) for those with HbA1c of 9% to less than 11%, and 10·5 (9·7-11·5) for those with HbA1c of at least 11%. Diabetes was not strongly associated with the combination of deaths from other causes apart from acute glycaemic crises. Among participants without diabetes, higher HbA1c was not positively related to mortality.

INTERPRETATION

In Mexico, the rates of death from causes strongly associated with diabetes increased steeply with duration of diabetes and were higher still among people with poor glycaemic control. Delaying the onset of type 2 diabetes, as well as improving its treatment, is essential to reduce premature adult mortality in Mexico.

FUNDING

Wellcome Trust, the Mexican Health Ministry, the Mexican National Council of Science and Technology, Cancer Research UK, British Heart Foundation, and the UK Medical Research Council Population Health Research Unit.

Declining comorbidity-adjusted mortality rates in English patients receiving maintenance renal replacement therapy

We aimed to compare long-term mortality trends in end-stage renal disease versus general population controls after accounting for differences in age, sex and comorbidity. Cohorts of 45,000 patients starting maintenance renal replacement therapy (RRT) and 5.3 million hospital controls were identified from two large electronic hospital inpatient data sets: the Oxford Record Linkage Study (1965-1999) and all-England Hospital Episode Statistics (2000-2011). All-cause and cause-specific three-year mortality rates for both populations were calculated using Poisson regression and standardized to the age, sex, and comorbidity structure of an average 1970-2008 RRT population. The median age at initiation of RRT in 1970-1990 was 49 years, increasing to 61 years by 2006-2008. Over that period, there were increases in the prevalence of vascular disease (from 10.0 to 25.2%) and diabetes (from 6.7 to 33.9%). After accounting for age, sex and comorbidity differences, standardized three-year all-cause mortality rates in treated patients with end-stage renal disease between 1970 and 2011 fell by about one-half (relative decline 51%, 95% confidence interval 41-60%) steeper than the one-third decline (34%, 31-36%) observed in the general population. Declines in three-year mortality rates were evident among those who received a kidney transplant and those who remained on dialysis, and among those with and without diabetes. These data suggest that the full extent of mortality rate declines among RRT patients since 1970 is only apparent when changes in comorbidity over time are taken into account, and that mortality rates in RRT patients appear to have declined faster than in the general population.

Effects of gastroprotectant drugs for the prevention and treatment of peptic ulcer disease and its complications: a meta-analysis of randomised trials

Background

Gastroprotectant drugs are used for the prevention and treatment of peptic ulcer disease and might reduce its associated complications, but reliable estimates of the effects of gastroprotectants in different clinical settings are scarce. We aimed to examine the effects of proton-pump inhibitors (PPIs), prostaglandin analogues, and histamine-2 receptor antagonists (H2RAs) in different clinical circumstances by doing meta-analyses of tabular data from all relevant unconfounded randomised trials of gastroprotectant drugs.

Methods

We searched MEDLINE and Embase from Jan 1, 1950, to Dec 31, 2015, to identify unconfounded, randomised trials of a gastroprotectant drug (defined as a PPI, prostaglandin analogue, or H2RA) versus control, or versus another gastroprotectant. Two independent researchers reviewed the search results and extracted the prespecified outcomes and key characteristics for each trial. We did meta-analyses of the effects of gastroprotectant drugs on ulcer development, bleeding, and mortality overall, according to the class of gastroprotectant, and according to the individual drug within a gastroprotectant class.

