Association of body mass index and weight change with all-cause mortality in the elderly

The impact of income on the weight of elderly Americans

This paper estimates the impact of income on the body weight and clinical weight classification of elderly Americans using a natural experiment that led otherwise identical retirees to receive significantly different Social Security payments based on their year of birth. We estimate models of instrumental variables using data from the National Health Interview Surveys and find no significant effect of income on weight. The confidence intervals rule out even moderate effects of income on weight and on the probability of being underweight or obese, especially for men. For example, they indicate that the income elasticity of body mass index is not greater in absolute value than 0.06 for men or 0.14 for women.

Life history context of reproductive aging in a wild primate model

The pace of reproductive aging has been of considerable interest, especially in regard to the long postreproductive period in modern women. Here we use data for both sexes from a 37-year longitudinal study of a wild baboon population to place reproductive aging within a life history context for this species, a primate relative of humans that evolved in the same savannah habitat as humans did. We examine the patterns and pace of reproductive aging, including birth rates and reproductive hormones for both sexes, and compare reproductive aging to age-related changes in several other traits. Reproductive senescence occurs later in baboon females than males. Delayed senescence in females relative to males is also found in several other traits, such as dominance status and body condition, but not in molar wear or glucocorticoid profiles. Survival, health, and well-being are the product of risk factors in morphological, physiological, and behavioral traits that differ in rate of senescence and in dependence on social or ecological conditions; some will be very sensitive to differences in circumstances and others less so.

Prevention of overweight and obesity: how effective is the current public health approach

Obesity is a public health problem that has become epidemic worldwide. Substantial literature has emerged to show that overweight and obesity are major causes of co-morbidities, including type II diabetes, cardiovascular diseases, various cancers and other health problems, which can lead to further morbidity and mortality. The related health care costs are also substantial. Therefore, a public health approach to develop population-based strategies for the prevention of excess weight gain is of great importance. However, public health intervention programs have had limited success in tackling the rising prevalence of obesity. This paper reviews the definition of overweight and obesity and the variations with age and ethnicity; health consequences and factors contributing to the development of obesity; and critically reviews the effectiveness of current public health strategies for risk factor reduction and obesity prevention.

Energy expenditure during weaning from mechanical ventilation: is there any difference between pressure support and T-tube?

BACKGROUND

The objectives of this study were to compare patients' energy expenditure (EE) during pressure support (PS) and T-tube (TT) weaning from mechanical ventilation (MV) through indirect calorimetry (IC) and to crosscheck these findings with the results calculated using Harris-Benedict (HB) equation.

METHODS

This study is a randomized crossover controlled trial. Patients with clinical criteria for weaning from MV were randomized to PS-TT or TT-PS, with EE measurement for 20 minutes in PS and TT through IC. Energy expenditure was estimated through HB equation with and without activity factor. Statistical analysis used the Student t test for paired samples and Pearson correlation coefficient, as well as Bland-Altman method.

RESULTS

Forty patients were included. The mean age and Acute Physiology and Chronic Health Evaluation II score were 56 ± 16 years and 23 ± 8, respectively, with predominance of male patients (70%). Mean EE of patients in TT (1782 ± 375 kcal/d) was 14.4% higher than in PS (1558 ± 304 kcal/d; P < .001). In relation to the EE obtained with the HB equation, the mean (SD) value calculated was 1455 (210) kcal/d, and when considering the activity factor, it was 1609 (236) kcal/d, all of them presenting correlation with the values from IC in PS (r = 0.647) and TT (r = 0.539). However, the limits of agreement between the measured EE and the estimated EE suggest that the HB equation tends to underestimate the EE.

CONCLUSION

Comparison of EE in PS and in TT through IC demonstrated that there is increased EE in the TT mode. The results suggest that the HB equation underestimates the EE of patients in weaning from MV.

Caloric restriction: from soup to nuts

Caloric restriction (CR), reduced protein, methionine, or tryptophan diets; and reduced insulin and/or IGFI intracellular signaling can extend mean and/or maximum lifespan and delay deleterious age-related physiological changes in animals. Mice and flies can shift readily between the control and CR physiological states, even at older ages. Many health benefits are induced by even brief periods of CR in flies, rodents, monkeys, and humans. In humans and nonhuman primates, CR produces most of the physiologic, hematologic, hormonal, and biochemical changes it produces in other animals. In primates, CR provides protection from type 2 diabetes, cardiovascular and cerebral vascular diseases, immunological decline, malignancy, hepatotoxicity, liver fibrosis and failure, sarcopenia, inflammation, and DNA damage. It also enhances muscle mitochondrial biogenesis, affords neuroprotection; and extends mean and maximum lifespan. CR rapidly induces antineoplastic effects in mice. Most claims of lifespan extension in rodents by drugs or nutrients are confounded by CR effects. Transcription factors and co-activators involved in the regulation of mitochondrial biogenesis and energy metabolism, including SirT1, PGC-1alpha, AMPK and TOR may be involved in the lifespan effects of CR. Paradoxically, low body weight in middle aged and elderly humans is associated with increased mortality. Thus, enhancement of human longevity may require pharmaceutical interventions.

Low mid-upper arm circumference, calf circumference, and body mass index and mortality in older persons

Background.

Low body mass index is a general measure of thinness. However, its measurement can be cumbersome in older persons and other simple anthropometric measures may be more strongly associated with mortality. Therefore, associations of low mid-upper arm circumference, calf circumference, and body mass index with mortality were examined in older persons.

Methods.

Data of the Longitudinal Aging Study Amsterdam, a population-based cohort study in the Netherlands, were used. The present study included community-dwelling persons 65 years and older in 1992–1993 (n = 1,667), who were followed until 2007 for their vital status. Associations between anthropometric measures and 15-year mortality were examined by spline regression models and, below the nadir, Cox regression models, transforming all measures to sex-specific Z scores.

Results.

