BMI and All-Cause Mortality in Normoglycemia, Impaired Fasting Glucose, Newly Diagnosed Diabetes, and Prevalent Diabetes: A Cohort Study

Impact of high body mass index on hepatocellular carcinoma risk in chronic liver disease: A population-based prospective cohort study

BACKGROUND AND AIMS

We investigated associations between body mass index (BMI) and hepatocellular carcinoma (HCC) in patients with hepatitis B (HBV) C (HCV) virus infection, alcoholic liver disease (ALD), non-alcoholic fatty liver disease (NAFLD), and liver cirrhosis (LC).

METHODS

We followed 350,608 Korean patients with liver disease who underwent routine health examinations from 2003-2006 until December 2018 via national hospital discharge records. Multivariable adjusted hazard ratios (HRs) per 5-kg/m2 BMI increase (BMI ≥25 kg/m2) for HCC risk were calculated using Cox models. HCC developed in 17,752 patients.

RESULTS

The HRs (95% CI) were 1.17 (1.06-1.28), 1.08 (0.87-1.34), 1.34 (1.14-1.58), 1.51 (1.17-1.94), and 1.11 (1.00-1.23) for HBV, HCV, ALD, NAFLD, and LC, respectively. The HRs for HBV were 1.45 (1.23-1.70) and 1.06 (0.95-1.19) in women and men, respectively; the corresponding HRs for LC were 1.27 (1.07-1.50) and 1.02 (0.90-1.16), respectively. In patients <65 years old with HBV, HCV, and NAFLD, the HRs were 1.17 (1.07-1.29), 1.33 (1.03-1.73), and 1.20 (0.87-1.64), respectively; the corresponding HRs were 1.05 (0.70-1.59), 0.74 (0.50-1.10), and 2.40 (1.62-3.54), respectively, in patients ≥65 years old. A BMI of 27.5-29.9 kg/m2 showed significantly higher HCC risks in patients with HBV, ALD, NAFLD, and LC.

CONCLUSIONS

Higher BMIs were associated with increased HCC risks in patients with HBV, ALD, NAFLD, and LC. Overweight status increased HCC risk. Women with HBV and LC had stronger BMI-HCC associations than men. The effect of high BMI was stronger in older patients with NAFLD and younger patients with viral hepatitis.

Conventional and genetic associations of BMI with major vascular and non-vascular disease incidence and mortality in a relatively lean Chinese population: U-shaped relationship revisited

BACKGROUND

Higher body mass index (BMI) is associated with higher incidence of cardiovascular and some non-cardiovascular diseases (CVDs/non-CVDs). However, uncertainty remains about its associations with mortality, particularly at lower BMI levels.

METHODS

The prospective China Kadoorie Biobank recruited >512 000 adults aged 30-79 years in 2004-08 and genotyped a random subset of 76 000 participants. In conventional and Mendelian randomization (MR) analyses, Cox regression yielded adjusted hazard ratios (HRs) associating measured and genetically predicted BMI levels with incident risks of major vascular events (MVEs; conventional/MR 68 431/23 621), ischaemic heart disease (IHD; 50 698/12 177), ischaemic stroke (IS; 42 427/11 897) and intracerebral haemorrhage (ICH; 7644/4712), and with mortality risks of CVD (15 427/6781), non-CVD (26 915/4355) and all causes (42 342/6784), recorded during ∼12 years of follow-up.

RESULTS

Overall, the mean BMI was 23.8 (standard deviation: 3.2) kg/m2 and 13% had BMIs of <20 kg/m2. Measured and genetically predicted BMI showed positive log-linear associations with MVE, IHD and IS, but a shallower positive association with ICH in conventional analyses. Adjusted HRs per 5 kg/m2 higher genetically predicted BMI were 1.50 (95% CI 1.41-1.58), 1.49 (1.38-1.61), 1.42 (1.31-1.54) and 1.64 (1.58-1.69) for MVE, IHD, IS and ICH, respectively. These were stronger than associations in conventional analyses [1.21 (1.20-1.23), 1.28 (1.26-1.29), 1.31 (1.29-1.33) and 1.14 (1.10-1.18), respectively]. At BMIs of ≥20 kg/m2, there were stronger positive log-linear associations of BMI with CVD, non-CVD and all-cause mortality in MR than in conventional analyses.

CONCLUSIONS

Among relatively lean Chinese adults, higher genetically predicted BMI was associated with higher risks of incident CVDs. Excess mortality risks at lower BMI in conventional analyses are likely not causal and may reflect residual reverse causality.

The association between triglyceride glucose-body mass index and all-cause and cardiovascular mortality in diabetes patients: a retrospective study from NHANES database

The triglyceride glucose body mass index (TyG-BMI) is a potential indicator for insulin resistance, but its association with mortality in diabetic patients is unclear. This study investigates the relationship between TyG-BMI and all-cause and cardiovascular mortality in diabetics. The study included 3109 diabetic patients from the National Health and Nutrition Examination Survey (2001-2018). Mortality data were obtained from National Death Index records until 31 December 2019. Multivariate Cox models analyzed the association between TyG-BMI and mortality. Non-linear correlations were assessed using restricted cubic splines, and a two-piecewise Cox model evaluated the relationship on both sides of the inflection point. Over a median 7.25-year follow-up, 795 total and 238 cardiovascular deaths occurred. A U-shaped link was found between initial TyG-BMI and mortality in diabetic patients. Low TyG-BMI (< 279.67 for all-cause, < 270.19 for CVD) reduced death risks (all-cause: HR 0.77, 95% CI 0.69-0.86; CVD: HR 0.64, 95% CI 0.48-0.86). High TyG-BMI (> 279.67 for all-cause, > 270.19 for CVD) increased these risks (all-cause: HR 1.26, 95% CI 1.10-1.44; CVD: HR 1.33, 95% CI 1.06-1.68). In the NHANES study population, a U-shaped association was observed between the baseline TyG-BMI index and all-cause mortality or CVD in diabetic patients.

Classification, Diagnosis, and Treatment of Obesity-Related Heart Diseases

Evidence-based medicine shows that obesity is associated with a wide range of cardiovascular (CV) diseases. Obesity can lead to changes in cardiac structure and function, which can lead to obese cardiomyopathy, subclinical cardiac dysfunction, and even heart failure. It also increases the risk of atrial fibrillation and sudden cardiac death. Many invasive and noninvasive diagnostic methods can detect obesity-related heart disease at an early stage, so that appropriate measures can be selected to prevent adverse CV events. However, studies have shown a protective effect of obesity on clinical outcomes of CV disease, a phenomenon that has been termed the obesity paradox. The "obesity paradox" essentially refers to the fact that the classification of obesity defined by body mass index (BMI) does not consider the impact of obesity heterogeneity on CV disease prognosis, but simply puts subjects with different clinical and biochemical characteristics into the same category. In any case, indicators such as waist-to-hip ratio, ectopic body fat qualitative and quantitative, and CV fitness have been shown to be able to distinguish different CV risks in patients with the same BMI, which is convenient for early intervention in an appropriate way. A multidisciplinary approach, including lifestyle modification, evidence-based generic and novel pharmacotherapy, and surgical intervention, can improve CV outcomes in overweight/obese patients.

The impact of obesity on different glucose tolerance status with incident cardiovascular disease and mortality events over 15 years of follow-up: a pooled cohort analysis

BACKGROUND

The effect of obesity in different glucose tolerance statuses i.e. normoglycemia (NGT), pre-diabetes, and type 2 diabetes (T2DM) on cardiovascular disease (CVD) and mortality has been an area of ongoing debate and uncertainty. In the present study, we aimed to examine the impact of being obese, whether general or central separately, in comparison with non-obese in different glucose tolerance statuses on the above outcomes.

METHODS

The study population included 18,184 participants aged 30-60 years (9927 women) from three longitudinal studies, including Atherosclerosis Risk in Communities, Multi-Ethnic Study of Atherosclerosis, and Tehran Lipid and Glucose Study. Glucose tolerance status was defined as NGT (fasting plasma glucose < 5.55 mmol/L), pre-diabetes (5.55-7.00 mmol/L), and T2DM (≥ 7 mmol/L or taking any medication for diabetes). Moreover, general and central obesity were defined based on body mass index and waist circumference (WC), respectively. Multivariable stratified Cox regression analysis was used to estimate hazard ratios (HRs (95% CI)) for CVD and mortality events.

RESULTS

During a 16-year follow-up, 2733 CVD events, 1101 CV mortality, and 3678 all-cause mortality events were recorded. We observed that being generally obese in comparison with non-obese increased the risk of CV and all-cause mortality in all glucose tolerance statuses; while considering CVD events, only among individuals with T2DM, the presence of general obesity was associated with marginally significant higher risk [1.19 (0.98-1.43); p-value = 0.07]. Regarding central adiposity, multivariate analysis revealed that elevated WC in NGT participants is associated with incident CVD [1.27(1.12-1.46)] and all-cause mortality [1.13(1.00-1.28)]. Moreover, central adiposity increased the risk of CV mortality in pre-diabetes individuals [1.47 (1.11-1.95)].

CONCLUSION

Findings from this pooled prospective cohort studies provide evidence that general obesity shows an unfavorable association with CV and all-cause mortality among the general population irrespective of their glucose tolerance statusThe findings imply that it's important to take into account the requirement and magnitude of weight reduction in people who are obese when offering guidance.

