Past body mass index and risk of mortality among women

Behavioral Lifestyles and Survival: A Meta-Analysis

The aim of the study is to determine the association between Behavioral Lifestyles (regular physical activity, healthy diet, sleeping, and weight control) and longevity in the elderly. A search strategy was conducted in the PsycInfo, Medline, PubMed, Web of Science (WoS), and Scopus databases. The primary outcome was mortality/survival. Four variables (mean of participant's age at the baseline of the study, follow-up years of the study, gender, and year of publication) were analyzed to evaluate the role of potential moderators. Ninety-three articles, totaling more than 2,800,000 people, were included in the meta-analysis. We found that the lifestyles analyzed predict greater survival. Specifically, doing regular physical activity, engaging in leisure activities, sleeping 7-8 h a day, and staying outside the BMI ranges considered as underweight or obesity are habits that each separately has a greater probability associated with survival after a period of several years.

Underweight rather than adiposity is an important predictor of death in rural Chinese adults: a cohort study

BACKGROUND

To assess the associations of body mass index (BMI) with all-cause and cause-specific mortalities among rural Chinese.

METHODS

A prospective study of 28 895 individuals was conducted from 2006 to 2014 in rural Deqing, China. Height and weight were measured. The association of BMI with mortality was assessed by using Cox proportional hazards model and restricted cubic spline regression.

RESULTS

There were a total of 2062 deaths during an average follow-up of 7 years. As compared with those with BMI of 22.0-24.9 kg/m², an increased risk of all-cause mortality was found for both underweight men (BMI <18.5 kg/m²) (adjusted HR (aHR): 1.45, 95% CI: 1.18 to 1.79) and low normal weight men (BMI of 18.5-21.9 kg/m²) (aHR: 1.20, 95% CI: 1.03 to 1.38). A J-shaped association was observed between BMI and all-cause mortality in men. Underweight also had an increased risk of cardiovascular disease and cancer mortalities in men. The association of underweight with all-cause mortality was more pronounced in ever smokers and older men (60+ years). The results remained after excluding participants who were followed up less than 1 year.

CONCLUSION

The present study suggests that underweight is an important predictor of mortality, especially for elderly men in the rural community of China.

Association between obesity and sickness in the past two weeks among middle-aged and elderly women: A cross-sectional study in Southern China

OBJECTIVES

Sickness situation in the past two weeks, an indicator of health service needs, is an increasing major health concern. However, data on the relationship between obesity and two-week morbidity in the female population, particularly in middle-aged and elderly women, is sparse. The present study aimed to examine the association between obesity and two-week morbidity among middle-aged and elderly women in Southern China, and to explore the independent contributions of socio-demographic variables, health-related factors, and obesity to two-week morbidity.

METHODS

In total, 2364 middle-aged and elderly women were included in this cross-sectional, community-based survey. Obesity was assessed using body mass index (BMI). The outcome variable was sickness situation over the past two weeks (two-week morbidity). Clustered logistic regression was applied to analyze the independent contribution of obesity to two-week morbidity.

RESULTS

Approximately 14.6% of participants experienced sickness in the past two weeks. Obesity (odds ratio [OR] = 1.47, 95% confidence interval [CI] = 1.02-2.12) was significantly associated with two-week morbidity and its independent contribution accounted for 3.7%, lower than that of socio-demographic variables (73.7%) and health-related factors(22.6%).

CONCLUSIONS

Some degree of correlation was observed between obesity and two-week morbidity among middle-aged and elderly women in Southern China, which can be used as a reference for health-related decision-making.

The use and interpretation of anthropometric measures in cancer epidemiology: A perspective from the world cancer research fund international continuous update project

Anthropometric measures relating to body size, weight and composition are increasingly being associated with cancer risk and progression. Whilst practical in epidemiologic research, where population-level associations with disease are revealed, it is important to be aware that such measures are imperfect markers of the internal physiological processes that are the actual correlates of cancer development. Body mass index (BMI), the most commonly used marker for adiposity, may mask differences between lean and adipose tissue, or fat distribution, which varies across individuals, ethnicities, and stage in the lifespan. Other measures, such as weight gain in adulthood, waist circumference and waist-to-hip ratio, contribute information on adipose tissue distribution and insulin sensitivity. Single anthropometric measures do not capture maturational events, including the presence of critical windows of susceptibility (i.e., age of menarche and menopause), which presents a challenge in epidemiologic work. Integration of experimental research on underlying dynamic genetic, hormonal, and other non-nutritional mechanisms is necessary for a confident conclusion of the overall evidence in cancer development and progression. This article discusses the challenges confronted in evaluating and interpreting the current evidence linking anthropometric factors and cancer risk as a basis for issuing recommendations for cancer prevention.

