Life expectancy associated with different ages at diagnosis of type 2 diabetes in high-income countries: 23 million person-years of observation

BACKGROUND

The prevalence of type 2 diabetes is increasing rapidly, particularly among younger age groups. Estimates suggest that people with diabetes die, on average, 6 years earlier than people without diabetes. We aimed to provide reliable estimates of the associations between age at diagnosis of diabetes and all-cause mortality, cause-specific mortality, and reductions in life expectancy.

METHODS

For this observational study, we conducted a combined analysis of individual-participant data from 19 high-income countries using two large-scale data sources: the Emerging Risk Factors Collaboration (96 cohorts, median baseline years 1961-2007, median latest follow-up years 1980-2013) and the UK Biobank (median baseline year 2006, median latest follow-up year 2020). We calculated age-adjusted and sex-adjusted hazard ratios (HRs) for all-cause mortality according to age at diagnosis of diabetes using data from 1 515 718 participants, in whom deaths were recorded during 23·1 million person-years of follow-up. We estimated cumulative survival by applying age-specific HRs to age-specific death rates from 2015 for the USA and the EU.

FINDINGS

For participants with diabetes, we observed a linear dose-response association between earlier age at diagnosis and higher risk of all-cause mortality compared with participants without diabetes. HRs were 2·69 (95% CI 2·43-2·97) when diagnosed at 30-39 years, 2·26 (2·08-2·45) at 40-49 years, 1·84 (1·72-1·97) at 50-59 years, 1·57 (1·47-1·67) at 60-69 years, and 1·39 (1·29-1·51) at 70 years and older. HRs per decade of earlier diagnosis were similar for men and women. Using death rates from the USA, a 50-year-old individual with diabetes died on average 14 years earlier when diagnosed aged 30 years, 10 years earlier when diagnosed aged 40 years, or 6 years earlier when diagnosed aged 50 years than an individual without diabetes. Using EU death rates, the corresponding estimates were 13, 9, or 5 years earlier.

INTERPRETATION

Every decade of earlier diagnosis of diabetes was associated with about 3-4 years of lower life expectancy, highlighting the need to develop and implement interventions that prevent or delay the onset of diabetes and to intensify the treatment of risk factors among young adults diagnosed with diabetes.

FUNDING

British Heart Foundation, Medical Research Council, National Institute for Health and Care Research, and Health Data Research UK.

Trajectories of high-sensitivity cardiac troponin I in the two decades before cardiovascular death in Whitehall II

Background

High-sensitivity cardiac troponin may be a promising biomarker that could be used for personalised cardiovascular risk prediction and monitoring in the general population. Temporal changes in high-sensitivity cardiac troponin before cardiovascular death are largely unexplored.

Purpose

Using the longitudinal Whitehall II cohort, we evaluated whether three serial high-sensitivity cardiac troponin I measurements over 15 years improved prediction of cardiovascular death when compared to a single time point at baseline.

Methods

Whitehall II is an ongoing longitudinal observation cohort study of 10,308 civil servants, and we included participants who had at least one cardiac troponin measurement and outcome data available. We constructed time trajectories to evaluate the temporal pattern of cardiac troponin I in those who died from cardiovascular disease as compared to those who did not. Cox regression and joint models were used to investigate the association of cardiac troponin I in relation to cardiovascular death using single time point (at baseline) and repeated measurements (at baseline, 10 and 15 years), respectively. The discriminative ability was assessed by the concordance index.

Results

In total, we included 7,293 individuals (mean age of 58 years [SD 7] at baseline, 29.4% women). Of these, 5,818 (79.8%) and 4,045 (55.5%) individuals had a second and third cardiac troponin I concentration measured, respectively. Cardiovascular death occurred in 281 (3.9%) individuals during a median follow-up of 21.4 [IQR, 15.8 to 21.8] years. In the 21-year trajectories of cardiac troponin I, we observed higher baseline concentrations in those who died due to cardiovascular disease as compared to those who did not (median 5 [IQR, 2 to 9] ng/L versus 3 [IQR, 2 to 5] ng/L respectively, Figure). Cardiac troponin I was an independent predictor of cardiovascular death, and the hazard ratio (HR) derived from the joint model that included serial cardiac troponin measurements was higher than the HR derived from the single time point model (single time point model: adjusted HR 1.53, 95% Confidence Interval [CI] 1.37 to 1.70 per naturally log transformed unit of cardiac troponin I, versus repeated measurements model: adjusted HR 1.79, 95% CI 1.58 to 2.02). The discriminative ability of the cardiac troponin model improved when using repeated measurements (concordance index of unadjusted cardiac troponin models, single time point: 0.668 versus repeated measurements: 0.724).