Prevalence of prediabetes by the fasting plasma glucose and HbA1c screening criteria among the children and adolescents of Shenzhen, China

Background

Prediabetes is associated with an increased risk of cardiovascular diseases and all-cause mortality. Rare research in China has evaluated the prevalence of prediabetes among children and adolescents using the HbA1c criterion or the combined FPG-or-HbA1c diagnostic criterion, and researchers paid no attention to the distributions of blood glucose in Shenzhen, especially for juveniles.

Methods

We conducted a school-based cross-sectional study based on the first-year students from 17 primary, middle, and high schools. Prediabetes was defined as FPG of 5.6-6.9 mmol/L or HbA1c of 5.7%-6.4%. The crude and standardized prevalence of prediabetes with 95% confidence interval (95% CI) was estimated.

Results

A total of 7519 participants, aged 6 to 17 years, were included. For all subjects, the crude prevalence (95% CI) of prediabetes was 1.49% (1.21-1.77), 8.72% (8.08-9.36), and 9.80% (9.13-10.47) by the FPG-only, HbA1c-only, and FPG-or-HbA1c criteria, respectively. Based on the 2010 Shenzhen census population, the standardized prevalence was 1.56% (males 1.85%, females 1.19%), 11.05% (males 11.47%, females 10.53%), and 12.19% (males 13.01%, females 11.15%) by the corresponding criteria. The proportion of prediabetes was higher for males than females, and the prevalence decreased with grade for males but increased for females. The association of BMI and prediabetes was U-shaped curve, indicating higher rates of prediabetes for underweight and obesity people.

Conclusion

The blood glucose status of children and adolescents in Shenzhen is worrisome, and the early detection and management of prediabetes are imperative.

Associations Between Mid- to Late-Life Body Mass Index and Chronic Disease-Free Survival: A Nationwide Twin Study

BACKGROUND

Some studies have linked late-life overweight to a reduced mortality risk compared to normal body mass index (BMI). However, the impact of late-life overweight and its combination with mid-life BMI status on healthy survival remains unclear. We aimed to investigate whether and to what extent mid- and/or late-life overweight are associated with chronic disease-free survival.

METHODS

Within the Swedish Twin Registry, 11 597 chronic disease-free twins aged 60-79 years at baseline were followed up for 18 years. BMI (kg/m2) was recorded at baseline and 25-35 years before baseline (ie, midlife) and divided as underweight (<20), normal (≥20-25), overweight (≥25-30), and obese (≥30). Incident chronic diseases (cardiovascular diseases, type 2 diabetes, and cancer) and deaths were ascertained via registries. Chronic disease-free survival was defined as years lived until the occurrence of any chronic diseases or death. Data were analyzed using multistate survival analysis.

RESULTS

Of all participants, 5 640 (48.6%) were overweight/obese at baseline. During the follow-up, 8 772 (75.6%) participants developed at least 1 chronic disease or died. Compared to normal BMI, late-life overweight and obesity were associated with 1.1 (95% CI, 0.3, 2.0) and 2.6 (1.6, 3.5) years shorter chronic disease-free survival. Compared to normal BMI through mid- to late life, consistent overweight/obesity and overweight/obesity only in mid-life led to 2.2 (1.0, 3.4) and 2.6 (0.7, 4.4) years shorter disease-free survival, respectively.

CONCLUSIONS

Late-life overweight and obesity may shorten disease-free survival. Further research is needed to determine whether preventing overweight/obesity from mid- to late life might favor longer and healthier survival.

Failure to decrease HbA1c levels following TB treatment is associated with elevated Th1/Th17 CD4+ responses

Introduction

The rising global burden of metabolic disease impacts the control of endemic tuberculosis (TB) in many regions, as persons with diabetes mellitus (DM) are up to three times more likely to develop active TB than those without DM. Active TB can also promote glucose intolerance during both acute infection and over a longer term, potentially driven by aspects of the immune response. Identifying patients likely to have persistent hyperglycemia following TB treatment would enable closer monitoring and care, and an improved understanding of underlying immunometabolic dysregulation.

Methods

We measured the relationship of plasma cytokine levels, T cell phenotypes and functional responses with the change in hemoglobin A1c (HbA1c) before and after treatment of pulmonary TB in a prospective observational cohort in Durban, South Africa. Participants were stratified based on stable/increased HbA1c (n = 16) versus decreased HbA1c (n = 46) levels from treatment initiation to 12 month follow-up.

Results

CD62 P-selectin was up- (1.5-fold) and IL-10 downregulated (0.85-fold) in plasma among individuals whose HbA1c remained stable/increased during TB treatment. This was accompanied by increased pro-inflammatory TB-specific IL-17 production (Th17). In addition, Th1 responses were upregulated in this group, including TNF-α production and CX3CR1 expression, with decreased IL-4 and IL-13 production. Finally, the TNF-α+ IFNγ+ CD8+ T cells were associated with stable/increased HbA1c. These changes were all significantly different in the stable/increased HbA1c relative to the decreased HbA1c group.

Discussion

Overall, these data suggest that patients with stable/increased HbA1c had an increased pro-inflammatory state. Persistent inflammation and elevated T cell activity in individuals with unresolved dysglycemia following TB treatment may indicate failure to fully resolve infection or may promote persistent dysglycemia in these individuals, and further studies are needed to explore potential mechanisms.

Obesity paradox and stroke outcomes according to stroke subtype: a propensity score-matched analysis

OBJECTIVE

Obesity has traditionally been considered a risk factor for ischemic stroke. However, some clinical observations have reported a complex relationship between patients who are overweight or obese with paradoxically better stroke outcomes. Stroke subtypes have differing distributions of risk factors, so this study aimed to explain the relationship between body mass index (BMI) and functional prognosis according to stroke subtype.

METHODS

A prospective institutional database on stroke was accessed between March 2014 and December 2021, and consecutive patients with ischemic stroke were retrospectively selected. BMI was categorized into five groups (underweight, normal weight, overweight, obese, and morbid obesity). The outcome of interest in this study was the modified Rankin Scale (mRS) at 90 d, which was divided into favorable (mRS = 0-2) and unfavorable (mRS ≥ 3) groups. The relationship between functional outcome and BMI was analyzed according to stroke subtype.

RESULTS

Among 2779 patients with stroke, 913 (32.9%) had unfavorable outcomes. After a propensity score-matched analysis, obesity was inversely associated with unfavorable outcomes (adjusted odds ratio [aOR] = 0.61, 95% confidence interval [95% CI]: 0.46-0.80) in all patients with stroke. Among the stroke subtypes, overweight (aOR = 0.38, 95% CI: 0.20-0.74) and obese (aOR = 0.40, 95% CI: 0.21-0.76) groups were inversely associated with unfavorable outcomes in the cardioembolism subtype. Obesity (aOR = 0.55, 95% CI: 0.32-0.95) was inversely associated with unfavorable outcomes in the small vessel disease subtype. There was no significant relationship between stroke outcome and BMI classification in the large artery disease subtype.

CONCLUSIONS

These findings suggest that the obesity paradox in ischemic stroke outcomes might differ according to the stroke subtype.

Obesity Paradox: Fact or Fiction?

PURPOSE OF REVIEW

Obesity is related to several comorbidities such as type 2 diabetes mellitus, cardiovascular disease, heart failure, and various types of cancers. While the detrimental effect of obesity in both mortality and morbidity has been well established, the concept of the obesity paradox in specific chronic diseases remains a topic of continuous interest. In the present review, we examine the controversial issues around the obesity paradox in certain conditions such as cardiovascular disease, several types of cancer and chronic obstructive pulmonary disease, and the factors that may confound the relation between obesity and mortality.

RECENT FINDINGS

We refer to the obesity paradox when particular chronic diseases exhibit an interesting "paradoxical" protective association between the body mass index (BMI) and clinical outcomes. This association, however, may be driven by multiple factors among which the limitations of the BMI itself; the unintended weight loss precipitated by chronic illness; the various phenotypes of obesity, i.e., sarcopenic obesity or the athlete's obesity phenotype; and the cardiorespiratory fitness levels of the included patients. Recent evidence highlighted that previous cardioprotective medications, obesity duration, and smoking status seem to play a role in the obesity paradox. The obesity paradox has been described in a plethora of chronic diseases. It cannot be emphasized enough that the incomplete information received from a single BMI measurement may interfere with outcomes of studies arguing in favor of the obesity paradox. Thus, the development of carefully designed studies, unhampered by confounding factors, is of great importance.

Associations of BMI with all-cause mortality in normoglycemia, impaired fasting glucose and type 2 diabetes mellitus among an elderly Chinese population: a cohort study

Aim

To explore the associations of body mass index (BMI) and mortality among people with normal fasting glucose (NFG), impaired fasting glucose (IFG), and type 2 diabetes mellitus (T2DM) in an elderly Chinese population. 

Methods

A retrospective cohort study was conducted that included 59,874 elderly people who were aged 60 and older at baseline. Data for the study came from a health check-up program in China between 2011 and 2019. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using multivariable Cox proportional hazard models of BMI categories by glycemic status.