The future of the Roux-en-Y gastric bypass

Archaic surgical procedures such as the jejunoileal bypass, vertical banded gastroplasty and duodenal switch have contributed to the current best practice of Roux-en-Y gastric bypass (RYGB) procedure for the treatment of obesity and its consequences. Despite this, RYGB has been blighted with late occurring adverse events such as severe malnutrition, marginal ulcer and reactive hypoglycemia. Despite this, RYGB has given us an opportunity to examine the effect of surgery on gut hormones and the impact on metabolic syndrome which in turn has allowed us to carry out a lower impact but equally, if not more effective, procedure - the vertical sleeve gastrectomy (VSG). We examine the benefits of sleeve gastrectomy from the less challenging technical aspect to the effect on obesity and its metabolic syndrome long-term and have concluded that sleeve gastrectomy is possibly the next current best practice.

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

OBJECTIVE

To conduct a systematic review and meta-analysis of cohort studies of body mass index (BMI) and the risk of all cause mortality, and to clarify the shape and the nadir of the dose-response curve, and the influence on the results of confounding from smoking, weight loss associated with disease, and preclinical disease.

DATA SOURCES

PubMed and Embase databases searched up to 23 September 2015.

STUDY SELECTION

Cohort studies that reported adjusted risk estimates for at least three categories of BMI in relation to all cause mortality.

DATA SYNTHESIS

Summary relative risks were calculated with random effects models. Non-linear associations were explored with fractional polynomial models.

RESULTS

230 cohort studies (207 publications) were included. The analysis of never smokers included 53 cohort studies (44 risk estimates) with >738 144 deaths and >9 976 077 participants. The analysis of all participants included 228 cohort studies (198 risk estimates) with >3 744 722 deaths among 30 233 329 participants. The summary relative risk for a 5 unit increment in BMI was 1.18 (95% confidence interval 1.15 to 1.21; I(2)=95%, n=44) among never smokers, 1.21 (1.18 to 1.25; I(2)=93%, n=25) among healthy never smokers, 1.27 (1.21 to 1.33; I(2)=89%, n=11) among healthy never smokers with exclusion of early follow-up, and 1.05 (1.04 to 1.07; I(2)=97%, n=198) among all participants. There was a J shaped dose-response relation in never smokers (Pnon-linearity <0.001), and the lowest risk was observed at BMI 23-24 in never smokers, 22-23 in healthy never smokers, and 20-22 in studies of never smokers with ≥20 years' follow-up. In contrast there was a U shaped association between BMI and mortality in analyses with a greater potential for bias including all participants, current, former, or ever smokers, and in studies with a short duration of follow-up (<5 years or <10 years), or with moderate study quality scores.

CONCLUSION

Overweight and obesity is associated with increased risk of all cause mortality and the nadir of the curve was observed at BMI 23-24 among never smokers, 22-23 among healthy never smokers, and 20-22 with longer durations of follow-up. The increased risk of mortality observed in underweight people could at least partly be caused by residual confounding from prediagnostic disease. Lack of exclusion of ever smokers, people with prevalent and preclinical disease, and early follow-up could bias the results towards a more U shaped association.

Central adiposity, obesity during early adulthood, and pancreatic cancer mortality in a pooled analysis of cohort studies

BACKGROUND

Body mass index (BMI), a measure of obesity typically assessed in middle age or later, is known to be positively associated with pancreatic cancer. However, little evidence exists regarding the influence of central adiposity, a high BMI during early adulthood, and weight gain after early adulthood on pancreatic cancer risk.