Findings

We identified comparisons of gastroprotectant versus control in 849 trials (142 485 participants): 580 prevention trials (110 626 participants), 233 healing trials (24 033 participants), and 36 trials for the treatment of acute upper gastrointestinal bleeding (7826 participants). Comparisons of one gastroprotectant drug versus another were available in 345 trials (64 905 participants), comprising 160 prevention trials (32 959 participants), 167 healing trials (28 306 participants), and 18 trials for treatment of acute upper gastrointestinal bleeding (3640 participants). The median number of patients in each trial was 78 (IQR 44·0–210·5) and the median duration was 1·4 months (0·9–2·8). In prevention trials, gastroprotectant drugs reduced development of endoscopic ulcers (odds ratio [OR] 0·27, 95% CI 0·25–0·29; p<0·0001), symptomatic ulcers (0·25, 0·22–0·29; p<0·0001), and upper gastrointestinal bleeding (0·40, 0·32–0·50; p<0·0001), but did not significantly reduce mortality (0·85, 0·69–1·04; p=0·11). Larger proportional reductions in upper gastrointestinal bleeding were observed for PPIs than for other gastroprotectant drugs (PPIs 0·21, 99% CI 0·12–0·36; prostaglandin analogues 0·63, 0·35–1·12; H2RAs 0·49, 0·30–0·80; p_het=0·0005). Gastroprotectant drugs were effective in preventing bleeding irrespective of the use of non-steroidal anti-inflammatory drugs (p_het=0·56). In healing trials, gastroprotectants increased endoscopic ulcer healing (3·49, 95% CI 3·28–3·72; p<0·0001), with PPIs more effective (5·22, 99% CI 4·00–6·80) than prostaglandin analogues (2·27, 1·91–2·70) and H2RAs (3·80, 3·44–4·20; p_het<0·0001). In trials among patients with acute bleeding, gastroprotectants reduced further bleeding (OR 0·68, 95% CI 0·60–0·78; p<0·0001), blood transfusion (0·75, 0·65–0·88; p=0·0003), further endoscopic intervention (0·56, 0·45–0·70; p<0·0001), and surgery (0·72, 0·61–0·84; p<0·0001), but did not significantly reduce mortality (OR 0·90, 0·72–1·11; p=0·31). PPIs had larger protective effects than did H2RAs for further bleeding (p_het=0·0107) and blood transfusion (p_het=0·0130).

Interpretation

Gastroprotectants, in particular PPIs, reduce the risk of peptic ulcer disease and its complications and promote healing of peptic ulcers in a wide range of clinical circumstances. However, this meta-analysis might have overestimated the benefits owing to small study bias.

Funding

UK Medical Research Council and the British Heart Foundation.

Adiposity and Blood Pressure in 110 000 Mexican Adults

Previous studies have reached differing conclusions about the importance of general versus central markers of adiposity to blood pressure, leading to suggestions that population-specific adiposity thresholds may be needed. We examined the relevance of adiposity to blood pressure among 111 911 men and women who, when recruited into the Mexico City Prospective Study, were aged 35 to 89 years, had no chronic disease, and were not taking antihypertensives. Linear regression was used to estimate the effects on systolic and diastolic blood pressure of 2 markers of general adiposity (body mass index and height-adjusted weight) and 4 markers of central adiposity (waist circumference, hip circumference, waist:hip ratio, and waist:height ratio), adjusted for relevant confounders. Mean (SD) adiposity levels were: body mass index (28.7±4.5 kg/m²), height-adjusted weight (70.2±11.2 kg), waist circumference (93.3±10.6 cm), hip circumference (104.0±9.0 cm), waist:hip ratio (0.90±0.06), and waist:height ratio (0.60±0.07). Associations with blood pressure were linear with no threshold levels below which lower general or central adiposity was not associated with lower blood pressure. On average, each 1 SD higher measured adiposity marker was associated with a 3 mm Hg higher systolic blood pressure and 2 mm Hg higher diastolic blood pressure (SEs <0.1 mm Hg), but for the waist:hip ratio, associations were only approximately half as strong. General adiposity associations were independent of central adiposity, but central adiposity associations were substantially reduced by adjustment for general adiposity. Findings were similar for men and women. In Mexican adults, often overweight or obese, markers of general adiposity were stronger independent predictors of blood pressure than measured markers of central adiposity, with no threshold effects.

Diabetes and Cause-Specific Mortality in Mexico City

BACKGROUND

Most large, prospective studies of the effects of diabetes on mortality have focused on high-income countries where patients have access to reasonably good medical care and can receive treatments to establish and maintain good glycemic control. In those countries, diabetes less than doubles the rate of death from any cause. Few large, prospective studies have been conducted in middle-income countries where obesity and diabetes have become common and glycemic control may be poor.

METHODS

From 1998 through 2004, we recruited approximately 50,000 men and 100,000 women 35 years of age or older into a prospective study in Mexico City, Mexico. We recorded the presence or absence of previously diagnosed diabetes, obtained and stored blood samples, and tracked 12-year disease-specific deaths through January 1, 2014. We accepted diabetes as the underlying cause of death only for deaths that were due to acute diabetic crises. We estimated rate ratios for death among participants who had diabetes at recruitment versus those who did not have diabetes at recruitment; data from participants who had chronic diseases other than diabetes were excluded from the main analysis.