Results

During the median of 5.96 years of follow-up, 7928 participants died (6457/49057 with NFG, 712/5898 with IFG and 759/4919 with T2DM). In adjusted Cox models, risk of mortality showed a decreasing trend with BMI < 18.5 kg/m², 24 ≤ BMI < 28 kg/m², and BMI ≥ 28 kg/m² compared to 18.5 ≤ BMI < 24 kg/m²: HR (95% CI): 1.33 (1.18 to 1.49), 0.88 (0.83 to 0.93), and 0.90 (0.82 to 0.98), respectively, for NFG; 0.89 (0.55 to 1.46), 0.84 (0.71 to 0.99), and 0.88 (0.70 to 1.11), respectively, for IFG; and 1.42 (0.88 to 2.29), 0.75 (0.64 to 0.89), and 0.76 (0.62 to 0.93), respectively, for T2DM. There were curvilinear-shaped associations between BMI and mortality in the NFG and T2DM groups (P overall < 0.001 and P overall < 0.001, respectively; P nonlinearity < 0.001 and P nonlinearity = 0.027, respectively) and no significantly association between BMI and all-cause mortality was observed in the IFG group (P overall = 0.170).

Conclusion

High BMI compared to normal BMI was associated with decreased mortality, especially in the old populations with NFG and T2DM. Future studies are needed to explain the obesity paradox in elderly patients with T2DM.

Relationship between body mass index and fracture risk at different skeletal sites: a nationwide cohort study

The association between obesity and fracture was skeletal site-specific with no gender difference. Obesity was associated with a higher risk of proximal humerus fractures but not for wrist or clinical vertebral fractures.

PURPOSE

The association between body mass index (BMI) and the risk of clinical fractures at different sites is unclear. This study aimed to examine associations between BMI and fractures at different sites in Korean men and women.

METHODS

This study analyzed 285,643 Korean adults (aged 50-80 years) who participated in health examinations from 2002 to 2003 and were followed up until 2015. The incidences of osteoporotic fractures were assessed using the International Classification of Diseases (10th revision; ICD-10) and procedure or radiographic codes. After adjusting for confounders, hazard ratios (HRs) were calculated using Cox proportional hazard models for fracture risk.

RESULTS

Site-specific associations between BMI and fractures were found without gender difference. Specifically, an L-shaped association was found for clinical vertebral fractures, wherein the adjusted HRs per 5 kg/m² increase were 0.80 (95% confidence interval [CI] = 0.76-0.83) in BMI groups < 25 kg/m² and 0.97 (95% CI = 0.92-1.03) in BMI ≥ 25 kg/m². A linear inverse correlation for wrist fractures was observed, wherein the HRs were 0.83 (95% CI = 0.81-0.86) per 5 kg/m² increase. For proximal humerus fractures, a non-linear U-shape association was found, wherein the adjusted HRs per 5 kg/m² increase were 0.66 (95% CI = 0.50-0.88) in BMI groups < 23 kg/m² and 1.25 (95% CI = 1.08-1.45) in BMI ≥ 23 kg/m².

CONCLUSION

Low BMI was a risk factor for all tested fractures. Obesity was a risk factor for proximal humerus fracture, but it is a protective factor for wrist fracture.

Impact of overweight and obesity on the risk of hepatocellular carcinoma: a prospective cohort study in 14.3 million Koreans

BACKGROUND

Whether obesity and being overweight, defined by body mass index (BMI), increase hepatocellular carcinoma (HCC) has been less apparent in Asian populations.

METHODS

Overall, 14,265,822 Korean adults who underwent routine health examinations during 2003-2006 were followed up for HCC. Multivariable-adjusted hazard ratios (HRs) associated with BMI were calculated.

RESULTS

During 13.7 years (mean) of follow-up, 47,308 individuals developed HCC. HRs of HCC associated with BMIs of 25.0-26.4, 26.5-27.9, 28.0-29.4, 29.5-30.9 and ≥31 kg/m² compared to those for 23.5-24.9 kg/m² were 1.05, 1.20, 1.39, 1.59 and 2.13, respectively. For BMI < 25 kg/m², linear associations were not apparent. For BMI ≥ 25 kg/m², the HR per 5 kg/m² increase in BMI was 1.60 (total), 1.60 (men), and 1.59 (women). The corresponding HRs were 1.56, 1.61 and 1.60 for individuals aged <45, 45-64 and ≥65 years, respectively. Further adjustment for alanine transaminase (ALT) levels substantially reduced the HRs for high BMI, especially in men and younger adults.

CONCLUSIONS

Overweight and obesity clearly increase HCC risk in Koreans. ALT levels are a mediator of the impact of obesity, but it may not accurately predict high BMI-induced liver damage that can potentially progress to HCC, especially in women and older adults.

Body mass index and 12-year mortality among older Mexican Americans aged 75 years and older

Background

The role of obesity in mortality in the very old and old-oldest Hispanic population has not been studied. The objective of this study was to examine the effect of body mass index (BMI) on 12-year mortality among older Mexican Americans aged 75 years and older.

Methods

Twelve year prospective cohort study consisting of a population-based sample of 1415 non-institutionalized Mexican American men and women aged 75 and older from 5 southwestern states: Arizona, California, Colorado, New Mexico, and Texas. Data was from Wave 5 of the Hispanic Established Population for the Epidemiologic Study of the Elderly (2004/2005–2016). Socio-demographics, body mass index (BMI), self-reported medical conditions, disability, depressive symptoms, falls, Mini-Mental-State-Examination (MMSE), and Short Physical Performance Battery (SPPB) were assessed at baseline during 2004–2005. BMI (Kg/m²) was classified as underweight (< 18.5), normal weight (18.5 to < 25), overweight (25 to < 30), obesity category I (30 to < 35), and obesity category II/morbid obesity (≥ 35). For assessment of mortality, deaths were ascertained through the National Death Index and report from relatives. Cox proportional hazards regression analysis was performed to estimate the hazard ratio (HR) of 12-year mortality as a function of BMI categories at baseline.

Results

The mean BMI was 27.5 ± 1.7 with participants classified as 1.8% underweight, 30.8% normal weight, 39.2% overweight, 20.7% obesity category I, and 7.6% obesity category II/morbid obesity. Mexican Americans aged ≥75 years with overweight or obesity category I had a reduced HR of death (0.82, 95% CI = 0.70–0.96 and 0.75, 95% CI = 0.62–0.91, respectively) over 12-years of follow-up. The HR of death for underweight and obesity category II/morbid obesity participants was 1.59 (95% CI = 1.03–2.45) and 1.12 (95% CI = 0.85–1.46), respectively. Female participants and those with high scores in the MMSE and SPPB had decreased risk of death.

Conclusions

This study showed the protective effect of overweight and obesity on mortality in Mexican Americans above 75 years of age, which might have implications when treating older adults with overweight and obesity.

Association Between Obesity and Cardiovascular Disease in Elderly Patients With Diabetes: A Retrospective Cohort Study

CONTEXT

Some studies have suggested that patients with type 2 diabetes mellitus (T2DM) concomitant with obesity have better clinical outcomes than normal-weight patients with T2DM.

OBJECTIVE

We evaluated associations among obesity, cardiovascular disease (CVD) events, and mortality in elderly patients with T2DM without CVD.

METHODS

This retrospective observational study from 2009 to 2017, with a mean follow-up of 7.26 years, included 249 903 elderly (≥ 65 years) patients with T2DM and no preexisting CVD from the Korean National Health Information Database. We categorized subjects according to body mass index (BMI) and waist circumference (WC) and analyzed a composite of stroke, myocardial infarction, and all-cause death using Cox proportional hazards regression analysis, adjusting for baseline covariates.

RESULTS

The incidence rate of composite primary outcomes was 30.95/1000 person-years. The primary outcome risk had an L-shaped and a U-shaped association with BMI and WC, respectively. In the multivariable Cox proportional hazard models, the risk of primary composite outcomes in the highest BMI group (≥ 30 kg/m2; hazard ratio [HR] = 0.824; 95% CI, 0.794-0.855) was lower than in the normal BMI group (≥ 18.5 and < 23 kg/m2). Conversely, that in the highest WC group (≥ 100 cm/≥ 95 cm; men/women; HR = 1.434; 95% CI, 1.384-1.486) was higher than in the normal WC group (< 90 cm/< 85 cm; men/women).

CONCLUSION

Our study with elderly patients with diabetes results suggest that while BMI is an inadequate risk indicator for outcomes related to obesity, WC is a suitable alternative.

Adiposity and risks of vascular and non-vascular mortality among Chinese adults with type 2 diabetes: a 10-year prospective study

INTRODUCTION

Among individuals with diabetes, high adiposity has been associated with lower cardiovascular disease (CVD) mortality (the so-called 'obesity paradox' phenomenon) in Western populations, for reasons that are still not fully elucidated. Moreover, little is known about such phenomena in Chinese adults with diabetes among whom very few were obese. We aimed to assess the associations of adiposity with vascular and non-vascular mortality among individuals with diabetes, and compare these with associations among individuals without diabetes.

RESEARCH DESIGN AND METHODS

In 2004-2008, the prospective China Kadoorie Biobank recruited >512 000 adults from 10 areas in China. After ~10 years of follow-up, 3509 deaths (1431 from CVD) were recorded among 23 842 individuals with diabetes but without prior major diseases at baseline. Cox regression yielded adjusted HRs associating adiposity with mortality.