DESIGN

We conducted a pooled analysis of individual-level data from 20 prospective cohort studies in the National Cancer Institute BMI and Mortality Cohort Consortium to examine the association of pancreatic cancer mortality with measures of central adiposity (e.g. waist circumference; n = 647 478; 1947 pancreatic cancer deaths), BMI during early adulthood (ages 18-21 years) and BMI change between early adulthood and cohort enrollment, mostly in middle age or later (n = 1 096 492; 3223 pancreatic cancer deaths). Multivariable hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using Cox proportional hazards regression models.

RESULTS

Higher waist-to-hip ratio (HR = 1.09, 95% CI 1.02-1.17 per 0.1 increment) and waist circumference (HR = 1.07, 95% CI 1.00-1.14 per 10 cm) were associated with increased risk of pancreatic cancer mortality, even when adjusted for BMI at baseline. BMI during early adulthood was associated with increased pancreatic cancer mortality (HR = 1.18, 95% CI 1.11-1.25 per 5 kg/m(2)), with increased risk observed in both overweight and obese individuals (compared with BMI of 21.0 to <23 kg/m(2), HR = 1.36, 95% CI 1.20-1.55 for BMI 25.0 < 27.5 kg/m(2), HR = 1.48, 95% CI 1.20-1.84 for BMI 27.5 to <30 kg/m(2), HR = 1.43, 95% CI 1.11-1.85 for BMI ≥30 kg/m(2)). BMI gain after early adulthood, adjusted for early adult BMI, was less strongly associated with pancreatic cancer mortality (HR = 1.05, 95% CI 1.01-1.10 per 5 kg/m(2)).

CONCLUSIONS

Our results support an association between pancreatic cancer mortality and central obesity, independent of BMI, and also suggest that being overweight or obese during early adulthood may be important in influencing pancreatic cancer mortality risk later in life.

Underweight and mortality

OBJECTIVE

According to most prospective studies, being underweight (BMI<18·5 kg/m2) is associated with significantly higher mortality than being of normal weight, especially among smokers. We aimed to explore in a generally lean population whether being underweight is significantly associated with increased all-cause mortality.

DESIGN

Prospective cohort study.

SETTING

Korea Medical Insurance Corporation study with 14 years of follow-up.

SUBJECTS

After excluding deaths within the first 5 years of follow-up (1993-1997) to minimize reverse causation and excluding participants without information about smoking and health status, 94 133 men and 48 496 women aged 35-59 years in 1990 were included.

RESULTS

We documented 5411 (5·7 %) deaths in men and 762 (1·6 %) in women. Among never smokers, hazard ratios (HR) for underweight individuals were not significantly higher than those for normal-weight individuals (BMI=18·5-22·9 kg/m2): HR=0·87 (95 % CI 0·41, 1·84, P=0·72) for underweight men and HR=1·12 (95 % CI 0·76, 1·65, P=0·58) for underweight women. Among ex-smokers, HR=0·86 (95 % CI 0·38, 1·93, P=0·72) for underweight men and HR=3·77 (95 % CI 0·42, 32·29, P=0·24) for underweight women. Among current smokers, HR=1·60 (95 % CI 1·28, 2·01, P<0·001) for underweight men and HR=2·07 (95 % CI 0·43, 9·94, P=0·36) for underweight women.

CONCLUSIONS

The present study does not support that being underweight per se is associated with increased all-cause mortality in Korean men and women.

Lifetime direct medical costs of childhood obesity

BACKGROUND AND OBJECTIVES

An estimate of the lifetime medical costs of an obese child provides a benchmark of the potential per capita savings that could accrue from successful childhood obesity prevention efforts. We reviewed the literature to identify the best current estimate of the incremental lifetime per capita medical cost of an obese child in the United States today relative to a normal weight child.

METHODS

We searched PubMed and Web of Science for US-based studies published within the 15 years preceding May 2013 from which lifetime medical cost estimates can be extracted or imputed. Two reviewers independently screened search results and extracted data from eligible articles. All estimates were inflated to 2012 dollars and discounted to reflect costs from the perspective of a 10-year-old child today.

RESULTS

We identified 6 studies. The incremental lifetime direct medical cost from the perspective of a 10-year-old obese child relative to a 10-year-old normal weight child ranges from $12 660 to $19 630 when weight gain through adulthood among normal weight children is accounted for and from $16 310 to $39 080 when this adjustment is not made.

