Long-term effects of change in body weight on all-cause mortality. A review

Signaling proteins that influence energy intake may affect unintentional weight loss in elderly persons

After age 70 to 75 years, average body weight decreases both in ailing and healthy people because of a loss of appetite that results in reduced energy intake and the loss of body fat and lean muscle tissue. This so-called anorexia of aging predisposes elderly people to continued pathologic weight loss and malnutrition-major causes of morbidity and mortality. Health care professionals must understand the many factors involved in the anorexia of aging to help older adults prevent unintentional weight loss. Psychological, social, and cultural factors are important effectors; however, physiological factors are emphasized here because they are not thoroughly understood and they make it inherently difficult for most people to alter their body weight. Monoamines, steroid hormones (glucocorticoids and mineralocorticoids), endocannabinoids, and proteins all influence body weight. This review is an analysis of proteins from the brain, pancreas, adipose tissue, and gastrointestinal tract that are known to affect energy intake and energy balance, with an attempt to identify those factors that may change with aging. The articles included in this review were obtained by a PubMed database search using the keywords mouse OR rat OR human AND aged OR aging OR older OR elderly AND adult AND anorexia OR "unintentional weight loss," and each of the individual proteins discussed, as well as from the reference lists of those articles. The results reveal that some proteins may be important in the development of unintentional weight loss in elderly persons, whereas others may not have a significant role. However, many of the proteins that could conceivably have a role in unintentional weight loss have not yet been studied with that question in mind. Preventing unintentional weight loss in older adults is an important goal and further research on the role of proteins important for the maintenance of energy balance and the development of unintentional weight loss in elderly persons is warranted.

Weight loss in older persons

Weight loss is common in older people. It is associated with increased morbidity and mortality, particularly when unintentional, excessive (>5% body weight), or associated with low body weight (body mass index <22 kg/m(2)). It is often unrecognized, the associated adverse effects not appreciated, and underlying causes not addressed. Intentional weight loss by overweight older people is probably appropriate only when functional problems have resulted from the excess weight. It is important to include, wherever possible, exercise in weight-loss measures to preserve skeletal muscle mass.

Weight science: evaluating the evidence for a paradigm shift

Current guidelines recommend that "overweight" and "obese" individuals lose weight through engaging in lifestyle modification involving diet, exercise and other behavior change. This approach reliably induces short term weight loss, but the majority of individuals are unable to maintain weight loss over the long term and do not achieve the putative benefits of improved morbidity and mortality. Concern has arisen that this weight focus is not only ineffective at producing thinner, healthier bodies, but may also have unintended consequences, contributing to food and body preoccupation, repeated cycles of weight loss and regain, distraction from other personal health goals and wider health determinants, reduced self-esteem, eating disorders, other health decrement, and weight stigmatization and discrimination. This concern has drawn increased attention to the ethical implications of recommending treatment that may be ineffective or damaging. A growing trans-disciplinary movement called Health at Every Size (HAES) challenges the value of promoting weight loss and dieting behavior and argues for a shift in focus to weight-neutral outcomes. Randomized controlled clinical trials indicate that a HAES approach is associated with statistically and clinically relevant improvements in physiological measures (e.g., blood pressure, blood lipids), health behaviors (e.g., eating and activity habits, dietary quality), and psychosocial outcomes (such as self-esteem and body image), and that HAES achieves these health outcomes more successfully than weight loss treatment and without the contraindications associated with a weight focus. This paper evaluates the evidence and rationale that justifies shifting the health care paradigm from a conventional weight focus to HAES.

Dynamic determinants of longevity and exceptional health

It is well known from epidemiology that values of indices describing physiological state in a given age may influence human morbidity and mortality risks. Studies of connection between aging and life span suggest a possibility that dynamic properties of age trajectories of the physiological indices could also be important contributors to morbidity and mortality risks. In this paper we use data on longitudinal changes in body mass index, diastolic blood pressure, pulse pressure, pulse rate, blood glucose, hematocrit, and serum cholesterol in the Framingham Heart Study participants, to investigate this possibility in depth. We found that some of the variables describing individual dynamics of the age-associated changes in physiological indices influence human longevity and exceptional health more substantially than the variables describing physiological state. These newly identified variables are promising targets for prevention aiming to postpone onsets of common elderly diseases and increase longevity.

Changes in weight at the end of life: characterizing weight loss by time to death in a cohort study of older men

The purpose of this analysis was to characterize the natural history of weight change in the years prior to death among older persons and to examine how this pattern varies according to longevity and cause of death. Weight trajectories were analyzed by using data from 800 male decedents from the Baltimore Longitudinal Study of Aging (Maryland, 1958-2005) observed beginning an average of 19 years before death. A model including 3 distinct periods of weight change (weight stability/gain, mild weight loss, and accelerated weight loss before death) provided the best fit for all age-at-death groups. Approximately 9 years before death, the rate of weight loss increased to an average of 0.39 kg/year (P < 0.001) for all-cause mortality. For cancer deaths, weight loss accelerated significantly 3 years before death, regardless of age group. For cardiovascular deaths, the best-fitting inflection point increased with age, from 5 years for participants aged 60-69 years to 9-10 years before death for those aged 80 years or older. Results suggest that weight loss in older persons may begin earlier than previously believed. The duration of weight loss for noncancer deaths suggests that even distal changes in energy balance may be linked to risk of death.

Differential associations of weight dynamics with coronary artery calcium versus common carotid artery intima-media thickness: The CARDIA Study

Change and fluctuation in body mass index (BMI; weight (kg)/height (m)(2)) may be associated differently with coronary artery calcification (CAC) than with carotid artery intima-media thickness (IMT). The authors analyzed data on 2,243 participants in the Coronary Artery Risk Development in Young Adults (CARDIA) Study, initially aged 18-30 years, who were examined every 2-5 years over a 20-year period (1985-2006). BMI at year 0 was associated positively and linearly with CAC at year 20; however, the association of BMI with year 20 CAC became progressively U-shaped in subsequent examinations (years 10, 15, and 20). To understand the deepening U shape, the authors modeled year 20 BMI and its history using 3 indices: year 0 BMI, linear slope of BMI during 20 years, and BMI fluctuation during 20 years. In models including these 3 terms, year 0 BMI was associated positively with CAC, as was BMI fluctuation. However, adjusted odds ratios across quintiles of BMI slope (vs. the lowest quintile) were 0.7, 0.4, 0.5, and 0.4 (P(trend) < 0.01), suggesting higher risk of CAC with weight loss, plateauing after moderate weight gain. In contrast, IMT was associated positively with BMI at all examinations and with 20-year BMI slope and was unassociated with BMI fluctuation. Surprisingly, CAC risk was higher with BMI loss and lower with BMI gain, whereas associations with IMT were as expected.

Weight loss from maximum body weight and mortality: the Third National Health and Nutrition Examination Survey Linked Mortality File

OBJECTIVE

The aim of this longitudinal study is to examine the relationship between weight loss from maximum body weight, body mass index (BMI), and mortality in a nationally representative sample of men and women.

DESIGN

Longitudinal cohort study.

SUBJECTS

In all, 6117 whites, blacks, and Mexican-Americans 50 years and over at baseline who survived at least 3 years of follow-up, from the Third National Health and Nutrition Examination Survey Linked Mortality Files (1988-1994 with passive mortality follow-up through 2000), were included.

