Cardiovascular effects of intensive lifestyle intervention in type 2 diabetes.

BACKGROUND: Weight loss is recommended for overweight or obese patients with type 2 diabetes on the basis of short-term studies, but long-term effects on cardiovascular disease remain unknown. We examined whether an intensive lifestyle intervention for weight loss would decrease cardiovascular morbidity and mortality among such patients. METHODS: In 16 study centers in the United States, we randomly assigned 5145 overweight or obese patients with type 2 diabetes to participate in an intensive lifestyle intervention that promoted weight loss through decreased caloric intake and increased physical activity (intervention group) or to receive diabetes support and education (control group). The primary outcome was a composite of death from cardiovascular causes, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for angina during a maximum follow-up of 13.5 years. RESULTS: The trial was stopped early on the basis of a futility analysis when the median follow-up was 9.6 years. Weight loss was greater in the intervention group than in the control group throughout the study (8.6% vs. 0.7% at 1 year; 6.0% vs. 3.5% at study end). The intensive lifestyle intervention also produced greater reductions in glycated hemoglobin and greater initial improvements in fitness and all cardiovascular risk factors, except for low-density-lipoprotein cholesterol levels. The primary outcome occurred in 403 patients in the intervention group and in 418 in the control group (1.83 and 1.92 events per 100 person-years, respectively; hazard ratio in the intervention group, 0.95; 95% confidence interval, 0.83 to 1.09; P=0.51). CONCLUSIONS: An intensive lifestyle intervention focusing on weight loss did not reduce the rate of cardiovascular events in overweight or obese adults with type 2 diabetes. (Funded by the National Institutes of Health and others; Look AHEAD ClinicalTrials.gov number, NCT00017953.).

Modeling the impact of prevention policies on future diabetes prevalence in the United States: 2010-2030.

BACKGROUND: Although diabetes is one of the most costly and rapidly increasing serious chronic diseases worldwide, the optimal mix of strategies to reduce diabetes prevalence has not been determined. METHODS: Using a dynamic model that incorporates national data on diabetes prevalence and incidence, migration, mortality rates, and intervention effectiveness, we project the effect of five hypothetical prevention policies on future US diabetes rates through 2030: 1) no diabetes prevention strategy; 2) a "high-risk" strategy, wherein adults with both impaired fasting glucose (IFG) (fasting plasma glucose of 100-124 mg/dl) and impaired glucose tolerance (IGT) (2-hour post-load glucose of 141-199 mg/dl) receive structured lifestyle intervention; 3) a "moderate-risk" strategy, wherein only adults with IFG are offered structured lifestyle intervention; 4) a "population-wide" strategy, in which the entire population is exposed to broad risk reduction policies; and 5) a "combined" strategy, involving both the moderate-risk and population-wide strategies. We assumed that the moderate- and high-risk strategies reduce the annual diabetes incidence rate in the targeted subpopulations by 12.5% through 2030 and that the population-wide approach would reduce the projected annual diabetes incidence rate by 2% in the entire US population. RESULTS: We project that by the year 2030, the combined strategy would prevent 4.6 million incident cases and 3.6 million prevalent cases, attenuating the increase in diabetes prevalence by 14%. The moderate-risk approach is projected to prevent 4.0 million incident cases, 3.1 million prevalent cases, attenuating the increase in prevalence by 12%. The high-risk and population approaches attenuate the projected prevalence increases by 5% and 3%, respectively. Even if the most effective strategy is implemented (the combined strategy), our projections indicate that the diabetes prevalence rate would increase by about 65% over the 23 years (i.e., from 12.9% in 2010 to 21.3% in 2030). CONCLUSIONS: While implementation of appropriate diabetes prevention strategies may slow the rate of increase of the prevalence of diabetes among US adults through 2030, the US diabetes prevalence rate is likely to increase dramatically over the next 20 years. Demand for health care services for people with diabetes complications and diabetes-related disability will continue to grow, and these services will need to be strengthened along with primary diabetes prevention efforts.

Reverse causation and illness-related weight loss in observational studies of body weight and mortality.