Conclusions

Our study shows that cardiac troponin I trajectories were persistently higher among individuals who died from cardiovascular disease. Cardiac troponin I is a strong independent predictor of cardiovascular death, and incorporating repeated measurements of cardiac troponin improves cardiovascular risk prediction in the general population.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Cardiac troponin I measurements and analysis were supported by were supported by Siemens Healthineers. The study was supported by Health Data Research UK which receives its funding from HDR UK Ltd (HDR-5012) funded by the UK Medical Research Council, Engineering and Physical Sciences Research Council, Economic and Social Research Council, Department of Health and Social Care (England), Chief Scientist Office of the Scottish Government Health and Social Care Directorates, Health and Social Care Research and Development Division (Welsh Government), Public Health Agency (Northern Ireland), British Heart Foundation and the Wellcome Trust. NLM is supported by the British Heart Foundation through a Senior Clinical Research Fellowship (FS/16/14/32023), Programme Grant (RG/20/10/34966) and a Research Excellence Award (RE/18/5/34216). The funders had no role in the study and the decision to submit this work to be considered for publication.

Neutrophil content predicts lymphocyte depletion and anti-PD1 treatment failure in NSCLC

Immune checkpoint inhibitor (ICI) treatment has recently become a first-line therapy for many non-small cell lung cancer (NSCLC) patients. Unfortunately, most NSCLC patients are refractory to ICI monotherapy, and initial attempts to address this issue with secondary therapeutics have proven unsuccessful. To identify entities precluding CD8+ T cell accumulation in this process, we performed unbiased analyses on flow cytometry, gene expression, and multiplexed immunohistochemical data from a NSCLC patient cohort. The results revealed the presence of a myeloid-rich subgroup, which was devoid of CD4+ and CD8+ T cells. Of all myeloid cell types assessed, neutrophils were the most highly associated with the myeloid phenotype. Additionally, the ratio of CD8+ T cells to neutrophils (CD8/PMN) within the tumor mass optimally distinguished between active and myeloid cases. This ratio was also capable of showing the separation of patients responsive to ICI therapy from those with stable or progressive disease in 2 independent cohorts. Tumor-bearing mice treated with a combination of anti-PD1 and SX-682 (CXCR1/2 inhibitor) displayed relocation of lymphocytes from the tumor periphery into a malignant tumor, which was associated with induction of IFN-γ-responsive genes. These results suggest that neutrophil antagonism may represent a viable secondary therapeutic strategy to enhance ICI treatment outcomes.

Tumor-derived Autoantibodies Identify Malignant Pulmonary Nodules

Rationale: Screening for non-small cell lung cancer is associated with earlier diagnosis and reduced mortality but also increased harm caused by invasive follow-up of benign pulmonary nodules. Lung tumorigenesis activates the immune system, components of which could serve as tumor-specific biomarkers. Objectives: To profile tumor-derived autoantibodies as peripheral biomarkers of malignant pulmonary nodules. Methods: High-density protein arrays were used to define the specificity of autoantibodies isolated from B cells of 10 resected lung tumors. These tumor-derived autoantibodies were also examined as free or complexed to antigen in the plasma of the same 10 patients and matched benign nodule control subjects. Promising autoantibodies were further analyzed in an independent cohort of 250 nodule-positive patients. Measurements and Main Results: Thirteen tumor B-cell-derived autoantibodies isolated ex vivo showed greater than or equal to 50% sensitivity and greater than or equal to 70% specificity for lung cancer. In plasma, 11 of 13 autoantibodies were present both complexed to and free from antigen. In the larger validation cohort, 5 of 13 tumor-derived autoantibodies remained significantly elevated in cancers. A combination of four of these autoantibodies could detect malignant nodules with an area under the curve of 0.74 and had an area under the curve of 0.78 in a subcohort of indeterminate (8-20 mm in the longest diameter) pulmonary nodules. Conclusions: Our novel pipeline identifies tumor-derived autoantibodies that could effectively serve as blood biomarkers for malignant pulmonary nodule diagnosis. This approach has future implications for both a cost-effective and noninvasive approach to determine nodule malignancy for widespread low-dose computed tomography screening.

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).

Optimized Protocol for Quantitative Multiple Reaction Monitoring-Based Proteomic Analysis of Formalin-Fixed, Paraffin-Embedded Tissues

Despite a clinical, economic, and regulatory imperative to develop companion diagnostics, precious few new biomarkers have been successfully translated into clinical use, due in part to inadequate protein assay technologies to support large-scale testing of hundreds of candidate biomarkers in formalin-fixed paraffin-embedded (FFPE) tissues. Although the feasibility of using targeted, multiple reaction monitoring mass spectrometry (MRM-MS) for quantitative analyses of FFPE tissues has been demonstrated, protocols have not been systematically optimized for robust quantification across a large number of analytes, nor has the performance of peptide immuno-MRM been evaluated. To address this gap, we used a test battery approach coupled to MRM-MS with the addition of stable isotope-labeled standard peptides (targeting 512 analytes) to quantitatively evaluate the performance of three extraction protocols in combination with three trypsin digestion protocols (i.e., nine processes). A process based on RapiGest buffer extraction and urea-based digestion was identified to enable similar quantitation results from FFPE and frozen tissues. Using the optimized protocols for MRM-based analysis of FFPE tissues, median precision was 11.4% (across 249 analytes). There was excellent correlation between measurements made on matched FFPE and frozen tissues, both for direct MRM analysis (R(2) = 0.94) and immuno-MRM (R(2) = 0.89). The optimized process enables highly reproducible, multiplex, standardizable, quantitative MRM in archival tissue specimens.