Mortality rates were 599 of 826 (73%) in men and 479 of 841 (57%) in women. Below the nadir, the hazard ratio of mortality per 1 standard deviation lower mid-upper arm circumference was 1.79 (95% confidence interval, 1.48–2.16) in men and 2.26 (1.71–3.00) in women. For calf circumference, the hazard ratio was 1.45 (1.22–1.71) in men and 1.30 (1.15–1.48) in women and for body mass index 1.38 (1.17–1.61) in men and 1.56 (1.10–2.21) in women. Excluding deaths within the first 3 years after baseline did not change these associations. Excluding those with a smoking history, obstructive lung disease, or cancer attenuated the associations of calf circumference (men) and body mass index (women).

Conclusions.

Based on the stronger association with mortality and given a more easy assessment in older persons, mid-upper arm circumference seems a more feasible and valid anthropometric measure of thinness than body mass index in older men and women.

Rapid loss of appendicular skeletal muscle mass is associated with higher all-cause mortality in older men: the prospective MINOS study

BACKGROUND

Changes in body composition underlying the association between weight loss and higher mortality are not clear.

OBJECTIVE

The objective was to investigate the association between changes in body composition of the appendicular (4 limbs) and central (trunk) compartments and all-cause mortality in men.

DESIGN

In men aged > or = 50 y, body composition was assessed every 18 mo for 7.5 y with a whole-body dual-energy X-ray absorptiometry scan. Mortality was assessed for 10 y. Data were analyzed by logistic regression and Cox model and adjusted for age, body mass index (BMI), educational level, lifestyle, physical performance, comorbidities, body composition, and serum concentrations of 17beta-estradiol and 25-hydroxycholecalciferol.

RESULTS

Of 715 men who were followed up, 137 (19.2%) died. Mortality was higher in men with the fastest weight loss [lowest compared with middle tertile odds ratio (OR): 2.31; 99% CI: 1.05, 5.09]. Faster loss of appendicular skeletal muscle mass (ASMM) was predictive of mortality (lowest compared with middle tertile OR: 3.60; 99% CI: 1.64, 7.89). Faster loss in ASMM remained a strong predictor of mortality after adjustment for weight loss (OR: 3.41; 99% CI: 1.51, 7.71). Faster loss in ASMM was the strongest predictor of death in the stepwise procedures when it was analyzed jointly with changes in the mass of other compartments. Loss in ASMM calculated over 36 mo was also a stronger predictor of death than were changes in the mass of other compartments (hazard ratio: 1.33 per 1-SD decrease; 95% CI: 1.06, 1.66).

CONCLUSION

The accelerated loss of ASMM is predictive of all-cause mortality in older men regardless of age, BMI, lifestyle, physical performance, health status, body composition, and serum 17beta-estradiol and 25-hydroxycholecalciferol.

The obesity paradox in the elderly: potential mechanisms and clinical implications

The prevalence of overweight and obesity in the elderly has become a growing concern. Recent evidence indicates that in the elderly, obesity is paradoxically associated with a lower, not higher, mortality risk. Although obesity in the general adult population is associated with higher mortality, this relationship is unclear for persons of advanced age and has lead to great controversy regarding the relationship between obesity and mortality in the elderly, the definition of obesity in the elderly, and the need for its treatment in this population. This article examines the evidence on these controversial issues, explores potential explanations for these findings, discusses the clinical implications, and provides recommendations for further research in this area.

Prevention of overweight and obesity: how effective is the current public health approach

Obesity is a public health problem that has become epidemic worldwide. Substantial literature has emerged to show that overweight and obesity are major causes of co-morbidities, including type II diabetes, cardiovascular diseases, various cancers and other health problems, which can lead to further morbidity and mortality. The related health care costs are also substantial. Therefore, a public health approach to develop population-based strategies for the prevention of excess weight gain is of great importance. However, public health intervention programs have had limited success in tackling the rising prevalence of obesity. This paper reviews the definition of overweight and obesity and the variations with age and ethnicity; health consequences and factors contributing to the development of obesity; and critically reviews the effectiveness of current public health strategies for risk factor reduction and obesity prevention.

Weight change, initial BMI, and mortality among middle- and older-aged adults

BACKGROUND

It is not known how the relationship between weight change and mortality is influenced by initial body mass index (BMI) or the magnitude of weight change.

METHODS

We use the nationally representative Health and Retirement Study (n = 13,104; follow-up 1992-2006) and Cox regression analysis to estimate relative mortality risks for 2-year weight change by initial BMI among 50- to-70-year-old Americans. We defined small weight loss or gain as a change of 1-2.9 BMI units and large weight loss or gain as a change of 3-5 BMI units.

RESULTS

Large and small weight losses were associated with excess mortality for all initial BMI levels below 32 kg/m (eg, hazard ratio [HR] for large weight loss from BMI of 30 = 1.61 [95% confidence interval = 1.31-1.98]; HR for small weight loss from BMI of 30 = 1.19 [1.06-1.28]). Large weight gains were associated with excess mortality only at high BMIs (eg, HR for large weight gain from BMI of 35 = 1.33 [1.00-1.77]). Small weight gains were not associated with excess mortality for any initial BMI level. The weight loss-mortality association was robust to adjustments for health status and to sensitivity analyses considering unobserved confounders.

CONCLUSIONS

Weight loss is associated with excess mortality among normal, overweight, and mildly obese middle- and older-aged adults. The excess risk increases for larger losses and lower initial BMI. These results suggest that the potential benefits of a lower BMI may be offset by the negative effects associated with weight loss. Weight gain may be associated with excess mortality only among obese people with an initial BMI over 35.

Difference of body compositional changes according to the presence of weight cycling in a community-based weight control program

Many obese people who try to control body weight experience weight cycling (WC). The present study evaluated the importance of WC in a community-based obesity intervention program. We analyzed the data of 109 Korean participants (86% women) among 177 subjects who had completed a 12-week intervention program at two public health centers in Korea from April to December, 2007. Completion of a self-administrated questionnaire at baseline was used to obtain anthropometric measurements, and laboratory testing was done before and after the program. Differences in body composition change and obesity-related life style between the two groups were compared with respect to WC and non-weight cycling (NWC). After 12 weeks, both groups showed reductions in weight, waist circumference, and body mass index. The group differences were not significant. However, significant differences were evident for the WC group compared to the NWC group in fat percent mass (WC vs. NWC, -3.49+/-2.31% vs. -4.65+/-2.59%, P=0.01), fat free mass (WC vs. NWC, -0.95+/-1.37 kg vs. -0.38+/-1.05 kg, P=0.01), and total cholesterol (WC vs. NWC, -3.32+/-14.63 vs. -16.54+/-32.39, P=0.005). In conducting a community-based weight control program that predominantly targets women, changes of body composition and total cholesterol may be less effective in weight cyclers than in non-weight cyclers.