RESULTS

At the time of recruitment, obesity was common and the prevalence of diabetes rose steeply with age (3% at 35 to 39 years of age and >20% by 60 years of age). Participants who had diabetes had poor glycemic control (mean [±SD] glycated hemoglobin level, 9.0±2.4%), and the rates of use of other vasoprotective medications were low (e.g., 30% of participants with diabetes were receiving antihypertensive medication at recruitment and 1% were receiving lipid-lowering medication). Previously diagnosed diabetes was associated with rate ratios for death from any cause of 5.4 (95% confidence interval [CI], 5.0 to 6.0) at 35 to 59 years of age, 3.1 (95% CI, 2.9 to 3.3) at 60 to 74 years of age, and 1.9 (95% CI, 1.8 to 2.1) at 75 to 84 years of age. Between 35 and 74 years of age, the excess mortality associated with previously diagnosed diabetes accounted for one third of all deaths; the largest absolute excess risks of death were from renal disease (rate ratio, 20.1; 95% CI, 17.2 to 23.4), cardiac disease (rate ratio, 3.7; 95% CI, 3.2 to 4.2), infection (rate ratio, 4.7; 95% CI, 4.0 to 5.5), acute diabetic crises (8% of all deaths among participants who had previously diagnosed diabetes), and other vascular disease (mainly stroke). Little association was observed between diabetes and mortality from cirrhosis, cancer, or chronic obstructive pulmonary disease.

CONCLUSIONS

In this study in Mexico, a middle-income country with high levels of obesity, diabetes was common, glycemic control was poor, and diabetes was associated with a far worse prognosis than that seen in high-income countries; it accounted for at least one third of all deaths between 35 and 74 years of age. (Funded by the Wellcome Trust and others.).

Extent of regression dilution for established and novel coronary risk factors: results from the British Regional Heart Study

BACKGROUND

Imprecision in measurement of risk factors leads to underestimation of associations with disease outcomes (through regression dilution bias). We examine the extent of this bias for established and novel risk factors for coronary heart disease (CHD) and consider the consequences for CHD prevention.

DESIGN

Prospective cardiovascular study of middle-aged British men followed up over 20 years.

METHODS

Repeated measurements of blood lipids, blood pressure and insulin were available at intervals of 1 week, 4, 16 and 20 years; repeated measurements of homocysteine and haemostatic factors were available over 1 week and 4 years.

RESULTS

The use of single baseline measures of both established and novel risk factors in analysis results in marked underestimation of risk associations, increasing over time. The use of a single baseline measurement of total cholesterol results in a 47% (95% confidence interval 44 to 50%) underestimation of its association with CHD risk during the third decade of follow-up; for diastolic blood pressure the corresponding underestimation is 76% (95% confidence interval 73 to 78%). Ignoring the consequences of regression dilution can also lead to error in the assessment of other risk markers, even those measured precisely.

CONCLUSIONS

The importance of risk factors for CHD can be greatly underestimated by using a single baseline measure in prospective study analyses. Studies that wish to estimate associations between disease risk and usual exposure levels need to take regression dilution effects into account. Failure to do so can lead to serious misinterpretation of the importance of CHD risk factors.

Uptake of systematic reviews and meta-analyses based on individual participant data in clinical practice guidelines: descriptive study

OBJECTIVE

To establish the extent to which systematic reviews and meta-analyses of individual participant data (IPD) are being used to inform the recommendations included in published clinical guidelines.

DESIGN

Descriptive study.

SETTING

Database maintained by the Cochrane IPD Meta-analysis Methods Group, supplemented by records of published IPD meta-analyses held in a separate database.

POPULATION

A test sample of systematic reviews of randomised controlled trials that included a meta-analysis of IPD, and a separate sample of clinical guidelines, matched to the IPD meta-analyses according to medical condition, interventions, populations, and dates of publication.

DATA EXTRACTION

Descriptive information on each guideline was extracted along with evidence showing use or critical appraisal, or both, of the IPD meta-analysis within the guideline; recommendations based directly on its findings and the use of other systematic reviews in the guideline.