Noise sensitivity and future risk of illness and mortality

Aircraft and road traffic noise exposure increase the risk of cardiovascular disease (CVD). Noise annoyance is the most frequent response to environmental noise. Noise annoyance has been shown to modify the association of transport noise exposure on CVD and noise sensitivity moderates the annoyance response to noise. This study uses prospective data from phases 1, 3, 5, 7 and 9 in 3630 male and female civil servants from the UK Whitehall II Study to examine whether a single question on noise sensitivity measured by annoyance responses to noise in general predicts physical and mental ill-health and mortality. Non-fatal myocardial infarction and stroke morbidity over the follow-up were defined by MONICA criteria based on study ECGs, hospital records, hospital admission statistics or General Practitioner confirmation. Depressive symptoms were measured by the Center for Epidemiologic Studies Depression Scale (CES-D) and psychological distress by the General Health questionnaire (GHQ). There was no association between noise sensitivity and CVD morbidity or mortality except in people from lower employment grades where there was an association with angina. Noise sensitivity was a consistent predictor of depressive symptoms and psychological distress at phases 3, 5 and 7. High noise sensitivity scores at baseline predicted GHQ caseness at phase 3 adjusting for age, sex, employment grade, self-rated health and GHQ caseness at baseline (OR=1.56 95% CI 1.29-1.88). Noise sensitivity has been identified as a predictor of mental ill-health. More longitudinal research is needed including measures of noise exposure.

Physical activity patterns over 10 years in relation to body mass index and waist circumference: the Whitehall II cohort study

OBJECTIVE

Physical activity patterns over 10-years in relation to changes in body mass index (BMI) and waist circumference (WC) were examined.

DESIGN AND METHODS

Participants (4,880, mean age 49.3 years at baseline) from the Whitehall II cohort study were included. Self-reported physical activity and anthropometric data were collected at baseline (1991) and twice during follow-up (1997 and 2002).

RESULTS

At baseline, meeting established guidelines for physical activity, particularly through vigorous activity, was associated with lower WC (multivariable adjusted B compared to not meeting the guidelines -2.08 cm, 95% CI, -1.39, -0.75) and BMI (-0.34 kg/m(2) , -0.10, -0.59). Based on repeat data, "high adherence" to the guidelines compared to "rare adherence" over follow-up was associated with lower BMI (adjusted difference, -0.43 kg/m(2) , 95% CI, -0.79, -0.08) and WC (-2.50 cm, 95% CI, -3.46, -1.54) at follow-up. Compared to participants that remained stable between 1997 and 2002 (change of <2.5 h/week), those that reported an increase in moderate-vigorous physical activity of at least 2.5 h/week displayed lower BMI (-0.40 kg/m(2) , 95% CI, -0.71, -0.08) and WC (-1.10 cm, 95% CI, -1.95, -0.75).

CONCLUSION

Regular physical activity, confirmed by repeated assessments, is associated with relatively favorable levels of adiposity markers after 10 years follow-up.

An unusual cause of fever in an HIV-positive patient

Patients with HIV frequently present with fever. However, the spectrum of diseases affecting patients with HIV has changed in the era of antiretroviral therapy (ART). Here we present a patient who has an unusual cause for his fever with an eventual diagnosis of adult-onset Still's disease.

Hyperuricaemia and gout

Gout is increasing in prevalence throughout the world, particularly in developed countries. The causes are dietary--purine-rich foods, high saturated fats, fructose-containing drinks and alcohol. Gout is also drug-related and associated with increased obesity, hypertension, insulin resistance and metabolic syndrome. Although very readily treated, there is evidence that physicians fail to optimise the treatment and achieve low enough serum urate levels, while patients fail to comply with the treatment and dietary advice. Standard treatment of acute attacks is with non-steroidal anti-inflammatory drugs, colchicine or steroids. The standard urate-lowering agents are allopurinol and uricosuric agents. Newer urate lowering agents are now available for refractory gout. Increased understanding of the membrane transporters involved in urate excretion in the kidney and the genes that control them and of the way that sodium urate crystals cause inflammation via the innate immune system and the inflammasome offers hope for new therapeutic approaches.