MEASUREMENTS

Measured body weight and self-reported maximum body weight obtained at baseline. Weight loss (maximum body weight minus baseline weight) was categorized as <5%, 5-<15%, and >or=15%. Maximum BMI (reported maximum weight (kg)/measured baseline height (m)(2)) was categorized as healthy weight (18.5-24.9), overweight (25.0-29.9), and obese (>or=30.0).

RESULTS

In all, 1602 deaths were identified. After adjusting for age, race, smoking, health status, and preexisting illness, overweight men with weight loss of 15% or more, overweight women with weight loss of 5-<15%, and women in all BMI categories with weight loss of 15% or more were at increased risk of death from all causes compared with those in the same BMI category who lost <5%; hazard ratios ranged from 1.46 to 2.70. Weight loss of 5-<15% reduced risk of death from cardiovascular diseases among obese men.

CONCLUSIONS

Weight loss of 15% or more from maximum body weight is associated with increased risk of death from all causes among overweight men and among women regardless of maximum BMI.

Benefits of moderate weight loss in patients with type 2 diabetes

Weight loss is a primary goal of therapy in overweight patients with type 2 diabetes. This review examines whether positive patient outcomes are observed even after relatively small amounts of weight loss, that is, weight loss being more easily attainable in practice. Clinical studies demonstrate that therapeutic benefit rises with increasing weight loss, but that losses as low as 0.45-4 kg (1-9 lb) have positive effects on metabolic control, cardiovascular risk factors and mortality rates. Even the intention to lose weight, without significant success, can improve outcomes in patients with diabetes, presumably because of the healthy behaviours associated with the attempt. The current data support a continued focus on weight loss, including moderate weight loss, as a key component of good care for overweight patients with type 2 diabetes.

Metabolic syndrome and weight gain in adulthood

BACKGROUND

The influence of long-term adult weight history on metabolic risk independent of attained body mass index (BMI) is unknown.

METHODS

Using nationally representative data on adults aged 50-64 years from the 1999-2006 National Health and Nutrition Examination Surveys, we examined weight change for two periods of adulthood: prime age (age 25-10 years ago) and midlife (the last 10 years). Weight changes in each period were categorized as stable (gain <10 kg) or gain (gain >or=10 kg) to create weight history comparison groups: stable-stable, gain-stable (prime age gain), stable-gain (midlife gain), and gain-gain (continuous gain). Persons who lost weight were excluded. Logistic regression predicted odds of metabolic syndrome and its subcomponents based on weight history, adjusting for current BMI and covariates.

RESULTS

Participants in the gain-stable group had 89% elevated odds of metabolic syndrome (odds ratio = 1.89, 95% CI: 1.19-3.01) relative to the stable-stable group, even after adjustment for current BMI. All weight gain groups had increased odds of low HDL and high triglycerides relative to participants with continuously stable weights. No significant associations were found between weight history and hypertension or high glucose.

CONCLUSIONS

Weight history confers information about metabolic risk factors above and beyond attained weight status. In particular, adult weight gain is related to risk of low HDL and high triglycerides. Weight history may contribute to our understanding of why some obese older persons are metabolically healthy but others are not.

Anthropometric, metabolic, psychosocial, and dietary characteristics of overweight/obese postmenopausal women with a history of weight cycling: a MONET (Montreal Ottawa New Emerging Team) study

Characteristics of weight cyclers have not been fully assessed. The objective of this study was to determine the anthropometric, metabolic, psychosocial, and dietary profile of postmenopausal women according to weight-cycling history, defined as the frequency of going on a diet and losing >10 kg: never (0 times), low (1 time), moderate (2 to 3 times), or frequent (> or = 4 times). The sample of this cross-sectional study consisted of 121 overweight/obese postmenopausal women enrolled in a 6-month randomized weight-loss intervention between 2003 and 2006. Measures at baseline were used to evaluate body composition (fat mass by dual-energy x-ray absorptiometry and visceral fat by computed tomography); resting metabolic rate by indirect calorimetry; insulin sensitivity by hyperinsulinemic-euglycemic clamp; fasting plasma levels of glucose, lipids, leptin, ghrelin, and adiponectin; blood pressure; psychosocial profile (eg, body-esteem, self-esteem, stress, perceived risks, perceived benefits, self-efficacy, quality of life, dietary restraint, disinhibition, hunger); and dietary profile (3-day food record). Differences among groups of weight cyclers were determined using analyses of variance. Among the 121 women, 15.7%, 24.8%, 33.9%, and 25.6% were non-, low, moderate, and frequent cyclers, respectively. Frequent cyclers were characterized by higher body mass index (calculated as kg/m(2)) (current and at 25 years of age) and percent body fat mass, larger waist circumference, and lower resting metabolic rate/kg body weight than noncyclers (P<0.05); and moderate cyclers had lower plasma adiponectin values than noncyclers (P<0.05). For psychosocial measures, frequent cyclers were characterized by greater disinhibition and lower body esteem after controlling for body mass index (P<0.05). In conclusion, weight cycling was found to be associated with some unfavorable metabolic and psychosocial parameters.

All-cause mortality among Japanese-Brazilians according to nutritional characteristics

The aim of this study was to verify the association between nutritional variables and mortality in a Japanese-Brazilian cohort. In 1993, 647 subjects were interviewed with food frequency questionnaires and scheduled for physical procedures (weight, height, blood pressure) and biochemical tests (oral glucose tolerance test). Student's t test was used to compare the mean values of target variables between living and deceased subjects. Mortality rate and hazard ratios were obtained (crude and adjusted) according to the nutritional variables. Overall mortality rates were 21.4 and 11.7/1,000 person-years for males and females, respectively. Smoking, diabetes, sedentary lifestyle, hypertension, higher mean age, high blood pressure, high blood glucose, and higher percent weight gain and rate of weight gain were observed in the history of deceased subjects. After adjusting for control variables, an increase was observed in mortality among individuals with lower carbohydrate and cholesterol intake. The results suggest that mortality risk factors like age, chronic diseases, sedentary lifestyle, smoking, and inadequate diet must also be acting in the Japanese-Brazilian population.

Exenatide as a treatment for diabetes and obesity: implications for cardiovascular risk reduction

Among the challenges in improving outcomes in patients with diabetes is effectively implementing existing pharmacotherapies. However, current therapies for diabetes are often limited by adverse effects such as edema, hypoglycemia, and weight gain. Understanding the role of the incretin effect on the pathophysiology of diabetes has led to the development of new therapeutic agents. Exenatide is the first in a new class of agents termed "incretin mimetics," which replicate several glucoregulatory effects of the endogenous incretin hormone, glucagon-like peptide-1. In clinical trials, patients with type 2 diabetes treated with exenatide demonstrate sustained improvements in glycemic control, with reductions in fasting and postprandial glucose levels and improvements in glycosylated hemoglobin levels. Improvements in glycemic control with exenatide are coupled with reductions in body weight. Lipid parameters, blood pressure, and C-reactive protein have been shown to improve favorably in patients treated with exenatide. The sustained glycemic improvements and progressive reduction in body weight with exenatide treatment support a shift toward a more favorable cardiovascular risk profile and may have a positive impact on decreasing the risk of associated long-term complications.