RESULTS

Based on 33 IPD meta-analyses and 177 eligible, matched clinical guidelines there was evidence that IPD meta-analyses were being under-utilised. Only 66 guidelines (37%) cited a matched IPD meta-analysis. Around a third of these (n=22, 34%) had critically appraised the IPD meta-analysis. Recommendations based directly on the matched IPD meta-analyses were identified for only 18 of the 66 guidelines (27%). For the guidelines that did not cite a matched IPD meta-analysis (n=111, 63%), search dates had preceded the publication of the IPD meta-analysis in 23 cases (21%); however, for the remainder, there was no obvious reasons why the IPD meta-analysis had not been cited.

CONCLUSIONS

Our results indicate that systematic reviews and meta-analyses based on IPD are being under-utilised. Guideline developers should routinely seek good quality and up to date IPD meta-analyses to inform guidelines. Increased use of IPD meta-analyses could lead to improved guidelines ensuring that routine patient care is based on the most reliable evidence available.

Comparison of risk prediction using the CKD-EPI equation and the MDRD study equation for estimated glomerular filtration rate

CONTEXT

The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation more accurately estimates glomerular filtration rate (GFR) than the Modification of Diet in Renal Disease (MDRD) Study equation using the same variables, especially at higher GFR, but definitive evidence of its risk implications in diverse settings is lacking.

OBJECTIVE

To evaluate risk implications of estimated GFR using the CKD-EPI equation compared with the MDRD Study equation in populations with a broad range of demographic and clinical characteristics.

DESIGN, SETTING, AND PARTICIPANTS

A meta-analysis of data from 1.1 million adults (aged ≥ 18 years) from 25 general population cohorts, 7 high-risk cohorts (of vascular disease), and 13 CKD cohorts. Data transfer and analyses were conducted between March 2011 and March 2012.

MAIN OUTCOME MEASURES

All-cause mortality (84,482 deaths from 40 cohorts), cardiovascular mortality (22,176 events from 28 cohorts), and end-stage renal disease (ESRD) (7644 events from 21 cohorts) during 9.4 million person-years of follow-up; the median of mean follow-up time across cohorts was 7.4 years (interquartile range, 4.2-10.5 years).

RESULTS

Estimated GFR was classified into 6 categories (≥90, 60-89, 45-59, 30-44, 15-29, and <15 mL/min/1.73 m(2)) by both equations. Compared with the MDRD Study equation, 24.4% and 0.6% of participants from general population cohorts were reclassified to a higher and lower estimated GFR category, respectively, by the CKD-EPI equation, and the prevalence of CKD stages 3 to 5 (estimated GFR <60 mL/min/1.73 m(2)) was reduced from 8.7% to 6.3%. In estimated GFR of 45 to 59 mL/min/1.73 m(2) by the MDRD Study equation, 34.7% of participants were reclassified to estimated GFR of 60 to 89 mL/min/1.73 m(2) by the CKD-EPI equation and had lower incidence rates (per 1000 person-years) for the outcomes of interest (9.9 vs 34.5 for all-cause mortality, 2.7 vs 13.0 for cardiovascular mortality, and 0.5 vs 0.8 for ESRD) compared with those not reclassified. The corresponding adjusted hazard ratios were 0.80 (95% CI, 0.74-0.86) for all-cause mortality, 0.73 (95% CI, 0.65-0.82) for cardiovascular mortality, and 0.49 (95% CI, 0.27-0.88) for ESRD. Similar findings were observed in other estimated GFR categories by the MDRD Study equation. Net reclassification improvement based on estimated GFR categories was significantly positive for all outcomes (range, 0.06-0.13; all P < .001). Net reclassification improvement was similarly positive in most subgroups defined by age (<65 years and ≥65 years), sex, race/ethnicity (white, Asian, and black), and presence or absence of diabetes and hypertension. The results in the high-risk and CKD cohorts were largely consistent with the general population cohorts.

CONCLUSION

The CKD-EPI equation classified fewer individuals as having CKD and more accurately categorized the risk for mortality and ESRD than did the MDRD Study equation across a broad range of populations.

Prediction of ESRD and death among people with CKD: the Chronic Renal Impairment in Birmingham (CRIB) prospective cohort study

Background

Validated prediction scores are required to assess the risks of end-stage renal disease (ESRD) and death in individuals with chronic kidney disease (CKD).

Study Design

Prospective cohort study with validation in a separate cohort.

