BMI and all cause mortality: systematic review and non-linear dose-response meta-analysis of 230 cohort studies with 3.74 million deaths among 30.3 million participants

Predictors of all-cause mortality among 514,866 participants from the Korean National Health Screening Cohort

Background

There is not enough evidence regarding how information obtained from general health check-ups can predict individual mortality based on long-term follow-ups and large sample sizes. This study evaluated the applicability of various health information and measurements, consisting of self-reported data, anthropometric measurements and laboratory test results, in predicting individual mortality.

Methods

The National Health Screening Cohort included 514,866 participants (aged 40–79 years) who were randomly selected from the overall database of the national health screening program in 2002–2003. Death was determined from causes of death statistics provided by Statistics Korea. We assessed variables that were collected at baseline and repeatedly measured for two consecutive years using traditional and time-variant Cox proportional hazards models in addition to random forest and boosting algorithms to identify predictors of 10-year all-cause mortality. Participants’ age at enrollment, lifestyle factors, anthropometric measurements and laboratory test results were included in the prediction models. We used c-statistics to assess the discriminatory ability of the models, their external validity and the ratio of expected to observed numbers to evaluate model calibration. Eligibility of Medicaid and household income levels were used as inequality indexes.

Results

After the follow-up by 2013, 38,031 deaths were identified. The risk score based on the selected health information and measurements achieved a higher discriminatory ability for mortality prediction (c-statistics = 0.832, 0.841, 0.893, and 0.712 for Cox model, time-variant Cox model, random forest and boosting, respectively) than that of the previous studies. The results were externally validated using the community-based cohort data (c-statistics = 0.814).

Conclusions

Individuals’ health information and measurements based on health screening can provide early indicators of their 10-year death risk, which can be useful for health monitoring and related policy decisions.

Risk of unintentional injuries in children and adolescents with ADHD and the impact of ADHD medications: protocol for a systematic review and meta-analysis

INTRODUCTION

Attention-deficit hyperactivity disorder (ADHD) has been related to increased rates of unintentional injuries. However, the magnitude of the effect and to which extent variables such as sex, age or comorbidity can influence this relationship is unknown. Additionally, and importantly, it is unclear if, and to which degree, ADHD medications can decrease the number of unintentional injuries. Due to the amount of economic and social resources invested in the treatment of injuries, filling these gaps in the literature is highly relevant from a public health standpoint. Here, we present a protocol for a systematic review and meta-analysis to estimate the relationship between ADHD and unintentional injuries and assess the impact of pharmacological treatment for ADHD METHODS AND ANALYSIS: We will combine results from 114 bibliographic databases for studies relating ADHD and risk of injuries. Bibliographic searches and data extraction will be carried out independently by two researchers. The studies' risk of bias will be assessed using the Newcastle-Ottawa Scale. Articles reporting ORs or HRs of suffering an injury in ADHD compared with controls (or enough data to calculate them) will be combined using Robust Variance Estimation, a method that permits to include multiple non-independent outcomes in the analysis. All analyses will be carried out in Stata. Age, sex and comorbid conduct disorders will be considered as potential causes of variance and their effect analysed through meta-regression and subgroup analysis. Sensitivity analyses will exclude articles with longer follow-ups, non-stringent definitions of ADHD or controls and statistically uncontrolled/controlled outcomes. Studies implementing a self-controlled case series methodology to investigate if ADHD drugs reduce the risk of injuries will be combined with a generalised linear mixed model using the Poisson distribution and a log link function.

REGISTRATION DETAILS

PROSPERO-Prospective Register of Systematic Reviews (CRD42017064967).

Influence of Socioeconomic and Anthropometric Factors on Respiratory Function in Female University Students

The purpose of this study was to evaluate lung function in healthy young female university students and to seek the relation of lung function to socioeconomic and anthropometric indices. The methodology consisted of spirometry tests, anthropometric measures and a questionnaire conducted in November of 2015 among 152 female university students. At first, lung function was analyzed for any relationship with socioeconomic factors and smoking. The results of a multi-factor analysis of variance demonstrate significant differences in the FEV1/FVC ratio depending on the general socioeconomic status. Then, anthropometric and spirometric parameters were tested for correlations. A comparison of underweight, normal weigh, overweight, and obese subjects revealed statistically significant differences for FVC% and FEV1/FVC, with the highest values noted in the subjects of normal weight. Individuals with abdominal obesity had lower FVC% and FEV1% and a higher FEV1/FVC ratio. The findings of our study confirm that both general obesity and abdominal obesity are related to a reduced lung function.

Reducing the Global Burden of Cardiovascular Disease, Part 1: The Epidemiology and Risk Factors

Current global health policy goals include a 25% reduction in premature mortality from noncommunicable diseases by 2025. In this 2-part review, we provide an overview of the current epidemiological data on cardiovascular diseases (CVD), its risk factors, and describe strategies aimed at reducing its burden. In part 1, we examine the global epidemiology of cardiac conditions that have the greatest impact on CVD mortality; the predominant risk factors; and the impact of upstream, societal health determinants (eg, environmental factors, health policy, and health systems) on CVD. Although age-standardized mortality from CVD has decreased in many regions of the world, the absolute number of deaths continues to increase, with the majority now occurring in middle- and low-income countries. It is evident that multiple factors are causally related to CVD, including traditional individual level risk factors (mainly tobacco use, lipids, and elevated blood pressure) and societal level health determinants (eg, health systems, health policies, and barriers to CVD prevention and care). Both individual and societal risk factors vary considerably between different regions of the world and economic settings. However, reliable data to estimate CVD burden are lacking in many regions of the world, which hampers the establishment of nationwide prevention and management strategies. A 25% reduction in premature CVD mortality globally is feasible but will require better implementation of evidence-based policies (particularly tobacco control) and integrated health systems strategies that improve CVD prevention and management. In addition, there is a need for better health information to monitor progress and guide health policy decisions.

Text messaging (SMS) as a tool to facilitate weight loss and prevent metabolic deterioration in clinically healthy overweight and obese subjects: a randomised controlled trial

OBJECTIVE

To examine whether SMS text messaging facilitates a reduction of weight and waist circumference (WC) and favourable changes in lipid profile and insulin levels in clinically healthy overweight and obese subjects.

DESIGN

A randomised controlled trial.

SETTING AND INTERVENTION

Primary care health centre in Riga, Latvia. Text messaging once in two weeks.

SUBJECTS

A total of 123 overweight and obese men and women aged 30-45 years with no cardiovascular diseases (CVDs) or diabetes.

MAIN OUTCOME MEASURES

changes in anthropometric parameters (weight, WC, body mass index (BMI)) and biochemical parameters (lipids, fasting glucose and insulin).