Examining the dynamic association of BMI and mortality in the Framingham Heart Study

Based on the 40-year follow-up of the Framingham Heart Study (FHS), we used logistic regression models to demonstrate that different designs of an observational study may lead to different results about the association between BMI and all-cause mortality. We also used dynamic survival models to capture the time-varying relationships between BMI and mortality in FHS. The results consistently show that the association between BMI and mortality is dynamic, especially for men. Our analysis suggests that the dynamic property may explain part of the heterogeneity observed in the literature about the association of BMI and mortality.

Mortality attributable to obesity among middle-aged adults in the United States

Obesity is considered a major cause of premature mortality and a potential threat to the longstanding secular decline in mortality in the United States. We measure relative and attributable risks associated with obesity among middle-aged adults using data from the Health and Retirement Study (1992-2004). Although class II/III obesity (BMI > or = or = 35.0 kg/m2) increases mortality by 40% in females and 62% in males compared with normal BMI (BMI = 18.5-24.9), class I obesity (BMI = 30.0-34.9) and being overweight (BMI = 25.0-29.9) are not associated with excess mortality. With respect to attributable mortality, class II/III obesity (BMI > or = 35.0) is responsible for approximately 4% of deaths among females and 3% of deaths among males. Obesity is often compared with cigarette smoking as a major source of avoidable mortality. Smoking-attributable mortality is much larger in this cohort: about 36% in females and 50% in males. Results are robust to confounding by preexisting diseases, multiple dimensions of socioeconomic status (SES), smoking, and other correlates. These findings challenge the viewpoint that obesity will stem the long-term secular decline in U.S. mortality.

Serum concentrations of 17beta-E2 and 25-hydroxycholecalciferol (25OHD) in relation to all-cause mortality in older men--the MINOS study

OBJECTIVE

To examine the association of serum hormone levels with all-cause mortality in older community-dwelling men.

DESIGN

Single centre cohort study.

SUBJECTS

Men aged 50 and older, insured by Société de Secours Minière de Bourgogne (Montceau les Mines, France). Among 3400 men invited to participate, 782 volunteers had serum hormone measurements and were followed up for 10 years. No exclusion criteria were used.

RESULTS

Nonsurvivors (n = 182) were older, had more comorbidities and lower physical performance. The lowest quartile of 25-hydroxycholecalciferol (25OHD) level predicted mortality [HR = 1.44, 95% confidence interval (CI): 1.03-2.03, P < 0.05] regardless of age, BMI, smoking, physical activity, vitamin D supplementation, and health status; mainly for the first 3 years. The 17beta-E(2) level predicted mortality independent of confounders after the third year (HR = 1.21 per 1 SD increase, 95% CI: 1.09-1.35, P < 0.001). In the fully adjusted models, risk of death increased per quartiles of 17beta-E(2) (trend -P < 0.001) and was higher in the third and the fourth quartiles compared with the lowest quartile (HR = 1.80, 95% CI: 1.09-2.98, P < 0.05 and HR = 2.83, 95% CI: 1.71-4.67, P < 0.001). Concentrations of testosterone and PTH did not predict mortality independent of the model.

CONCLUSIONS

In older men, increased 17beta-E(2) level predicted mortality after 3 years of follow-up. Thus, high 17beta-E(2) level may reflect presence of risk factors precipitating development of diseases. Low 25OHD level predicted mortality more weakly, mainly for the first 3 years of the follow-up, and was strongly influenced by the confounding variables. Thus, low 25OHD level may reflect poor current health status and unhealthy lifestyle.

Increased mortality in the slim elderly: a 42 years follow-up study in a general population

The Bergen Clinical Blood Pressure Study in Norway was used to examine the relationship between body mass index (BMI (kg/m(2))) and total mortality in different age segments. Of 6,811 invited subjects, 5,653 (84%) participated in the study (1965-1971) and 4,520 (66%) died during 182,798 person-years of follow-up (1965-2007). Mean age at baseline was 47.5 years; range 22-75 years. BMI (kg/m(2)) was calculated from standardized measurements of body height and weight and divided into four groups (<22.0, 22.0-24.9, 25.0-27.9, > or =28.0). The 20 years cumulative risk of death related to baseline BMI was U-shaped in the elderly (aged 65-75 years), whereas the pattern was more linear in the youngest age group (20-44 years). In contrast to the younger age groups, the highest mortality in the elderly was in the lower BMI range (<22.0 kg/m(2)) (adjusted Cox proportional Hazard Ratio 1.39, 95% Confidence Interval 1.10, 1.75) compared to the BMI reference group (22.0-24.9 kg/m(2)). This pattern persisted after 72 months of early follow-up exclusion and it was robust to adjustments for a wide range of possible confounders including gender, history of cardiovascular disease, respiratory disease or hypertension, smoking habits, physical activity, socioeconomic status, physical appearance and other anthropometric measures. The study shows that a low BMI is an appreciable independent risk factor of total mortality in the elderly, and not a result of subclinical disease or confounding factors such as current or previous smoking. Awareness of this issue ought to be emphasized in advice, care and treatment of elderly subjects.

Exercise and obesity

Obesity and overweight are linked to a wide range of medical conditions, such as hypertension, diabetes mellitus, osteoarthritis, obstructive sleep apnea, and coronary artery disease. Overweight and obese patients who are unable to lose weight with diet alone can benefit from well-structured exercise. Potentially, an individual exercise prescription can become one of the most important components of an obesity treatment program, along with an appropriate diet. Short-term (<6 months of duration) interventions consisting of exercise combined with appropriate diet and counseling can produce a significant weight loss. No consensus exists on the amount of physical activity necessary to maintain the weight loss achieved during a short-term intervention. Long-term intervention is frequently influenced by weight regain related to complex interactions between physiologic and psychosocial factors.