Body mass index, weight change and mortality risk in a prospective study in India

BACKGROUND

Although the detrimental effect of overweight and obesity has been extensively reported in Western populations, little is known on the association between body weight, weight change and mortality in Asian populations whose weight distribution and mortality differ considerably from the West.

METHODS

A cohort of 75 868 subjects aged 35 years and above, participants of the Trivandrum Oral Cancer Study-a cluster-randomized controlled trial originally implemented to evaluate the efficacy of visual inspection on oral cancer, in Kerala State, South India-were followed up from 1995 to 2004. Weight and height were measured both at baseline and in 3.5-year follow-up surveys. Early years of follow-up were excluded from the analyses. Relative risks of overall death and cause-specific death were estimated according to the body mass index (BMI) category of the WHO Asian population definitions, and to weight changes between two surveys.

RESULTS

Low BMI was a predictor of mortality, while high BMI was not. Mortality risks in men adjusted for age, smoking habits and other potential confounders, as compared with a BMI 18.5-22.9 kg/m(2), were 1.26 (95% CI 1.03-1.55) for BMI < 16 kg/m(2); 1.16 (1.03-1.32) for BMI = 16-18.4 kg/m(2); 0.95 (0.81-1.12) for BMI = 23-24.9 kg/m(2); 0.85 (0.69-1.05) for BMI = 25-27.4 kg/m(2); and 0.89 (0.65-1.21) for BMI >/= 27.5 kg/m(2). Similar findings were observed in women. BMI was not associated with deaths from cancer, cardiovascular and cerebrovascular diseases, and diabetes. A low BMI (<16 kg/m(2)) was associated with increased deaths from chronic respiratory diseases. Smoking and socio-economical status did modify the association. A moderate weight gain of 4-10% between the two surveys was associated with decreased risk of death, while moderate and severe weight loss were predictive factors of death. Similar results were observed in both men and women.

CONCLUSIONS

Among this Indian rural population, mild to severe leanness (BMI < 16 kg/m(2)) and weight loss were important determinants of mortality, especially from chronic respiratory diseases, while overweight and above (BMI > 23 kg/m(2)) did not show any detrimental effect.

Unintended weight loss in older persons

Unintended weight loss has a profound effect on morbidity and mortality in older persons. A therapeutic approach to unintended weight loss in older persons depends on correct classification. A careful differential diagnostic approach is mandatory, combined with nutritional and often pharmacological interventions. While starvation due to protein-energy undernutrition is widely regarded as the primary cause of loss of fat and fat-free mass in older persons, a failure to improve with nutritional replacement should trigger a consideration of other causes. Both sarcopenia and cachexia are resistant to hypercaloric feeding. Cachexia may be amenable to suppression of proinflammatory cytokines in known inflammatory disease states.

The Impact of Body-Mass Index and Steps per Day on Blood Pressure and Fasting Glucose in Older Adults

The purpose of this study was to investigate the combined impact of obesity and physical activity (PA) on the health of older adults. Pedometer-determined steps/d, body-mass index (BMI), resting blood pressure, and fasting glucose (FG) were assessed in 137 older adults (69.0 ± 8.9 yr). The active group (>4,227 steps/d) had lower systolic blood pressure (SBP;p= .001), diastolic blood pressure (DBP;p= .028), and FG (p< .001) than the inactive group (≤4,227 steps/d). The normal-BMI group (18.5-24.9 kg/m2) had lower SBP (p< .001) and DBP (p= .01) than the obese group (≤30 kg/m2). There were no differences in SBP (p= .963) or DBP (p= 1.0) between active obese and inactive normal-BMI groups. The active obese group, however, had a more favorable FG than the inactive normal-BMI group (χ2= 18.9,df= 3,p= .001). Efforts to increase PA of older adults should receive the same priority as reducing obesity to improve BP and FG levels.

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.

Long-term weight loss effects on all cause mortality in overweight/obese populations

This systematic review assesses the long-term effectiveness of weight loss on all cause mortality in overweight/obese people. Medline, Embase and Cinahl were searched (1966-2005). Cohort studies and trials on participants with body mass index > or =25 kg m(-2), with weight change and mortality with > or =2-year follow-up, were included finally identifying 11 papers based on eight studies. There may be gender differences in the benefits for all cause mortality. The impact of weight loss in men on mortality was not clear with some studies indicating weight loss to be detrimental, while a recent cohort study showed benefits, if it were a personal decision. Other studies with no gender separation had similarly mixed results. However, one study indicated that overweight/obese women with obesity-related illness, who lost weight intentionally within 1 year, had significantly reduced mortality rates of 19-25%. In contrast, studies of overweight/obese diabetics irrespective of gender showed significant benefit of intentional weight loss on mortality in a meta-analysis, hazard ratios = 0.75 (0.67-0.83). There is some evidence that intentional weight loss has long-term benefits on all cause mortality for women and more so for diabetics. Long-term effects especially for men are not clear and need further investigation.

Síndrome metabólica em adolescentes com sobrepeso e obesidade

OBJETIVO: Estudar a prevalência da síndrome metabólica em adolescentes acompanhados em ambulatório de obesidade. MÉTODOS: Foram avaliados 84 adolescentes com idades entre dez e 19 anos, divididos em dois grupos, de acordo com o escore Z do índice de massa corpórea (Z IMC), sendo um o grupo de adolescentes com sobrepeso (GSP) e o outro, o grupo de adolescentes obesos (GOB). GSP: Z IMC>1 e <2 (1,6±0,2, 13M/13F), e GOB: Z IMC>2 (2,4±0,6, 32M/26F). Três ou mais dos critérios a seguir foram considerados no diagnóstico da síndrome metabólica e avaliados pelo teste do qui-quadrado entre os grupos: Z IMC>2; triglicérides em jejum >130mg/dL; lipoproteína de alta densidade <35mg/dL; glicemia em jejum >100mg/dL ou homeostatic model assessment index (HOMA) >2,5; elevação da pressão arterial acima do percentil 90 ajustada para gênero, estatura e idade. RESULTADOS: A prevalência da síndrome metabólica esteve significantimente elevada nos adolescentes obesos (GOB: 40% versus GSP: 4%, p=0,0008). O grupo GOB mostrou maiores valores referentes a insulinismo (54% versus 19%, p=0,003), HOMA (66% versus 38%, p=0,01) e trigliceridemia (21% versus 4%; p=0,04). CONCLUSÕES: É importante que o pediatra fique atento aos sinais de síndrome metabólica em adolescentes obesos. A detecção precoce pode ser feita por meio de simples parâmetros e permite a adoção de medidas preventivas para o desenvolvimento da doença cardiovascular em adolescentes.