RESULTS

Among people with diabetes, body mass index (BMI) (mean 25.0 kg/m²) was positively log linearly associated with CVD incidence (n=9943; HR=1.19 (95% CI 1.15 to 1.22) per 5 kg/m²), but showed U-shaped associations with CVD and overall mortality, with lowest risk at 22.5-24.9 kg/m². At lower BMI, risk of death (n=671) within 28 days of CVD onset was particularly elevated, with an HR of 3.26 (95% CI 2.29 to 4.65) at <18.5 kg/m² relative to 22.5-24.9 kg/m², but no higher mortality risk at BMI ≥25.0 kg/m². These associations were similar in self-reported and screen-detected diabetes, and persisted after extensive attempts to address reverse causality and confounding. Among individuals without diabetes (mean BMI 23.6 kg/m²; n=23 305 deaths), there were less extreme excess mortality risks at low BMI.

CONCLUSIONS

Among relatively lean Chinese adults with diabetes, there were contrasting associations of adiposity with CVD incidence and with mortality. The high mortality risk at low and high BMI levels highlights, if causal, the importance of maintaining normal weight among people with diabetes.

A Higher Serum Anion Gap Is Associated with the Risk of Progressing to Impaired Fasting Glucose and Diabetes

Impaired fasting glucose (IFG) is a reversible intermediate hyperglycemia stage with an increasing risk of diabetes and related complications. Our study was designed to identify the relationship between the serum anion gap and the risk of progressing to impaired fasting glucose and diabetes. Here, we performed a prospective, population-based study among 1191 Chinese individuals aged 22-87 years who took health examinations annually between 2006 and 2012 including clinical features and plasma metabolites. All of the participants had no history of diabetes or related chronic complications. Logistic regression analysis was designed to examine the associations between clinical and metabolomic factors and the risk of developing IFG or diabetes. Among them, 58 subjects whose fasting glucose were between 6.1 and 7 mmol/L were diagnosed as IFG or diabetes. After adjusting for age, sex, body mass index (BMI), high-density lipoprotein (HDL), low-density lipoprotein (LDL), alanine aminotransferase (ALT), aspartate aminotransferase (AST), systolic blood pressure (SBP), diastolic blood pressure (DBP), potassium, and albumin at baseline, the participants in the upper tertiles of serum anion gap (SAG) had higher odds of progressing to IFG or diabetes than those in the lower tertiles. A receiver operating characteristic (ROC) curve was analyzed, and the optimal cutoff level for the anion gap to predict incident IFG or diabetes was 13.76 mmol/L, and the area under the ROC curve (AUC) was 0.623. Our data demonstrate that a higher serum anion gap is associated with the risk of developing IFG or diabetes.

Association of glaucoma with 10-year mortality in a population-based longitudinal study in urban Southern China: the Liwan Eye Study

OBJECTIVES

To investigate the association between glaucoma and 10-year mortality rate in an adult population in China.

DESIGN

Population-based cohort study.

SETTING

The Liwan Eye Study, China.

PARTICIPANTS

1405 baseline participants aged 50 years and older were invited to attend a 10-year follow-up examination.

PRIMARY AND SECONDARY OUTCOME MEASURES

The International Society of Geographic and Epidemiologic Ophthalmology criteria was used to define glaucoma. Detailed information of mortality was confirmed using the Chinese Centre for Disease Control and Prevention. Presenting visual impairment (PVI) was defined as a presenting visual acuity of less than 20/40 in the better-seeing eye. The 10-year mortality rates were compared using the log-rank test. Cox proportional hazards regression models were used to investigate the association between glaucoma and mortality.

RESULTS

A total of 1372 (97.7%) participants with available gonioscopic data were included in the analysis. Of these, 136 (9.9%), 33 (2.4%) and 21 (1.5%) participants had primary angle closure (PAC) suspect (PACS), PAC and PAC glaucoma (PACG), and 29 (2.1%) had primary open angle glaucoma (POAG). After 10 years, 306 (22.3%) participants were deceased. The 10-year mortality was significantly associated with PACG (HR, 2.15, 95% CI 1.14 to 4.04, p=0.018) but not associated with PAC (HR, 1.27, 95% CI 0.67 to 2.39, p=0.463), PACS (HR, 1.32, 95% CI 0.95 to 1.83, p=0.099) and POAG (HR, 0.74, 95% CI 0.36 to 1.49, p=0.395) when age and gender were adjusted for. This association was no longer statistically significant (HR, 1.60, 95% CI 0.70 to 3.61, p=0.263) when covariables, such as income, education, body mass index, PVI, history of diabetes and hypertension, were adjusted for. Larger vertical cup-to-disc ratio (VCDR >0.30) was only a significant risk factor in multivariable analysis (HR, 1.60, 95% CI 1.11 to 2.33, p=0.011).

CONCLUSIONS

PACG was significantly associated with higher long-term mortality, but this association was likely to be confounded by other systemic risk factors. VCDR >0.3 was the only independent predictor, implying that it may be a marker of ageing and frailty.

Effect of empagliflozin on cardiorenal outcomes and mortality according to body mass index: A subgroup analysis of the EMPA-REG OUTCOME trial with a focus on Asia

AIM

To investigate whether the cardiorenal benefits of the sodium-glucose co-transporter-2 inhibitor empagliflozin are affected by body mass index (BMI) in type 2 diabetes patients with established cardiovascular (CV) disease, including Asians.

METHODS

In this exploratory analysis of the EMPA-REG OUTCOME trial, we used Cox regression to evaluate the effects of empagliflozin on all-cause mortality, hospitalization for heart failure (HHF) or CV death, and incident or worsening nephropathy by baseline BMI category.

RESULTS

Of the 7020 participants (1517 Asians [21.6%]), 934 (13.3%), 2465 (35.1%) and 3621 (51.6%) had a BMI of less than 25, 25 to less than 30, and 30 kg/m² or higher, respectively. Overall, hazard ratios for empagliflozin versus placebo for all-cause mortality, HHF or CV death, and incident or worsening nephropathy were 0.68 (95% CI 0.57, 0.82), 0.66 (0.55, 0.79) and 0.61 (0.53, 0.70), respectively, and were consistent across BMI categories (P values for interaction between treatment and BMI were .6772, .3087 and .6265, respectively). Results were similar in Asians using these BMI categories and categories of less than 24, 24 to less than 28, and 28 kg/m² or higher.

CONCLUSION

Empagliflozin reduced cardiorenal and mortality risk regardless of BMI at baseline, including in Asians with a lower BMI.

The obesity paradox and diabetes

BACKGROUND

Obesity has been proven to be a risk factor for type 2 diabetes mellitus (T2DM) through numerous pathogenetic mechanisms. Unexpectedly, some studies suggest that subjects with overweight/obesity and T2DM have better clinical outcome than their normal weight peers. This finding is described as "obesity paradox" and calls into question the importance of weight loss in this specific population.

OBJECTIVE

This article is a narrative overview on the obesity and type 2 diabetes mellitus, particularly regarding the obesity paradox in T2DM patients.

METHODS

We used as sources MEDLINE/PubMed, CINAHL, EMBASE, and Cochrane Library, from inception to March 2020; we chose 30 relevant papers regarding the association of obesity with clinical outcome and mortality of patients affected by T2DM.

RESULTS

Many studies report that in patients with T2DM, overweight and obesity are associated with a better prognosis than underweight or normal weight, suggesting the presence of an obesity paradox. However, these studies have numerous limitations due to their mainly retrospective nature and to numerous confounding factors, such as associated pathologies, antidiabetic treatments, smoking habit, lack of data about distribution of body fat or weight history.

CONCLUSION

Literature data regarding the phenomenon of obesity paradox in T2DM patients are controversial due to the several limitations of the studies; therefore in the management of patients with overweight/obesity and T2DM is recommended referring to the established guidelines, which indicate diet and physical activity as the cornerstone of the treatment.

LEVEL OF EVIDENCE

Level V: narrative review.

Energy Requirements for Older Patients with Type 2 Diabetes: A Narrative Review of the Current Findings and Future Tasks

Aging patients with type 2 diabetes (T2DM) have a high risk of frailty and disability. This narrative review summarizes the current findings and future tasks regarding the following issues: (1) the optimum body mass index (BMI) target for patients with T2DM, (2) energy expenditure and requirements of patients with T2DM, and (3) the significance of low-intensity physical activity (LPA) as a key determinant of total energy expenditure (TEE) among the older population. While weight reduction is associated with an improvement in glycemic control, an increased risk of mortality as well as disability related to unhealthy BMI must also be considered, especially in older patients. The optimum BMI range and energy requirements for maintaining a healthy BMI should be identified. Limited evidence has shown that the TEE measured using the doubly labeled water method in patients with T2DM did not differ from that of subjects without diabetes, suggesting that the energy requirement data of subjects without diabetes may be applicable to these populations. LPA is one of the determinants of variability in the energy requirements of older patients with T2DM, and the beneficial effects of increasing LPA on nutritional intake and frailty prevention should be investigated further.