CONCLUSIONS

We recommend use of an estimate of $19 000 as the incremental lifetime medical cost of an obese child relative to a normal weight child who maintains normal weight throughout adulthood. The alternative estimate, which considers the reality of eventual weight gain among normal weight youth, is $12 660. Additional research is needed to include estimates of indirect costs of childhood obesity.

BMI and all-cause mortality in older adults: a meta-analysis

BACKGROUND

Whether the association between body mass index (BMI) and all-cause mortality for older adults is the same as for younger adults is unclear.

OBJECTIVE

The objective was to determine the association between BMI and all-cause mortality risk in adults ≥65 y of age.

DESIGN

A 2-stage random-effects meta-analysis was performed of studies published from 1990 to 2013 that reported the RRs of all-cause mortality for community-based adults aged ≥65 y.

RESULTS

Thirty-two studies met the inclusion criteria; these studies included 197,940 individuals with an average follow-up of 12 y. With the use of a BMI (in kg/m2) of 23.0-23.9 as the reference, there was a 12% greater risk of mortality for a BMI range of 21.0-21.9 and a 19% greater risk for a range of 20.0-20.9 [BMI of 21.0-21.9; HR (95% CI): 1.12 (1.10, 1.13); BMI of 20.0-20.9; HR (95% CI): 1.19 (1.17, 1.22)]. Mortality risk began to increase for BMI >33.0 [BMI of 33.0-33.9; HR (95% CI): 1.08 (1.00, 1.15)]. Self-reported anthropometric measurements, adjustment for intermediary factors, and exclusion of early deaths or preexisting disease did not markedly alter the associations, although there was a slight attenuation of the association in never-smokers.

CONCLUSIONS

For older populations, being overweight was not found to be associated with an increased risk of mortality; however, there was an increased risk for those at the lower end of the recommended BMI range for adults. Because the risk of mortality increased in older people with a BMI <23.0, it would seem appropriate to monitor weight status in this group to address any modifiable causes of weight loss promptly with due consideration of individual comorbidities.

Age-dependent decline of association between obesity and mortality: a systematic review and meta-analysis

OBJECTIVE

It is debatable if the strength of obesity-mortality association depends on age. The objective of this study was to investigate the influence of age on the obesity-mortality association in men and women, and to assess if adjusting for major confounding factors altered the age-dependent trend of the obesity-mortality association.

DESIGN AND METHODS

Articles were identified by searches of PubMed through 15 August 2013. Twenty studies which reported two or more age-specific effect estimates were identified. A random-effect approach was applied to estimate pooled effect sizes for different age groups.

RESULTS

There was a significant heterogeneity among studies within each age group in the effect estimates for the association between obesity and mortality. The pooled hazard ratio estimates decreased with increasing age from 1.59 (95% confidence interval, 1.46-1.72) for men and 1.60 (1.49-1.72) for women under 35 years to 1.11 (1.08-1.15) for men and 1.11 (1.09-1.14) for women 75 years or older. On average, the effect estimate was decreased by about 10% with every 10 years increase in age.

CONCLUSIONS

Adjusting for known confounding factors of smoking, pre-existing illness, hypertension and diabetes has little impact on the age-dependent decline trend of the obesity-mortality association. Therefore, the strength of the association between obesity and mortality weakens with increasing age.

Body mass index and risk of death in Asian Americans

OBJECTIVES

We investigated the association between body mass index (BMI) and mortality among Asian Americans.

METHODS

We pooled data from prospective cohort studies with 20 672 Asian American adults with no baseline cancer or heart disease history. We estimated hazard ratios and 95% confidence intervals (CIs) with Cox proportional hazards models.

RESULTS

A high, but not low, BMI was associated with increased risk of total mortality among individuals aged 35 to 69 years. The BMI was not related to total mortality among individuals aged 70 years and older. With a BMI 22.5 to < 25 as the reference category among never-smokers aged 35 to 69 years, the hazard ratios for total mortality were 0.83 (95% CI = 0.47, 1.47) for BMI 15 to < 18.5; 0.91 (95% CI = 0.62, 1.32) for BMI 18.5 to < 20; 1.08 (95% CI = 0.86, 1.36) for BMI 20 to < 22.5; 1.14 (95% CI = 0.90, 1.44) for BMI 25 to < 27.5; 1.13 (95% CI = 0.79, 1.62) for BMI 27.5 to < 30; 1.82 (95% CI = 1.25, 2.64) for BMI 30 to < 35; and 2.09 (95% CI = 1.06, 4.11) for BMI 35 to 50. Higher BMI was also related to increased cardiovascular disease and cancer mortality.