Survival in older men may benefit from being slightly overweight and centrally obese--a 5-year follow-up study in 4,000 older adults using DXA

BACKGROUND

Whether overweight in old age is hazardous remains controversial. Body mass index (BMI) overestimates adiposity and fails to measure central adiposity. We used dual-energy x-ray absorptiometry (DXA) to measure adiposity and hypothesized that overall adiposity, distribution of adiposity, and muscle mass might individually affect survival.

METHODS

We recruited 2000 men and 2000 women aged 65 years or older. Baseline BMI, waist-hip ratio (WHR), body fat index (BFI = total body fat/height square), relative truncal fat (RTF = trunk fat/total body fat), and body muscle mass index (BMMI = total body muscle mass/height square) were measured. Mortality was ascertained by death registry after 63.3 (median) months.

RESULTS

Two hundred and forty-two men and 78 women died. In men, mortality hazard ratio (HR) decreased consistently by 0.85 (p < .005), 0.86 (p < .005), and 0.86 (p < .005) per every quintile increase in BMI, BFI, and BMMI, respectively. A J-shaped relationship was observed in central adiposity (RTF and WHR) quintiles; the minimum values were at the 3rd WHR quintile (0.92-0.94) and 4th RTF quintile (mean WHR, 0.94). When RTF was tested with BFI, both high and low central adiposity were unfavorable while general adiposity became marginally insignificant (p = 0.062). When BFI and BMMI were tested together, increasing adiposity rather than muscle mass favored survival (BFI quintile, HR 0.97, p .015; BMMI quintile, HR 1.00, p .997).

CONCLUSIONS

Older men were resistive to hazards of overweight and adiposity; and mild-grade overweight, obesity, and even central obesity might be protective. This may bear significant implication on the recommended cutoff values for BMI and WHR in the older population.

Body weight dynamics and their association with physical function and mortality in older adults: the Cardiovascular Health Study

BACKGROUND

To estimate the associations of weight dynamics with physical functioning and mortality in older adults.

METHODS

Longitudinal cohort study using prospectively collected data on weight, physical function, and health status in four U.S. Communities in the Cardiovascular Health Study. Included were 3,278 participants (2,013 women and 541 African Americans), aged 65 or older at enrollment, who had at least five weight measurements. Weight was measured at annual clinic visits between 1992 and 1999, and summary measures of mean weight, coefficient of variation, average annual weight change, and episodes of loss and gain (cycling) were calculated. Participants were followed from 1999 to 2006 for activities of daily living (ADL) difficulty, incident mobility limitations, and mortality.

RESULTS

Higher mean weight, weight variability, and weight cycling increased the risk of new onset of ADL difficulties and mobility limitations. After adjustment for risk factors, the hazard ratio (95% confidence interval) for weight cycling for incident ADL impairment was 1.28 (1.12, 1.47), similar to that for several comorbidities in our model, including cancer and diabetes. Lower weight, weight loss, higher variability, and weight cycling were all risk factors for mortality, after adjustment for demographic risk factors, height, self-report health status, and comorbidities.

CONCLUSIONS

Variations in weight are important indicators of future physical limitations and mortality in the elderly and may reflect difficulties in maintaining homeostasis throughout older ages. Monitoring the weight of an older person for fluctuations or episodes of both loss and gain is an important aspect of geriatric care.

Elderly people with low body weight may have subtle low-grade inflammation

Low-grade inflammation, which plays important roles in the development of fatal diseases, is commonly observed in obese people. However, this has not been evaluated in lean people, who have relatively increased mortality risk compared with people of normal weight. Here, we elucidate the association between systemic low-grade inflammation and low body weight, with particular emphasis on aging. We examined the relationship between circulating C-reactive protein (CRP) and BMI in a cross-sectional study of 2,675 apparently healthy adults who had undergone a medical check-up. Overall, subjects with low BMI (<21.0 kg/m(2), n = 585) showed a favorable cardiovascular profile without being undernourished. In the elderly (>or=55 years old), logarithmic CRP (LogCRP) showed a sigmoid curve against BMI with a base at BMI 21.0-22.9 kg/m(2), but not against waist circumference (WC), even in nonsmokers. In contrast, in middle-aged people, LogCRP showed an almost linear relationship with both BMI and WC. LogCRP levels in elderly nonsmokers with low BMI, but not normal or high BMI, were significantly higher than those in middle-aged with corresponding BMI (P < 0.05). After adjustment for age, sex, smoking status, and weight change over the past 2 years, the adjusted means of LogCRP still had a similar sigmoid curve against BMI in the elderly. These results suggest that elderly people with low body weight may have subtle low-grade inflammation irrespective of a favorable cardiovascular risk, which remains to be confirmed in further studies.

Assessing residual confounding of the association between antipsychotic medications and risk of death using survey data

BACKGROUND

Nonrandomised studies on the causal effects of psychotropic medications may be biased by patient characteristics that are not fully adjusted.

OBJECTIVE

Studies using linked claims databases found that typical antipsychotic medications were associated with increased short-term mortality compared with atypical antipsychotics. It has been suggested that such results may be due to residual confounding by factors that cannot be measured in claims databases. Using detailed survey data we identified the direction and magnitude of such residual confounding.

DESIGN

Cross-sectional survey data.

PARTICIPANTS

17 776 participants aged > or =65 years from the Medicare Current Beneficiary Survey (MCBS).

MEASUREMENTS

To determine the association between typical antipsychotic use and potential confounding factors we assessed five factors not measured in Medicare claims data but in the MCBS, i.e. body mass index, smoking, activities of daily living (ADL) score, cognitive impairment and Rosow-Breslau physical impairment scale. We estimated adjusted associations between these factors and antipsychotic use. Combined with literature estimates of the independent effect of confounders on death, we computed the extent of residual confounding caused by a failure to adjust for these factors.