Ultrasonic plaque echolucency and emboli signals predict stroke in asymptomatic carotid stenosis

OBJECTIVES

Better methods are required to identify patients with asymptomatic carotid stenosis (ACS) at risk of future stroke. Two potential markers of high risk are echolucent plaque morphology on carotid ultrasound and embolic signals (ES) in the ipsilateral middle cerebral artery on transcranial Doppler ultrasound (TCD). We explored the predictive value of a score based on these 2 measures in the prospective, observational, international multicenter Asymptomatic Carotid Emboli Study.

METHODS

A total of 435 recruited subjects with ACS ≥70% had baseline ultrasound images and TCD data available. Subjects were prospectively followed up for 2 years.

RESULTS

A total of 164 (37.7%) plaques were graded as echolucent. Plaque echolucency at baseline was associated with an increased risk of ipsilateral stroke alone (hazard ratio [HR] 6.43, 95% confidence interval [CI] 1.36-30.44, p = 0.019). A combined variable of plaque echolucency and ES positivity at baseline was associated with a markedly increased risk of ipsilateral stroke alone (HR 10.61, 95% CI 2.98-37.82, p = 0.0003). This association remained significant after controlling for risk factors, degree of carotid stenosis, and antiplatelet medication.

CONCLUSIONS

Plaque morphology assessed using a simple, and clinically applicable, visual rating scale predicts ipsilateral stroke risk in ACS. The combination of ES detection and plaque morphology allows a greater prediction than either measure alone and identifies a high-risk group with an annual stroke risk of 8%, and a low-risk group with a risk of <1% per annum. This risk stratification may prove useful in the selection of patients with ACS for endarterectomy.

The effectiveness and cost-effectiveness of biomarkers for the prioritisation of patients awaiting coronary revascularisation: a systematic review and decision model

OBJECTIVE

To determine the effectiveness and cost-effectiveness of a range of strategies based on conventional clinical information and novel circulating biomarkers for prioritising patients with stable angina awaiting coronary artery bypass grafting (CABG).

DATA SOURCES

MEDLINE and EMBASE were searched from 1966 until 30 November 2008.

REVIEW METHODS

We carried out systematic reviews and meta-analyses of literature-based estimates of the prognostic effects of circulating biomarkers in stable coronary disease. We assessed five routinely measured biomarkers and the eight emerging (i.e. not currently routinely measured) biomarkers recommended by the European Society of Cardiology Angina guidelines. The cost-effectiveness of prioritising patients on the waiting list for CABG using circulating biomarkers was compared against a range of alternative formal approaches to prioritisation as well as no formal prioritisation. A decision-analytic model was developed to synthesise data on a range of effectiveness, resource use and value parameters necessary to determine cost-effectiveness. A total of seven strategies was evaluated in the final model.

RESULTS

We included 390 reports of biomarker effects in our review. The quality of individual study reports was variable, with evidence of small study (publication) bias and incomplete adjustment for simple clinical information such as age, sex, smoking, diabetes and obesity. The risk of cardiovascular events while on the waiting list for CABG was 3 per 10,000 patients per day within the first 90 days (184 events in 9935 patients with a mean of 59 days at risk). Risk factors associated with an increased risk, and included in the basic risk equation, were age, diabetes, heart failure, previous myocardial infarction and involvement of the left main coronary artery or three-vessel disease. The optimal strategy in terms of cost-effectiveness considerations was a prioritisation strategy employing biomarker information. Evaluating shorter maximum waiting times did not alter the conclusion that a prioritisation strategy with a risk score using estimated glomerular filtration rate (eGFR) was cost-effective. These results were robust to most alternative scenarios investigating other sources of uncertainty. However, the cost-effectiveness of the strategy using a risk score with both eGFR and C-reactive protein (CRP) was potentially sensitive to the cost of the CRP test itself (assumed to be 6 pounds in the base-case scenario).

CONCLUSIONS

Formally employing more information in the prioritisation of patients awaiting CABG appears to be a cost-effective approach and may result in improved health outcomes. The most robust results relate to a strategy employing a risk score using conventional clinical information together with a single biomarker (eGFR). The additional prognostic information conferred by collecting the more costly novel circulating biomarker CRP, singly or in combination with other biomarkers, in terms of waiting list prioritisation is unlikely to be cost-effective.

Systematically missing confounders in individual participant data meta-analysis of observational cohort studies

One difficulty in performing meta-analyses of observational cohort studies is that the availability of confounders may vary between cohorts, so that some cohorts provide fully adjusted analyses while others only provide partially adjusted analyses. Commonly, analyses of the association between an exposure and disease either are restricted to cohorts with full confounder information, or use all cohorts but do not fully adjust for confounding. We propose using a bivariate random-effects meta-analysis model to use information from all available cohorts while still adjusting for all the potential confounders. Our method uses both the fully adjusted and the partially adjusted estimated effects in the cohorts with full confounder information, together with an estimate of their within-cohort correlation. The method is applied to estimate the association between fibrinogen level and coronary heart disease incidence using data from 154 012 participants in 31 cohorts.† Copyright © 2009 John Wiley & Sons, Ltd.