RESULTS

We found a statistically significant decrease in weight (2.4%), BMI and WC (4.8%) in the intervention group, while the control group showed a statistically non-significant increase in weight and BMI and decrease in WC. Between group results obtained over the course of a year showed statistically significant mean differences between weight (-3.4 kg (95% CI -5.5, -1.3)), BMI kg/m² (-1.14 (95% CI -1.9, -0.41)), WC (-4.6 cm (95% CI -6.8, -2.3)), hip circumference (-4.0 cm (95% CI -5.9, -2.0)) and fasting insulin (2.43 μU/ml (95% CI 0.6, 4.3)). Mean differences of changes in glucose and lipid levels were statistically non significant: fasting glucose (-0.01 mmol/l (95% CI -0.19, 0.17)), TC mmol/l (-0.04 mmol/l (95% CI -0.29, 0.21)), HDL-C (0.14 mmol/l (95% CI -0.65, 0.09)), LDL-C (-0.02 mmol/l (95% CI -0.22, 0.18)) and TG (0.23 mmol/l (95% CI -0.06, 0.52)).

CONCLUSIONS

SMS messaging in clinically healthy overweight and obese subjects facilitates a slight decrease in weight, BMI and WC. It is anticipated that the implications of this strategy might facilitate the design of preventive and promotive strategies among high risk groups in Latvia.

Body mass index and all-cause mortality among type 2 diabetes mellitus patients: Findings from the 5-year follow-up of the MADIABETES cohort

PURPOSE

To analyse the association between body mass index (BMI) and all-cause mortality in a 5-year follow-up study with Spanish type 2 diabetes mellitus (T2DM) patients, seeking gender differences.

METHODS

3443 T2DM outpatients were studied. At baseline and annually, patients were subjected to anamnesis, a physical examination, and biochemical tests. Data about demographic and clinical characteristics was also recorded, as was the treatment each patient had been prescribed. Mortality records were obtained from the Spanish National Institute of Statistics. Survival curves for BMI categories (Gehan-Wilcoxon test) and a multivariate Cox proportional hazard analysis were performed to identify adjusted Hazard Ratios (HRs) of mortality.

RESULTS

Mortality rate was 26.38 cases per 1000patient-years (95% CI, 23.92-29.01), with higher rates in men (28.43 per 1000patient-years; 95% CI, 24.87-32.36) than in women (24.31 per 1000patient-years; 95% CI, 21.02-27.98) (p=0.079). Mortality rates according to BMI categories were: 56.7 (95% CI, 40.8-76.6), 28.4 (95% CI, 22.9-34.9), 24.8 (95% CI, 21.5-28.5), 21 (95% CI, 16.3-26.6) and 23.7 (95% CI, 14.3-37) per 1000person-years for participants with a BMI of <23, 23-26.8, 26.9-33.1, 33.2-39.4, and >39.4kg/m², respectively. The BMI values associated with the highest all-cause mortality were <23kg/m², but only in males [HR: 2.78 (95% CI, 1.72-4.49; p<0.001)], since in females this association was not significant [HR: 1.14 (95% CI, 0.64-2.04; p=0.666)] (reference category for BMI: 23.0-26.8kg/m²). Higher BMIs were not associated with higher mortality rates.

CONCLUSIONS

In an outpatient T2DM Mediterranean population sample, low BMI predicted all-cause mortality only in males.

The Non-Linear Relationship between BMI and Health Care Costs and the Resulting Cost Fraction Attributable to Obesity

This study aims to analyse the non-linear relationship between Body Mass Index (BMI) and direct health care costs, and to quantify the resulting cost fraction attributable to obesity in Germany. Five cross-sectional surveys of cohort studies in southern Germany were pooled, resulting in data of 6757 individuals (31–96 years old). Self-reported information on health care utilisation was used to estimate direct health care costs for the year 2011. The relationship between measured BMI and annual costs was analysed using generalised additive models, and the cost fraction attributable to obesity was calculated. We found a non-linear association of BMI and health care costs with a continuously increasing slope for increasing BMI without any clear threshold. Under the consideration of the non-linear BMI-cost relationship, a shift in the BMI distribution so that the BMI of each individual is lowered by one point is associated with a 2.1% reduction of mean direct costs in the population. If obesity was eliminated, and the BMI of all obese individuals were lowered to 29.9 kg/m², this would reduce the mean direct costs by 4.0% in the population. Results show a non-linear relationship between BMI and health care costs, with very high costs for a few individuals with high BMI. This indicates that population-based interventions in combination with selective measures for very obese individuals might be the preferred strategy.

Hypertension in Obesity and the Impact of Weight Loss

PURPOSE OF REVIEW

Several interrelated mechanisms promote the development of hypertension in obesity, often contributing to end organ damage including cardiovascular disease and chronic kidney disease.

RECENT FINDINGS

The treatment of hypertension in obesity is complicated by a high prevalence of resistant hypertension, as well as unpredictable hemodynamic effects of many medications. Weight loss stabilizes neurohormonal activity and causes clinically significant reductions in blood pressure. While lifestyle interventions can improve blood pressure, they fail to consistently yield sustained weight loss and have not demonstrated long-term benefits. Bariatric surgery provides more permanent weight reduction, corresponding with dramatic declines in blood pressure and attenuation of long-term cardiovascular risk. Hypertension is closely linked to the prevalence, pathophysiology, and morbidity of obesity. There are multiple barriers to managing hypertension in obesity. Surgical weight loss offers the most promise in reducing blood pressure and decreasing end organ damage in this patient population.

Obesity, Underweight, and Smoking Are Associated with Worse Cardiorespiratory Fitness in Finnish Healthy Young Men: A Population-Based Study

Background

Obesity and smoking are strongly associated with worse cardiorespiratory fitness (CRF). Most previous studies that have examined the association of body composition with CRF have neither assessed non-linearity nor separately examined the effects of underweight. Thus, very little is known on how underweight affects CRF. Possible joint effects of obesity and smoking on CRF have not been adequately explored.

Aims

We examined the association between body mass index (BMI) and smoking with CRF in 1,629 Finnish army conscripts. We focused on non-linear effects of BMI in order to assess the importance of underweight. We also examined whether the cooccurrence of obesity and smoking potentiates their deleterious effects on CRF.

Methods

We used the Cooper’s 12-minute run test (12MR) to measure CRF. The 12MR score was analyzed as continuous (linear, polynomial, and restricted cubic spline regression) and categorical. In categorical analyses, we used binary logistic regression with the 12MR score in two groups (low = lowest quintile vs. intermediate/high = quintiles 2–5) and multinomial logistic regression with the 12MR score in three groups (low = lowest quintile, intermediate = quintiles 2 and 3, and high = quintiles 4 and 5).