Body mass index and all-cause mortality in older adults: A scoping review of observational studies

In older age, body composition changes as fat mass increases and redistributes. Therefore, the current body mass index (BMI) classification may not accurately reflect risk in older adults (65+). This study aimed to review the evidence on the association between BMI and all-cause mortality in older adults and specifically, the findings regarding overweight and obese BMI. A systematic search of the OVID MEDLINE and Embase databases was conducted between 2013 and September 2018. Observational studies examining the association between BMI and all-cause mortality within a community-dwelling population aged 65+ were included. Seventy-one articles were included. Studies operationalized BMI categorically (n = 60), continuously (n = 8) or as a numerical change/group transition (n = 7). Reduced risk of mortality was observed for the overweight BMI class compared with the normal BMI class (hazard ratios [HR] ranged 0.41-0.96) and for class 1 or 2 obesity in some studies. Among studies examining BMI change, increases in BMI demonstrated lower mortality risks compared with decreases in BMI (HR: 0.83-0.95). Overweight BMI classification or a higher BMI value may be protective with regard to all-cause mortality, relative to normal BMI, in older adults. These findings demonstrate the potential need for age-specific BMI cut-points in older adults.

Complex interaction of fasting glucose, body mass index, age and sex on all-cause mortality: a cohort study in 15 million Korean adults

AIMS/HYPOTHESIS

The aim of this work was to examine whether synergistic associations with mortality exist for BMI and fasting blood glucose (FBG) and to identify FBG-BMI combined subgroups with higher mortality according to sex and age.

METHODS

A total of 15,149,275 Korean adults participated in health examinations during 2003-2006 and were followed up until December 2018. Mortality HRs of 40 FBG-BMI combined groups were assessed by Cox proportional hazards models.

RESULTS

During a mean 13.7 years of follow-up, 1,213,401 individuals died. A J-shaped association was seen between FBG and all-cause mortality for all BMI categories. Those with BMI <20 kg/m² had the highest mortality for any given FBG level, followed by those with BMI 20-22.4 kg/m². The detrimental effect of elevated FBG was greater among leaner individuals than more corpulent individuals. Moreover, the synergistic adverse effects of hyperglycaemia and leanness was stronger in younger adults than in older adults. Compared with the reference group (overweight with normoglycaemia), age- and sex-adjusted HRs of the leanest with normoglycaemia (BMI <20 kg/m² and FBG 4.4-5.2 mmol/l), overweight with diabetes (BMI 25-27.4 kg/m² and FBG ≥10.0 mmol/l) and leanest with diabetes (BMI <20 kg/m² and FBG ≥10.0 mmol/l) were 1.29, 2.59 and 11.18, respectively, in those aged 18-44 years and 1.56, 1.72 and 2.87, respectively, in those aged 75-99 years. The identification of BMI-FBG subgroups associated with higher mortality was not straightforward, illustrated by the group with FBG 6.1-6.9 mmol/l and BMI 20-22.4 kg/m² having a similar or higher mortality compared with the group with FBG 7.0-9.9 mmol/l and BMI ≥22.5 kg/m². In women aged <45 years with FBG <6.9 mmol/l, those with BMI ≥27.5 kg/m² had the highest mortality, whereas individuals with BMI <20 kg/m² had the highest mortality for each given FBG level in other age and sex groups.

CONCLUSIONS/INTERPRETATION

Leanness and hyperglycaemia interact together to increase mortality in a supra-multiplicative manner, especially in younger adults; the interactions of BMI, FBG, sex and age with mortality are complex. Graphical abstract.

Is the Obesity Paradox in Type 2 Diabetes Due to Artefacts of Biases? An Analysis of Pooled Cohort Data from the Heinz Nixdorf Recall Study and the Study of Health in Pomerania

AIMS/HYPOTHESIS

There is controversy on whether an obesity paradox exists in type 2 diabetes, ie, that mortality is lowest in overweight or obesity. We examined the role of potential biases in the obesity paradox.

METHODS

From two regional population-based German cohort studies - the Heinz Nixdorf Recall Study and the Study of Health in Pomerania (baseline examinations 2000-2003/1997-2001) - 1187 persons with diabetes at baseline were included (mean age 62.6 years, 60.9% males). Diabetes was ascertained by self-report of physician's diagnosis, antidiabetic medication, fasting/random glucose or haemoglobin A1c. Mortality data were assessed for up to 17.7 years. We used restricted cubic splines and Cox regression models to assess associations between body mass index (BMI) and mortality. Sensitivity analyses addressed, inter alia, exclusion of early death cases, of persons with cancer, kidney disease or with history of cardiovascular diseases, and of ever smokers. Furthermore, we examined the role of treatment bias and collider bias for the obesity paradox.

RESULTS

In spline models, mortality risk was lowest for BMI at about 31 kg/m2. Sensitivity analyses carried out one after another had hardly any impact on this result. In our cohort, persons with diabetes and BMI ≥30 kg/m2 did not have better treatment than non-obese patients, and we found that collider bias played only a minor role in the obesity paradox.

CONCLUSION

In a cohort of 1187 persons with diabetes, mortality risk was lowest in persons with moderate obesity. We cannot explain this result by a variety of sensitivity analyses.

Body mass index and mortality among middle-aged Japanese individuals with diagnosed diabetes: The Japan Public Health Center-based prospective study (JPHC study)

AIM

To examine the association between body mass index (BMI) and mortality among middle-aged people with diabetes in Japan.

METHODS

A total of 3032 men and 1615 women, aged 40-69 years, with diabetes were analyzed. Cox proportional hazards models, adjusted for potential confounding factors, were used to estimate mortality hazard ratios (HRs) across BMI categories at the baseline.

RESULTS

There were 1761 deaths during a mean follow-up period of 18.5 years. Increased all-cause mortality was observed at both ends of the BMI distribution; compared with the reference BMI category (23.0-24.9 kg/m²), the HRs were 1.25 (95% confidence interval [CI], 0.9997-1.56) in the lowest (14.0-18.9 kg/m²) and 1.36 (95% CI, 1.06-1.74) in the highest (30.0-39.9 kg/m²) categories (P = 0.001). Similar all-cause mortality trends were observed after excluding deaths within 3 years of follow-up, as well as for men and men who had ever smoked. While a similar non-linear pattern was observed for cancer-specific mortality, heart disease-specific mortality was only increased in the highest BMI category (HR, 1.86; 95% CI, 1.06-3.25).

CONCLUSION

This population-based prospective study demonstrated increased all-cause mortality at both ends of the BMI distribution among Japanese people with diabetes.

Association of Body Mass Index with the Risk of Incident Type 2 Diabetes, Cardiovascular Disease, and All-Cause Mortality: A Community-Based Prospective Study

BACKGROUND

Type 2 diabetes and cardiovascular disease (CVD) are the most important sequelae of obesity and the leading cause of death. We evaluated the association between body mass index (BMI) and the risk of incident type 2 diabetes, CVD, and all-cause mortality in a prospective study of a Korean population.

METHODS

The shapes of the associations were modeled by restricted cubic splines regression analysis. After categorizing all subjects (n=8,900) into octiles based on their BMI levels, we estimated the hazard ratio (HR) for the association of categorized BMI levels with the risk of incident CVD and type 2 diabetes using a Cox's proportional hazard analysis.

RESULTS

The mean age of participants was 52 years and 48% were men. Of the subjects at baseline, 39.0% of men and 45.6% of women were classified as obese (BMI ≥25 kg/m2). Over a mean follow-up of 8.1 years, CVD events occurred in 509 participants; 436 died; and 1,258 subjects developed type 2 diabetes. The increased risk of incident diabetes began to be significant at BMI 23 to 24 kg/m2 in both sexes (HR, 1.8). For CVD events, the risk began to increase significantly at BMI 26 to 28 kg/m2 (HR, 1.6). We found a reverse J-shaped relationship between BMI and all-cause mortality, with an increased risk among individuals with BMI values in lower range (BMI &lt;21 kg/m2).

CONCLUSION

These results suggest that the BMI cut-off points for observed risk were varied depending on the diseases and that the BMI classification of obesity need to be revised to reflect differential risk of obesity-related diseases.

Influence of Diabetic Retinopathy on the Relationship Between Body Mass Index and Mortality in Patients with Poorly Controlled Type 2 Diabetes

PURPOSE

An "obesity paradox" has been observed in patients with type 2 diabetes. However, the optimal body mass index (BMI) for survival may be influenced by the stage of diabetes. We examined the relationship between BMI and mortality in patients with type 2 diabetes and the influence of diabetic retinopathy (DR).

PATIENTS AND METHODS

This is a retrospective cohort composing patients with type 2 diabetes who were admitted due to poor glucose control. Presence of DR was confirmed by ophthalmologists. The primary outcome was all-cause mortality. The association between BMI and mortality was assessed using a Cox proportional hazards model with adjustment for age, sex, and traditional risk factors.

RESULTS

A total of 2053 patients were enrolled. Over median follow-up of 6.7 years, there were 1060 deaths. Patients were classified into five categories based on admission BMI (kg/m²): <18.5, 18.5‒23, 23‒25, 25‒27 (reference), 25‒30 and >30. Mortality risk was significantly higher in the <18.5 kg/m², 18.5-23 kg/m², and 23-25 kg/m² categories than in the reference category (P <0.001). The similar obesity paradox was observed in the subgroup of patients without DR. However, in patients with DR, only patients with BMI <18.5 kg/m² had significantly increased mortality than those in the reference category. The presence of DR significantly modified the shape of the association between BMI and mortality (P = 0.019).

