Impact of overweight on the risk of developing common chronic diseases during a 10-year period.

BACKGROUND: Overweight adults are at an increased risk of developing numerous chronic diseases. METHODS: Ten-year follow-up (1986-1996) of middle-aged women in the Nurses' Health Study and men in the Health Professionals Follow-up Study to assess the health risks associated with overweight. RESULTS: The risk of developing diabetes, gallstones, hypertension, heart disease, and stroke increased with severity of overweight among both women and men. Compared with their same-sex peers with a body mass index (BMI) (calculated as weight in kilograms divided by the square of height in meters) between 18.5 and 24.9, those with BMI of 35.0 or more were approximately 20 times more likely to develop diabetes (relative risk [RR], 17.0; 95% confidence interval [CI], 14.2-20.5 for women; RR, 23.4; 95% CI, 19.4-33.2 for men). Women who were overweight but not obese (ie, BMI between 25.0 and 29.9) were also significantly more likely than their leaner peers to develop gallstones (RR, 1.9), hypertension (RR, 1.7), high cholesterol level (RR, 1.1), and heart disease (RR, 1.4). The results were similar in men. CONCLUSIONS: During 10 years of follow-up, the incidence of diabetes, gallstones, hypertension, heart disease, colon cancer, and stroke (men only) increased with degree of overweight in both men and women. Adults who were overweight but not obese (ie, 25.0 < or = BMI < or = 29.9) were at significantly increased risk of developing numerous health conditions. Moreover, the dose-response relationship between BMI and the risk of developing chronic diseases was evident even among adults in the upper half of the healthy weight range (ie, BMI of 22.0-24.9), suggesting that adults should try to maintain a BMI between 18.5 and 21.9 to minimize their risk of disease.

Association between psychosocial work characteristics and health functioning in American women: prospective study.

OBJECTIVE: To examine prospectively the relation between psychosocial work characteristics and changes in health related quality of life over four years in a cohort of working women in the United States. DESIGN: Longitudinal cohort study. SETTING: United States. PARTICIPANTS: 21 290 female registered nurses who completed the Karasek's job content questionnaire and a modified version of the short form 36 questionnaire (SF-36) as used for a survey of health status by the medical outcomes study. MAIN OUTCOME MEASURES: Seven dimensions of health status: physical functioning, role limitations due to physical health problems, bodily pain, vitality, social functioning, role limitations due to emotional problems, and mental health. RESULTS: Examined separately low job control, high job demands, and low work related social support were associated with poor health status at baseline as well as greater functional declines over the four year follow up period. Examined in combination, women with low job control, high job demands, and low work related social support ("iso-strain" jobs) had the greatest functional declines. These associations could not be explained by age, body mass index, comorbid disease status, alcohol consumption, smoking status, education level, exercise level, employment status, marital status, or presence of a confidant. CONCLUSIONS: Adverse psychosocial work conditions are important predictors of poor functional status and its decline over time.

A prospective study of weight change and health-related quality of life in women.

CONTEXT: The mean body weight of US adults increased by 3.6 kg (7.6 lb) during the past 15 years, but few studies exist that examine the impact of such weight change on functional health status. OBJECTIVE: To investigate, prospectively, the association between weight change and health-related quality of life in women. DESIGN AND SETTING: Nurses' Health Study, a 4-year prospective observational study from 1992 to 1996, using the Medical Outcomes Study Short-Form 36 Health Status Survey (a self-administered 36-item questionnaire) to measure quality of life. PARTICIPANTS: A cohort of 40098 women (from 46-71 years old in 1992) grouped according to 3 patterns of weight change over the 4-year period: women whose weight remained within 2.25 kg (5 lb) of their baseline weight, women who lost 2.25 kg (5 lb) or more, and women who gained 2.25 kg (5 lb) or more. MAIN OUTCOME MEASURES: Change in scores on 7 health-related quality-of-life dimensions: physical functioning, vitality, bodily pain, limitations in role functioning due to emotional or physical problems, social functioning, and mental health, measured by the Short-Form 36 Health Status Survey. RESULTS: A total of 15602 women (39%) maintained their weight, 15160 (38%) gained between 2.25 and 9.0 kg (5-20 lb), and 6667 (17%) lost between 2.25 and 9.0 kg (5-20 lb). Weight gain was associated with decreased physical function and vitality, and increased bodily pain regardless of baseline weight. For example, the odds ratio for developing role limitations due to physical problems was 2.05 (95% confidence interval, 1.69-2.49) for the leanest women who gained 9.0 kg (20 lb) or more. Weight loss in overweight women was associated with improved physical function and vitality as well as decreased bodily pain. Weight change was more strongly associated with physical rather than mental health. The impact of weight change, especially weight gain, was just as strong in women 65 years and older as in women younger than 65 years. CONCLUSIONS: These longitudinal data support current US guidelines for women of all body mass index levels to avoid weight gain. Weight maintenance and, in cases of overweight, weight loss are desirable and likely to be beneficial for physical function, vitality, and bodily pain.

The disease burden associated with overweight and obesity.