Results

Non-linearity in the spline model was statistically significant (p < 0.001). In addition, the non-linear models had a clearly better fit than the linear one in terms of Akaike Information Criterion and R-squared values. There was a statistically significant interaction between smoking and BMI (p < 0.01). In the categorical analysis, overweight/obese regular smokers were at a particularly high risk of not achieving high CRF.

Conclusion

In healthy young men, not only overweight/obesity but also underweight may be associated with worse CRF. This provides a potential mechanism for the previously reported association between underweight and increased mortality. The cooccurrence of overweight/obesity and regular smoking may have a deleterious effect on CRF.

Obesity as defined by waist circumference but not body mass index is associated with higher renal mass complexity

OBJECTIVES

Obesity, typically defined as a body mass index (BMI)≥30kg/m², is an established risk factor for renal cell carcinoma (RCC) but is paradoxically linked to less advanced disease at diagnosis and improved outcomes. However, BMI has inherent flaws, and alternate obesity-defining metrics that emphasize abdominal fat are available. We investigated 3 obesity-defining metrics, to better examine the associations of abdominal fat vs. generalized obesity with renal tumor stage, grade, or R.E.N.A.L. nephrometry score.

METHODS AND MATERIALS

In a prospective cohort of 99 subjects with renal masses undergoing resection and no evidence of metastatic disease, obesity was assessed using 3 metrics: body mass index (BMI), radiographic waist circumference (WC), and retrorenal fat (RRF) pad distance. R.E.N.A.L. nephrometry scores were calculated based on preoperative CT or MRI. Univariate and multivariate analyses were performed to identify associations between obesity metrics and nephrometry score, tumor grade, and tumor stage.

RESULTS

In the 99 subjects, surgery was partial nephrectomy in 51 and radical nephrectomy in 48. Pathology showed benign masses in 11 and RCC in 88 (of which 20 had stage T3 disease). WC was positively correlated with nephrometry score, even after controlling for age, sex, race, and diabetes status (P = 0.02), whereas BMI and RRF were not (P = 0.13, and P = 0.57, respectively). WC in stage T2/T3 subjects was higher than in subjects with benign masses (P = 0.03). In contrast, subjects with Fuhrman grade 1 and 2 tumors had higher BMI (P<0.01) and WC (P = 0.04) than subjects with grade 3 and 4 tumors.

CONCLUSIONS

Our data suggest that obesity measured by WC, but not BMI or RRF, is associated with increased renal mass complexity. Tumor Fuhrman grade exhibited a different trend, with both high WC and BMI associated with lower-grade tumors. Our findings indicate that WC and BMI are not interchangeable obesity metrics. Further evaluation of RCC-specific outcomes using WC vs. BMI is warranted to better understand the complex relationship between general vs. abdominal obesity and RCC characteristics.

Dental Status and Compression of Life Expectancy with Disability

This study examined whether the number of teeth contributes to the compression of morbidity, measured as a shortening of life expectancy with disability, an extension of healthy life expectancy, and overall life expectancy. A prospective cohort study was conducted. A self-reported baseline survey was given to 126,438 community-dwelling older people aged ≥65 y in Japan in 2010, and 85,161 (67.4%) responded. The onset of functional disability and all-cause mortality were followed up for 1,374 d (follow-up rate = 96.1%). A sex-stratified illness-death model was applied to estimate the adjusted hazard ratios (HRs) for 3 health transitions (healthy to dead, healthy to disabled, and disabled to dead). Absolute differences in life expectancy, healthy life expectancy, and life expectancy with disability according to the number of teeth were also estimated. Age, denture use, socioeconomic status, health status, and health behavior were adjusted. Compared with the edentulous participants, participants with ≥20 teeth had lower risks of transitioning from healthy to dead (adjusted HR, 0.58 [95% confidence interval (CI), 0.50-0.68] for men and 0.70 [95% CI, 0.57-0.85] for women) and from healthy to disabled (adjusted HR, 0.52 [95% CI, 0.44-0.61] for men and 0.58 [95% CI, 0.49-0.68] for women). They also transitioned from disabled to dead earlier (adjusted HR, 1.26 [95% CI, 0.99-1.60] for men and 2.42 [95% CI, 1.72-3.38] for women). Among the participants aged ≥85 y, those with ≥20 teeth had a longer life expectancy (men: +57 d; women: +15 d) and healthy life expectancy (men: +92 d; women: +70 d) and a shorter life expectancy with disability (men: -35 d; women: -55 d) compared with the edentulous participants. Similar associations were observed among the younger participants and those with 1 to 9 or 10 to 19 teeth. The presence of remaining teeth was associated with a significant compression of morbidity: older Japanese adults' life expectancy with disability was compressed by 35 to 55 d within the follow-up of 1,374 d.

Combined Effect of Obesity and Mobility Limitation with Incidence of Type 2 Diabetes and Mortality in Chinese Elderly

This article aims to examine the effect of mobility limitation and obesity on the risk of new incidence of type 2 diabetes mellitus (T2DM) and mortality. The design was a cohort study (n = 1075) among adults aged 60 years and older. Obesity was defined as body-mass index greater than or equal to 28 kg/m². Mobility limitation was defined as participants scoring in the top 20% on the timed up and go test or in the slowest 20% for the 4-m walking test. The mean age of the study population was 67.4 ± 5.4 years (age range: 60-86 years), and 57.4% were women. Overall, 5.1% of women and 1.9% of men had both obesity and mobility limitations. During 3-year follow-up, the new incidence of T2DM was 2.98% and the adjusted risk of the new incidence of T2DM was progressively greater in obese subjects without mobility limitation, but not greater in the single mobility limitation subjects. The combination of mobility limitation and obesity (odds ratio = 10.3, 95% confidence interval = 2.25-70.13) has a significantly higher risk than obesity only or mobility limitation only. What is more, obesity with mobility limitation could be an independent predictor of 3-year mortality compared with the other subjects. We demonstrated the associations between obesity and mobility limitation and thus the increased risk of developing, with the combination over time, T2DM and mortality.

Causal Associations of Adiposity and Body Fat Distribution With Coronary Heart Disease, Stroke Subtypes, and Type 2 Diabetes Mellitus: A Mendelian Randomization Analysis

BACKGROUND

The implications of different adiposity measures on cardiovascular disease etiology remain unclear. In this article, we quantify and contrast causal associations of central adiposity (waist-to-hip ratio adjusted for body mass index [WHRadjBMI]) and general adiposity (body mass index [BMI]) with cardiometabolic disease.