In studies of weight and mortality, the construct of reverse causation has come to be used to imply that the exposure-outcome relation is biased by weight loss due to preexisting illness. Observed weight-mortality associations are sometimes thought to result from this bias. Evidence for the occurrence of such bias is weak and inconsistent, suggesting that either the analytical methods used have been inadequate or else illness-related weight loss is not an important source of bias. Deleting participants has been the most frequent approach to control possible bias. As implemented, this can lead to deletion of almost 90% of all deaths in a sample and to deletion of more overweight and obese participants than participants with normal or below normal weight. Because it has not been demonstrated that the procedures used to adjust for reverse causation increase validity or have large or systematic effects on relative risks, it is premature to consider reverse causation as an important cause of bias. Further research would be useful to elucidate the potential effects and importance of reverse causation or illness-related weight loss as a source of bias in the observed associations between weight and mortality in cohort studies.

Prevention of type 2 diabetes: risk status, clinic, and community.

Although the idea of preventing type 2 diabetes has been articulated since the discovery of insulin, only in the past decade have clinical trials demonstrated that diabetes can be prevented or delayed. These trials found lifestyle intervention reduces diabetes incidence by over 50% and is more efficacious than metformin. Evidence from prevention trials comes from persons with "pre-diabetes" in which blood glucose levels are elevated but not yet in the diabetes range. In normoglycemic persons, lifestyle or drug intervention has little impact on diabetes incidence. Prevention programs are often conducted outside the clinical sector where participants' glycemic status is usually unknown; these programs may include many normoglycemic participants, which greatly reduces cost-effectiveness. An economically sustainable system for diabetes prevention will require effective partnerships among the clinical sector, community-based lifestyle programs, and third-party payers to ensure that limited resources for diabetes prevention are focused on persons at high risk of diabetes.

Projection of the year 2050 burden of diabetes in the US adult population: dynamic modeling of incidence, mortality, and prediabetes prevalence.

BACKGROUND: People with diabetes can suffer from diverse complications that seriously erode quality of life. Diabetes, costing the United States more than $174 billion per year in 2007, is expected to take an increasingly large financial toll in subsequent years. Accurate projections of diabetes burden are essential to policymakers planning for future health care needs and costs. METHODS: Using data on prediabetes and diabetes prevalence in the United States, forecasted incidence, and current US Census projections of mortality and migration, the authors constructed a series of dynamic models employing systems of difference equations to project the future burden of diabetes among US adults. A three-state model partitions the US population into no diabetes, undiagnosed diabetes, and diagnosed diabetes. A four-state model divides the state of "no diabetes" into high-risk (prediabetes) and low-risk (normal glucose) states. A five-state model incorporates an intervention designed to prevent or delay diabetes in adults at high risk. RESULTS: The authors project that annual diagnosed diabetes incidence (new cases) will increase from about 8 cases per 1,000 in 2008 to about 15 in 2050. Assuming low incidence and relatively high diabetes mortality, total diabetes prevalence (diagnosed and undiagnosed cases) is projected to increase from 14% in 2010 to 21% of the US adult population by 2050. However, if recent increases in diabetes incidence continue and diabetes mortality is relatively low, prevalence will increase to 33% by 2050. A middle-ground scenario projects a prevalence of 25% to 28% by 2050. Intervention can reduce, but not eliminate, increases in diabetes prevalence. CONCLUSIONS: These projected increases are largely attributable to the aging of the US population, increasing numbers of members of higher-risk minority groups in the population, and people with diabetes living longer. Effective strategies will need to be undertaken to moderate the impact of these factors on national diabetes burden. Our analysis suggests that widespread implementation of reasonably effective preventive interventions focused on high-risk subgroups of the population can considerably reduce, but not eliminate, future increases in diabetes prevalence.

Preventing type 2 diabetes: public health implications for women with a history of gestational diabetes mellitus.