CONCLUSIONS

High BMI is associated with increased mortality risk among Asian Americans.

A pooled analysis of waist circumference and mortality in 650,000 adults

OBJECTIVES

To assess the independent effect of waist circumference on mortality across the entire body mass index (BMI) range and to estimate the loss in life expectancy related to a higher waist circumference.

PATIENTS AND METHODS

We pooled data from 11 prospective cohort studies with 650,386 white adults aged 20 to 83 years and enrolled from January 1, 1986, through December 31, 2000. We used proportional hazards regression to estimate hazard ratios (HRs) and 95% CIs for the association of waist circumference with mortality.

RESULTS

During a median follow-up of 9 years (maximum, 21 years), 78,268 participants died. After accounting for age, study, BMI, smoking status, alcohol consumption, and physical activity, a strong positive linear association of waist circumference with all-cause mortality was observed for men (HR, 1.52 for waist circumferences of ≥110 vs <90 cm; 95% CI, 1.45-1.59; HR, 1.07 per 5-cm increment in waist circumference; 95% CI, 1.06-1.08) and women (HR, 1.80 for waist circumferences of ≥95 vs <70 cm; 95% CI, 1.70-1.89; HR, 1.09 per 5-cm increment in waist circumference; 95% CI, 1.08-1.09). The estimated decrease in life expectancy for highest vs lowest waist circumference was approximately 3 years for men and approximately 5 years for women. The HR per 5-cm increment in waist circumference was similar for both sexes at all BMI levels from 20 to 50 kg/m(2), but it was higher at younger ages, higher for longer follow-up, and lower among male current smokers. The associations were stronger for heart and respiratory disease mortality than for cancer.

CONCLUSIONS

In white adults, higher waist circumference was positively associated with higher mortality at all levels of BMI from 20 to 50 kg/m(2). Waist circumference should be assessed in combination with BMI, even for those in the normal BMI range, as part of risk assessment for obesity-related premature mortality.

Body mass index, weight change, and survival in non-Hodgkin lymphoma patients in Connecticut women

Evidence is emerging that obesiy and weight gain may affect the prognosis of several types of cancer. We investigated the impact of body mass index (BMI) as well as pre-and postdiagnosis weight changes on non-Hodgkin lymphoma (NHL) prognosis. A cohort of 573 female incident NHL cases diagnosed during 1996-2000 in Connecticut was followed for a median of 7.8 yr. Self-reported height and weight at 3 time points before and after diagnosis were collected. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated using proportional hazard models adjusting for factors believed to be associated with overall survival of NHL. Underweight (BMI < 18.5; HR = 2.84; 95% CI = 1.12-7.15) before diagnosis was associated with poorer survival compared to being normal weight (18.5 ≤ BMI < 25). Prediagnosis weight loss (HR = 1.42; 95% CI = 1.02-1.97) and posttreatment weight loss (HR = 1.98; 95% CI = 1.14-3.45) and weight gain (HR = 1.85; 95% CI = 1.04-3.32) were associated with poorer survival. NHL patients who were underweight, lost weight prediagnosis, or change weight after treatment were found to have a poorer survival.

Body mass index and mortality in an ethnically diverse population: the Multiethnic Cohort Study