Loss of skeletal muscle mass in aging: Examining the relationship of starvation, sarcopenia and cachexia

A loss of body weight or skeletal muscle mass is common in older persons and is a harbinger of poor outcome. Involuntary weight loss can be categorized into three primary etiologies of starvation, sarcopenia, and cachexia. Starvation results in a loss of body fat and non-fat mass due to inadequate intake of protein and energy. Sarcopenia is associated with a reduction in muscle mass and strength occurring with normal aging, associated with a reduction in motor unit number and atrophy of muscle fibers, especially the type IIa fibers. The loss of muscle mass with aging is clinically important because it leads to diminished strength and exercise capacity. Cachexia is widely recognized as severe wasting accompanying disease states such as cancer or immunodeficiency disease, but does not have a universally accepted definition. The key clinical question is whether these changes in body composition are distinct entities or represent an interdependent continuum. The importance of defining the distinction lies in developing a targeted therapeutic approach to skeletal muscle loss and muscle strength in older persons. Failure to distinguish among these causes of skeletal muscle loss often results in frustration over the clinical response to therapeutic interventions.

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.

Benefits of snacking in older Americans

OBJECTIVE

Because energy intakes decline with age, the purpose of this study was to evaluate the influence of snacking on energy intakes and energy density in older adults.

DESIGN

Twenty-four-hour dietary recall data from the National Health and Nutrition Examination Survey 1999-2002 were used to compare the diets of snackers and nonsnackers.

SUBJECTS

This study included 2,002 adults aged 65 years and older.

STATISTICAL ANALYSIS PERFORMED

All statistical analyses accounted for the survey design and sample weights. Linear regression was used to estimate energy and energy-yielding nutrient intakes, eating occasions, energy intake per eating occasions, and energy density of eating occasions.

RESULTS

The prevalence of snacking was high (84%) among this age group, and snackers had significantly higher daily intakes of energy, protein, carbohydrate, and total fat. Alcohol intakes were not significantly different. For those who snacked, it contributed almost a quarter of their energy and carbohydrate intakes and a fifth of their daily fat intakes. Snacking contributed 14% of their daily protein intakes. Snackers had, on average, two and a half snacking occasions per day, with each snacking occasion contributing 150 kcal. The average energy contribution of meals was not different between snackers and nonsnackers. The energy density of meals is significantly greater for snackers than for nonsnackers.

CONCLUSIONS

Results from this study demonstrate that snacking is an important dietary behavior among older adults. Whereas snacking may promote energy imbalance resulting in obesity among other age groups, our results suggest snacking may ensure older adults consume diets adequate in energy.

Obesity and health in Europeans aged 50 years and older

BACKGROUND

Obesity is increasing globally across all population groups. Limited data are available on how obesity patterns differ across countries.

OBJECTIVE

To document the prevalence of obesity and related health conditions for Europeans aged 50 years and older, and to estimate the association between obesity and health outcomes across 10 European countries.

METHODS

Data were obtained from the 2004 Survey of Health, Ageing and Retirement in Europe, a cross-national survey of 22,777 Continental Europeans over the age of 50 years. The health outcomes included self-reported health, disability, doctor-diagnosed chronic health conditions and depression. Multivariate regression analysis was used to predict health outcomes across weight classes (defined by body mass index [BMI] from self-reported weight and height) in the pooled sample and individually in each country.

RESULTS

The prevalence of obesity (BMI >or=30) ranged from 12.8% in Sweden to 20.2% in Spain for men and from 12.3% in Switzerland to 25.6% in Spain for women. Adjusting for compositional differences across countries changed little in the observed large heterogeneity in obesity rates throughout Europe. Compared with normal weight individuals, men and women with greater BMI had significantly higher risks for all chronic health conditions examined except heart disease in overweight men. Depression was linked to obesity in women only. Particularly pronounced risks of impaired health and chronic health conditions were found among severely obese people. The effects of obesity on health did not vary significantly across countries.

CONCLUSIONS

Cross-country differences in the prevalence of obesity in older Europeans are substantial and exceed socio-demographic differentials in excessive body weight. Obesity is associated with significantly poorer health outcomes among Europeans aged 50 years and over, with effects similar across countries. Large heterogeneity in obesity throughout Europe should be investigated further to identify areas for effective public policy.

Impact of colorectal cancer screening on future lifestyle choices: a three-year randomized controlled trial

BACKGROUND & AIMS

A potential downside of colorectal cancer screening is that a "health certificate effect" might have negative effects on lifestyle. The aim of the present randomized controlled trial was to evaluate lifestyle changes in a group of individuals offered flexible sigmoidoscopy screening compared with a control group and also in relation to screening outcome.

METHODS

Men and women aged 50-55 years were drawn by randomization from the population registry to be invited for flexible sigmoidoscopy screening (n = 6961) or not to be invited (n = 7000). Both groups were asked to fill in a questionnaire on selected lifestyle indicators at baseline and 3 years later. From both rounds, 3598 pairs of completed questionnaires were available for analysis from the screening group and 3462 from the control group.

RESULTS

Both groups revealed a desirable change in most lifestyle indicators. A weight gain in the screening group was, on average, 0.24 kg higher than in the control group (P = .023). The screening group had poorer improvement in score for smoking (mean difference, 0.05; P = .013) and exercise habits (mean difference, -0.12; P = .001) and a lower increase in servings/day of fruit, berries, and vegetables (mean difference, -0.10; P = .001) compared with controls. The weight gain in screen-negative individuals (ie, no neoplasia) was, on average, 0.5 kg (P = .020) more than for screen positives.

CONCLUSIONS

The present study has demonstrated a possible health certificate effect of flexible sigmoidoscopy screening and screening outcome on lifestyle. Although modest, these findings indicate a potential need for patient education in screening programs.

Effect of weight loss on predicted cardiovascular risk: change in cardiac risk after bariatric surgery

OBJECTIVE

Our goal was to assess the effect of bariatric surgery on cardiovascular risk estimations of preventable, long-term adverse outcomes.

RESEARCH METHODS AND PROCEDURES

We performed a population-based, historical cohort study between 1990 and 2003 of 197 consecutive patients from Olmsted County, MN, with Class II to III obesity (defined as BMI > or = 35 kg/m2) treated with Roux-en-Y gastric bypass and 163 non-operative patients assessed in a weight-reduction program. We used the observed change in cardiovascular risk factors and risk models derived from data from the National Health and Nutrition Examination Survey (NHANES) I and the NHANES I Epidemiological Follow-up Study (NHEFS) to calculate the predicted impact on cardiovascular events and mortality for the operative and non-operative groups.

RESULTS

Mean follow-up was 3.3 years. Hypertension, diabetes, and dyslipidemia all improved after bariatric surgery. The estimated 10-year risk for cardiovascular events for the operative group decreased from 37% at baseline to 18% at follow-up, while the estimated risk for the non-operative group did not change from 30% at baseline to 30% at follow-up. Risk modeling to predict 10-year outcomes estimated 4 overall deaths and 16 cardiovascular events prevented by bariatric surgery per 100 patients compared with the non-operative group.

CONCLUSIONS

Bariatric surgery induces an improvement in cardiovascular risk factors in patients with Class II to III obesity. Weight loss predicts a major, 10-year reduction in cardiovascular events and deaths. Bariatric surgery should be considered as an alternative approach to reduce cardiovascular risk in patients with Class II to III obesity.

Effects of Intended Weight Loss on Morbidity and Mortality: Possible Explanations of Controversial Results

Long-term, population-based, observational studies have shown that intended weight loss does not always reduce the mortality associated with obesity. The effects of weight loss on mortality may be a balance between the effects of the loss of harmful abdominal and ectopic fat mass and the loss of beneficial peripheral subcutaneous fat mass and lean body mass.