There is now strong evidence that lifestyle modification can prevent or delay the development of type 2 diabetes mellitus in high-risk individuals. Women with gestational diabetes mellitus are at increased risk for type 2 diabetes and so are candidates for prevention programs. We review literature on type 2 diabetes risk in women with gestational diabetes, examine current recommendations for postpartum and long-term follow-up, and summarize findings from a 2007 expert-panel meeting. We found data to support that women with gestational diabetes have an increase in risk of type 2 diabetes comparable in magnitude with that of individuals with impaired glucose tolerance and/or impaired fasting glucose and that prevention interventions likely are effective in this population. Current recommendations from leading organizations on follow-up of women after delivery are conflicting and compliance is poor. Clinicians and public health workers face numerous challenges in developing intervention strategies for this population. Translation research will be critical in addressing this important public health issue.

REPRINT OF: Relationship of Childhood Abuse and Household Dysfunction to Many of the Leading Causes of Death in Adults: The Adverse Childhood Experiences (ACE) Study.

BACKGROUND: The relationship of health risk behavior and disease in adulthood to the breadth of exposure to childhood emotional, physical, or sexual abuse, and household dysfunction during childhood has not previously been described. METHODS: A questionnaire about adverse childhood experiences was mailed to 13,494 adults who had completed a standardized medical evaluation at a large HMO; 9,508 (70.5%) responded. Seven categories of adverse childhood experiences were studied: psychological, physical, or sexual abuse; violence against mother; or living with household members who were substance abusers, mentally ill or suicidal, or ever imprisoned. The number of categories of these adverse childhood experiences was then compared to measures of adult risk behavior, health status, and disease. Logistic regression was used to adjust for effects of demographic factors on the association between the cumulative number of categories of childhood exposures (range: 0-7) and risk factors for the leading causes of death in adult life. RESULTS: More than half of respondents reported at least one, and one-fourth reported ≥2 categories of childhood exposures. We found a graded relationship between the number of categories of childhood exposure and each of the adult health risk behaviors and diseases that were studied (P < .001). Persons who had experienced four or more categories of childhood exposure, compared to those who had experienced none, had 4- to 12-fold increased health risks for alcoholism, drug abuse, depression, and suicide attempt; a 2- to 4-fold increase in smoking, poor self-rated health, ≥50 sexual intercourse partners, and sexually transmitted disease; and a 1.4- to 1.6-fold increase in physical inactivity and severe obesity. The number of categories of adverse childhood exposures showed a graded relationship to the presence of adult diseases including ischemic heart disease, cancer, chronic lung disease, skeletal fractures, and liver disease. The seven categories of adverse childhood experiences were strongly interrelated and persons with multiple categories of childhood exposure were likely to have multiple health risk factors later in life. CONCLUSIONS: We found a strong graded relationship between the breadth of exposure to abuse or household dysfunction during childhood and multiple risk factors for several of the leading causes of death in adults.

Excess Deaths Associated With Underweight, Overweight, and Obesity: An Evaluation of Potential Bias.

As the prevalence of obesity has increased over time in the United States (1,2), concern over the association between body weight and excess mortality also increased. In 2005, an analysis of estimated excess deaths, relative to the normal weight category (body mass index [BMI] 18.5-24.9), that were associated with underweight (BMI less than 18.5), overweight (BMI 25.0-29.9), and obesity (BMI greater than or equal to 30) in U.S. adults in 2000 was published (3). Both underweight and obesity, particularly higher levels of obesity, were associated with increased mortality relative to the normal weight category. Obesity was estimated to be associated with 111,909 excess deaths (95% confidence interval [CI]: 53,754 to 170,064) in 2000 relative to the normal weight category, and underweight with 33,746 excess deaths (95% CI: 15,726 to 51,766). Overweight was associated with reduced mortality (-86,094 deaths; 95% CI: -161,223 to -10,966). This report evaluates several potential sources of bias in that analysis.

The association between quality of care and the intensity of diabetes disease management programs.