Setting & Participants

Cox regression was used to assess the relevance of baseline characteristics to risk of ESRD (mean follow-up, 4.1 years) and death (mean follow-up, 6.0 years) in 382 patients with stages 3-5 CKD not initially on dialysis therapy in the Chronic Renal Impairment in Birmingham (CRIB) Study. Resultant risk prediction equations were tested in a separate cohort of 213 patients with CKD (the East Kent cohort).

Factors

44 baseline characteristics (including 30 blood and urine assays).

Outcomes

ESRD and all-cause mortality.

Results

In the CRIB cohort, 190 patients reached ESRD (12.1%/y) and 150 died (6.5%/y). Each 30% lower baseline estimated glomerular filtration rate was associated with a 3-fold higher ESRD rate and a 1.3-fold higher death rate. After adjustment for each other, only baseline creatinine level, serum phosphate level, urinary albumin-creatinine ratio, and female sex remained strongly (P < 0.01) predictive of ESRD. For death, age, N-terminal pro-brain natriuretic peptide, troponin T level, and cigarette smoking remained strongly predictive of risk. Using these factors to predict outcomes in the East Kent cohort yielded an area under the receiver operating characteristic curve (ie, C statistic) of 0.91 (95% CI, 0.87-0.96) for ESRD and 0.82 (95% CI, 0.75-0.89) for death.

Limitations

Other important factors may have been missed because of limited study power.

Conclusions

Simple laboratory measures of kidney and cardiac function plus age, sex, and smoking history can be used to help identify patients with CKD at highest risk of ESRD and death. Larger cohort studies are required to further validate these results.

Cystatin C and risk of vascular and nonvascular mortality: a prospective cohort study of older men

OBJECTIVE

To assess the relevance of cystatin C, as a marker of mild-to-moderate renal impairment, for vascular and nonvascular mortality in older people.

DESIGN

Prospective cohort study.

SETTING

Re-survey in 1997 to 1998 of survivors in the 1970 Whitehall study of London civil servants.

SUBJECTS

Five thousand three hundred and seventy-one men (mean age at resurvey: 77 years) who took part in the resurvey and had plasma cystatin C concentration measured.

MAIN OUTCOME MEASURES

Cause-specific mortality over subsequent 11 years (1997 to 2008).

METHODS

Cox regression was used to estimate the associations of cystatin C with vascular and nonvascular mortality, before and after adjustment for prior disease and other risk factors (including lifetime blood pressure).

RESULTS

During an 11.0-year follow-up period, there were 1171 deaths from vascular causes [26 per 1000 per year (py)] and 1615 deaths from nonvascular causes (36 per 1000 py). Compared with men with cystatin C in the bottom fifth of the distribution, men in the top 10th had about two-fold higher mortality rates from vascular and nonvascular mortality (fully adjusted P both <0.001) even after adjustment for prior disease and all measured confounders, including lifetime blood pressure. The fully adjusted relative risks per 50% higher cystatin C concentrations were 1.66 [95% CI 1.48 to 1.85] for vascular mortality, 1.92 [95% CI 1.66 to 2.22] for ischaemic heart disease mortality and 1.46 [95% CI 1.31 to 1.61] for nonvascular mortality.

CONCLUSIONS

In older men, plasma concentration of cystatin C, probably as a marker of mild renal disease, is a strong independent predictor of both vascular and nonvascular mortality.

Biomarkers of inflammation predict both vascular and non-vascular mortality in older men

AIMS

To compare the predictive value of inflammatory biomarkers and lipids for vascular and non-vascular mortality in older men.

METHODS AND RESULTS

The relevance of inflammatory biomarkers and lipids for vascular and non-vascular mortality was assessed in a prospective study of 5360 men (mean age 77 years) followed for 7 years. Vascular mortality was positively associated with log C-reactive protein (lnCRP), fibrinogen and total/HDL-C (high-density lipoprotein cholesterol), and inversely associated with albumin [age adjusted hazard ratio (HR) per 2-SD higher usual level (approximately the difference between the top and the bottom thirds of the distribution): 2.09 for lnCRP; 1.70 for fibrinogen; 0.50 for albumin and 1.45 for total/HDL-C]. The associations with the inflammatory markers were attenuated after adjustment for established risk factors, including lipids [adjusted HRs: 1.86 (lnCRP); 1.44 (fibrinogen); 0.51 (albumin)], and further attenuated (and, for fibrinogen, no longer predictive) after adjustment for each other [fully adjusted HRs: 1.60 (lnCRP); 1.01 (fibrinogen); 0.61 (albumin)]. Higher CRP and lower albumin levels were also associated with significantly raised non-vascular mortality independently of other characteristics [fully adjusted HRs: 1.62 (lnCRP); 0.65 (albumin)].