Body mass index (BMI) has been strongly related to overall mortality, but the consistency of this association across diverse ethnic groups and the effects of early adult BMI versus BMI in later adulthood have not been adequately studied. A prospective analysis was performed using data from 183,211 adults aged 45-75 who enrolled the population-based Multiethnic Cohort Study by completing a questionnaire that included self-reported weight and height information in 1993-1996. Participants were African Americans, Native Hawaiians, Japanese Americans, Latinos, and whites living in Hawaii and California. During an average 12.5 years of follow-up, 35,664 deaths were identified. To control for confounding caused by conditions that lead to weight loss and mortality, we excluded participants with a history of cancer or heart disease, who ever smoked, and who died within the first 3 years of follow-up. An increased risk of mortality was observed in participants with a BMI ≥ 27.5 in both men and women compared with the reference category of BMI 23.0-24.9; a BMI ≥ 35.0 carried a greater risk of mortality in men than in women. Although the findings were generally similar across ethnic groups, the association of higher BMI with mortality in Latino men appeared to be weaker than in the other groups. A BMI of 25.0-34.9 at age 21 showed a stronger positive association, with no further increase in risk for a BMI ≥ 35.0, than did BMI in later adulthood. These results indicate that the association of BMI with mortality is generally consistent across sex and ethnic groups, with some variation in the strength of the effect. Most notably, the effect of overweight in young adulthood appears to be much stronger than that of overweight in later adulthood on mortality in later life. This emphasizes the importance of weight management in childhood and adolescence.

Association between smoking and risk of bladder cancer among men and women

CONTEXT

Previous studies indicate that the population attributable risk (PAR) of bladder cancer for tobacco smoking is 50% to 65% in men and 20% to 30% in women and that current cigarette smoking triples bladder cancer risk relative to never smoking. During the last 30 years, incidence rates have remained stable in the United States in men (123.8 per 100,000 person-years to 142.2 per 100,000 person-years) and women (32.5 per 100,000 person-years to 33.2 per 100,000 person-years); however, changing smoking prevalence and cigarette composition warrant revisiting risk estimates for smoking and bladder cancer.

OBJECTIVE

To evaluate the association between tobacco smoking and bladder cancer.

DESIGN, SETTING, AND PARTICIPANTS

Men (n = 281,394) and women (n = 186,134) of the National Institutes of Health-AARP (NIH-AARP) Diet and Health Study cohort completed a lifestyle questionnaire and were followed up between October 25, 1995, and December 31, 2006. Previous prospective cohort studies of smoking and incident bladder cancer were identified by systematic review and relative risks were estimated from fixed-effects models with heterogeneity assessed by the I(2) statistic.

MAIN OUTCOME MEASURES

Hazard ratios (HRs), PARs, and number needed to harm (NNH).

RESULTS

During 4,518,941 person-years of follow-up, incident bladder cancer occurred in 3896 men (144.0 per 100,000 person-years) and 627 women (34.5 per 100,000 person-years). Former smokers (119.8 per 100,000 person-years; HR, 2.22; 95% confidence interval [CI], 2.03-2.44; NNH, 1250) and current smokers (177.3 per 100,000 person-years; HR, 4.06; 95% CI, 3.66-4.50; NNH, 727) had higher risks of bladder cancer than never smokers (39.8 per 100,000 person-years). In contrast, the summary risk estimate for current smoking in 7 previous studies (initiated between 1963 and 1987) was 2.94 (95% CI, 2.45-3.54; I(2) = 0.0%). The PAR for ever smoking in our study was 0.50 (95% CI, 0.45-0.54) in men and 0.52 (95% CI, 0.45-0.59) in women.

CONCLUSION

Compared with a pooled estimate of US data from cohorts initiated between 1963 and 1987, relative risks for smoking in the more recent NIH-AARP Diet and Health Study cohort were higher, with PARs for women comparable with those for men.

Body-mass index and mortality among 1.46 million white adults

BACKGROUND

A high body-mass index (BMI, the weight in kilograms divided by the square of the height in meters) is associated with increased mortality from cardiovascular disease and certain cancers, but the precise relationship between BMI and all-cause mortality remains uncertain.

METHODS

We used Cox regression to estimate hazard ratios and 95% confidence intervals for an association between BMI and all-cause mortality, adjusting for age, study, physical activity, alcohol consumption, education, and marital status in pooled data from 19 prospective studies encompassing 1.46 million white adults, 19 to 84 years of age (median, 58).