CONCLUSION

The obesity paradox exists in patients with poorly controlled type 2 diabetes. The presence of DR appears to significantly influence the shape of the association between BMI and mortality.

Fasting Blood Glucose and HbA1c Correlate With Severity of Coronary Artery Disease in Elective PCI Patients With HbA1c 5.7% to 6.4

Diabetes mellitus, and even prediabetes, has been shown to be independently associated with cardiovascular disease. Our study explored whether the combination of glycosylated hemoglobin (HbA_1c) and fasting blood glucose (FBG) can better assess the severity of coronary heart disease (CHD) in elective percutaneous coronary intervention (PCI) patients. We consecutively enrolled 1006 prediabetic patients with HbA_1c 5.7% to 6.4% who underwent elective PCI. Patients were divided into 2 groups: a normal fasting glucose (NFG) group (FBG <6.1 mmol/L) and an impaired fasting glucose (IFG) group (6.1 ≤FBG<7.0 mmol/L) with defined values. Baseline characteristics and angiography data of the 2 groups were compared. The prevalence of 3-vessel disease (P = .002), the GENSINI (the score is named after a professor) score (P = .002), and the SYNTAX (SYNergy between PCI with TAXUS™ and Cardiac Surgery) score (P = .002) of the IFG group was significantly higher compared to the NFG group. After multiple regression analysis, FBG was found to be independently associated with prevalence of 3-vessel disease (adjusted odds ratio: 1.62; 95% confidence interval: 1.21-2.36; P = .013), the GENSINI score (standardized β = .138, P = .008), and the SYNTAX score (standardized β = .145, P = .005). In addition, HbA_{1 c} was independently associated with the prevalence of 3-vessel disease, the GENSINI, score, and the SYNTAX score (P < .05). Both FBG and HbA_1c are independently correlated with the severity of CHD in prediabetic patients with HbA_1c 5.7% to 6.4%.

Low-normal hemoglobin levels and anemia are associated with increased risk of end-stage renal disease in general populations: A prospective cohort study

Background

The impact of low-normal hemoglobin (Hb) levels and anemia on the risk of end-stage renal disease (ESRD) in general populations has rarely been examined.

Methods

510,620 Korean adults aged 40–80 years without known chronic kidney disease (CKD) underwent health examinations during 2002–2003 and were followed-up until 2013. Incidence of ESRD was identified by hospital discharge and clinical visit records.

Results

During a mean follow-up of 10.5, 575 women and 1047 men were diagnosed with ESRD. Lower Hb levels were associated with an increased risk of ESRD at given severity of albuminuria and at given estimated glomerular filtration rate (eGFR). Hb 13–13.9 g/dL in men, Hb 11–11.9 g/dL in women, and trace albuminuria assessed by dipstick urinalysis were associated with more than doubled risk. The risk associated with lower Hb was stronger in older (≥60 years) than younger women. Among 349,993 participants with information on eGFR, the multivariable-adjusted HRs associated with 1 g/dL lower Hb in participants with eGFR values ≥60, 30–59, and <30 mL/min/1.73 m² were 1.34 (95% CI, 1.17–1.54), 1.55 (1.38–1.74), and 1.75 (1.47–2.09), respectively (Pinteraction between eGFR groups = .06).

Conclusions

Low-normal Hb levels and anemia are risk factors for ESRD incidence in person without CKD and for CKD progression to ESRD. Lower Hb increases the risk of ESRD through synergistic biological interactions with lower eGFR and albuminuria. The impacts of lower Hb may be stronger in older than younger women. Proper management and screening at earlier stage of Hb decline and anemia might reduce the burden of CKD.

Body mass index and mortality in people with and without diabetes: A UK Biobank study

BACKGROUND AND AIMS

To investigate the association of body mass index with all-cause, cardiovascular and cancer mortality in individuals with and without diabetes.

METHODS AND RESULTS

We used data on 490,852 participants from the UK Biobank, with linkage to national mortality data between 2006 and 2016. Using Cox regression, we calculated hazard ratios (HRs) and 95% confidence intervals (95%CI) for all-cause, cardiovascular and cancer mortality within body mass index categories in people with and without diabetes adjusting for potential confounders. 24,789 (5.0%) participants reported having diabetes at baseline. Over a median follow-up of 6.9 years, 13,896 participants died, of which 1800 had diabetes. Compared with normal body mass index (18.5-24.9 kg/m²), mortality risk in the overweight group (25.0-29.9 kg/m²) was 33% lower in people with diabetes (HR 0.67, 95%CI 0.62-0.73) and 12% lower in participants without (HR 0.88, 95%CI 0.85-0.90). For class I obesity (30.0-34.9 kg/m²), mortality risk was 35% lower in participants with diabetes (HR 0.65, 95%CI 0.59-0.71) and 5% lower in participants without (HR 0.95, 95%CI 0.91-0.99). For class III obesity (≥40 kg/m²), there was a 10% non-significant lower mortality risk compared to normal body mass index in people with diabetes (HR 0.90, 95%CI 0.77-1.05); in contrast, the risk was 29% higher in people without diabetes (HR 1.29, 95%CI 1.13-1.45). Similar patterns were observed for cardiovascular mortality but not for cancer mortality.

CONCLUSION

The impact of obesity on the risk of mortality was dependent on the presence of diabetes: for the same level of obesity, mortality risk was higher in people without diabetes compared to those with diabetes.

Development of type 2 diabetes mellitus in people with intermediate hyperglycaemia

BACKGROUND

Intermediate hyperglycaemia (IH) is characterised by one or more measurements of elevated blood glucose concentrations, such as impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and elevated glycosylated haemoglobin A1c (HbA1c). These levels are higher than normal but below the diagnostic threshold for type 2 diabetes mellitus (T2DM). The reduced threshold of 5.6 mmol/L (100 mg/dL) fasting plasma glucose (FPG) for defining IFG, introduced by the American Diabetes Association (ADA) in 2003, substantially increased the prevalence of IFG. Likewise, the lowering of the HbA1c threshold from 6.0% to 5.7% by the ADA in 2010 could potentially have significant medical, public health and socioeconomic impacts.

OBJECTIVES

To assess the overall prognosis of people with IH for developing T2DM, regression from IH to normoglycaemia and the difference in T2DM incidence in people with IH versus people with normoglycaemia.

SEARCH METHODS

We searched MEDLINE, Embase, ClincialTrials.gov and the International Clinical Trials Registry Platform (ICTRP) Search Portal up to December 2016 and updated the MEDLINE search in February 2018. We used several complementary search methods in addition to a Boolean search based on analytical text mining.

SELECTION CRITERIA

We included prospective cohort studies investigating the development of T2DM in people with IH. We used standard definitions of IH as described by the ADA or World Health Organization (WHO). We excluded intervention trials and studies on cohorts with additional comorbidities at baseline, studies with missing data on the transition from IH to T2DM, and studies where T2DM incidence was evaluated by documents or self-report only.

DATA COLLECTION AND ANALYSIS

One review author extracted study characteristics, and a second author checked the extracted data. We used a tailored version of the Quality In Prognosis Studies (QUIPS) tool for assessing risk of bias. We pooled incidence and incidence rate ratios (IRR) using a random-effects model to account for between-study heterogeneity. To meta-analyse incidence data, we used a method for pooling proportions. For hazard ratios (HR) and odds ratios (OR) of IH versus normoglycaemia, reported with 95% confidence intervals (CI), we obtained standard errors from these CIs and performed random-effects meta-analyses using the generic inverse-variance method. We used multivariable HRs and the model with the greatest number of covariates. We evaluated the certainty of the evidence with an adapted version of the GRADE framework.