Socioeconomic position and cognitive decline using data from two waves: what is the role of the wave 1 cognitive measure?

BACKGROUND

Analysis of change in health status using data from two waves can be examined either adjusted or unadjusted for baseline health status. The effect of socioeconomic position (SEP) on cognitive change was assessed using both these strategies and the implications of the analyses are discussed.

METHODS

Data from 1261 men and 483 women of the Whitehall II cohort study, aged 50-55 years at wave 1, were used. Cognition was assessed at both waves using a test of verbal memory, and two tests of verbal fluency. Analysis of variance (ANOVA) was used to estimate the effect of SEP on change score and analysis of covariance (ANCOVA) was used to estimate this effect adjusted for the baseline cognitive score. The ANCOVA estimates were corrected for bias due to measurement error (estimated based on 3-month test-retest). Finally, ANCOVA estimates were examined for increasing levels of measurement error.

RESULTS

The results of the ANOVA suggest no effect of SEP on cognitive decline. In contrast, the ANCOVA suggests significantly greater cognitive decline in the lower SEP groups. However, the ANCOVA estimates for the effect of wave 1 cognition show evidence for regression to the mean due to the presence of measurement error. The corrected ANCOVA estimates show no association between SEP and cognitive decline.

CONCLUSIONS

Results from analysis of change using two waves of observational data, when adjusted for baseline, should be interpreted with caution.

Who benefits most from the cardioprotective properties of alcohol consumption--health freaks or couch potatoes?

BACKGROUND

The cardioprotective properties of moderate alcohol consumption, compared with abstinence or heavy drinking, are widely reported, but whether the benefits are experienced equally by all moderate drinkers is less well known.

AIMS

To examine the association between average alcohol intake per week and the incidence of fatal and non-fatal myocardial infarction during 17 years of follow-up for 9655 men and women without prevalent disease in the general population; and to test whether the level of cardioprotection differs according to subjects' other health behaviours (healthy, moderately healthy, unhealthy) at entry to the study.

METHOD

A longitudinal, British civil service-based cohort study, baseline in 1985-8.

RESULTS

A significant benefit of moderate drinking compared with abstinence or heavy drinking was found among those with poor health behaviours (little exercise, poor diet and smokers). No additional benefit from alcohol was found among those with the healthiest behaviour profile (> or =3 hours of vigorous exercise per week, daily fruit or vegetable consumption and non-smokers).

CONCLUSION

The cardioprotective benefit from moderate drinking does not apply equally to all drinkers, and this variability should be emphasised in public health messages.

The Emerging Risk Factors Collaboration: analysis of individual data on lipid, inflammatory and other markers in over 1.1 million participants in 104 prospective studies of cardiovascular diseases

Many long-term prospective studies have reported on associations of cardiovascular diseases with circulating lipid markers and/or inflammatory markers. Studies have not, however, generally been designed to provide reliable estimates under different circumstances and to correct for within-person variability. The Emerging Risk Factors Collaboration has established a central database on over 1.1 million participants from 104 prospective population-based studies, in which subsets have information on lipid and inflammatory markers, other characteristics, as well as major cardiovascular morbidity and cause-specific mortality. Information on repeat measurements on relevant characteristics has been collected in approximately 340,000 participants to enable estimation of and correction for within-person variability. Re-analysis of individual data will yield up to approximately 69,000 incident fatal or nonfatal first ever major cardiovascular outcomes recorded during about 11.7 million person years at risk. The primary analyses will involve age-specific regression models in people without known baseline cardiovascular disease in relation to fatal or nonfatal first ever coronary heart disease outcomes. This initiative will characterize more precisely and in greater detail than has previously been possible the shape and strength of the age- and sex-specific associations of several lipid and inflammatory markers with incident coronary heart disease outcomes (and, secondarily, with other incident cardiovascular outcomes) under a wide range of circumstances. It will, therefore, help to determine to what extent such associations are independent from possible confounding factors and to what extent such markers (separately and in combination) provide incremental predictive value.

Plasma fibrinogen level and the risk of major cardiovascular diseases and nonvascular mortality: an individual participant meta-analysis

CONTEXT

Plasma fibrinogen levels may be associated with the risk of coronary heart disease (CHD) and stroke.

OBJECTIVE

To assess the relationships of fibrinogen levels with risk of major vascular and with risk of nonvascular outcomes based on individual participant data.

DATA SOURCES

Relevant studies were identified by computer-assisted searches, hand searches of reference lists, and personal communication with relevant investigators.