Obesity

There is a widespread epidemic of obesity in the United States, which has been associated with an increased risk of diabetes mellitus, cancer, and cardiovascular diseases. Although lifestyle modifications and long-term dietary vigilance remain cornerstones of weight reduction treatment, the continued availability of U.S. Food and Drug Administration-approved pharmacotherapies has expanded the options available for the management of obesity. These agents include anorexiants, thermogenic drugs, and lipid-partitioning drugs. As knowledge regarding the possible causes of obesity increases, there are new drugs under investigation, which include beta3-adrenergic receptor agonists, modifiers of leptin, and cannabinoid receptor-1 antagonists (rimonabant). Also under investigation are antidiabetic agents (metformin, exenatide), anticonvulsant drugs (topiramate, zonisamide), antidepressants (bupropion, fluoxetine), and growth hormones. New targets for pharmacotherapy include uncoupling proteins, fatty acid synthase, neuropeptide Y, melanocortin, ghrelin, various regulatory gut peptides, and ciliary neurotropic factor. Pharmacologic agents are in clinical development that target these substances.

Heart Disease Risk Determines Menopausal Age Rather Than the Reverse

OBJECTIVES

The purpose of this study was to investigate whether a harmful cardiovascular risk profile accelerates menopause.

BACKGROUND

Women with an early menopause are at an increased risk of cardiovascular disease. Although increased cardiovascular risk has been proposed as consequence of menopause, the alternative hypothesis, that increased premenopausal cardiovascular risk promotes early menopause, needs to be examined.

METHODS

We used data from the Framingham Heart Study cohort. This study started in 1948 and has followed up participants biennially since then. Women who were premenopausal at study entry and who reached natural menopause after at least two examination rounds were included in the study (n = 695). Premenopausal age-independent levels of serum total cholesterol, relative weight, blood pressure, and Framingham risk score were determined, as well as premenopausal changes in cholesterol, body weight, and blood pressure.

RESULTS

A higher premenopausal serum total cholesterol level was statistically significantly associated with an earlier age at menopause, as were increases in total serum cholesterol, relative weight, and blood pressure in the premenopausal period. A decrease in total serum cholesterol during premenopause was statistically significantly associated with later age at menopause. Decreasing blood pressure was associated with a later menopausal age, but this association was not statistically significant. A decrease in relative weight was associated with a significant earlier age at menopause. Each 1% higher premenopausal Framingham risk score was associated with a decrease in menopausal age of 1.8 years (95% confidence interval -2.72 to -0.92).

CONCLUSIONS

The findings support the view that heart disease risk determines age at menopause. This offers a novel explanation for the inconsistent findings on cardiovascular disease rate and its relationship to menopausal age and effects of hormone replacement therapy.

Obesity: prevalence, theories, medical consequences, management, and research directions

Obesity and its associated disorders are a growing epidemic across the world. Many genetic, physiological, and behavioral factors play a role in the etiology of obesity. Diet and exercise are known to play a valuable role in the treatment and prevention of obesity and associated disorders such as hypertension, heart disease, and diabetes. Therefore, the purpose of this review is to examine the prevalence, etiology, consequences, and treatment of obesity.

Cause-specific mortality in old age in relation to body mass index in middle age and in old age: follow-up of the Whitehall cohort of male civil servants

BACKGROUND

The relevance of body mass index (BMI) to cause-specific mortality in old age is uncertain.

OBJECTIVES

To examine cause-specific 5 year mortality in old age by BMI in old age and middle age (40-69 years).

METHODS

Cox proportional hazards for mortality rates among 4862 former male civil servants in relation to quartiles of BMI measured when screened in 1968-70 and when resurveyed in 1997-98 (median age 76 years).

RESULTS

The association between all-cause mortality after resurvey and BMI in old age was U-shaped with hazard ratios (HRs) of 1.3 (95% CI 1.1-1.5) for the lightest and heaviest categories relative to the middle two. Among 'healthy' men the lightest (<22.7 kg/m2) had greatest all-cause mortality. The heaviest men (>26.6 kg/m2) had increased risk of cardiovascular disease (CVD) mortality in the first two years or for the whole period if never-smokers. Respiratory mortality was inversely associated with BMI in old age [adjusted HR for trend per BMI category increase 0.6 (0.5-0.7)] but cancer mortality lacked a clear pattern. Net gain or loss of 10 kg or more between middle and old age was a strong predictor of all-cause and CVD mortality.

CONCLUSIONS

The shape of the association between BMI in old age and mortality differs by cause of death. Major weight change over time is a warning signal for higher CVD mortality. Having BMI<22.7 kg/m2 in old age is associated with above-average mortality rates even if apparently healthy.

Obesity in older adults: technical review and position statement of the American Society for Nutrition and NAASO, The Obesity Society

Obesity causes serious medical complications and impairs quality of life. Moreover, in older persons, obesity can exacerbate the age-related decline in physical function and lead to frailty. However, appropriate treatment for obesity in older persons is controversial because of the reduction in relative health risks associated with increasing body mass index and the concern that weight loss could have potential harmful effects in the older population. This joint position statement from the American Society for Nutrition and the NAASO, The Obesity Society reviews the clinical issues related to obesity in older persons and provides health professionals with appropriate weight-management guidelines for obese older patients. The current data show that weight-loss therapy improves physical function, quality of life, and the medical complications associated with obesity in older persons. Therefore, weight-loss therapy that minimizes muscle and bone losses is recommended for older persons who are obese and who have functional impairments or medical complications that can benefit from weight loss.

The seduction of general practice and illegitimate birth of an expanded role in population health care

To reduce health inequalities and improve quality in health care, health policy initiatives in countries including New Zealand and the United Kingdom are expecting general practice to share responsibilities for a population approach to health care. This is giving increased emphasis to preventative care, including health promotion. Reasoned debate on this policy is overdue, not least in New Zealand, where clinicians within general practice appear to have been seduced by the lack of clarity in health policy into accepting this policy without question. They appear to disregard implications of the policy for redefining the nature and scope of their discipline (and of public health), including their own role as providers of personal care. This paper suggests that a population health approach is inappropriate in general practice when this approach weakens personal care and involves health promotion activity of unknown safety and effectiveness. The example of intentional weight loss to reduce overweight is used to illustrate these issues. We argue for a restricted range of general practice services.

Intention to lose weight, weight changes, and 18-y mortality in overweight individuals without co-morbidities

BACKGROUND

Weight loss in the obese improves risk factors for cardiovascular diseases and diabetes. However, several studies have shown inconsistent long-term effects of weight loss on mortality. We investigated the influence on mortality of intention to lose weight and subsequent weight changes among overweight individuals without known co-morbidities.

METHODS AND FINDINGS

In 1975, a cohort of individuals reported height, weight, and current attempts (defined as "intention") to lose weight, and in 1981, they reported current weight. Mortality of the 2,957 participants with body mass index > or = 25 kg/m2 in 1975 and without pre-existing or current diseases was followed from 1982 through 1999, and 268 participants died. The association of intention to lose weight in 1975 and actual weight change until 1981 with mortality was analysed while controlling for behavioural and psychosocial risk factors and hypertension as possible confounders. Compared with the group not intending to lose and able to maintain stable weight, the hazard ratios (with 95% confidence intervals) in the group intending to lose weight were 0.84 (0.49-1.48) for those with stable weight, 1.86 (1.22-2.87) for those losing weight, and 0.93 (0.55-1.56) for those gaining weight. In the group not intending to lose weight, hazard ratios were 1.17 (0.82-1.66) for those who did lose weight, and 1.57 (1.08-2.30) for those gaining weight.