CONCLUSION

In this cohort of older men, higher CRP and lower albumin levels strongly predicted both vascular and non-vascular mortality, independently of other characteristics.

Ensuring trial validity by data quality assurance and diversification of monitoring methods

Errors in the design, the conduct, the data collection process, and the analysis of a randomized trial have the potential to affect not only the safety of the patients in the trial, but also, through the introduction of bias, the safety of future patients. Trial monitoring, defined broadly to include methods of oversight which begin when the study is designed and continue until it is reported in a publication, has a role to play in eliminating such errors. On-site monitoring can be extremely inefficient for the identification of errors most likely to compromise patient safety or bias study results. However, a variety of other monitoring strategies offer alternatives to on-site monitoring. Each new trial should conduct a risk assessment to identify the optimal means of monitoring, taking into account the likely sources of error, their consequences for patients, the study's validity, and the available resources. Trial management committees should consider central statistical monitoring a key aspect of such monitoring. The systematic application of this approach would be likely to lead to tangible benefits, and resources that are currently wasted on inefficient on-site monitoring could be diverted to increasing trial sample sizes or conducting more trials. Clinical Trials 2008; 5: 49—55. http://ctj.sagepub.com

A practical method of measuring glomerular filtration rate by iohexol clearance using dried capillary blood spots

BACKGROUND

Exogenous tracer-based methods of measuring glomerular filtration rate (GFR) are difficult to perform, whilst creatinine-based estimation formulae are inaccurate.

METHODS

We assessed a new technique of measuring iohexol clearance using timed dried capillary blood spots. A reference GFR was measured in 81 subjects (GFR 15-124 ml/min/1.73 m(2)) by iohexol clearance using three venous samples (2, 3 and 4 h after an intravenous bolus). GFR was estimated by six test methods; iohexol clearance using (i) 3 blood spots (2, 3, 4 h); (ii) 2 blood spots (2, 4 h) and (iii) 1 blood spot (4 h); (iv) the Modification of Diet in Renal Disease (MDRD) formula; (v) the Cockcroft-Gault formula, and (vi) a formula estimating GFR from serum cystatin C concentration. For each test method the bias and precision were calculated as the mean and standard deviation (SD) of the 'GFR differences' (test method GFR - reference GFR).

RESULTS

The limits of agreement (bias +/-1.96 x SD; in ml/min/1.73 m(2)) were: (i) 1.1 +/- 15.1 for 3-spot iohexol clearance; (ii) 0.6 +/- 14.9 for 2-spot iohexol clearance; (iii) 4.5 +/- 21.2 for 1-spot iohexol clearance; (iv) -15.7 +/- 33.3 for the MDRD formula; (v) -9.6 +/- 32.9 for the Cockcroft-Gault formula, and (vi) -12.1 +/- 31.7 for the Cystatin C formula. The accuracy of all six test methods was similar among individuals with GFR <60 ml/min/ 1.73 m(2); however, in individuals with GFR > or =60 ml/min/ 1.73 m(2), the MDRD, Cockcroft-Gault and Cystatin C formulae were all imprecise and systematically underestimated GFR.

CONCLUSIONS

Blood spot iohexol clearance provides a potentially practical method of estimating GFR accurately in large-scale epidemiological studies especially among individuals without established chronic kidney disease.

Cholesterol fractions and apolipoproteins as risk factors for heart disease mortality in older men

BACKGROUND

The relevance of blood lipid levels as risk factors for ischemic heart disease (IHD) in older people is uncertain; hence, cholesterol-lowering therapy is not routinely prescribed in older populations.

METHODS

We assessed IHD mortality associations with plasma levels of total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, apolipoprotein B, and apolipoprotein A(1) measured in older men. Ischemic heart disease was assessed in a 7-year follow-up of a cohort of 5344 men (mean age, 76.9 years), including 74.3% without cardiovascular disease (CVD) or statin use and 25.6% with CVD or statin use. Hazard ratios (HRs) for 447 deaths from IHD were estimated for a 2-SD difference in usual plasma lipid levels.