RESULTS

Comparing typical antipsychotic users with atypical antipsychotic users, we found that not adjusting for impairments in the ADL score led to an underestimation of the association with death (-13%), as did a failure to adjust for cognitive impairment (-7%). The combination of all five unmeasured confounders resulted in a net confounding of -5% (range -19% to +2%). After correction, the reported association between typical antipsychotic use and death compared with atypical antipsychotic use was slightly increased from a relative risk (RR) of 1.37 to 1.44 (95% CI 1.33, 1.56). Comparing any antipsychotic use with non-users would result in overestimations of >50% if cognitive impairment remained unadjusted.

CONCLUSION

Claims data studies tend to underestimate the association of typical antipsychotics with death compared with atypical antipsychotics because of residual confounding by measures of frailty. Studies comparing antipsychotic use with non-users may substantially overestimate harmful effects of antipsychotics.

Convergence of body mass with aging: the longitudinal interrelationship of health, weight, and survival

There has been ongoing debate about the health risks associated with increased body weight among the elderly population. One issue has not been investigated thoroughly is that body weight changes over time, as both the reasons and results of, the development of chronic diseases and functional disabilities. Structural models have the ability to unravel the complicated simultaneous relationship between body weight, disability, and mortality along the aging process. Using longitudinal data from the Medicare Current Beneficiary Survey from 1992 to 2001, we constructed a structural model to estimate the longitudinal dynamic relationship between weight, chronic diseases, functional status, and mortality among the aging population. A simulation of an age cohort from 65 to 100 was conducted to show the changes in weight and health outcomes among the cohorts with different baseline weight based on the parameters estimated by the model. The elderly with normal weight at age 65 experience higher life expectancy and lower disability rates than the same age cohorts in other weight categories. The interesting prediction of our model is that the average body size of an elderly cohort will converge to the normal weight range through a process of survival, senescence, and behavioral adjustment.

Prevalência de sobrepeso e obesidade geral e central em mulheres idosas da cidade de Curitiba, Paraná

OBJETIVO: Investigar a prevalência de sobrepeso e obesidade geral e central em uma amostra representativa da população de mulheres idosas do município de Curitiba, Paraná. MÉTODOS: Este estudo apresentou delineamento observacional, transversal e descritivo. As variáveis índice de massa corporal e da circunferência de cintura foram obtidas para a determinação do sobrepeso e obesidade geral e central, respectivamente. Medidas de tendência central, variabilidade, freqüências relativas e absolutas em cada faixa etária, dentro das categorias de índice de massa corporal e circunferência de cintura, foram verificadas. RESULTADOS: Participaram deste estudo 1069 mulheres com idade superior a 60 anos (média=69,5, desvio-padrão=6,1 anos). Em relação às categorias do índice de massa corporal, a maioria dos sujeitos teve seu estado nutricional classificado como sobrepeso (43,5%), seguido por obesidade (34,0%) e normalidade (22,5%). Por sua vez, a obesidade (45,1%) foi a condição nutricional prevalente em relação às categorias para a circunferência de cintura, seguida por sobrepeso (33,1%) e normalidade (21,8%). Além disso, o sobrepeso e a obesidade geral diminuíram da primeira para a última faixa etária (-20,4% e -11,6%, respectivamente), enquanto a normalidade elevou-se substancialmente (+75,3%). Resultados similares foram verificados em relação à adiposidade central, nos quais as condições de sobrepeso e obesidade declinaram 14,3% e 8,3%, respectivamente. CONCLUSÃO: Uma elevada prevalência de sobrepeso e obesidade geral e central foi verificada entre as mulheres idosas da cidade de Curitiba (PR), independentemente da idade. Programas públicos visando à prevenção e à redução do excesso de adiposidade corporal a partir de intervenção nos padrões de ingestão dietética e gasto energético, como a prática regular de exercício físico, tornam-se necessários nesta população.

Trauma

In terms of cost and years of potential lives lost, injury arguably remains the most important public health problem facing the United States. Care of traumatically injured patients depends on early surgical intervention and avoiding delays in the diagnosis of injuries that threaten life and limb. In the critical care phase, successful outcomes after injury depend almost solely on diligence, attention to detail, and surveillance for iatrogenic infections and complications.

Are there regional differences in gynecologic cancer outcomes in the context of a single-payer, publicly-funded health care system? A population-based study

BACKGROUND

Canada has a single-payer, publicly-funded health care system that provides comprehensive health care, and therefore significant disparities in health outcomes are not expected in our population. The objective of this study was to determine if differences exist in endometrial cancer outcomes across regions in Ontario.

METHODS

This was a population-based study of all endometrial (uterine) cancer cases diagnosed from 1996 to 2000 in Ontario and linked to various administrative databases. Univariate analyses examined trends in demographics (age, income, co-morbidities), treatment (surgical staging and adjuvant pelvic radiotherapy), and pathology (grade, histology, stage) across 14 geographic regions defined by local health integration networks (LHINs) in Ontario. Primary outcome was 5-year overall survival among LHINs, which were compared in a multilevel Cox regression model to account for clustering of patient data at the hospital level.

RESULTS

There were 3,875 evaluable cases with complete information on demographics, treatment, pathology, and outcomes. There was significant variation in patient demographics, treatment, and pathology across the 14 LHINs. Low income level and surgery at a low-volume, community hospital without gynecologic oncologists were not associated with a higher risk of death. There was a trend towards clustering of patients within hospitals. After adjustment for covariates, there was no significant difference in survival across LHINs.

CONCLUSIONS

In the context of a single-payer, publicly-funded health care system, we did not find significant regional differences in endometrial cancer outcomes.

Obesity, physical function, and mortality in older adults

OBJECTIVES

To estimate the effects of excess body weight on objective and subjective physical function and mortality risks in noninstitutionalized older adults.

DESIGN

Population-based cohort study.

SETTING

The English Longitudinal Study of Ageing (ELSA).

PARTICIPANTS

Three thousand seven hundred ninety-three participants in the ELSA aged 65 and older followed up for 5 years.

MEASUREMENTS

Analyses compared the risks of impaired physical function and mortality for subjects who were at the recommended weight (body mass index (BMI)=20.0-24.9) with those who were overweight (BMI=25.0-29.9), obese (BMI=30.0-34.9) or severely obese (BMI>or=35.0). Outcome measures were difficulties with activities of daily living (ADLs), score on the Short Physical Performance Battery, and mortality.