BACKGROUND: Although disease management programs are widely implemented, little is known about their effectiveness. OBJECTIVE: To determine whether disease management by physician groups is associated with diabetes care processes, control of intermediate outcomes, or the amount of medication used when intermediate outcomes are above target levels. DESIGN: Cross-sectional study. SETTING: Patients were randomly sampled from 63 physician groups nested in 7 health plans sponsored by Translating Research into Action for Diabetes (87%) and from 4 health plans with individual physician contracts (13%). PATIENTS: 8661 adults with diabetes who completed a survey (2000-2001) and had medical record data. MEASUREMENTS: Physician group and health plan directors described their organizations' use of physician reminders, performance feedback, and structured care management on a survey; their responses were used to determine measures of intensity of disease management. The current study measured 8 processes of care, including most recent hemoglobin A1c level, systolic blood pressure, serum low-density lipoprotein cholesterol level, and several measures of medication use. RESULTS: Increased use of any of 3 disease management strategies was significantly associated with higher adjusted rates of retinal screening, nephropathy screening, foot examinations, and measurement of hemoglobin A1c levels. Serum lipid level testing and influenza vaccine administration were associated with greater use of structured care management and performance feedback. Greater use of performance feedback correlated with an increased rate of foot examinations (difference, 5 percentage points [95% CI, 1 to 8 percentage points]), and greater use of physician reminders was associated with an increased rate of nephropathy screening (difference, 15 percentage points [CI, 6 to 23 percentage points]). No strategies were associated with intermediate outcome levels or level of medication management. LIMITATIONS: Physician groups were not randomly sampled from population-based listings, and disease management strategies were not randomly allocated across groups. CONCLUSIONS: Disease management strategies were associated with better processes of diabetes care but not with improved intermediate outcomes or level of medication management. A greater focus on direct measurement, feedback, and reporting of intermediate outcome levels or of level of medication management may enhance the effectiveness of these programs.

Cause-specific excess deaths associated with underweight, overweight, and obesity.

CONTEXT: The association of body mass index (BMI) with cause-specific mortality has not been reported for the US population. OBJECTIVE: To estimate cause-specific excess deaths associated with underweight (BMI <18.5), overweight (BMI 25-<30), and obesity (BMI > or =30). DESIGN, SETTING, AND PARTICIPANTS: Cause-specific relative risks of mortality from the National Health and Nutrition Examination Survey (NHANES) I, 1971-1975; II, 1976-1980; and III, 1988-1994, with mortality follow-up through 2000 (571,042 person-years of follow-up) were combined with data on BMI and other covariates from NHANES 1999-2002 with underlying cause of death information for 2.3 million adults 25 years and older from 2004 vital statistics data for the United States. MAIN OUTCOME MEASURES: Cause-specific excess deaths in 2004 by BMI levels for categories of cardiovascular disease (CVD), cancer, and all other causes (noncancer, non-CVD causes). RESULTS: Based on total follow-up, underweight was associated with significantly increased mortality from noncancer, non-CVD causes (23,455 excess deaths; 95% confidence interval [CI], 11,848 to 35,061) but not associated with cancer or CVD mortality. Overweight was associated with significantly decreased mortality from noncancer, non-CVD causes (-69 299 excess deaths; 95% CI, -100 702 to -37 897) but not associated with cancer or CVD mortality. Obesity was associated with significantly increased CVD mortality (112,159 excess deaths; 95% CI, 87,842 to 136,476) but not associated with cancer mortality or with noncancer, non-CVD mortality. In further analyses, overweight and obesity combined were associated with increased mortality from diabetes and kidney disease (61 248 excess deaths; 95% CI, 49 685 to 72,811) and decreased mortality from other noncancer, non-CVD causes (-105,572 excess deaths; 95% CI, -161 816 to -49,328). Obesity was associated with increased mortality from cancers considered obesity-related (13,839 excess deaths; 95% CI, 1920 to 25,758) but not associated with mortality from other cancers. Comparisons across surveys suggested a decrease in the association of obesity with CVD mortality over time. CONCLUSIONS: The BMI-mortality association varies by cause of death. These results help to clarify the associations of BMI with all-cause mortality.

A structured review of randomized controlled trials of weight loss showed little improvement in health-related quality of life.