RESULTS

Ischemic heart disease mortality was not significantly associated with total cholesterol levels in all men (HR, 1.05), but a significant positive association in men without CVD and a slight nonsignificant inverse association in men with CVD were observed (HR, 1.47 vs 0.84). The patterns were similar for low-density lipoprotein cholesterol levels (HR, 1.50 vs 0.98) and for apolipoprotein B levels (HR, 1.68 vs 0.93). Ischemic heart disease risks were inversely associated with high-density lipoprotein cholesterol levels and with apolipoprotein A(1) levels in men with and without CVD. Ischemic heart disease risks were strongly associated with total/high-density [corrected] lipoprotein cholesterol levels (HR, 1.57) and apolipoprotein B/apolipoprotien [corrected] A(1) levels (HR, 1.54), and remained strongly related at all ages.

CONCLUSIONS

Blood lipid levels other than total cholesterol levels were associated with IHD in older men. Differences in lipid levels that are achievable by statin use were associated with about a one-third lower risk of IHD, irrespective of age.

Effect of alcohol on risk of coronary heart disease and stroke: causality, bias, or a bit of both?

Epidemiological studies of middle-aged populations generally find the relationship between alcohol intake and the risk of coronary heart disease (CHD) and stroke to be either U- or J-shaped. This review describes the extent that these relationships are likely to be causal, and the extent that they may be due to specific methodological weaknesses in epidemiological studies. The consistency in the vascular benefit associated with moderate drinking (compared with non-drinking) observed across different studies, together with the existence of credible biological pathways, strongly suggests that at least some of this benefit is real. However, because of biases introduced by: choice of reference categories; reverse causality bias; variations in alcohol intake over time; and confounding, some of it is likely to be an artefact. For heavy drinking, different study biases have the potential to act in opposing directions, and as such, the true effects of heavy drinking on vascular risk are uncertain. However, because of the known harmful effects of heavy drinking on non-vascular mortality, the problem is an academic one. Studies of the effects of alcohol consumption on health outcomes should recognise the methodological biases they are likely to face, and design, analyse and interpret their studies accordingly. While regular moderate alcohol consumption during middle-age probably does reduce vascular risk, care should be taken when making general recommendations about safe levels of alcohol intake. In particular, it is likely that any promotion of alcohol for health reasons would do substantially more harm than good.

N-terminal Pro-B-type natriuretic peptide, vascular disease risk, and cholesterol reduction among 20,536 patients in the MRC/BHF heart protection study

OBJECTIVES

We sought to assess the ability of N-terminal pro-B-type natriuretic peptide (N-BNP) to predict vascular events in high-risk people and to test whether statins benefit people with high levels of N-BNP.

BACKGROUND

The predictive value of N-BNP for occlusive vascular events and the effects of statins in people with high N-BNP levels are uncertain.

METHODS

A total of 20,536 people were assigned randomly to simvastatin 40 mg daily or placebo for an average of 5 years. Five baseline N-BNP groups were defined (<386; 386 to 1,171; 1,172 to 2,617; 2,618 to 5,758; and > or =5,759 pg/ml).

RESULTS

Baseline N-BNP was strongly predictive of future vascular events independently of other characteristics. Compared with participants with N-BNP <386 pg/ml, those with levels > or =5,759 pg/ml had adjusted relative risks for major vascular events (MVEs) (i.e., major coronary events [MCE] [nonfatal myocardial infarction or coronary death], stroke, or revascularization) of 2.26, for MCE of 3.09, for stroke of 1.80, and for heart failure (hospitalization or death) of 9.23 (all p < 0.0001). Overall, simvastatin allocation reduced the relative risk of MVE by 24% (95% confidence interval 19 to 28). There was a trend toward smaller (but still significant) proportional reductions in MVE among participants with greater baseline N-BNP levels, but the absolute benefits of simvastatin allocation were similar at all N-BNP levels. Simvastatin allocation was also associated with a 14% (95% confidence interval 0 to 25) proportional reduction in heart failure. No excess risk of other vascular and nonvascular outcomes was observed with simvastatin allocation among participants with greater baseline values of N-BNP.

CONCLUSIONS

In this study, N-BNP levels were strongly predictive not only of heart failure but also of MVEs. In people with high N-BNP levels consistent with heart failure, statin allocation significantly reduced vascular risk, with no evidence of hazard. (http://www.controlledtrials.com/ISRCTN48489393/48489393).