RESULTS

Participants in higher BMI categories had greater risk of impaired physical function at follow-up but little or no greater risk of mortality. For example, compared with men of recommended weight, obese men (BMI=30.0-34.9) had relative risk ratios of difficulties with ADLs of 1.99 (95% confidence interval (CI)=1.42-2.78), of measured functional impairment of 1.51 (95% CI=1.05-2.16), and of mortality of 0.99 (95% CI=0.60-1.61). Findings were robust when excluding those who lost weight, smoked, or had poor self-rated health.

CONCLUSION

Excess body weight in people aged 65 and older is associated with greater risk of impaired physical function but not with greater mortality risk. Societies with growing numbers of overweight and obese older people are likely to face increasing burdens of disability-associated health and social care costs.

Obesidad y Esperanza de Vida en México Obesity and life expectancy in Mexico

The high and increasing prevalence of overweight and obesity in Latin American and the Caribbean and the increasing prevalence of some obesity-related chronic diseases could be changing the current mortality patterns and the improvements in life expectancy of this population. The main objective of this study is to measure the effect of overweight and obesity on mortality in Mexico among elderly people (60 years and older). We use the Mexican Health and Ageing Study (MHAS, 2001 and 2003) that is a panel nationally-representative study of the population 50 years and older in Mexico. Our results show that excess body weight (defined by the two highest quintiles of Body Mass Index-BMI-) increases the risk of mortality at 60 years and older in Mexico. As much as 11% of the deaths among elderly that occurred during the period 2001-2003 in Mexico would have been avoided if overweight and obese people (individuals belonging to the highest two quintiles of BMI) had had the "ideal" weight (defined by the middle quintile, or third quintile, of BMI). At individual level, we estimate that individuals 60 years old with excess body weight (fourth and fifth quintiles of BMI) survive four years less, in average, than individuals with normal body weight (third quintile of BMI).

Sex hormone binding globulin levels across the adult lifespan in women--the role of body mass index and fasting insulin

SHBG is a major carrier of androgens. In men, SHBG levels increase with age, while in women data are scant. There is evidence that body mass index (BMI) and fasting insulin influence SHBG concentration. Since low SHBG levels are predictors of insulin resistance and diabetes, understanding the relationship of SHBG with age, insulin, and BMI is important to gain insight into the role of SHBG as a cardiovascular risk factor in women. Differences in SHBG across adult life span and their relationship with insulin and BMI were evaluated in a representative cohort of 616 Italian women free of diabetes and not on hormone replacement therapy enrolled in the InCHIANTI Study. The relationship of SHBG with age, BMI, and fasting insulin levels was analyzed using linear regression and by loess smoother. Serum SHBG levels showed a U-shaped trajectory with age, declining from the 2nd to the 6th decade of life and increasing after the 6th decade (p<0.0001). Age-related trends for BMI and fasting insulin mirrored the trend observed for SHBG. After adjusting for fasting insulin, the relationship between log (SHBG) and age square was attenuated (beta coefficient from 0.00044 to 0.00039) and was further reduced after adjustment for BMI (from 0.00039 to 0.00028). SHBG levels show an age-related U-shaped trajectory. These changes mirror the age-related changes in BMI and fasting insulin, suggesting that BMI and insulin negatively influence SHBG concentration.

The positive association between number of children and obesity in Iranian women and men: results from the National Health Survey

BACKGROUND

To date, few studies have assessed the association between the number of children and obesity in couples. We aimed to investigate this association in men and women aged 20-75 years.

METHODS

Data from the National Health Survey were considered in this investigation. It included 2728 women and men (1364 couples) aged 20-75 years. Height and weight were actually measured rather than self-reported. A generalized estimating equation model was used to estimate the odds of obesity (body mass index (BMI > or = 30)) as a function of the number of children adjusted for age, sex, education, economic index, workforce, smoking and place of residence.

RESULTS

We infer that each additional child has at least 5% and at most 34% increase in the odds of obesity in men and at least 4% and at most 29% increase in the odds of obesity in women. Our test of interaction by sex showed that the association between the number of children and obesity was not different among men and women. Among women, factors that increased obesity included age, low education, having more children, being inactive workforce and being nonsmoker. Among men, these factors included high economic index, low education, having more children, and being nonsmoker.

CONCLUSION

Our results show an association between the number of children and obesity among men. We would recommend interventions to reduce the number of children to prevent obesity in men.

A comparison of measured height and demi-span equivalent height in the assessment of body mass index among people aged 65 years and over in England

OBJECTIVES

to examine differences between measured height and demi-span equivalent height (DEH) among people aged >or=65 and investigate the impact on body mass index (BMI) of using DEH.

DESIGN AND SETTING

nationally representative cross-sectional sample of adults living in England.

PARTICIPANTS

3,346 non-institutionalised adults aged >or=65, taking part in the Health Survey for England (HSE) 2001.

MEASUREMENTS

height, weight and demi-span measurements were taken according to standardised HSE protocols. DEH was calculated using Bassey's equation.

RESULTS

the height measurement was lower than the DEH from age group 70-74 years onwards in men and in each age group in women. No significant differences in mean DEH and measured height were found for men (-0.46) or women (-2.64). BMI derived from measured height did not differ significantly from BMI derived from DEH. The prevalence of underweight was lower when using measured height than when using DEH in women aged >or=65, particularly in those aged 80 years and over. The prevalence of overweight and obesity was higher using measured height than DEH in women aged >or=65.

CONCLUSION

we confirmed in a large nationally representative sample that demi-span measurement may be a useful estimate of stature in people (particularly women) aged >or=65 for BMI calculations.

Body mass index, weight loss, and mortality in community-dwelling older adults

BACKGROUND

The relationship between body mass index (BMI), weight loss, and mortality in older adults is not entirely clear. The purpose of this article is to evaluate the associations between BMI, weight loss (either intentional or unintentional), and 3-year mortality in a cohort of older adults participating in the University of Alabama at Birmingham (UAB) Study of Aging.