OBJECTIVE: To estimate the effect of weight-loss interventions on health-related quality of life (HrQoL) in randomized controlled trials (RCTs); to conduct a meta-analysis of weight-loss treatment on depressive symptoms; and, to examine methodological and presentation issues that compromise study validity. STUDY DESIGN AND SETTING: We conducted a structured review of 34 RCTs with weight-loss interventions that reported the relationship between HrQoL and treatment at two or more time points. We also evaluated study quality. RESULTS: Trials lasted 6 weeks to 208 weeks and evaluated behavioral, surgical, or pharmacologic interventions. Nine of 34 trials showed HrQoL improvements in generic measures. Obesity-specific measures were more likely to show improvement in response to treatment than non-obesity-specific measures. Meta-analysis showed no treatment effect on depressive symptoms. Most trials tracked loss to follow-up and conducted intent-to-treat analysis, but only four trials concealed recruitment staff to randomization and 14 blinded the investigation team to randomization. CONCLUSION: HrQoL outcomes, including depression, were not consistently improved in RCTs of weight loss. The overall quality of these clinical trials was poor. Better-designed RCTs using standardized HrQoL measures are needed to determine the extent to which weight loss improves HrQoL.

Childhood residential mobility and multiple health risks during adolescence and adulthood: the hidden role of adverse childhood experiences.

BACKGROUND: Throughout US history, US society has been characterized by its high degree of residential mobility. Previous data suggest a relationship between mobility and increased health risk, but this relationship might be confounded by unmeasured adverse childhood experiences (ACEs). OBJECTIVES: To examine the relationship of childhood residential mobility to health problems during adolescence and adulthood and to determine how much these apparent relationships may result from underlying ACEs. DESIGN, SETTING, AND PARTICIPANTS: Retrospective cohort study of 8116 adults who completed a survey that included childhood residential mobility, ACEs (childhood abuse, childhood neglect, and household dysfunction), and multiple health problems. MAIN OUTCOME MEASURES: Number of childhood residential moves and number of ACEs (ACE score) were assessed for relationships to depressed affect, attempted suicide, alcoholism, smoking, early sexual initiation, and teenaged pregnancy. RESULTS: After adjustment for demographic variables, the risk of high residential mobility during childhood (> or = 8 moves) was 1.7- to 3.1-fold for each ACE, and increased with the number of ACEs. Compared with respondents who never moved, the odds of health risk for respondents with high mobility during childhood ranged from 1.3 (for smoking) to 2.5 (for suicide). However, when the number of ACEs was entered into multivariate models, the relationship between mobility and health problems was greatly reduced. CONCLUSIONS: Adverse childhood experiences are strongly associated with frequent residential mobility. Moreover, the apparent relationship between childhood mobility and various health risks is largely explained by ACEs. Thus, previous studies showing a relationship between residential mobility and negative outcomes were likely confounded by unmeasured ACEs.

Combination pharmacotherapy for cardiovascular disease prevention: threat or opportunity for public health?

In a series of three papers in the British Medical Journal (June 28, 2003), Wald et al. proposed that the Polypill can reduce the incidence of coronary heart disease by 88%, and stroke by 80%, if taken by all people aged > or = 55, as well as people of any age with existing cardiovascular disease or diabetes. We review the rationale and uniqueness behind this idea, identify the concerns and questions that need to be addressed, discuss whether this strategy is a threat or an opportunity for public health, and hope that this will stimulate further debate.

Relationship of walking to mortality among US adults with diabetes.