MAIN RESULTS

We included 103 prospective cohort studies. The studies mainly defined IH by IFG5.6 (FPG mmol/L 5.6 to 6.9 mmol/L or 100 mg/dL to 125 mg/dL), IFG6.1 (FPG 6.1 mmol/L to 6.9 mmol/L or 110 mg/dL to 125 mg/dL), IGT (plasma glucose 7.8 mmol/L to 11.1 mmol/L or 140 mg/dL to 199 mg/dL two hours after a 75 g glucose load on the oral glucose tolerance test, combined IFG and IGT (IFG/IGT), and elevated HbA1c (HbA1c5.7: HbA1c 5.7% to 6.4% or 39 mmol/mol to 46 mmol/mol; HbA1c6.0: HbA1c 6.0% to 6.4% or 42 mmol/mol to 46 mmol/mol). The follow-up period ranged from 1 to 24 years. Ninety-three studies evaluated the overall prognosis of people with IH measured by cumulative T2DM incidence, and 52 studies evaluated glycaemic status as a prognostic factor for T2DM by comparing a cohort with IH to a cohort with normoglycaemia. Participants were of Australian, European or North American origin in 41 studies; Latin American in 7; Asian or Middle Eastern in 50; and Islanders or American Indians in 5. Six studies included children and/or adolescents.Cumulative incidence of T2DM associated with IFG5.6, IFG6.1, IGT and the combination of IFG/IGT increased with length of follow-up. Cumulative incidence was highest with IFG/IGT, followed by IGT, IFG6.1 and IFG5.6. Limited data showed a higher T2DM incidence associated with HbA1c6.0 compared to HbA1c5.7. We rated the evidence for overall prognosis as of moderate certainty because of imprecision (wide CIs in most studies). In the 47 studies reporting restitution of normoglycaemia, regression ranged from 33% to 59% within one to five years follow-up, and from 17% to 42% for 6 to 11 years of follow-up (moderate-certainty evidence).Studies evaluating the prognostic effect of IH versus normoglycaemia reported different effect measures (HRs, IRRs and ORs). Overall, the effect measures all indicated an elevated risk of T2DM at 1 to 24 years of follow-up. Taking into account the long-term follow-up of cohort studies, estimation of HRs for time-dependent events like T2DM incidence appeared most reliable. The pooled HR and the number of studies and participants for different IH definitions as compared to normoglycaemia were: IFG5.6: HR 4.32 (95% CI 2.61 to 7.12), 8 studies, 9017 participants; IFG6.1: HR 5.47 (95% CI 3.50 to 8.54), 9 studies, 2818 participants; IGT: HR 3.61 (95% CI 2.31 to 5.64), 5 studies, 4010 participants; IFG and IGT: HR 6.90 (95% CI 4.15 to 11.45), 5 studies, 1038 participants; HbA1c5.7: HR 5.55 (95% CI 2.77 to 11.12), 4 studies, 5223 participants; HbA1c6.0: HR 10.10 (95% CI 3.59 to 28.43), 6 studies, 4532 participants. In subgroup analyses, there was no clear pattern of differences between geographic regions. We downgraded the evidence for the prognostic effect of IH versus normoglycaemia to low-certainty evidence due to study limitations because many studies did not adequately adjust for confounders. Imprecision and inconsistency required further downgrading due to wide 95% CIs and wide 95% prediction intervals (sometimes ranging from negative to positive prognostic factor to outcome associations), respectively.This evidence is up to date as of 26 February 2018.

AUTHORS' CONCLUSIONS

Overall prognosis of people with IH worsened over time. T2DM cumulative incidence generally increased over the course of follow-up but varied with IH definition. Regression from IH to normoglycaemia decreased over time but was observed even after 11 years of follow-up. The risk of developing T2DM when comparing IH with normoglycaemia at baseline varied by IH definition. Taking into consideration the uncertainty of the available evidence, as well as the fluctuating stages of normoglycaemia, IH and T2DM, which may transition from one stage to another in both directions even after years of follow-up, practitioners should be careful about the potential implications of any active intervention for people 'diagnosed' with IH.

Circulating Adipocyte Fatty Acid–Binding Protein Concentrations Predict Multiple Mortality Outcomes among Men and Women with Diabetes

INTRODUCTION

Raised circulating adipocyte fatty acid–binding protein (AFABP) concentrations are associated with various adverse health conditions. However, their relationship with mortality remains to be defined, especially in view of the sexual dimorphism of circulating AFABP concentrations. Here we investigated prospectively whether serum AFABP concentrations predict multiple mortality outcomes in men and women alike, using a large clinic-based cohort of individuals with type 2 diabetes, a condition with raised AFABP concentrations.

METHODS

Baseline serum AFABP concentrations were measured in 5305 research participants with a monoclonal antibody-based sandwich immunoassay. The role of circulating AFABP concentrations in predicting mortality outcomes was evaluated by multivariable Cox regression analysis.

RESULTS

Among the 5305 participants (59% men) in this study, over a median follow-up of 5 years, there were 512 deaths (19.3 deaths per 1000 person-years). Circulating AFABP concentrations, with higher levels in women at baseline, predicted all-cause mortality (P &lt; 0.001), cardiovascular mortality (P = 0.037), and infection-related deaths (P &lt; 0.002) among all participants. In sex-specific analyses, circulating AFABP concentration was an independent predictor of all-cause mortality in both men and women and a predictor of cancer-related deaths and infection-related deaths in men only. Furthermore, the addition of serum AFABP concentrations improved the time-dependent c statistics in predicting all-cause mortality in participants with type 2 diabetes (P = 0.008).

CONCLUSIONS

Circulating AFABP concentration was an independent predictor of various mortality outcomes in type 2 diabetes over and above known risk factors of reduced survival in men and women. The role of AFABP as a prognostic biomarker and therapeutic target warrants further investigation.

Insulin therapy, weight gain and prognosis

Insulin therapy is mainly used by people with type 2 diabetes who have failed other therapies and have become insulin-deficient. This group represents about a quarter of all people with type 2 diabetes. Almost all those with type 2 diabetes who start insulin therapy or intensify it gain weight, which may potentially diminish the prognostic advantage of improved glycaemia. To date, all available guidelines emphasize both the attainment of glycated haemoglobin (HbA1c) goals and weight control, without directing the clinician as to which element is of a higher priority. The following review attempts to clarify the issue using the available literature. The body of evidence presented in this review indicates that glycaemic management with exogenous insulin replacement is of a much higher priority than weight gain. Lower weight or weight loss do not show prognostic benefit in advanced stages of diabetes; therefore, weight gain should not discourage providers from achieving and maintaining HbA1c goals with insulin therapy, regardless of insulin dosage or other medications.

Body mass index and risk of all-cause mortality with normoglycemia, impaired fasting glucose and prevalent diabetes: results from the Rural Chinese Cohort Study

BACKGROUND

Previous evidence of an association between body mass index (BMI) and mortality in patients with diabetes was inconsistent. The BMI-mortality association with normal fasting glucose (NFG), impaired fasting glucose (IFG) and prevalent diabetes is still unclear in the Chinese population.

METHODS

We analysed data for 17 252 adults from the Rural Chinese Cohort Study during 2007-2008 and followed for mortality during 2013-2014. Participants were classified with NFG, IFG and diabetes according to baseline measurement values of fasting glucose and self-reported diabetes. Multivariable Cox proportional hazard models were used to calculate HRs and 95% CIs across BMI categories by glycemic status.

RESULTS

During the 6-year follow-up, 1109 participants died (563/10 181 with NFG, 349/5572 with IFG and 197/1499 with diabetes). The BMI-mortality association was curvilinear, with low BMI (even in normal range) associated with increased mortality regardless of glycemic status. In adjusted Cox models, risk of mortality showed a decreasing trend with BMI≤18 kg/m², 18<BMI≤20 kg/m² and 20<BMI≤22 kg/m² vs 22<BMI≤24 kg/m²: HR 2.83 (95% CI 1.78 to 4.51), 2.05 (1.46 to 2.87) and 1.45 (1.10 to 1.90), respectively, for NFG; 2.53 (1.25 to 5.14), 1.36 (0.86 to 2.14) and 1.09 (0.76 to 1.57), respectively, for IFG; and 4.03 (1.42 to 11.50), 2.00 (1.05 to 3.80) and 1.52 (0.88 to 2.60), respectively, for diabetes. The risk of mortality was lower for patients with diabetes who were overweight or obese versus normal weight.

CONCLUSIONS

Low BMI was associated with increased mortality regardless of glycemic status. Future studies are needed to explain the 'obesity paradox' in patients with diabetes.

The Evidence for an Obesity Paradox in Type 2 Diabetes Mellitus

Although overweight/obesity is a major risk factor for the development of type 2 diabetes mellitus, there is increasing evidence that overweight or obese patients with type 2 diabetes mellitus experience lower mortality compared with patients of normal weight. This paradoxical finding, known as the "obesity paradox," occurs in other chronic diseases, and in type 2 diabetes mellitus is particularly perplexing given that lifestyle intervention with one goal being weight reduction is an important feature of the management of this condition. We summarize in this review the findings from clinical and epidemiologic studies that have investigated the association between overweight and obesity (usually assessed using body mass index [BMI]) and mortality in type 2 diabetes mellitus and discuss potential causes of the obesity paradox. We conclude that most studies show evidence of an obesity paradox, but important conflicting findings still exist. We also evaluate if potential bias might explain the obesity paradox in diabetes, including, for example, the presence of confounding factors, measurement error due to use of BMI as an index of obesity, and reverse causation.

Body mass index and mortality in patients with and without diabetes mellitus

OBJECTIVE

Investigate the association between body mass index (BMI), length of stay (LOS), and mortality in hospitalized patients with and without diabetes mellitus (DM).

METHODS

Historical prospectively collected data of adult patients hospitalized between 2011 and 2013. Body mass index was calculated according to measurement or self-report on admission and classified as follows: underweight (<18.5), normal weight (18.5-24.9), overweight (25-29.9), obese (30-34.9), and severely obese (≥35). The main outcomes were LOS, in-hospital, and end-of-follow-up mortality.

RESULTS

Cohort included 24 233 patients (53% male; mean age ± SD, 65 ± 18), including 7397 patients with DM (31%). Among patients with normal BMI, LOS was shorter compared with underweight patients, but it was longer compared with overweight and obese patients. Following multivariate adjustment, this difference remained significant only for patients with DM. There was a significant interaction between DM status and BMI group, in the models for in-hospital and end-of-follow-up mortality. Compared with normal BMI, in-hospital mortality risk was increased by 80% and 100% for the underweight with and without DM, respectively. For patients with and without DM, in-hospital mortality risk was 30% to 40% lower among overweight and obese patients, and there was no difference between severely obese and normal weight patients. At the end-of-follow-up, mortality risk was 1.6-fold and 1.7-fold higher among underweight patients with and without DM, respectively. For overweight, obese, and severely obese patients, mortality risk was decreased by 30% to 40% in those with DM and by 20% to 30% in those without DM.