METHODS

This article reports on 983 community-dwelling older adults who were enrolled in the UAB Study of Aging, a longitudinal observational study of mobility among older African American and white adults.

RESULTS

In both raw and adjusted Cox proportional hazards models, unintentional weight loss and underweight BMI were associated with elevated 3-year mortality rates. There was no association with being overweight or obese on mortality, nor was there an association with intentional weight loss and mortality.

CONCLUSIONS

Our study suggests that undernutrition, as measured by low BMI and unintentional weight loss, is a greater mortality threat to older adults than is obesity or intentional weight loss.

Is weight loss beneficial for reduction of morbidity and mortality? What is the controversy about?

The increase of obesity and type 2 diabetes on a global scale has increased the interest in how to counteract this epidemic. Improved lifestyle in general is a fundamental approach, but other remedies such as specific weight reduction or diabetes preventive drugs and surgery have also been tested. One problem to understand is what really happens after weight loss. Ongoing studies will try to address this question, such as the Swedish Obese Subjects (SOS) surgery study, the Look AHEAD (Action for Health in Diabetes) trial in the U.S. (recruiting obese type 2 diabetic patients), and the Comprehensive Rimonabant Evaluation Study of Cardiovascular End Points and Outcomes (CRESCENDO) trial (by use of rimonabant versus placebo). This is very important, since previously, several observational studies in large population-based cohorts have indicated some detrimental effects of weight loss, even after intentional weight loss, with increased morbidity and mortality rates.

Past body mass index and risk of mortality among women

BACKGROUND

Epidemiologic studies of body mass index (BMI) in relation to mortality commonly exclude persons with health conditions and/or a history of smoking to prevent bias resulting from illness-related weight loss ('reverse causation'). Analysis of BMI from an earlier time period may minimize reverse causation without requiring exclusion of participants based on disease or smoking history.

METHODS

We prospectively examined BMI based on technician measurements of weight and height from 10 years prior to start of follow-up in relation to subsequent mortality in a cohort of 50 186 women who were 40-93 years old at baseline in 1987-1989. Deaths were ascertained through the US National Death Index. Proportional hazards regression was used to estimate hazard ratios (HRs) of mortality, adjusted for age, education, race/ethnicity, income, menopausal hormone use, smoking and physical activity.

RESULTS

During 10 years of follow-up through 1997, 5201 women died. Overall, we observed a J-shaped association between BMI and mortality, with increased risk for women who were underweight, overweight or obese. The HRs and 95% confidence intervals of mortality for BMI categories of <18.5, 18.5-20.9, 21.0-23.4 (reference), 23.5-24.9, 25.0-27.4, 27.5-29.9, 30.0-34.9 and 35.0+ kg m(-2) were 1.43 (1.19, 1.72), 1.07 (0.98, 1.17), 1.00 (reference), 1.10 (1.00, 1.20), 1.20 (1.11, 1.31), 1.23 (1.11, 1.37), 1.60 (1.44, 1.77) and 1.92 (1.64, 2.24). There was little evidence that pre-existing conditions (heart disease, diabetes and/or cancer) or smoking history modified the past BMI and mortality relation (P=0.54 and 0.76).

CONCLUSIONS

In this large cohort of women, BMI based on technician measurements of weight and height from 10 years prior to baseline showed increased risk for mortality across the range of overweight and obesity, regardless of disease and smoking history. Observed associations between overweight, obesity and mortality in healthy individuals may also apply to persons with a history of disease or smoking.

The oldest old and the 90+ Study

Memories are the gifts from friends and family that stay with us forever, unless a person develops Alzheimer's disease. Leon J. Thal left many, many memories, along with his desire to create a world where people did not lose them to the ravages of dementing illnesses. Working from the bench to the clinic, he was an incomparable leader, scientist, and educator to whom many, including myself, owe much. The present description of a clinical, genetic, and pathologic study of the oldest old contains much of Leon's influence. With data from >950 subjects, a brain repository, and our collection of DNA, the investigators of the 90+ Study are receptive to collaborations. Through our collective efforts, we will continue the scientific work that Leon so strongly supported.

Eight-year change in body mass index and subsequent risk of cardiovascular disease among healthy non-smoking men

OBJECTIVE

To determine how change in BMI over 8 years is associated with risk of subsequent cardiovascular disease (CVD) among middle aged men.

METHODS

Prospective cohort study among 13,230 healthy men (aged 51.6+/-8.7 years) in the Physicians' Health Study. BMI was collected at baseline in 1982 and after 8 years, at which time follow-up began. Subsequent CVD events were collected and confirmed through March 31, 2005. Cox proportional hazards models evaluated BMI at 8 years and risk of CVD, 8-year change in BMI and risk of CVD, and whether change in BMI added prognostic information after the consideration of BMI at 8 years.

RESULTS

1308 major CVD events occurred over 13.5 years. A higher BMI at year 8 was associated with an increased risk of CVD. Compared to a stable BMI (+/-0.5 kg/m(2)), a 0.5-2.0 kg/m(2) increase had a multivariable-adjusted RR of 1.00 (0.86-1.16). A >/=2.0 kg/m(2) increase had a multivariable-adjusted RR of 1.39 (1.16-1.68), however further adjustment for BMI reduced the RR to 1.00 (0.81-1.23). A decrease in BMI had a multivariable RR of 1.23 (1.07-1.42) which was unaffected by adjustment for BMI at 8 years.

CONCLUSION

A higher BMI and a rising BMI were both associated with an increased risk of CVD, however an increasing BMI did not add prognostic information once current BMI was considered. In contrast, a declining BMI was associated with an increased risk of CVD independent of current BMI.

Body mass index and depressive symptoms in older adults: the moderating roles of race, sex, and socioeconomic status

OBJECTIVE

Although the long-term health risks associated with obesity in older adults have been well documented, less is known about the psychological consequences. The current study examined the relationship between body mass index (BMI) and subsequent depressive symptoms. The authors anticipated that BMI would predict depressive symptoms, and that this relationship would be greater among women, individuals of higher socioeconomic status (SES), and white subjects.