METHODS

Ninety-seven independent single-nucleotide polymorphisms for BMI and 49 single-nucleotide polymorphisms for WHRadjBMI were used to conduct Mendelian randomization analyses in 14 prospective studies supplemented with coronary heart disease (CHD) data from CARDIoGRAMplusC4D (Coronary Artery Disease Genome-wide Replication and Meta-analysis [CARDIoGRAM] plus The Coronary Artery Disease [C4D] Genetics; combined total 66 842 cases), stroke from METASTROKE (12 389 ischemic stroke cases), type 2 diabetes mellitus from DIAGRAM (Diabetes Genetics Replication and Meta-analysis; 34 840 cases), and lipids from GLGC (Global Lipids Genetic Consortium; 213 500 participants) consortia. Primary outcomes were CHD, type 2 diabetes mellitus, and major stroke subtypes; secondary analyses included 18 cardiometabolic traits.

RESULTS

Each one standard deviation (SD) higher WHRadjBMI (1 SD≈0.08 U) associated with a 48% excess risk of CHD (odds ratio [OR] for CHD, 1.48; 95% confidence interval [CI], 1.28-1.71), similar to findings for BMI (1 SD≈4.6 kg/m²; OR for CHD, 1.36; 95% CI, 1.22-1.52). Only WHRadjBMI increased risk of ischemic stroke (OR, 1.32; 95% CI, 1.03-1.70). For type 2 diabetes mellitus, both measures had large effects: OR, 1.82 (95% CI, 1.38-2.42) and OR, 1.98 (95% CI, 1.41-2.78) per 1 SD higher WHRadjBMI and BMI, respectively. Both WHRadjBMI and BMI were associated with higher left ventricular hypertrophy, glycemic traits, interleukin 6, and circulating lipids. WHRadjBMI was also associated with higher carotid intima-media thickness (39%; 95% CI, 9%-77% per 1 SD).

CONCLUSIONS

Both general and central adiposity have causal effects on CHD and type 2 diabetes mellitus. Central adiposity may have a stronger effect on stroke risk. Future estimates of the burden of adiposity on health should include measures of central and general adiposity.

Weight History and All-Cause and Cause-Specific Mortality in Three Prospective Cohort Studies

BACKGROUND

The relationship between body mass index (BMI) and mortality is controversial.

OBJECTIVE

To investigate the relationship between maximum BMI over 16 years and subsequent mortality.

DESIGN

3 prospective cohort studies.

SETTING

Nurses' Health Study I and II and Health Professionals Follow-Up Study.

PARTICIPANTS

225 072 men and women with 32 571 deaths observed over a mean of 12.3 years of follow-up.

MEASUREMENTS

Maximum BMI over 16 years of weight history and all-cause and cause-specific mortality.

RESULTS

Maximum BMIs in the overweight (25.0 to 29.9 kg/m2) (multivariate hazard ratio [HR], 1.06 [95% CI, 1.03 to 1.08]), obese I (30.0 to 34.9 kg/m2) (HR, 1.24 [CI, 1.20 to 1.29]), and obese II (≥35.0 kg/m2) (HR, 1.73 [CI, 1.66 to 1.80]) categories were associated with increases in risk for all-cause death. The pattern of excess risk with a maximum BMI above normal weight was maintained across strata defined by smoking status, sex, and age, but the excess was greatest among those younger than 70 years and never-smokers. In contrast, a significant inverse association between overweight and mortality (HR, 0.96 [CI, 0.94 to 0.99]) was observed when BMI was defined using a single baseline measurement. Maximum overweight was also associated with increased cause-specific mortality, including death from cardiovascular disease and coronary heart disease.

LIMITATION

Residual confounding and misclassification.

CONCLUSION

The paradoxical association between overweight and mortality is reversed in analyses incorporating weight history. Maximum BMI may be a useful metric to minimize reverse causation bias associated with a single baseline BMI assessment.

PRIMARY FUNDING SOURCE

National Institutes of Health.

Caregiving for Older Adults with Obesity in the United States

OBJECTIVES

To determine the difference in receipt of activity of daily living (ADL) assistance between obese and normal-weight older adults.

DESIGN

Retrospective cohort study.

SETTING

National Health and Aging Trends Study, 2011-2015.

PARTICIPANTS

U.S. adults aged 65 and older with ADL disability and a body mass index (BMI) of 18.5 kg/m² or greater (N = 5,612) MEASUREMENTS: BMI was classified as normal weight (18.5-24.9 kg/m² ), overweight (25.0-29.9 kg/m² ), or obese (≥30.0 kg/m² ). Primary outcome was self-reported receipt of help with specific ADLs. Models were adjusted for demographic characteristics (age, sex, race), degree of need (self-reported general health, severity of disability), household resources (income, marriage, people in household, number of children), and cognitive status (dementia, proxy respondent).

RESULTS

Obese with disabilities had lower rates of receiving assistance with walking inside (odds ratio (OR) = 0.63, 95% confidence interval (CI) = 0.50-0.81), walking outside (OR = 0.76, 95% CI = 0.59-0.97), toileting (OR = 0.68, 95% CI = 0.52-0.89), and getting in and out of bed (OR = 0.67, 95% CI = 0.50-0.87) than normal-weight older adults after adjustment for respondent demographic characteristics. Level of need and cognitive status partially explained the associations. In fully adjusted models, older adults with obesity still had significantly lower odds of receiving assistance in getting in and out of bed than normal weight adults (OR = 0.69, 95% CI = 0.49-0.98).

CONCLUSION

Older adults with obesity are less likely to receive assistance for ADL disabilities than their normal-weight counterparts-an important concern because of ongoing demographic changes in the United States.

Analysis of the prognostic value of BMI and the difference in its impact according to age and sex in DLBCL patients

Studies that have evaluated the prognostic value of body mass index (BMI) in patients with diffuse large B-cell lymphoma have recently been reported. However, the impact of BMI on survival outcomes remains controversial. We retrospectively analyzed the data of 406 diffuse large B-cell lymphoma patients treated with R-CHOP or R-CHOP-like regimens. The number (%) of patients that were categorized into 1 of 4 groups according to BMI were underweight (<18.5 kg/m² ), 58 (14.3%); normal weight (≥18.5 to <25 kg/m² ), 262 (64.5%); overweight (≥25 to <30 kg/m² ), 75 (18.5%); and obese (≥30.0 kg/m² ), 11 (2.7%). While the prognosis of overweight patients was good, being similar to that of normal weight, underweight, and obese patients had a worse prognosis (5-y overall survival [OS] was 57.9%, 74.3%, 73.4%, and 40.9% for underweight, normal weight, overweight, and obese patients, respectively; P = .004). In multivariate analysis, underweight and obesity were independent prognostic factors for OS compared with normal weight (hazard ratios 2.90 and 5.17, respectively). In elderly female patients (≥70 y), patients with a low BMI (<25 kg/m² ) had significantly inferior OS than those with a high BMI (≥25 kg/m² ) (5-y OS, 61.5% vs 85.7%; P = .039). In contrast, in young female patients (<70 years), patients with a low BMI had significantly better OS than those with a high BMI (5-y OS, 88.6% vs 46.4%; P < .001). In male patients, there were no differences in the effect of BMI on OS between young and elderly patients. In this study, we demonstrated that being underweight and obese were independent prognostic factors compared with being normal weight. In female patients, BMI had a different impact on the prognosis of young and elderly patients, whereas in male patients, there was no difference in the effect of BMI on prognosis according to age.