Do selective cyclo-oxygenase-2 inhibitors and traditional non-steroidal anti-inflammatory drugs increase the risk of atherothrombosis? Meta-analysis of randomised trials

OBJECTIVE

To assess the effects of selective cyclo-oxygenase-2 (COX 2) inhibitors and traditional non-steroidal anti-inflammatory drugs (NSAIDs) on the risk of vascular events.

DESIGN

Meta-analysis of published and unpublished tabular data from randomised trials, with indirect estimation of the effects of traditional NSAIDs.

DATA SOURCES

Medline and Embase (January 1966 to April 2005); Food and Drug Administration records; and data on file from Novartis, Pfizer, and Merck.

REVIEW METHODS

Eligible studies were randomised trials that included a comparison of a selective COX 2 inhibitor versus placebo or a selective COX 2 inhibitor versus a traditional NSAID, of at least four weeks' duration, with information on serious vascular events (defined as myocardial infarction, stroke, or vascular death). Individual investigators and manufacturers provided information on the number of patients randomised, numbers of vascular events, and the person time of follow-up for each randomised group.

RESULTS

In placebo comparisons, allocation to a selective COX 2 inhibitor was associated with a 42% relative increase in the incidence of serious vascular events (1.2%/year v 0.9%/year; rate ratio 1.42, 95% confidence interval 1.13 to 1.78; P = 0.003), with no significant heterogeneity among the different selective COX 2 inhibitors. This was chiefly attributable to an increased risk of myocardial infarction (0.6%/year v 0.3%/year; 1.86, 1.33 to 2.59; P = 0.0003), with little apparent difference in other vascular outcomes. Among trials of at least one year's duration (mean 2.7 years), the rate ratio for vascular events was 1.45 (1.12 to 1.89; P = 0.005). Overall, the incidence of serious vascular events was similar between a selective COX 2 inhibitor and any traditional NSAID (1.0%/year v 0.9%/year; 1.16, 0.97 to 1.38; P = 0.1). However, statistical heterogeneity (P = 0.001) was found between trials of a selective COX 2 inhibitor versus naproxen (1.57, 1.21 to 2.03) and of a selective COX 2 inhibitor versus non-naproxen NSAIDs (0.88, 0.69 to 1.12). The summary rate ratio for vascular events, compared with placebo, was 0.92 (0.67 to 1.26) for naproxen, 1.51 (0.96 to 2.37) for ibuprofen, and 1.63 (1.12 to 2.37) for diclofenac.

CONCLUSIONS

Selective COX 2 inhibitors are associated with a moderate increase in the risk of vascular events, as are high dose regimens of ibuprofen and diclofenac, but high dose naproxen is not associated with such an excess.

Effects of older age on fibrin D-dimer, C-reactive protein, and other hemostatic and inflammatory variables in men aged 60-79 years

BACKGROUND

Previous studies have suggested that several hemostatic and inflammatory variables, which are risk predictors for arterial or venous thrombosis, increase with age. However, there is a lack of data from large population studies for reliable estimates of reference ranges.

OBJECTIVES

To establish reliable reference ranges of hemostatic and inflammatory variables for 5-year age groups in older men and their implications for pathogenesis and diagnosis.

PATIENTS AND METHODS

A total of 3861 men aged 60-79 years at the 20 years follow-up of the British Regional Heart Study.

RESULTS

Several variables increased with age. The greatest median increases between 60-64 and 75-79 years age groups were observed for fibrin D-dimer (91%) and C-reactive protein (CRP) (57%). Significant median increases were also observed for von Willebrand factor antigen (23%), tissue plasminogen activator antigen (11%), factor VIII (10%), and fibrinogen (8%). In contrast, levels of classical cardiovascular risk factors neither decreased nor increased substantially with age, with the exception of systolic blood pressure (median increase 10%).

CONCLUSIONS

The exponential increases in risk of arterial and venous thrombotic events in men between age 60 and 79 years (when most such events occur) may be related in part to increasing activation of blood coagulation, fibrinolysis, and inflammation; possibly related to the increasing inflammatory burden of both atherosclerotic and non-vascular disease. These increases also have implications for diagnosis of suspected acute venous thromboembolism (D-dimer), and recently proposed screening for prediction of coronary heart disease risk and detection of occult disease (CRP).