CONCLUSIONS

In hospitalized patients with and without DM, there was an inverse association between BMI and mortality.

Risk factors for hepatocellular carcinoma by age, sex, and liver disorder status: A prospective cohort study in Korea

BACKGROUND

To the authors' knowledge, relatively little is known regarding the interaction of risk factors for hepatocellular carcinoma (HCC) with age, sex, and liver disorder status.

METHODS

The authors followed 504,646 Korean patients aged 40 to 80 years who underwent routine health checkups between 2002 and 2003 until 2013 via linkage to national hospital discharge records.

RESULTS

HCC occurred in 2744 individuals. In the sex-adjusted and age-adjusted analysis, cirrhosis increased the incidence of HCC by 42-fold, followed by hepatitis B virus (21-fold), hepatitis C virus (HCV; 19-fold), male sex (4.3-fold), and each 5-year age increment (1.24-fold). In the multivariable adjusted analysis, diabetes increased the risk of HCC by 80%, alcohol consumption ≥80 g/day increased the risk by 75%, alcohol consumption of 40 to 79 g/day increased the risk by 37%, and being a current smoker increased the risk by 25%. The multivariable adjusted hazard ratios of male sex and HCV were 6.27 and 5.72, respectively, at age <50 years, but were 2.09 and 22.51, respectively, at age ≥70 years. Each 20 g/day of alcohol consumption increased the risk of HCC by 6% (P = .11), 8% (P = .02), 16% (P<.001), and 30% (P<.001), respectively, in individuals aged <50 years, 50 to 59 years, 60 to 69 years, and 70 to 80 years. In individuals without a liver disorder, body mass index was found to be positively associated with HCC, whereas patients with a liver disorder demonstrated an inverse association. Women had higher adjusted hazard ratios associated with age and cirrhosis compared with men.

CONCLUSIONS

With advancing age, the effects of alcohol use and HCV on the development of HCC become stronger, whereas the effect of male sex weakens. Lifetime moderate alcohol consumption may cause HCC in the elderly. Smoking increases the risk of HCC irrespective of viral hepatitis, and diabetes increases the risk of HCC independent of cirrhosis. Cancer 2018;124:2748-2757. © 2018 American Cancer Society.

Association of Body Mass Index with Risk of Major Adverse Cardiovascular Events and Mortality in People with Diabetes

Background

The relationship between cardiovascular and all-cause mortality and obesity in people with diabetes is still controversial. We investigated the association of body mass index (BMI) with the risk of major adverse cardiovascular events (MACE) and all-cause mortality in people with diabetes.

Methods

In total, 48,438 people with diabetes were enrolled in the Korean National Health Insurance Service-National Health Screening Cohort from 2002 to 2003 and were followed until 2013. Baseline BMI was categorized as underweight (<18.5 kg/m²), normal-weight (18.5–22.9 kg/m²), overweight (23.0–24.9 kg/m²), obese class I (25.0–29.9 kg/m²), and obese class II (≥30.0 kg/m²).

Results

During a median of 10.7 years of follow-up (interquartile range, 10.2–11.2 years), there were 7,360 MACE and 5,766 deaths. Compared to those in the normal-weight group, the fully adjusted hazard ratios (HRs) for MACE were 1.09 (95% confidence interval [CI], 0.92–1.29), 0.91 (95% CI, 0.85–0.97), 0.93 (95% CI, 0.88–0.98), and 0.95 (95% CI, 0.84–1.06) for underweight, overweight, obese class I, and obese class II groups, respectively. The HRs for all-cause mortality were 1.75 (95% CI, 1.54–1.99), 0.74 (95% CI, 0.69–0.79), 0.67 (95% CI, 0.63–0.71), and 0.73 (95% CI, 0.63–0.85) for underweight, overweight, obese class I, and obese class II groups, respectively.

Conclusion

In people with diabetes, underweight people had a higher risk for all-cause mortality, whereas overweight or obese people had a lower risk for MACE and all-cause mortality than those with a normal weight.

Fasting Glucose and All-Cause Mortality by Age in Diabetes: A Prospective Cohort Study

OBJECTIVE

To examine associations between fasting glucose and mortality and to identify the levels associated with lowest mortality by age in diabetes.

RESEARCH DESIGN AND METHODS

A total of 359,645 Korean adults with known prevalent diabetes participated in health screening during 2001-2004 and were followed up until 2013.

RESULTS

U-curve associations were found. Fasting glucose levels associated with the lowest mortality were ∼90-130 mg/dL, except for in those aged 18-44 years (∼80-95 mg/dL). Multivariable-adjusted hazard ratios of fasting glucose <65, 65-74, 75-84, 140-169, 170-199, and ≥200 mg/dL were 1.46, 1.12, 1.09, 1.12, 1.31, and 1.78, respectively, compared with 85-99 mg/dL.

CONCLUSIONS

Optimal fasting glucose range for survival is higher in adults with than without known prevalent diabetes, except, perhaps, younger adults. Tight glucose control may lessen premature death in younger adults with diabetes. Hypoglycemia (<65 mg/dL) was associated with higher mortality than was fasting glucose 170-199 mg/dL, while fasting glucose 65-84 mg/dL had risks comparable with those at levels 140-169 mg/dL in diabetes.

Low normal fasting glucose and risk of accidental death in Korean adults: A prospective cohort study

AIM

This study aimed to prospectively examine whether low normal glucose levels and hypoglycaemia are associated with increased mortality due to external causes, especially unintentional accidents.

METHODS

A total of 345,318 normoglycaemic Korean adults who had undergone health examinations during 2002-2003 were followed-up to 2013. To avoid potential biases related to glucose-lowering medication use, those with known diabetes or hyperglycaemia were excluded.

RESULTS

During 3.6 million person-years of follow-up, 1293 participants died because of unintentional accidents. Hazard ratios (HRs) for these accidental deaths were 1.26 (95% CI: 1.11-1.42), 1.60 (1.21-2.11) and 3.07 (1.37-6.85) for fasting serum glucose (FSG) levels of 70-79, 55-69 and <55mg/dL (3.9-4.4, 3.05-3.83 and <3.05mmol/L), respectively, compared with 80-99mg/dL (4.44-5.5mmol/L). FSG levels<80mg/dL were associated with an approximately 30% higher mortality due to accidents: specifically, 40% were non-fall-related injury; 50% were automobile-related; and 80% were motorcycle-related. The associations were weak (approximately 10% higher mortality, with P>0.05 for each cause) for deaths due to traffic accidents (pedestrians, pedal cyclists), falls, intentional self-harm and physical assault. The population attributable risks for FSG levels <80mg/dL were 10% (95% CI: 2-18%) for non-fall-related injury, 11% (6-17%) for car accidents and 17% (6-27%) for motorcycle accidents.

CONCLUSION

FSG levels of 70-79mg/dL (3.9-4.4mmol/L) as well as <70mg/dL are risk factors for accidental death. Appropriate management of the impact of FSG levels <80mg/dL might reduce unintended deaths due to non-fall-related injury, and automobile and motorcycle accidents, by ≥10%.

Body mass index and gastrointestinal cancer mortality in Korean adults: A prospective cohort study

BACKGROUND

The association between body mass index (BMI) and mortality from gastrointestinal (GI) cancer remains unclear, especially in Asian populations.

METHODS

A total of 510 148 Korean adults who participated in routine health examinations during the period 2002-2003 were followed up until 2013.

RESULTS

During a mean follow up of 10.5 years, 7831 individuals died of GI cancer. Various associations with BMI were found: U-curve (overall GI, colorectal, liver, and gallbladder cancer), L-curve (stomach cancer), linear (esophageal, extrahepatic bile duct [EBD], and small intestine cancer), and none (pancreatic cancer). Overall GI cancer mortality was lowest at approximately 23.5-26 kg/m2 . For cancers with linear associations, the multivariable adjusted hazard ratios per each 5 kg/m2 higher BMI were 0.53 (95% confidence interval = 0.43-0.65, esophagus), 1.19 (1.02-1.40, EBD), and 0.64 (0.41-0.999, small intestine). For cancers with U-curve or L-curve associations, the corresponding hazard ratios ≥25 kg/m2 were 1.19 (1.08-1.32, overall GI), 1.30 (1.04-1.64, colorectal), 1.28 (1.07-1.53, liver), and 1.30 (0.85-1.97, gallbladder), while in the range of <25 kg/m2 , they were 0.81 (0.76-0.87, overall GI), 0.43 (0.32-0.58, esophagus), 0.70 (0.62-0.79, stomach), and 0.77 (0.65-0.90, colorectal), and these inverse associations did not weaken after excluding the first 7 years of follow up and ever smokers.

CONCLUSIONS

Both low and high BMIs were associated with excess mortality from GI cancers in Korean adults. EBD cancer had a positive association, while esophageal and small intestine cancers had inverse associations. Above 25 kg/m2 , liver and colorectal cancers had positive associations with BMI, whereas below 25 kg/m2 , stomach and colorectal cancers had inverse associations.