BACKGROUND: Walking is associated with reduced diabetes incidence, but few studies have examined whether it reduces mortality among those who already have diabetes. OBJECTIVE: To estimate the association between walking and the risk for all-cause and cardiovascular disease (CVD) mortality among persons with diabetes. DESIGN: Prospective cohort study of a representative sample of the US population. SETTING: Interviewer-administered survey in the general community. PARTICIPANTS: We sampled 2896 adults 18 years and older with diabetes as part of the 1990 and 1991 National Health Interview Survey. MAIN OUTCOME MEASURE: All-cause and CVD mortality for 8 years. RESULTS: Compared with inactive individuals, those who walked at least 2 h/wk had a 39% lower all-cause mortality rate (hazard rate ratio [HRR], 0.61; 95% confidence interval [CI], 0.48-0.78; 2.8% vs 4.4% per year) and a 34% lower CVD mortality rate (HRR, 0.66; 95% CI, 0.45-0.96; 1.4% vs 2.1% per year). We controlled for sex, age, race, body mass index (calculated as weight in kilograms divided by the square of height in meters), smoking, and comorbid conditions. The mortality rates were lowest for persons who walked 3 to 4 h/wk (all-cause mortality HRR, 0.46; 95% CI, 0.29-0.71; CVD mortality HRR, 0.47; 95% CI, 0.24-0.91) and for those who reported that their walking involved moderate increases in heart and breathing rates (all-cause mortality HRR, 0.57; 95% CI, 0.41-0.80; CVD mortality HRR, 0.69; 95% CI, 0.43-1.09). The protective association of physical activity was observed for persons of varying sex, age, race, body mass index, diabetes duration, comorbid conditions, and physical limitations. CONCLUSIONS: Walking was associated with lower mortality across a diverse spectrum of adults with diabetes. One death per year may be preventable for every 61 people who could be persuaded to walk at least 2 h/wk.

Primary prevention of type 2 diabetes mellitus by lifestyle intervention: implications for health policy.

More than 18 million Americans currently have diabetes mellitus. The economic and human cost of the disease is devastating. In the United States, diabetes is the most common cause of blindness among working-age adults, the most common cause of nontraumatic amputations and end-stage renal disease, and the sixth most common cause of death. For the cohort of Americans born in 2000, the estimated lifetime risk for diabetes is more than 1 in 3. In the next 50 years, the number of diagnosed cases of diabetes is predicted to increase by 165% in the United States, with the largest relative increases seen among African Americans, American Indians, Alaska Natives, Asian and Pacific Islanders, and Hispanic/Latino persons. Compelling scientific evidence indicates that lifestyle change prevents or delays the occurrence of type 2 diabetes in high-risk groups. This body of evidence from randomized, controlled trials conducted in 3 countries has definitively established that maintenance of modest weight loss through diet and physical activity reduces the incidence of type 2 diabetes in high-risk persons by about 40% to 60% over 3 to 4 years. The number of persons at high risk for type 2 diabetes is similar to the number of persons who have diabetes. This paper summarizes scientific evidence supporting lifestyle intervention to prevent type 2 diabetes and discusses major policy challenges to broad implementation of lifestyle intervention in the health system.

Intentional weight loss and death in overweight and obese U.S. adults 35 years of age and older.

BACKGROUND: Although weight loss improves risk factors for cardiovascular and metabolic disease, it is unclear whether intentional weight loss reduces mortality rates. OBJECTIVE: To examine the relationships among intention to lose weight, weight loss, and all-cause mortality. DESIGN: Prospective cohort study using a probability sample of the U.S. population. SETTING: Interviewer-administered survey. PARTICIPANTS: 6391 overweight and obese persons (body mass index > or = 25 kg/m2) who were at least 35 years of age. MEASUREMENTS: Intention to lose weight and weight change during the past year were assessed by self-report in 1989. Vital status was followed for 9 years. Hazard rate ratios (HRRs) were adjusted for age, sex, ethnicity, education, smoking, health status, health care utilization, and initial body mass index. RESULTS: Compared with persons not trying to lose weight and reporting no weight change, those reporting intentional weight loss had a 24% lower mortality rate (HRR, 0.76 [95% CI, 0.60 to 0.97]) and those with unintentional weight loss had a 31% higher mortality rate (HRR, 1.31 [CI, 1.01 to 1.70]). However, mortality rates were lower in persons who reported trying to lose weight than those in not trying to lose weight, independent of actual weight change. Compared with persons not trying to lose weight and reporting no weight change, persons trying to lose weight had the following HRRs: no weight change, 0.80 (CI, 0.65 to 0.99); gained weight, 0.94 (CI, 0.65 to 1.37); and lost weight, 0.76 (CI, 0.60 to 0.97). CONCLUSIONS: Attempted weight loss is associated with lower all-cause mortality, independent of weight change. Self-reported intentional weight loss is associated with lower mortality rates, and weight loss is associated with higher mortality rates only if it is unintentional.