CONTEXT: Overweight and obesity are increasing dramatically in the United States and most likely contribute substantially to the burden of chronic health conditions. OBJECTIVE: To describe the relationship between weight status and prevalence of health conditions by severity of overweight and obesity in the US population. DESIGN AND SETTING: Nationally representative cross-sectional survey using data from the Third National Health and Nutrition Examination Survey (NHANES III), which was conducted in 2 phases from 1988 to 1994. PARTICIPANTS: A total of 16884 adults, 25 years and older, classified as overweight and obese (body mass index [BMI] > or =25 kg/m2) based on National Institutes of Health recommended guidelines. MAIN OUTCOME MEASURES: Prevalence of type 2 diabetes mellitus, gallbladder disease, coronary heart disease, high blood cholesterol level, high blood pressure, or osteoarthritis. RESULTS: Sixty-three percent of men and 55% of women had a body mass index of 25 kg/m2 or greater. A graded increase in the prevalence ratio (PR) was observed with increasing severity of overweight and obesity for all of the health outcomes except for coronary heart disease in men and high blood cholesterol level in both men and women. With normal-weight individuals as the reference, for individuals with BMIs of at least 40 kg/m2 and who were younger than 55 years, PRs were highest for type 2 diabetes for men (PR, 18.1; 95% confidence interval [CI], 6.7-46.8) and women (PR, 12.9; 95% CI, 5.7-28.1) and gallbladder disease for men (PR, 21.1; 95% CI, 4.1-84.2) and women (PR, 5.2; 95% CI, 2.9-8.9). Prevalence ratios generally were greater in younger than in older adults. The prevalence of having 2 or more health conditions increased with weight status category across all racial and ethnic subgroups. CONCLUSIONS: Based on these results, more than half of all US adults are considered overweight or obese. The prevalence of obesity-related comorbidities emphasizes the need for concerted efforts to prevent and treat obesity rather than just its associated comorbidities.

Part-time residency training in internal medicine: analysis of a ten-year experience.

PURPOSE: To evaluate a ten-year experience (1983-1993) with a part-time residency curriculum. METHOD: In 1994, the authors analyzed the curriculum through interviews with graduates of a part-time residency track, surveys of faculty and graduates of a full-time residency program, and a quantitative comparison of faculty evaluations of those part-time and full-time residents. RESULTS: Both participants and full-time residents supported the part-time track and reported no adverse effect on the residency program as a whole. Analysis of faculty evaluations found that part-time residents scored significantly higher with respect to clinical skills (p = .0005) and humanistic skills (p = .0001), while there was no difference between the groups in leadership or teaching skills. CONCLUSIONS: This part-time residency curriculum provided a highly useful program track for a group of internal medicine residents with concomitant obligations, allowing them to complete their training in an uninterrupted fashion. The part-time structure did not adversely affect clinical competence and may have fostered humanistic attributes. The authors believe that this form of curriculum deserves wider consideration in residency training.

Long-term weight patterns and risk for cholecystectomy in women.

BACKGROUND: Obesity and rapid weight loss in obese persons are known risk factors for gallstones. However, the effect of intentional, long-term, moderate weight changes on the risk for gallstones is unclear. OBJECTIVE: To study long-term weight patterns in a cohort of women and to examine the relation between weight pattern and risk for cholecystectomy. DESIGN: Prospective cohort study. SETTING: 11 U.S. states. PARTICIPANTS: 47,153 female registered nurses who did not undergo cholecystectomy before 1988. MEASUREMENTS: Cholecystectomy between 1988 and 1994 (ascertained by patient self-report). RESULTS: During the exposure period (1972 to 1988), there was evidence of substantial variation in weight due to intentional weight loss during adulthood. Among cohort patients, 54.9% reported weight cycling with at least one episode of intentional weight loss associated with regain. Of the total cohort, 20.1% were light cyclers (5 to 9 lb of weight loss and gain), 18.8% were moderate cyclers (10 to 19 lb of weight loss and gain), and 16.0% were severe cyclers (> or = 20 lb of weight loss and gain). Net weight gain without cycling occurred in 29.3% of women; net weight loss without cycling was the least common pattern (4.6%). Only 11.1% of the cohort maintained weight within 5 lb over the 16-year period. In the study, 1751 women had undergone cholecystectomy between 1988 and 1994. Compared with weight maintainers, the relative risk for cholecystectomy (adjusted for body mass index, age, alcohol intake, fat intake, and smoking) was 1.20 (95% CI, 0.96 to 1.50) among light cyclers, 1.31 among moderate cyclers (CI, 1.05 to 1.64), and 1.68 among severe cyclers (CI, 1.34 to 2.10). CONCLUSION: Weight cycling was highly prevalent in this large cohort of middle-aged women. The risk for cholecystectomy associated with weight cycling was substantial, independent of attained relative body weight.

Lower levels of physical functioning are associated with higher body weight among middle-aged and older women.