CONCLUSION

Deliberate weight loss in overweight individuals without known co-morbidities may be hazardous in the long term. The health effects of weight loss are complex, possibly composed of oppositely acting processes, and need more research.

Body Weight Change and Mortality in a Cohort of Elderly Patients Recently Discharged from the Hospital

OBJECTIVES

To evaluate the prognostic significance of weight change in frail elderly patients.

DESIGN

Prospective study.

SETTING

The general medical or surgical wards of a university-affiliated Department of Veterans Affairs hospital.

PARTICIPANTS

Six hundred sixty randomly selected subjects aged 65 or older.

MEASUREMENTS

At admission and discharge, each subject completed a standardized diagnostic evaluation, including demographic variables, and basic medical, functional, and nutritional assessments. Weights were recorded from hospital or clinic visits in the year before admission, during the current hospitalization, and after discharge for a median of 5.6 years. Average yearly intraindividual weight change was calculated using least-squares regression. Associations between intraindividual weight change and mortality were identified using Cox proportional hazards regression.

RESULTS

During the study, 314 subjects (48%) died. A U-shaped association between weight change and mortality was observed. Those who were relatively weight stable (+/-1 kg/y) had the lowest mortality (28%). Compared with this group, the adjusted relative risks (ARR) of death for those who lost 1 or more to less than 3 kg/y and 3 or more kg/y were 2.14 (95% confidence interval (CI)=1.52-3.00) and 3.59 (95% CI=2.58-4.99), respectively. The ARR associated with a weight gain of 1 or more to less than 3 kg/y and 3 or more kg/y was 1.38 (95% CI=0.91-2.10) and 3.73 (95% CI=2.34-5.94), respectively. The amount of bidirectional weight fluctuation (estimated using coefficient of variance) was not significantly associated with mortality.

CONCLUSION

For reasons that are not clear, elderly patients who gain 3 or more kg/y after hospital discharge are at nearly the same risk of mortality as those who lose this amount of weight.

Length of hospital stays among obese individuals

OBJECTIVES

We examined lengths of hospital stay among individuals categorized according to weight status.

METHODS

We used data from the First National Health and Nutrition Examination Survey Epidemiologic Followup Survey to estimate length-of-stay differences.

RESULTS

Individuals with body mass indexes (BMIs) of 35 kg/m2 or above, those with BMIs of 30 to 34 kg/m2, and those with BMIs of 25 to 29 kg/m2 had crude length-of-stay rates greater than those of normal-weight individuals. Association between BMI and length of stay varied over time.

CONCLUSIONS

Obese individuals experience longer hospital stays than normal-weight individuals.

Body mass index and short-term weight change in relation to mortality in Dutch women after age 50 y

BACKGROUND

The question of whether weight loss increases a person's longevity is important given the high prevalence of obesity and the large number of people trying to lose weight in industrialized countries.

OBJECTIVE

This study assessed the effect of body mass index (BMI) and weight change (within 1 y of baseline) on subsequent mortality.

DESIGN

This prospective cohort study had a median follow-up of 17 y. Subjects were 8100 women aged 50-66 y who participated in a population-based breast cancer-screening project in the Netherlands between 1974 and 1977. Weight and height were measured during the first and second screening visits. All women were followed until 1996 for causes of death. Cox proportional hazard analyses were conducted for mortality from all causes (n = 1269), cardiovascular disease (CVD; n = 402), and cancer (n = 492).

RESULTS

During follow-up we observed a statistically significant increased risk of mortality from all causes (hazard ratio: 1.4; 95% CI: 1.2, 1.6), cardiovascular disease, and cancer for women in the highest quartile of BMI (in kg/m(2)), > or =27.77. Mortality from all causes, CVD, and cancer did not increase significantly in women with a weight gain of > or =15%. Weight loss was also not significantly related to mortality from all causes, CVD, and cancer.

CONCLUSIONS

Mortality was highest for women in the highest BMI quartile (> or =27.77). Extreme weight gain or weight loss within 1 y was not statistically significantly associated with subsequent higher mortality.

Insulin resistance syndrome in children

The insulin resistance syndrome (syndrome X, metabolic syndrome) has become the major health problem of our times. Associated obesity, dyslipidemia, atherosclerosis, hypertension, and type 2 diabetes conspire to shorten life spans, while hyperandrogenism with polycystic ovarian syndrome affect the quality of life and fertility of increasing numbers of women. Whereas a growing number of single genetic diseases affecting satiety or energy metabolism have been found to produce the clinical phenotype, strong familial occurrences, especially in racially prone groups such as those from the Indian subcontinent, or individuals of African, Hispanic, and American Indian descents, together with emerging genetic findings, are revealing the polygenetic nature of the syndrome. However, the strong lifestyle factors of excessive carbohydrate and fat consumption and lack of exercise are important keys to the phenotypic expression of the syndrome. The natural history includes small for gestational age birth weight, excessive weight gains during childhood, premature pubarche, an allergic diathesis, acanthosis nigricans, striae compounded by gynecomastia, hypertriglyceridemia, hepatic steatosis, premature atherosclerosis, hypertension, polycystic ovarian syndrome, and focal glomerulonephritis appearing increasingly through adolescence into adulthood. Type 2 diabetes, which develops because of an inherent and/or an acquired failure of an insulin compensatory response, is increasingly seen from early puberty onward, as is atheromatous disease leading to coronary heart disease and stroke. A predisposition to certain cancers and Alzheimer's disease is also now recognized. The looming tragedy from growing numbers of individuals affected by obesity/insulin resistance syndrome requires urgent public health approaches directed at their early identification and intervention during childhood. Such measures include educating the public on the topic, limiting the consumption of sucrose-containing drinks and foods with high carbohydrate and fat contents, and promoting exercise programs in our nation's homes and schools.

Does intentional weight loss affect mortality rate?

Short-term studies indicate that intentional weight loss among obese persons significantly improves physiologic variables. Hence, it is logical to conjecture that intentional weight loss would lead to long-term benefits and increased longevity. Herein, we review recent epidemiologic studies that investigate the weight loss-mortality association using a conservative analytic approach that included distinguishing between intentional and unintentional weight loss, adjusting for potential confounders, and excluding unhealthy subjects. On balance, results indicate that intentional weight loss appears to neither increase nor decrease mortality rate. Discussion focuses on the problems of addressing this important public health question with observational data.

Trying to lose weight, losing weight, and 9-year mortality in overweight U.S. adults with diabetes

OBJECTIVE

The aim of this study was to examine the relationships between intention to lose weight, actual weight loss, and all-cause mortality among overweight individuals with diabetes.

RESEARCH DESIGN AND METHODS

We performed a prospective analysis among 1,401 overweight diabetic adults aged > or =35 years sampled in the National Health Interview Survey. The previous year intention to lose weight and weight change were assessed by self-report. Nine-year mortality rates were examined according to intent to lose weight and weight loss, which were adjusted for age, sex, education, ethnicity, smoking, initial body weight, and diabetes complications.