STUDY SELECTION

All identified prospective studies were included with information available on baseline fibrinogen levels and details of subsequent major vascular morbidity and/or cause-specific mortality during at least 1 year of follow-up. Studies were excluded if they recruited participants on the basis of having had a previous history of cardiovascular disease; participants with known preexisting CHD or stroke were excluded.

DATA EXTRACTION

Individual records were provided on each of 154,211 participants in 31 prospective studies. During 1.38 million person-years of follow-up, there were 6944 first nonfatal myocardial infarctions or stroke events and 13,210 deaths. Cause-specific mortality was generally available. Analyses involved proportional hazards modeling with adjustment for confounding by known cardiovascular risk factors and for regression dilution bias.

DATA SYNTHESIS

Within each age group considered (40-59, 60-69, and > or =70 years), there was an approximately log-linear association with usual fibrinogen level for the risk of any CHD, any stroke, other vascular (eg, non-CHD, nonstroke) mortality, and nonvascular mortality. There was no evidence of a threshold within the range of usual fibrinogen level studied at any age. The age- and sex- adjusted hazard ratio per 1-g/L increase in usual fibrinogen level for CHD was 2.42 (95% confidence interval [CI], 2.24-2.60); stroke, 2.06 (95% CI, 1.83-2.33); other vascular mortality, 2.76 (95% CI, 2.28-3.35); and nonvascular mortality, 2.03 (95% CI, 1.90-2.18). The hazard ratios for CHD and stroke were reduced to about 1.8 after further adjustment for measured values of several established vascular risk factors. In a subset of 7011 participants with available C-reactive protein values, the findings for CHD were essentially unchanged following additional adjustment for C-reactive protein. The associations of fibrinogen level with CHD or stroke did not differ substantially according to sex, smoking, blood pressure, blood lipid levels, or several features of study design.

CONCLUSIONS

In this large individual participant meta-analysis, moderately strong associations were found between usual plasma fibrinogen level and the risks of CHD, stroke, other vascular mortality, and nonvascular mortality in a wide range of circumstances in healthy middle-aged adults. Assessment of any causal relevance of elevated fibrinogen levels to disease requires additional research.

Gender differences in the relationship of partner's social class to behavioural risk factors and social support in the Whitehall II study

In most countries health inequality in women appears to be greater when their socio-economic position is measured according to the occupation of male partners or spouses than the women's own occupations. Very few studies show social gradients in men's health according to the occupation of their female partners. This paper aims to explore the reasons for the differences in social inequality in cardiovascular disease between men and women by analysing the associations between own or spouses (or partners) socio-economic position and a set of risk factors for prevalent chronic diseases. Study participants were married or cohabiting London based civil servants included in the Whitehall II study. Socio-economic position of study participants was measured according to civil service grade; socio-economic position of the spouses and partners according to the Registrar General's social class schema. Risk factors were smoking, diet, exercise, alcohol consumption, and measures of social support. In no case was risk factor exposure more affected by the socio-economic position of a female partner than that of a male study participant. Wives' social class membership made no difference at all to the likelihood that male Whitehall participants were smokers, or took little exercise. Female participants' exercise and particularly smoking habit was, in contrast, related to their spouse's social class independently of their own grade of employment. Diet quality was affected equally by the socio-economic position of both male and female partners. Unlike the behavioural risk factors, the degree of social support reported by women participants was in general not strongly negatively affected by their husband or partner being in a less advantaged social class. However, non-employment in the husband or partner was associated with relatively lower levels of positive, and higher negative social support, while men with non-working wives or partners were unaffected. Studying gender differences in health inequality highlights some of the problems in health inequality research more broadly. We are brought face to face with the fact that the development of conceptual models that can be applied consistently to aetiology in both men and women are still at an early stage of development. Closer attention is needed to the different processes behind material power and 'emotional power' within the household when investigating gender differences in health and risk factors.

Psychosocial risk factors for coronary disease in White, South Asian and Afro-Caribbean civil servants: the Whitehall II study

BACKGROUND

Psychosocial factors are associated with the etiology and prognosis of coronary heart disease (CHD) in White populations; however, previous studies have not examined the distribution of psychosocial factors in ethnic groups with coronary rates higher (South Asian) and lower (Afro-Caribbean) than those of Whites.

STUDY OBJECTIVE

To determine whether ethnic differences in psychosocial risk factors parallel those in CHD mortality.

DESIGN

Cross-sectional survey.

SETTING

20 civil service departments in London.

PARTICIPANTS

8973 White, 577 South Asian, and 360 Afro-Caribbean office-based civil servants, aged 35-55 years.

OUTCOME MEASURES

Minor psychiatric morbidity (General Health Questionnaire), social supports (marital status, social networks, negative aspects of support, confiding/emotional support, social support at work), psychosocial work characteristics (job control, effort-reward imbalance), hostility levels and presence of Type A personality.