OBJECTIVE: To compare levels of physical function, across levels of body mass index (BMI), among middle- to older-aged women. DESIGN: Cross-sectional study. Physical function, body weight and other covariates were measured in 1992. SUBJECTS: 56510 women aged 45-71 y, free of cardiovascular disease and cancer, participating in the Nurses' Health Study. MAIN OUTCOME MEASURES: The four physical function scores on the Medical Outcomes Study (MOS) Short Form-36 (SF36) Health Survey: physical functioning, vitality, bodily pain and role limitations. RESULTS: After adjusting for age, race, smoking status, menopausal status, physical activity and alcohol consumption, there was a significant dose-response gradient between increasing levels of BMI in 1992 and reduced function. For example, women with a BMI between 30-34.9 kg/m2 averaged: 9.0 point lower physical functioning score (95% Confidence interval (CI) -9.5, -8.5), 5.6 point lower vitality score (95% CI: -6.1, -5.1), and 7.0 point lower freedom from pain score (95% CI: -7.6, -6.4). These declines represent an approximate 10% loss of function compared to the reference category of women with BMIs ranging from 22.0-23.9 kg/m2. For the same BMI comparison, heavier women were at 66% increased risk of limitations in ability to work or perform other roles (RR = 1.66; 95% odds ratio (OR) CI: 1.56, 1.76). These findings were replicated when the sample was restricted to women who had maintained their BMI over a ten year period. CONCLUSIONS: In addition to increasing risk of chronic health conditions, greater adiposity is associated with lower every day physical functioning, such as climbing stairs or other moderate activities, as well as lower feelings of well-being and greater burden of pain.

Relationship of job strain and iso-strain to health status in a cohort of women in the United States.

OBJECTIVE: This study examined the relationships of job strain and iso-strain psychosocial work-environment exposures to health status in a cohort of working women in the United States. METHODS: In a cross-sectional survey, 33689 women responded to the Karasek job content and the MOS SF-36 health status questionnaires. The psychosocial work-environment exposures were characterized using the job strain and iso-strain frameworks. Health status was assessed with the following 6 scales: physical functioning, vitality, freedom from pain, mental health, role limitations due to physical health, and role limitations due to emotional health. RESULTS: When compared with active work, high-strain work (high job demands and low job control) was associated with lower vitality, mental health, higher pain, and increased risks of both physical and emotional role limitations. Iso-strain work (high strain and low work-related social support) increased the risks further. Job insecurity was also associated with lower health status. CONCLUSIONS: The analyses supported the hypothesis that the psychosocial work environment is an important determinant of health status among working women. The findings suggest that incorporating social conditions at work into the measurement of psychosocial work-environment exposure improves the identification of high-risk work arrangements.

Predictors of weight change in men: results from the Health Professionals Follow-up Study.

OBJECTIVE: Since the prevalence of adult obesity is increasing in the United States, we examined the effect of changing common habits (exercise, TV viewing, smoking and eating habits) on four year change in body weight. DESIGN: A prospective cohort study of US male health professionals with follow-up from 1988-1992. Participants were 19478 men aged 40-75 in 1986, who were free of cancer, coronary heart disease, stroke and diabetes. METHODS: Multiple regression was used to determine the association between four year change in body weight (from 1988-1992) and common habits, after adjusting for baseline age, hypertension and hypercholesterolemia. RESULTS: For middle aged men, vigorous activity was associated with weight reduction and TV/VCR viewing and eating between meals with weight gain. Quitting smoking and a history of voluntary weight loss prior to the study period were consistently related to weight increase. Recently being on a diet was more strongly associated with weight loss among older men. Over the four year follow-up period, middle-aged men who increased their exercise, decreased TV viewing and stopped eating between meals, lost an average weight of -1.4 kg (95% confidence interval (CI) -1.6 - -1.1 kg), compared to a weight gain of 1.4 kg among the overall population. The prevalence of obesity among middle-aged men was lowest among those who maintained a relatively high level of vigorous physical activity, compared to those who were relatively sedentary. CONCLUSION: These data suggest that improvement in the mix of health habits, particularly increasing vigorous activity, as well as decreasing TV use and changing eating habits, results in weight maintenance or a modest weight loss over four years.

Can physical activity minimize weight gain in women after smoking cessation?

OBJECTIVES: The purpose of this study was to examine prospectively whether exercise can modify weight gain after smoking cessation in women. METHODS: Data were analyzed from a 2-year follow-up period (1986-1988) in the Nurses' Health Study, an ongoing cohort of 121,700 US women aged 40 to 75 in 1986. RESULTS: The average weight gain over 2 years was 3.0 kg in the 1474 women who stopped smoking, and 0.6 kg among the 7832 women who continued smoking. Among women smoking 1 to 24 cigarettes per day, those who quit without changing their levels of exercise gained an average of 2.3 kg more (95% confidence interval [CI] = 1.9, 2.6) than women who continued smoking. Women who quit and increased exercise by between 8 to 16 MET-hours (the work metabolic rate divided by the resting metabolic rate) per week gained 1.8 kg (95% CI = 1.0, 2.5), and the excess weight gain was only 1.3 kg (95% CI = 0.7, 1.9) in women who increased exercise by more than 16 MET-hours per week. CONCLUSIONS: Smoking cessation is associated with a net excess weight gain of about 2.4 kg in middle-aged women. However, this weight gain is minimized if smoking cessation is accompanied by a moderate increase in the level of physical activity.