RESULTS

Individuals trying to lose weight had a 23% lower mortality rate (hazard rate ratio [HRR] 0.77, 95% CI 0.61-0.99) than those who reported not trying to lose weight. This association was as strong for those who failed to lose weight (0.72, 0.55-0.96) as for those who succeeded in losing weight (0.83, 0.63-1.08). Trying to lose weight was beneficial for overweight (BMI 25-30 kg/m2) individuals (0.62, 0.46-0.83) but not for obese (BMI>30) individuals (1.17, 0.72-1.92). Overall weight loss, without regard to intent, was associated with an increase of 22% (1.22, 0.99-1.50) in the mortality rate. This increase was largely explained by unintentional weight loss, which was associated with a 58% (1.58, 1.08-2.31) higher mortality rate.

CONCLUSIONS

Overweight diabetic adults trying to lose weight have a reduced risk of all-cause mortality, independent of whether they lose weight. Actual weight loss is associated with increased mortality only if the weight loss is unintentional.

Carotid atherosclerosis and cardiovascular risk factors: a comparison of residents of a rural area of Okinawa with residents of a typical suburban area of Fukuoka, Japan

Areas of Japan are known worldwide for the longevity of their residents. Okinawa has the highest longevity in Japan and a low rate of death due to cardiovascular disease. We investigated carotid atherosclerotic (CA) risk factors in islands of I city in Okinawa prefecture and compared them with K town, a suburban area of Fukuoka prefecture in Kyushu, to determine the relationship between cardiovascular risk factors and carotid atherosclerosis. We investigated conventional cardiovascular risk factors in 1078 I city residents (375 men, mean age 63.7 and 703 women, mean age 60.0) in 2000 and 2364 K town residents (676 men, mean age 57.1 and 1688 women, mean age 53.0) in 1999. Carotid atherosclerosis was assessed by mean intima-media thickness (IMT) by B-mode ultrasound. The mean IMT was significantly lower in the residents of I city than in those of K town (P < 0.05). Total cholesterol (TC) and low-density-lipoprotein cholesterol (LDL-C) levels and smoking rate were also lower in I city than in K town. Body mass index (BMI) and triglyceride (TG) level were higher in I city than in K town. In I city, multiple regression analysis found independent relationships between carotid atherosclerosis and age, sex (male), hypertension, LDL cholesterol, high-density-lipoprotein cholesterol (HDL-C), and diabetes. The lower mean IMT is probably related to a lower lifetime burden of atherosclerotic risk factors, which may in turn be related to the longevity of Okinawa residents. BMI was not a cardiovascular risk factor, although LDL cholesterol was a common important risk factor.

Long-term pharmacotherapy for obesity and overweight

BACKGROUND

Worldwide prevalence rates of obesity and overweight are rising and safe and effective treatment strategies are urgently needed. A number of anti-obesity agents have been studied in short-term clinical trials, but long-term efficacy and safety need to be established.

OBJECTIVES

To assess/compare the effects and safety of approved anti-obesity medications in clinical trials of at least one-year duration.

SEARCH STRATEGY

MEDLINE, EMBASE, the Cochrane Controlled Trials Register, the Current Science Meta-register of Controlled Trials, and reference lists of original studies and reviews were searched. Date of last search was December 2002. Drug manufacturers and two obesity experts were contacted in to detect unpublished trials. No language restrictions were imposed.

SELECTION CRITERIA

Double-blind, randomised controlled weight loss and weight maintenance trials of approved anti-obesity agents that 1) enrolled adult overweight or obese patients, 2) included a placebo control group or compared two or more anti-obesity drugs 3) used an intention-to-treat analysis, and 4) had a minimum follow-up period of one year. Abstracts and pseudo-randomised trials were not included.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed all potentially relevant citations for inclusion and methodological quality. The primary outcome measure was weight loss.

MAIN RESULTS

Of the eight anti-obesity agents investigated, only orlistat and sibutramine trials met inclusion criteria. Eleven orlistat weight loss studies (four of which reported a second year weight maintenance phase) and five sibutramine studies (three weight loss and two weight maintenance trials) were included. Attrition rates averaged 33% during the weight loss phase of orlistat trials and 43% in sibutramine studies. All patients received lifestyle modification as a co-intervention. Compared to placebo, orlistat-treated patients lost 2.7 kg (95% CI: 2.3 kg to 3.1 kg) or 2.9% (95% CI: 2.3 % to 3.4%) more weight and patients on sibutramine experienced 4.3 kg (95% CI: 3.6 kg to 4.9 kg) or 4.6% (95% CI: 3.8% to 5.4%) greater weight loss. The number of patients achieving ten percent or greater weight loss was 12% (95% CI: 8% to 16%) higher with orlistat and 15% (95% CI: 4% to 27%) higher with sibutramine therapy. Weight loss maintenance results were similar. Orlistat caused gastrointestinal side effects and sibutramine was associated with small increases in blood pressure and pulse rate.

REVIEWERS' CONCLUSIONS

Studies evaluating the long-term efficacy of anti-obesity agents are limited to orlistat and sibutramine. Both drugs appear modestly effective in promoting weight loss; however, interpretation is limited by high attrition rates. Longer and more methodologically rigorous studies of anti-obesity drugs that are powered to examine endpoints such as mortality and cardiovascular morbidity are required to fully evaluate any potential benefit of such agents.

The effect of weight change on nursing care facility admission in the NHANES I Epidemiologic Followup Survey

Data from the first National Health and Nutrition Examination Survey Epidemiologic Followup Survey were used to examine whether weight change was associated with an increased relative risk of nursing care facility admission. Hazard ratios were calculated with Cox proportional hazards models and stratified by overweight status at baseline. Moderate and large weight loss was associated with an increased risk of nursing care facility admission in overweight and non-overweight subjects. Large weight gain was associated with an increased relative risk in only overweight subjects. In the process of functional decline that results in nursing care facility admission, weight loss may be a sign of acute illness, starvation, or aging. Preventing weight loss may help delay this process of decline. In overweight subjects, preventing weight gain may also be important in delaying this process of decline.

Intentional weight loss and incidence of obesity-related cancers: the Iowa Women's Health Study

OBJECTIVE

To examine the association of voluntary vs involuntary weight loss with incidence of cancer in older women.

DESIGN

Prospective cohort study from 1993 to 2000, with cancer incidence identified through record linkage to a cancer registry.

SUBJECTS

A total of 21,707 postmenopausal women initially free of cancer.

MEASUREMENTS

Women completed a questionnaire about intentional and unintentional weight loss episodes of > or =20 pounds during adulthood.

RESULTS

Compared with women who never had any > or =20 pounds weight loss episode, women who ever experienced intentional weight loss > or =20 pounds but no unintentional weight loss had incidence rates lower by 11% for any cancer (RR=0.89, 95% CI 0.79-1.00), by 19% for breast cancer (RR=0.81, 95% CI 0.66-1.00), by 9% for colon cancer (RR=0.91, 95% CI 0.66-1.24), by 4% for endometrial cancer (RR=0.96, 95% CI 0.61-1.52), and by 14% for all obesity-related cancer (RR=0.86, 95% CI 0.74-1.01) after adjusting for age, body mass index, waist-to-hip ratio, physical activity, education, marital status, smoking status, pack-years of cigarettes, current estrogen use, alcohol use, parity, and multivitamin use. Furthermore, although overweight women were at increased risk of several cancers, women who experienced intentional weight loss episodes of 20 or more pounds and were not currently overweight were observed to have an incidence of cancer similar to nonoverweight women who never lost weight. Unintentional weight loss episodes were not associated with decreased cancer risk.