METHODS

A three-year longitudinal epidemiological design was employed. Participants were obtained from a biracial sample of community-dwelling older adults (N = 2,406) and were interviewed in their home by trained interviewers. A comprehensive survey assessed age, gender, race, SES (education and income), and health functioning variables. Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression Scale. BMI was derived from self-reported weight and height.

RESULTS

BMI was found to predict depressive symptoms. Contrary to predictions, the influence of BMI on depressive symptoms was greater for African Americans than whites and, in particular, African Americans with less education. There were no sex differences.

CONCLUSION

Among older adults, BMI was associated with depressive symptoms although the effect size was small. Factors contributing to this relationship may differ from those observed in younger populations, for example, health functioning may play a larger role. Obesity appears to have the most adverse impact on those who are most likely to be overweight, lower SES African Americans.

Role of genetic and environmental influences on heart rate variability in middle-aged men

Our aim was to estimate causal relationships of genetic factors and different specific environmental factors in determination of the level of cardiac autonomic modulation, i.e., heart rate variability (HRV), in healthy male twins and male twins with chronic diseases. The subjects were 208 monozygotic (MZ, 104 healthy) and 296 dizygotic (DZ, 173 healthy) male twins. A structured interview was used to obtain data on lifetime exposures of occupational loading, regularly performed leisure-time sport activities, coffee consumption, smoking history, and chronic diseases from 12 yr of age through the present. A 5-min ECG at supine rest was recorded for the HRV analyses. In univariate statistical analyses based on genetic models with additive genetic, dominance genetic, and unique environmental effects, genetic effects accounted for 31–57% of HRV variance. In multivariate statistical analysis, body mass index, percent body fat, coffee consumption, smoking, medication, and chronic diseases were associated with different HRV variables, accounting for 1–11% of their variance. Occupational physical loading and leisure-time sport activities did not account for variation in any HRV variable. However, in the subgroup analysis of healthy and diseased twins, occupational loading explained 4% of the variability in heart periods. Otherwise, the interaction between health status and genetic effects was significant for only two HRV variables. In conclusion, genetic factors accounted for a major portion of the interindividual differences in HRV, with no remarkable effect of health status. No single behavioral determinant appeared to have a major influence on HRV. The effects of medication and diseases may mask the minimal effect of occupational loading on HRV.

A food pattern predicting prospective weight change is associated with risk of fatal but not with nonfatal cardiovascular disease

Recently, a food pattern predictive for prospective weight change was identified within the European Prospective Investigation into Cancer and Nutrition-Potsdam cohort. Given the possible impact of weight change on cardiovascular disease (CVD) risk, we examined the association between the above mentioned food pattern and risk of CVD. The analyzed food pattern was defined by a high consumption of whole-grain bread, fruits, fruit juices, grain flakes and/or cereals, and raw vegetables, and a low consumption of processed meat, butter, high-fat cheese, margarine, and meat other than poultry. The associations between quartiles of the food pattern score and CVD morbidity and mortality were examined in 26,238 subjects of the European Prospective Investigation into Cancer and Nutrition-Potsdam cohort using a Cox's Proportional Hazards model for competing risks. During 6.4 y of follow-up, 379 incident cases of CVD were identified, of which 68 were fatal events. The food pattern was not associated with risk of nonfatal CVD. After adjusting for cardiovascular risk factors, the hazard ratios for fatal CVD across increasing quartiles of the score were 1.00, 0.85, 0.31, and 0.47, respectively (P for trend = 0.016). The association of the food pattern with CVD risk differed between fatal and nonfatal events (P for difference = 0.05). These findings from a large German cohort indicate that a food pattern predicting prospective weight change may be associated with the risk of fatal CVD.

Association Between Body Mass Index and Mortality in an 80-Year-Old Population

OBJECTIVES

To evaluate the association between body mass index (BMI) and all-cause mortality and cardiovascular disease (CVD) in an 80-year-old population.

DESIGN

Cohort study.

SETTING

Community-based.

PARTICIPANTS

Six hundred ninety-seven of 1,282 (54.4%) 80-year-old candidate individuals.

MEASUREMENTS

The dates and causes of all deaths were followed up for 4 years.

RESULTS

The relative hazard ratios (HRs) for all-cause mortality were lower in overweight subjects (BMI > or= 25.0) than in underweight (BMI<18.5) or normal-weight (BMI 18.5-24.9) subjects. Similarly, the HRs for mortality due to CVD in overweight subjects were 78% less (HR=0.22, 95% confidence interval (CI)=0.06-0.77) than those in underweight subjects, and those in normal weight subjects were 78% less (HR=0.22, 95% CI=0.08-0.60) than those in underweight subjects. Mortality due to CVD was 4.6 times (HR 4.64, 95% CI=1.68-12.80) as high in underweight subjects as in normal-weight subjects, and mortality due to cancers was 88% lower (HR=0.12, 95% CI=0.02-0.78) in the overweight group than in the underweight group. There were no differences in mortality due to pneumonia.

CONCLUSION

Overweight status was associated with longevity and underweight with short life, due to lower and higher mortality, respectively, from CVD and cancer.

Associations between body composition, anthropometry, and mortality in women aged 65 years and older

OBJECTIVES

We examined the relation between measures of body size and mortality in a predominantly White cohort of 8029 women aged 65 years and older who were participating in the Study of Osteoporotic Fractures.

METHODS

Body composition measures (fat and lean mass and percentage body fat) were calculated by bioelectrical impedance analysis. Anthropometric measures were body mass index (BMI; kg/m2) and waist circumference.

RESULTS

During 8 years of follow-up, there were 945 deaths. Mortality was lowest among women in the middle of the distribution of each body size measure. For BMI, the lowest mortality rates were in the range 24.6 to 29.8 kg/m2. The U-shaped relations were seen throughout the age ranges included in this study and were not attributable to smoking or measures of preexisting illness. Body composition measures were not better predictors of mortality than BMI or waist girth.

CONCLUSIONS

Our results do not support applying the National Institutes of Health categorization of BMI from 25 to 29.9 kg/m2 as overweight in older women, because women with BMIs in this range had the lowest mortality.