RESULTS

The median baseline BMI was 26.2. During a median follow-up period of 10 years (range, 5 to 28), 160,087 deaths were identified. Among healthy participants who never smoked, there was a J-shaped relationship between BMI and all-cause mortality. With a BMI of 22.5 to 24.9 as the reference category, hazard ratios among women were 1.47 (95 percent confidence interval [CI], 1.33 to 1.62) for a BMI of 15.0 to 18.4; 1.14 (95% CI, 1.07 to 1.22) for a BMI of 18.5 to 19.9; 1.00 (95% CI, 0.96 to 1.04) for a BMI of 20.0 to 22.4; 1.13 (95% CI, 1.09 to 1.17) for a BMI of 25.0 to 29.9; 1.44 (95% CI, 1.38 to 1.50) for a BMI of 30.0 to 34.9; 1.88 (95% CI, 1.77 to 2.00) for a BMI of 35.0 to 39.9; and 2.51 (95% CI, 2.30 to 2.73) for a BMI of 40.0 to 49.9. In general, the hazard ratios for the men were similar. Hazard ratios for a BMI below 20.0 were attenuated with longer-term follow-up.

CONCLUSIONS

In white adults, overweight and obesity (and possibly underweight) are associated with increased all-cause mortality. All-cause mortality is generally lowest with a BMI of 20.0 to 24.9.

Relationships of dietary patterns with body composition in older adults differ by gender and PPAR-γ Pro12Ala genotype

Purpose

Dietary patterns may better capture the multifaceted effects of diet on body composition than individual nutrients or foods. The objective of this study was to investigate the dietary patterns of a cohort of older adults, and examine relationships of dietary patterns with body composition. The influence of a polymorphism in the peroxisome proliferator-activated receptor-γ (PPAR-γ) gene was considered.

Methods

The Health, Aging and Body Composition (Health ABC) Study is a prospective cohort study of 3,075 older adults. Participants’ body composition and genetic variation were measured in detail. Food intake was assessed with a semi-quantitative food frequency questionnaire (Block Dietary Data Systems, Berkeley, CA), and dietary patterns of 1,809 participants with complete data were derived by cluster analysis.

Results

Six clusters were identified, including a ‘Healthy foods’ cluster characterized by higher intake of low-fat dairy products, fruit, whole grains, poultry, fish and vegetables. An interaction was found between dietary patterns and PPAR-γ Pro12Ala genotype in relation to body composition. While Pro/Pro homozygous men and women in the ‘Healthy foods’ cluster did not differ significantly in body composition from those in other clusters, men with the Ala allele in the ‘Healthy foods’ cluster had significantly lower levels of adiposity than those in other clusters. Women with the Ala allele in the ‘Healthy foods’ cluster differed only in right thigh intermuscular fat from those in other clusters.

Conclusions

Relationships between diet and body composition in older adults may differ by gender and by genetic factors such as PPAR-γ Pro12Ala genotype.

Individual and aggregate years-of-life-lost associated with overweight and obesity

This study presents nationally representative estimates of individual and aggregate years-of-life-lost (YLLs) associated with overweight and three categories of obesity separately by age, race, smoking status, and gender strata. Using proportional hazards analysis and data from the National Health Interview Survey (NHIS) Linked Mortality Files, we estimated life expectancies for each BMI strata and quantified YLLs by comparing differences between each strata and the normal BMI reference group. Our results provide further evidence that overweight and mild obesity are not associated with a reduction in life expectancy. However, higher BMI categories are associated with lower expected survival. In aggregate, excess BMI is responsible for approximately 95 million YLLs. White females account for more than two-thirds of the aggregate YLLs. Unless something is done to reduce the rising prevalence of those with BMIs >35, or to mitigate the impact of obesity or its correlates on YLLs, expected life expectancy for US adults may decrease in the future.

Obesity: focus on all-cause mortality and cancer

Excess body weight is a strong determinant as well as modifiable risk factor for all-cause and cancer mortality, and as such carries the potential for primary prevention. Recently published studies greatly enhance our knowledge about the impact of body fat distribution on relative risks specific to cancer type, and among women, there is further evidence for the role of menopausal status in modifying relative risks. However, the magnitude of all-cause as well as cancer mortality related to excess body weight varies between prospective cohort studies and the strength of the association, in particular in the overweight range, is still a matter of debate. The distribution of total body fat, how we measure it, and the ratio of body fat to fat-free mass explains to some degree the inconsistencies in associated disease risks in the literature. Physical activity, a potential confounder, has been shown to lower the risk of many chronic diseases, independently of the degree of adiposity. A review of the literature provides much support for public health messages that advocate the benefit of change to a more active lifestyle regardless of age and level of excess body fat.