Excess deaths associated with underweight, overweight, and obesity.

CONTEXT: As the prevalence of obesity increases in the United States, concern over the association of body weight with excess mortality has also increased. OBJECTIVE: To estimate deaths associated with underweight (body mass index [BMI] <18.5), overweight (BMI 25 to <30), and obesity (BMI > or =30) in the United States in 2000. DESIGN, SETTING, AND PARTICIPANTS: We estimated relative risks of mortality associated with different levels of BMI (calculated as weight in kilograms divided by the square of height in meters) from the nationally representative National Health and Nutrition Examination Survey (NHANES) I (1971-1975) and NHANES II (1976-1980), with follow-up through 1992, and from NHANES III (1988-1994), with follow-up through 2000. These relative risks were applied to the distribution of BMI and other covariates from NHANES 1999-2002 to estimate attributable fractions and number of excess deaths, adjusted for confounding factors and for effect modification by age. MAIN OUTCOME MEASURES: Number of excess deaths in 2000 associated with given BMI levels. RESULTS: Relative to the normal weight category (BMI 18.5 to <25), obesity (BMI > or =30) was associated with 111,909 excess deaths (95% confidence interval [CI], 53,754-170,064) and underweight with 33,746 excess deaths (95% CI, 15,726-51,766). Overweight was not associated with excess mortality (-86,094 deaths; 95% CI, -161,223 to -10,966). The relative risks of mortality associated with obesity were lower in NHANES II and NHANES III than in NHANES I. CONCLUSIONS: Underweight and obesity, particularly higher levels of obesity, were associated with increased mortality relative to the normal weight category. The impact of obesity on mortality may have decreased over time, perhaps because of improvements in public health and medical care. These findings are consistent with the increases in life expectancy in the United States and the declining mortality rates from ischemic heart disease.

Secular trends in cardiovascular disease risk factors according to body mass index in US adults.

CONTEXT: Prevalence of obesity in the United States has increased dramatically in recent decades, but the magnitude of change in cardiovascular disease (CVD) risk factors among the growing proportion of overweight and obese Americans remains unknown. OBJECTIVE: To examine 40-year trends in CVD risk factors by body mass index (BMI) groups among US adults aged 20 to 74 years. DESIGN, SETTING, AND PARTICIPANTS: Analysis of 5 cross-sectional, nationally representative surveys: National Health Examination Survey (1960-1962); National Health and Nutrition Examination Survey (NHANES) I (1971-1975), II (1976-1980), and III (1988-1994); and NHANES 1999-2000. MAIN OUTCOME MEASURES: Prevalence of high cholesterol level (> or =240 mg/dL [> or =6.2 mmol/L] regardless of treatment), high blood pressure (> or =140/90 mm Hg regardless of treatment), current smoking, and total diabetes (diagnosed and undiagnosed combined) according to BMI group (lean, <25; overweight, 25-29; and obese, > or =30). RESULTS: The prevalence of all risk factors except diabetes decreased over time across all BMI groups, with the greatest reductions observed among overweight and obese groups. Compared with obese persons in 1960-1962, obese persons in 1999-2000 had a 21-percentage-point lower prevalence of high cholesterol level (39% in 1960-1962 vs 18% in 1999-2000), an 18-percentage-point lower prevalence of high blood pressure (from 42% to 24%), and a 12-percentage-point lower smoking prevalence (from 32% to 20%). Survey x BMI group interaction terms indicated that compared with the first survey, the prevalence of high cholesterol in the fifth survey had fallen more in obese and overweight persons than in lean persons (P<.05). Survey x BMI changes in blood pressure and smoking were not statistically significant. Changes in risk factors were accompanied by increases in lipid-lowering and antihypertensive medication use, particularly among obese persons. Total diabetes prevalence was stable within BMI groups over time, as nonsignificant 1- to 2-percentage-point increases occurred between 1976-1980 and 1999-2000. CONCLUSIONS: Except for diabetes, CVD risk factors have declined considerably over the past 40 years in all BMI groups. Although obese persons still have higher risk factor levels than lean persons, the levels of these risk factors are much lower than in previous decades.

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.