Body mass index and outcome after revascularization for symptomatic carotid artery stenosis

OBJECTIVE

To determine whether the obesity paradox exists in patients who undergo carotid artery stenting (CAS) or carotid endarterectomy (CEA) for symptomatic carotid artery stenosis.

METHODS

We combined individual patient data from 2 randomized trials (Endarterectomy vs Angioplasty in Patients with Symptomatic Severe Carotid Stenosis and Stent-Protected Angioplasty vs Carotid Endarterectomy) and 3 centers in a third trial (International Carotid Stenting Study). Baseline body mass index (BMI) was available for 1,969 patients and classified into 4 groups: <20, 20-<25, 25-<30, and ≥30 kg/m². Primary outcome was stroke or death, investigated separately for the periprocedural and postprocedural period (≤120 days/>120 days after randomization). This outcome was compared between different BMI strata in CAS and CEA patients separately, and in the total group. We performed intention-to-treat multivariable Cox regression analyses.

RESULTS

Median follow-up was 2.0 years. Stroke or death occurred in 159 patients in the periprocedural (cumulative risk 8.1%) and in 270 patients in the postprocedural period (rate 4.8/100 person-years). BMI did not affect periprocedural risk of stroke or death for patients assigned to CAS (p_trend = 0.39) or CEA (p_trend = 0.77) or for the total group (p_trend = 0.48). Within the total group, patients with BMI 25-<30 had lower postprocedural risk of stroke or death than patients with BMI 20-<25 (BMI 25-<30 vs BMI 20-<25; hazard ratio 0.72; 95% confidence interval 0.55-0.94).

CONCLUSIONS

BMI is not associated with periprocedural risk of stroke or death; however, BMI 25-<30 is associated with lower postprocedural risk than BMI 20-<25. These observations were similar for CAS and CEA.

Lack of Association of the Fat Mass and Obesity Associated (FTO) Gene rs9939609 Polymorphism with Breast Cancer Risk: a Systematic Review and Meta-Analysis Based on Case - Control Studies

Background: Previously published data on any association of the fat mass and obesity-associated (FTO) gene with breast cancer risk remain inconclusive. Therefore, we conducted the present meta-analysis of links between breast cancer and the FTO rs9939609 polymorphism. Methods: We have conducted a systematic review of the English literature by searching PubMed, Google Scholar and ISI Web of Knowledge databases for studies on associations between the FTO rs9939609 polymorphism and breast cancer risk. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to estimate the strength of the association using fixed- or random-effects model. Results: We included five studies with 1134 cases and 1453 controls. Overall, no significant association between the FTO rs9939609 polymorphism and risk of breast cancer was found. On subgroup analysis by ethnicity, there was still no significant association detected. Conclusions: To our knowledge, this is the first meta-analysis of the FTO rs9939609 polymorphism and risk of breast cancer. However, the present meta-analysis suggested that only there might be a significant association of the CXCL12 rs1801157 polymorphisms with breast cancer risk.

Body Mass Index and Mortality

Although the prevalence of obesity, a well-known risk factor for various chronic diseases such as hypertension, type 2 diabetes and dyslipidemia, is rapidly increasing worldwide, the association of obesity with all-cause mortality remains controversial. Many previous epidemiologic studies have demonstrated a U-shaped relationship between obesity and mortality, suggesting that there is an obesity paradox. However, recent large-scale meta-analyses found contradictory results that both overweight and obese subjects exhibited a significant increase in all-cause mortality. This review summarizes the key epidemiologic studies on the association of obesity with mortality and thoroughly examines the causes of the obesity paradox and the precautions needed in the interpretation of this clinical evidence.

Obesity paradox and mortality in adults with and without incident type 2 diabetes: a matched population-level cohort study

OBJECTIVE

Among adults with type 2 diabetes (T2D), several (but not all) studies show that being overweight (body mass index (BMI): 25.0-29.9 kg/m2) or obese I (BMI: 30.0-34.9 kg/m2) near the time of diagnosis, is unexpectedly associated with reduced all-cause mortality compared with normal weight-the obesity paradox. We addressed whether this observation is causal (eg, a true protective effect); due to confounding (including effect modification); or due to selection ('collider') bias.

RESEARCH DESIGN AND METHODS

We performed a matched population-level cohort study using primary care records from Salford, UK (1995-2012) in 10 464 patients with incident T2D paired (1:3) with 31 020 individuals who never developed T2D. We estimated HRs for associations of BMI with all-cause mortality using Cox models, stratified by smoking status.

RESULTS

Median follow-up was 8.7 years. For never smokers, the hazard of all-cause mortality increased from 25 kg/m2, in a linear manner, with increasing BMI in the T2D cohort (HR per 5 kg/m2: 1.23, ptrend<0.001) and in the non-diabetes cohort (HR per 5 kg/m2: 1.34, ptrend<0.001). In contrast, among ever smokers, BMI-mortality relationships were U-shaped in the T2D and non-diabetes cohorts. Evidence of the obesity paradox in ever smokers, with and without T2D, argued against a selection bias, but supported a contribution of effect modification by smoking (pinteraction=0.009). Results were stable to various sensitivity analyses.

CONCLUSIONS

In this cohort, the obesity paradox is mainly explained by smoking as an effect modifier. These findings indicate that the obesity paradox does not challenge standard weight management recommendations among T2D patients.

Risk of all-cause mortality in abdominal obesity phenotypes: Tehran Lipid and Glucose Study

BACKGROUND AND AIM

Long-term health risks in the so-called "healthy obesity" phenotypes remain controversial. Also it is unknown if "metabolically healthy abdominal obese" (MHAO) phenotype is at increased risk of all-cause mortality compared to their non-abdominally obese counterparts. In this study we assessed the risk of all-cause mortality in different abdominal obesity phenotypes.