RESULTS

South Asians, compared to Whites, had more depression, higher negative supports, less social support at work, less job control, more effort-reward imbalance and higher levels of hostility, when adjusting for age and sex. Afro-Caribbeans, compared to Whites, had lower minor psychiatric morbidity and lower Type A scores. The remaining psychosocial factors showed either no ethnic differences in distribution, or differences contrary to those predicted from coronary event rates. Adjustment for employment grade made little difference to these associations.

CONCLUSION

Among South Asians, the majority of whom were Indian, the distribution of psychosocial factors was consistent with ethnic differences in coronary rates; the pattern for Afro-Caribbeans was less consistent. Further research is required to test the extent to which psychosocial factors predict coronary events within ethnic groups and to characterize better psychosocial measures.

Unique neuronal tracers show migration and differentiation of SVZ progenitors in organotypic slices

Continual neurogenesis in the subventricular zone (SVZ) of postnatal and adult mammalian forebrain has been well documented, but the mechanisms underlying cell migration and differentiation in this region are poorly understood. We have developed novel in vivo and in vitro methods to investigate these processes. Using stereotaxic injections of a variety of tracers/tracker [Cholera Toxin beta subunit (CTb-), Fluorogold (FG), and Cell Tracker Green (CTG)], we could efficiently label SVZ cells. Over several days, labeled cells migrate along the rostral migratory stream (RMS) to their final differentiation site in the olfactory bulb (OB). The compatibility of these tracers/trackers with immunohistochemistry allows for cell labeling with multiple dyes (e.g., CTb and CTG) and/or specific cell antigens. To investigate the dynamics of migration we labeled SVZ progenitor cells with small injections of CTG and monitored the movements of individual cells in fresh parasagittal brain slices over several hours using time-lapse confocal microscopy. Our observations suggest that tangential cell migration along the RMS occurs more rapidly than radial cell migration into the OB granule cell layer. To investigate migration over longer time periods, we developed an in vitro organotypic slice in which labeled SVZ progenitors migrate along the RMS and differentiate within the OB. The phenotypic characteristics of these cells in vitro were equivalent to those observed in vivo. Taken together, these methods provide useful tools investigating cell migration and differentiation in a preparation that maintains the anatomical organization of the RMS.

Relative contribution of early life and adult socioeconomic factors to adult morbidity in the Whitehall II study

STUDY OBJECTIVE

To determine the relative contribution of adult compared with early life socioeconomic status as predictors of morbidity attributable to coronary heart disease (CHD), chronic bronchitis and depression in the Whitehall II study of British civil servants.

DESIGN

Prospective observational study with mean 5.3 years (range 3.7-7.6) follow up.

SETTING

20 civil service departments originally located in London.

PARTICIPANTS

6895 male and 3413 female office-based civil servants aged 35-55 years at baseline.

OUTCOME MEASURES

New cases at follow up of CHD, chronic bronchitis and depression defined using validated questionnaires.

MAIN RESULTS

Employment grade was inversely associated with CHD, chronic bronchitis and depression in men (odds ratio per unit decrease in grade 1.30, 1.44 and 1.20 respectively). Employment grade was strongly related to father's social class. Chronic bronchitis, in women, and depression, in men, were more common among those with fathers of higher social class. When mutual adjustment was made for father's social class, grade at entry to the civil service and current grade, the strongest effects on adult morbidity were found for current grade. Among participants in whom neither parent had died < or =70 years of age the inverse association with adult SES was maintained.

CONCLUSIONS

Adult socioeconomic status was a more important predictor of morbidity attributable to coronary disease, chronic bronchitis and depression than measures of social status earlier in life. In this population, the importance of social circumstances early in life may be in the way they influence employment and social position and thus exposures in adult life.

Opinions and experiences in general practice on osteoporosis prevention, diagnosis and management

We determined to survey the general practice population regarding their attitudes to and knowledge of osteoporosis as a baseline prior to publication of national guidelines for the management of osteoporosis. All 2515 general practitioners registered in the 10 Health Authorities of the North Thames region, London, UK were surveyed by a postal questionnaire. Responses relating to epidemiology, public health and education on osteoporosis were analyzed. The overall response was 1153 (46%). General practitioners who responded were younger, predominantly female and in group practice. There is considerable awareness of the importance of preventing osteoporosis. General practitioners are active in identifying groups at risk, particularly those who are aged 40 years and older. A prevention strategy for osteoporosis is viewed as effective. However, two thirds of general practitioners remain unconvinced about the efficacy of drug therapy. Education on osteoporosis is considered inadequate. General practitioners would welcome further information on management issues and access to osteoporosis services. In conclusion, educational initiatives will be important both at undergraduate and postgraduate levels to increase awareness and knowledge of osteoporosis. General practitioners are aware of the public health impact of this condition and express a preference for educational material of direct relevance to the care of their patients. Therefore better cooperation between primary and secondary care should lead to ways of breaking down barriers to change in clinical practice and promoting fully integrated care of patients with osteoporosis.