CONCLUSIONS

These findings suggest that intentional weight loss might reduce risk of obesity-related cancers.

Look AHEAD (Action for Health in Diabetes): design and methods for a clinical trial of weight loss for the prevention of cardiovascular disease in type 2 diabetes

Overweight and obesity are major contributors to both type 2 diabetes and cardiovascular disease (CVD). Moreover, individuals with type 2 diabetes who are overweight or obese are at particularly high risk for CVD morbidity and mortality. Although short-term weight loss has been shown to ameliorate obesity-related metabolic abnormalities and CVD risk factors, the long-term consequences of intentional weight loss in overweight or obese individuals with type 2 diabetes have not been adequately examined. The primary objective of the Look AHEAD clinical trial is to assess the long-term effects (up to 11.5 years) of an intensive weight loss program delivered over 4 years in overweight and obese individuals with type 2 diabetes. Approximately 5000 male and female participants who have type 2 diabetes, are 45-74 years of age, and have a body mass index >or=25 kg/m(2) will be randomized to one of the two groups. The intensive lifestyle intervention is designed to achieve and maintain weight loss through decreased caloric intake and increased physical activity. This program is compared to a control condition given diabetes support and education. The primary study outcome is time to incidence of a major CVD event. The study is designed to provide a 0.90 probability of detecting an 18% difference in major CVD event rates between the two groups. Other outcomes include components of CVD risk, cost and cost-effectiveness, diabetes control and complications, hospitalizations, intervention processes, and quality of life.

Can obesity be a risk factor in elderly people?

Obesity is increasing in middle-aged adults and in elderly subjects (over 65 years), owing to the concurrence of different factors: inactivity, wrong nutritional habits, and basal metabolism and nutritional need reduction. This condition is becoming a serious problem because of the increasing numbers of the aged population all over the world. In the past, obesity was considered as a 'secondary' pathology of no medical importance in old age; but nowadays, obesity is increasingly being studied in Geriatrics too, because it causes disability and because of its quality-of-life impairment consequences. The Euronut-Seneca study has confirmed the presence of obesity in both men and women in Europe. The definition of obesity, the reference values of body mass index and obesity as a mortality factor in elderly persons are still under discussion. Even when overweight does not represent a serious problem in old age, obese elderly people are certainly at risk of disability, morbidity and mortality. This review focuses on the potential risks of overweight and obesity in the aged population.

Impact of midlife weight change on mortality and quality of life in old age. Prospective cohort study

OBJECTIVE

To examine the effects of weight change during midlife on long-term mortality risk and quality of life in old age.

DESIGN

Prospective cohort study with a 26-y follow-up.

SUBJECTS

Socioeconomically homogeneous sample of 1657 men (born 1919-1934) who had attended health checks during the 1960s, were healthy and professionally active in 1974, and could recall their weight at the age of 25 y.

MAIN OUTCOME MEASURES

Total mortality 1974-2000, scales of the RAND-36 (SF-36) health survey in 91% (n=1147) of the survivors in 2000.

RESULTS

Body weight increased from 25 y of age until midlife, but not thereafter. During the 26-y follow-up, 392 men (23.7% of the initial 1974 cohort) died. Weight at 25 y of age did not predict death, but the adjusted mortality risk was significantly increased in the highest quartile of midlife weight gain (>/=15.0 kg) compared with lower quartiles (RR 1.39, 95% CI 1.12-1.73). In 2000, multivariate analyses (adjusted for body weight at the age of 25 y and in 2000, age, smoking, alcohol and subjective health and physical fitness in 1974) showed impairment in all eight RAND-36 scales (statistically significantly in seven) with increasing weight gain in midlife.

CONCLUSION

In this homogeneous male cohort, only the largest weight gain from 25 y of age to midlife predicted long-term mortality. Weight gain sensitively affected later health-related quality of life, and zero weight gain up to midlife was associated with the best quality of life in old age.

Lifestyle and ethnicity play a role in all-cause mortality

The Israeli population is characterized by its marked ethnic diversity. These ethnic groups (originating mainly from Yemen/Aden, the Middle East, North Africa and Europe/America) have kept traditional distinct lifestyle habits and exhibit different morbidity and mortality trends. The aim of the present study was to evaluate the associations among ethnic background, lifestyle patterns and 18-y all-cause mortality. A subgroup of 632 individuals aged 41-70 y, drawn from a larger stratified cohort from the Israel Glucose Intolerance, Obesity and Hypertension study, were personally interviewed, using a quantified food-frequency questionnaire, including most food items consumed by the different subpopulations in Israel. Physical activity was also evaluated, as well as smoking status. Weight, height and blood pressure (BP) measurements were taken. Predictors of mortality were assessed using Cox proportional hazards models. Over the 18-y follow-up period, 151 deaths occurred (24%). In comparison with Yemenites, the adjusted hazard ratios (HR) for all cause mortality were HR = 1.77 [95% confidence interval (CI): 1.01-3.09] for Europeans/Americans; HR = 1.63 (95% CI: 0.89-2.99) for those from a Middle Eastern background; and HR = 1.56 (95% CI: 0.82-2.97) for North Africans. Mortality risk was 43% lower among those consuming > or =25 g of dietary fiber daily [HR = 0.57 (95% CI: 0.41-0.72)], and 42% lower for those consuming <300 mg/d of cholesterol [HR = 0.58 (95% CI: 0.34-0.96)]. Accumulating an average of 0.5 h/d of moderate physical activity reduced mortality by 47% [HR = 0.53 (95% CI: 0.29-0.97)]. Smoking, increased systolic BP, older age and male sex increased mortality risk. We conclude that in our study, although ethnic origin and lifestyle habits are interrelated, each affects mortality independently.

Weight loss causes increased mortality: pros

There are many good reasons to expect that weight loss in overweight and obese subjects should lead to reduced mortality, not least because the general risk factor profile of several diseases responsible for the excess mortality associated with overweight and obesity improves with weight loss. However, observational long-term population studies have shown that weight loss in overweight subjects leads to increased long-term mortality, even if the studies are well controlled with regard to known confounding factors, including hazardous behaviour and underlying diseases that may lead to both weight loss and increased mortality. It seems unfeasible to wait for the multiple randomized clinical trials of sufficient quality, size and duration that may resolve this question. Therefore, the recommendations about weight loss must be based on the weaker evidence that can be obtained in short-term clinical trials and the observational population studies. Several studies have tried to address the problem by distinguishing intentional from unintentional weight loss, but only few do so by gathering information about the intention to lose weight before weight loss is observed. These studies suggest that intentional weight loss is associated with increased mortality. Recommendations to healthy overweight and obese subjects to lose weight must be based on an explicit weighing of the short-term well-documented benefits of weight loss, including improvement of quality of life, against the possible risk of an increased mortality in the long-term