METHODS AND RESULTS

In this large population-based cohort, 8804 participants (aged ≥ 30 years), from the Tehran Lipid and Glucose Study (TLGS) were enrolled and followed for a median of 12.0 (8.7-12.5) years. Abdominal obesity was defined using national waist circumference (WC) cut-off points of ≥89 cm for men and ≥91 cm for women. Metabolic health was defined as ≤1 components of metabolic syndrome (excluding WC), using the Joint Interim Statement (JIS) definition. Baseline prevalence of MHAO phenotype was 12.8% in the whole population and 23.4% in those with abdominal obesity. A total of 540 all-cause death occurred during the follow-up. After multivariate adjustment, all-cause mortality risk in MHAO phenotype was not significantly increased compared to "metabolically healthy non abdominal obese" (MHNAO) as the reference group (HR: 1.35, CI: 0.89-2.03).

CONCLUSION

Our results indicate that MHAO individuals were not at higher risk for all-cause mortality over a median of 12 years follow-up. However, considering inadequate power of our analysis for fully adjusted model, larger studies with more follow-ups are needed.

Body mass index, abdominal fatness, fat mass and the risk of atrial fibrillation: a systematic review and dose-response meta-analysis of prospective studies

Different adiposity measures have been associated with increased risk of atrial fibrillation, however, results have previously only been summarized for BMI. We therefore conducted a systematic review and meta-analysis of prospective studies to clarify the association between different adiposity measures and risk of atrial fibrillation. PubMed and Embase databases were searched up to October 24th 2016. Summary relative risks (RRs) were calculated using random effects models. Twenty-nine unique prospective studies (32 publications) were included. Twenty-five studies (83,006 cases, 2,405,381 participants) were included in the analysis of BMI and atrial fibrillation. The summary RR was 1.28 (95% confidence interval: 1.20-1.38, I² = 97%) per 5 unit increment in BMI, 1.18 (95% CI: 1.12-1.25, I² = 73%, n = 5) and 1.32 (95% CI: 1.16-1.51, I² = 91%, n = 3) per 10 cm increase in waist and hip circumference, respectively, 1.09 (95% CI: 1.02-1.16, I² = 44%, n = 4) per 0.1 unit increase in waist-to-hip ratio, 1.09 (95% CI: 1.02-1.16, I² = 94%, n = 4) per 5 kg increase in fat mass, 1.10 (95% CI: 0.92-1.33, I² = 90%, n = 3) per 10% increase in fat percentage, 1.10 (95% CI: 1.08-1.13, I² = 74%, n = 10) per 5 kg increase in weight, and 1.08 (95% CI: 0.97-1.19, I² = 86%, n = 2) per 5% increase in weight gain. The association between BMI and atrial fibrillation was nonlinear, p _nonlinearity < 0.0001, with a stronger association at higher BMI levels, however, increased risk was observed even at a BMI of 22-24 compared to 20. In conclusion, general and abdominal adiposity and higher body fat mass increase the risk of atrial fibrillation.

Disability in long-term care residents explained by prevalent geriatric syndromes, not long-term care home characteristics: a cross-sectional study

Background

Self-care disability is dependence on others to conduct activities of daily living, such as bathing, eating and dressing. Among long-term care residents, self-care disability lowers quality of life and increases health care costs. Understanding the correlates of self-care disability in this population is critical to guide clinical care and ongoing research in Geriatrics. This study examines which resident geriatric syndromes and chronic conditions are associated with residents’ self-care disability and whether these relationships vary across strata of age, sex and cognitive status. It also describes the proportion of variance in residents’ self-care disability that is explained by residents’ geriatric syndromes versus long-term care home characteristics.

Methods

We conducted a cross-sectional study using a health administrative cohort of 77,165 long-term care home residents residing in 614 Ontario long-term care homes. Eligible residents had their self-care disability assessed using the RAI-MDS 2.0 activities of daily living long-form score (range: 0–28) within 90 days of April 1st, 2011. Hierarchical multivariable regression models with random effects for long-term care homes were used to estimate the association between self-care disability and resident geriatric syndromes, chronic conditions and long-term care home characteristics. Differences in findings across strata of sex, age and cognitive status (cognitively intact versus cognitively impaired) were examined.

Results

Geriatric syndromes were much more strongly associated with self-care disability than chronic conditions in multivariable models. The direction and size of some of these effects were different for cognitively impaired versus cognitively intact residents. Residents’ geriatric syndromes explained 50% of the variation in their self-care disability scores, while characteristics of long-term care homes explained an additional 2% of variation.

Conclusion

Differences in long-term care residents’ self-care disability are largely explained by prevalent geriatric syndromes. After adjusting for resident characteristics, there is little variation in self-care disability associated with long-term care home characteristics. This suggests that residents’ geriatric syndromes—not the homes in which they live—may be the appropriate target of interventions to reduce self-care disability, and that such interventions may need to differ for cognitively impaired versus unimpaired residents.

Electronic supplementary material

The online version of this article (doi:10.1186/s12877-017-0444-1) contains supplementary material, which is available to authorized users.

Body mass index as a predictor of healthy and disease-free life expectancy between ages 50 and 75: a multicohort study

BACKGROUND

While many studies have shown associations between obesity and increased risk of morbidity and mortality, little comparable information is available on how body mass index (BMI) impacts health expectancy. We examined associations of BMI with healthy and chronic disease-free life expectancy in four European cohort studies.

METHODS

Data were drawn from repeated waves of cohort studies in England, Finland, France and Sweden. BMI was categorized into four groups from normal weight (18.5-24.9 kg m^-2) to obesity class II (⩾35 kg m^-2). Health expectancy was estimated with two health indicators: sub-optimal self-rated health and having a chronic disease (cardiovascular disease, cancer, respiratory disease and diabetes). Multistate life table models were used to estimate sex-specific healthy life expectancy and chronic disease-free life expectancy from ages 50 to 75 years for each BMI category.

RESULTS

The proportion of life spent in good perceived health between ages 50 and 75 progressively decreased with increasing BMI from 81% in normal weight men and women to 53% in men and women with class II obesity which corresponds to an average 7-year difference in absolute terms. The proportion of life between ages 50 and 75 years without chronic diseases decreased from 62 and 65% in normal weight men and women and to 29 and 36% in men and women with class II obesity, respectively. This corresponds to an average 9 more years without chronic diseases in normal weight men and 7 more years in normal weight women between ages 50 and 75 years compared to class II obese men and women. No consistent differences were observed between cohorts.

CONCLUSIONS

Excess BMI is associated with substantially shorter healthy and chronic disease-free life expectancy, suggesting that tackling obesity would increase years lived in good health in populations.