Re-survey of the Whitehall study of London civil servants: changes in risk factors for cardiovascular disease during 29 years of follow-up

BACKGROUND

Substantial uncertainty persists about the relevance of blood pressure and cholesterol to the risk of cardiovascular disease in the elderly.

OBJECTIVE

To investigate the determinants of cardiovascular risk in old age, and the relevance of such risk factors when recorded in middle and old age.

METHODS

A re-survey in 1997 of 8537 survivors of a cohort of men who were originally examined in 1967-1970 when aged 40-69 years.

RESULTS

Completed questionnaires were received from 7050 (82%) of the survivors, and blood pressure and blood samples from 5427 (64%). The response rate declined with increasing age, was inversely related to markers of socioeconomic status in 1967-70 and in 1997, and was lower in those who had been current smokers or had a higher blood pressure level in 1967-70. After excluding those with reported cardiovascular disease (25% of respondents), the mean levels of total cholesterol and apolipoprotein B were lower in older age groups, whereas apolipoprotein A1 levels did not vary much with age. Among those with risk factors recorded both in 1967-70 and 1997, the prevalence of smoking had declined by two-thirds (32% in 1970 and 12% in 1997), the prevalence of diabetes had increased (0.3% versus 4.5%), and the mean systolic blood pressure had increased by 16 mmHg (130 versus 146 mmHg), but the diastolic blood pressure had not changed materially (80 versus 81 mmHg), and the measured levels of total cholesterol had increased by 0.5 mmol/l (although that change may be artefactual).

CONCLUSION

Follow-up of vital status in this cohort should permit an assessment of the relevance of risk factors recorded in middle and old age to cardiovascular disease in old age.

Impact of socioeconomic status on coronary mortality in people with symptoms, electrocardiographic abnormalities, both or neither: the original Whitehall study 25 year follow up

OBJECTIVES

To determine the impact of socioeconomic status (SES) on coronary heart disease (CHD) mortality in people with and without prevalent CHD at baseline.

DESIGN

Cohort study with 25 year follow up; prevalent CHD was defined by Q, ST or T wave electrocardiographic (ECG) abnormalities or symptoms (defined by the Rose chest pain questionnaire and self reported doctor diagnosis) or both. SES was defined by four civil service employment grades.

SETTING

London.

PARTICIPANTS

17 907 male civil servants aged 40-69 years.

MAIN OUTCOME MEASURES

CHD mortality (n=2695 deaths).

RESULTS

The lowest versus highest employment grade was associated with increased CHD mortality (age adjusted hazard ratio 1.56 (95% CI 1.2, 2.1)), prevalence of symptoms and, among symptomatic participants only, the prevalence of Q, ST or T abnormalities. Thirty one per cent of CHD deaths occurred in participants with prevalent CHD at baseline. Among participants without Q, ST or T abnormality employment grade was associated with CHD mortality; the hazard ratios (lowest v highest grade) adjusted for age, systolic and diastolic blood pressure were 1.72 (95% CI 1.4, 2.1) for asymptomatic and 1.52 (95% CI 1.1, 2.1) for symptomatic participants; among participants with Q, ST or T abnormality the corresponding hazard ratios were 1.46 (95% CI 0.7, 2.9) and 1.14 (95% CI 0.6, 2.0) respectively.

CONCLUSIONS

SES was inversely associated with CHD mortality in civil servants with and without prevalent CHD at baseline. Further distinguishing the relative contribution of SES to the initiation and progression of CHD requires repeated measures studies of pre-clinical and clinical measures of CHD.

Identification of Staphylococcus aureus enterotoxins A and B genes by PCR-ELISA

We developed PCR-enzyme linked immunosorbent (ELISA) assays to detect Staphylococcus aureus enterotoxins A and B genes. The assays use internal biotin-labelled oligonucleotides as capture probes for immobilizing and subsequently detecting target sequences on microtiter plates. The detection limits of the PCR-ELISAs were approximately 250 gene copies, versus 2500 gene copies by agarose gel analysis. The sensitivity of the assays, as determined from a reference panel of 46 coded samples that included DNA purified from 31 different bacterial species and strains, SEA and SEB plasmid controls, and no-template controls was 100%. No cross-reactivity was observed with DNA from non-staphylococcal species. Using 27 clinical isolates of S. aureus, the SEA PCR-ELISA identified the enterotoxin A (sea) gene in 26 samples, and the SEB PCR-ELISA identified the enterotoxin B (seb) gene in all 27 samples. Compared with conventional antigen capture ELISAs for SEA and SEB toxins, the PCR-ELISAs showed overall superior detection limits. The sensitivity and specificity levels of the SEA PCR-ELISA and the SEA toxin ELISA were comparable within their respective detection thresholds, but the sensitivity and specificity of the SEB PCR-ELISA was much greater than that of SEB toxin ELISA.