Body Mass Index at Accession and Incident Cardiometabolic Risk Factors in US Army Soldiers, 2001-2011

Individuals entering US Army service are generally young and healthy, but many are overweight, which may impact cardiometabolic risk despite physical activity and fitness requirements. This analysis examines the association between Soldiers' BMI at accession and incident cardiometabolic risk factors (CRF) using longitudinal data from 731,014 Soldiers (17.0% female; age: 21.6 [3.9] years; BMI: 24.7 [3.8] kg/m2) who were assessed at Army accession, 2001-2011. CRF were defined as incident diagnoses through 2011, by ICD-9 code, of metabolic syndrome, glucose/insulin disorder, hypertension, dyslipidemia, or overweight/obesity (in those not initially overweight/obese). Multivariable-adjusted proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) between BMI categories at accession and CRF. Initially underweight (BMI<18.5 kg/m2) were 2.4% of Soldiers, 53.5% were normal weight (18.5-<25), 34.2% were overweight (25-<30), and 10.0% were obese (≥30). Mean age range at CRF diagnosis was 24-29 years old, with generally low CRF incidence: 228 with metabolic syndrome, 3,880 with a glucose/insulin disorder, 26,373 with hypertension, and 13,404 with dyslipidemia. Of the Soldiers who were not overweight or obese at accession, 5,361 were eventually diagnosed as overweight or obese. Relative to Soldiers who were normal weight at accession, those who were overweight or obese, respectively, had significantly higher risk of developing each CRF after multivariable adjustment (HR [95% CI]: metabolic syndrome: 4.13 [2.87-5.94], 13.36 [9.00-19.83]; glucose/insulin disorder: 1.39 [1.30-1.50], 2.76 [2.52-3.04]; hypertension: 1.85 [1.80-1.90], 3.31 [3.20-3.42]; dyslipidemia: 1.81 [1.75-1.89], 3.19 [3.04-3.35]). Risk of hypertension, dyslipidemia, and overweight/obesity in initially underweight Soldiers was 40%, 31%, and 79% lower, respectively, versus normal-weight Soldiers. BMI in early adulthood has important implications for cardiometabolic health, even within young, physically active populations.

Association of BMI with risk of CVD mortality and all-cause mortality

OBJECTIVE

To determine the relationship between BMI and risk of CVD mortality and all-cause mortality among Malaysian adults.

DESIGN

Population-based, retrospective cohort study. Participants were followed up for 5 years from 2006 to 2010. Mortality data were obtained via record linkages with the Malaysian National Registration Department. Multiple Cox regression was applied to compare risk of CVD and all-cause mortality between BMI categories adjusting for age, gender and ethnicity. Models were generated for all participants, all participants the first 2 years of follow-up, healthy participants, healthy never smokers, never smokers, current smokers and former smokers.

SETTING

All fourteen states in Malaysia.

SUBJECTS

Malaysian adults (n 32 839) aged 18 years or above from the third National Health and Morbidity Survey.

RESULTS

Total follow-up time was 153 814 person-years with 1035 deaths from all causes and 225 deaths from CVD. Underweight (BMI<18·5 kg/m2) was associated with a significantly increased risk of all-cause mortality, while obesity (BMI ≥30·0 kg/m2) was associated with a heightened risk of CVD mortality. Overweight (BMI=25·0-29·9 kg/m2) was inversely associated with risk of all-cause mortality. Underweight was significantly associated with all-cause mortality in all models except for current smokers. Overweight was inversely associated with all-cause mortality in all participants. Although a positive trend was observed between BMI and CVD mortality in all participants, a significant association was observed only for severe obesity (BMI≥35·0 kg/m2).

CONCLUSIONS

Underweight was associated with increased risk of all-cause mortality and obesity with increased risk of CVD mortality. Therefore, maintaining a normal BMI through leading an active lifestyle and healthy dietary habits should continue to be promoted.

Does combining liraglutide with intragastric balloon insertion improve sustained weight reduction?

BACKGROUND/AIM

Intragastric balloon (IGB) is an effective and safe method of weight reduction. However, IGBs have been associated with a high rate of weight regain post removal. Accordingly, ways to improve sustained weight reduction including concomitant treatment with Glucagon-like peptide 1 (GLP-1) agonists have been proposed. This study aims to evaluate the effect of adding Liraglutide to IGB insertion on sustained weight reduction.

PATIENTS AND METHODS

A retrospective analysis of all cases treated with IGB with or without Liraglutide was performed. Outcomes were statistically compared.

RESULTS

A total of 108 patients were included; 64 were treated with IGB alone and 44 with IGB + Liraglutide. Six months after removing IGB, patients treated with IGB + Liraglutide had a higher mean weight loss post treatment completion (10.2 ± 6.7 vs. 18.5 ± 7.6, P = <0.0001) than those treated with IGB alone. After adjusting for covariates, patients treated with IGB alone demonstrated a higher mean body weight loss at the time of IGB removal (coefficient 7.71, 95% CI = 4.78-10.63), and a higher odds of treatment success 6 months post IGB removal (OR = 5.74, 95% CI = 1.79-188.42). Baseline body mass index appeared to be a significant predictor of mean body weight loss at the time of balloon removal.

CONCLUSIONS

Adding Liraglutide to IGB does not appear to decrease the risk of weight regain 6 months post IGB removal.

Body mass trajectories, diabetes mellitus, and mortality in a large cohort of Austrian adults

There are only few studies on latent trajectories of body mass index (BMI) and their association with diabetes incidence and mortality in adults.We used data of the Vorarlberg Health Monitoring & Prevention Program and included individuals (N=24,875) with BMI measurements over a 12-year period. Trajectory classes were identified using growth mixture modeling for predefined age groups (<50, 50-65, >65 years of age) and men, women separately. Poisson models were applied to estimate incidence and prevalence of diabetes for each trajectory class. Relative all-cause mortality and diabetes-related mortality was estimated using Cox proportional hazard regression.We identified 4 trajectory classes for the age groups <50 years and 50 to 65 years, and 3 for age groups >65 years. For all age groups, a stable BMI trajectory class was the largest, with about 90% of men and 70% to 80% of women. For the low stable BMI classes, the corresponding fasting glucose levels were the lowest. The highest diabetes prevalences were observed for decreasing trajectories. During subsequent follow-up of mean 8.1 (SD 2.0) years, 2741 individuals died. For men <50 years, highest mortality was observed for steady weight gainers. For all other age-sex groups, mortality was the highest for decreasing trajectories.We found considerably heterogeneity in BMI trajectories by sex and age. Stable weight, however, was the largest class over all age and sex groups, and was associated with the lowest diabetes incidence and mortality suggesting that maintaining weight at a moderate level is an important public health goal.

Combined associations of body weight and lifestyle factors with all cause and cause specific mortality in men and women: prospective cohort study

OBJECTIVE

 To evaluate the combined associations of diet, physical activity, moderate alcohol consumption, and smoking with body weight on risk of all cause and cause specific mortality.

DESIGN

 Longitudinal study with up to 32 years of follow-up.

SETTING

 Nurses' Health Study (1980-2012) and Health Professionals Follow-up Study (1986-2012).

PARTICIPANTS

 74 582 women from the Nurses' Health Study and 39 284 men from the Health Professionals Follow-up Study who were free from cardiovascular disease and cancer at baseline.

MAIN OUTCOME MEASURES

 Exposures included body mass index (BMI), score on the alternate healthy eating index, level of physical activity, smoking habits, and alcohol drinking while outcome was mortality (all cause, cardiovascular, cancer). Cox proportional hazard models were used to calculate the adjusted hazard ratios of all cause, cancer, and cardiovascular mortality with their 95% confidence intervals across categories of BMI, with 22.5-24.9 as the reference.

RESULTS

 During up to 32 years of follow-up, there were 30 013 deaths (including 10 808 from cancer and 7189 from cardiovascular disease). In each of the four categories of BMI studied (18.5-22.4, 22.5-24.9, 25-29.9, ≥30), people with one or more healthy lifestyle factors had a significantly lower risk of total, cardiovascular, and cancer mortality than individuals with no low risk lifestyle factors. A combination of at least three low risk lifestyle factors and BMI between 18.5-22.4 was associated with the lowest risk of all cause (hazard ratio 0.39, 95% confidence interval 0.35 to 0.43), cancer (0.40, 0.34 to 0.47), and cardiovascular (0.37, 0.29 to 0.46) mortality, compared with those with BMI between 22.5-24.9 and none of the four low risk lifestyle factors.

CONCLUSION

 Although people with a higher BMI can have lower risk of premature mortality if they also have at least one low risk lifestyle factor, the lowest risk of premature mortality is in people in the 18.5-22.4 BMI range with high score on the alternate healthy eating index, high level of physical activity, moderate alcohol drinking, and who do not smoke. It is important to consider diet and lifestyle factors in the evaluation of the association between BMI and mortality.

Validating a summary measure of weight history for modeling the health consequences of obesity

PURPOSE

Data on weight history may enhance the predictive validity of epidemiologic models of the health risks of obesity, but collecting such data is often not feasible. In this study, we investigate the validity of a summary measure of weight history.

METHODS

We evaluated the quality of reporting of maximum weight in a sample of adults aged 50-84 years using data from the Health and Retirement Study. Recalled max body mass index (BMI, measured in kilogram per square meter) based on recalled weight in 2004 was compared with calculated max BMI based on self-reported weight collected biennially between 1992 and 2004. Logistic regression was used to assess similarity between the measures in predicting prevalent conditions.

RESULTS

The correlation coefficient between recalled and calculated max weight in the overall sample was 0.95. Recalled max BMI value was within three BMI units of the calculated value 91.4% of the time. The proportions of individuals with obese I (BMI: 30.0-34.9), obese II (BMI: 35.0-39.9), and obese III (BMI: 40.0 and above) were 28.8%, 12.7%, and 6.6% using recalled values compared with 27.1%, 10.5%, and 4.9% using calculated values. In multivariate analyses, the two BMI measures similarly predicted disease prevalence across a number of chronic conditions.

CONCLUSIONS

Recalled max BMI was strongly correlated with max BMI calculated over the 12-year period before recall, suggesting that this measure can serve as a reliable summary measure of recent weight status.

Body-mass index and all-cause mortality: individual-participant-data meta-analysis of 239 prospective studies in four continents

BACKGROUND

Overweight and obesity are increasing worldwide. To help assess their relevance to mortality in different populations we conducted individual-participant data meta-analyses of prospective studies of body-mass index (BMI), limiting confounding and reverse causality by restricting analyses to never-smokers and excluding pre-existing disease and the first 5 years of follow-up.

METHODS

Of 10 625 411 participants in Asia, Australia and New Zealand, Europe, and North America from 239 prospective studies (median follow-up 13·7 years, IQR 11·4-14·7), 3 951 455 people in 189 studies were never-smokers without chronic diseases at recruitment who survived 5 years, of whom 385 879 died. The primary analyses are of these deaths, and study, age, and sex adjusted hazard ratios (HRs), relative to BMI 22·5-<25·0 kg/m(2).

FINDINGS

All-cause mortality was minimal at 20·0-25·0 kg/m(2) (HR 1·00, 95% CI 0·98-1·02 for BMI 20·0-<22·5 kg/m(2); 1·00, 0·99-1·01 for BMI 22·5-<25·0 kg/m(2)), and increased significantly both just below this range (1·13, 1·09-1·17 for BMI 18·5-<20·0 kg/m(2); 1·51, 1·43-1·59 for BMI 15·0-<18·5) and throughout the overweight range (1·07, 1·07-1·08 for BMI 25·0-<27·5 kg/m(2); 1·20, 1·18-1·22 for BMI 27·5-<30·0 kg/m(2)). The HR for obesity grade 1 (BMI 30·0-<35·0 kg/m(2)) was 1·45, 95% CI 1·41-1·48; the HR for obesity grade 2 (35·0-<40·0 kg/m(2)) was 1·94, 1·87-2·01; and the HR for obesity grade 3 (40·0-<60·0 kg/m(2)) was 2·76, 2·60-2·92. For BMI over 25·0 kg/m(2), mortality increased approximately log-linearly with BMI; the HR per 5 kg/m(2) units higher BMI was 1·39 (1·34-1·43) in Europe, 1·29 (1·26-1·32) in North America, 1·39 (1·34-1·44) in east Asia, and 1·31 (1·27-1·35) in Australia and New Zealand. This HR per 5 kg/m(2) units higher BMI (for BMI over 25 kg/m(2)) was greater in younger than older people (1·52, 95% CI 1·47-1·56, for BMI measured at 35-49 years vs 1·21, 1·17-1·25, for BMI measured at 70-89 years; pheterogeneity<0·0001), greater in men than women (1·51, 1·46-1·56, vs 1·30, 1·26-1·33; pheterogeneity<0·0001), but similar in studies with self-reported and measured BMI.

INTERPRETATION

The associations of both overweight and obesity with higher all-cause mortality were broadly consistent in four continents. This finding supports strategies to combat the entire spectrum of excess adiposity in many populations.

FUNDING

UK Medical Research Council, British Heart Foundation, National Institute for Health Research, US National Institutes of Health.