Weight gain and the risk of developing insulin resistance syndrome

OBJECTIVE: Obesity and weight gain have been associated independently with hypertension, hyperinsulinemia, and dyslipidemia; however, prior research has not looked at the relation between weight gain from early adulthood to middle age and the development of this cluster of risk factors, known as insulin resistance syndrome. RESEARCH DESIGN AND METHODS: The association between weight gain over 30 years (defined as the difference between measured weight in middle age and participant recall of their weight at age 20) and the odds of developing insulin resistance syndrome at middle age was examined in a population-based sample of 2,272 eastern Finnish men. RESULTS: Each 5% increase in weight over the reported weight at age 20 was associated with nearly a 20% greater risk of insulin resistance syndrome by middle age, after adjustment for age and height. Moreover, there was a strong graded association between categories of weight gain and risk of insulin resistance syndrome. Men with weight increases of 10-19%, 20-29%, or > or =30% since age 20 were 3.0, 4.7, or 10.6 times more likely to have insulin resistance syndrome, respectively, by middle age, compared with men within 10% of their weight at age 20. Adjustments for age, height, physical activity, smoking, education, and parental history of diabetes did not alter these findings. CONCLUSIONS: The odds of having developed the hemodynamic and metabolic abnormalities that characterize insulin resistance syndrome by middle adulthood were increasingly higher the greater the weight gain over the preceding 30 years. This study adds to the literature identifying deleterious effects of weight gain from young to middle adulthood.     

Weight change between age 50 years and old age is associated with risk of hip fracture in white women aged 67 years and older

BACKGROUND: Although changes in body weight with aging are common, little is known about the effects of weight change on health in old age. OBJECTIVES: To study the effects of weight loss and weight gain from age 50 years to old age on the risk of hip fracture among postmenopausal white women aged 67 years and older and to determine if the level of weight at age 50 years modifies this risk. METHODS: The association between weight change and the risk of hip fracture was studied in 3683 community-dwelling white women aged 67 years and older from three sites of the Established Populations for Epidemiologic Studies of the Elderly. RESULTS: Extreme weight loss (10% or more) beginning at age 50 years was associated in a proportional hazards model with increased risk of hip fracture (relative risk [RR], 2.9; 95% confidence interval [CI], 2.0-4.1). This risk was greatest among women in the lowest (RR, 2.3; CI, 1.1-4.8) and middle (RR, 2.8; CI, 1.5-5.3) tertiles of body mass index at age 50 years. Among the thinnest women, even more modest weight loss (5% to < 10%) was associated with increased risk of hip fracture (RR, 2.3; CI, 1.0-5.2). Weight gain of 10% or more beginning at age 50 years provided borderline protection against the risk of hip fracture (RR, 0.7; CI, 0.4-1.0). The RRs for weight gain of 10% or more were protective only among women in the middle and high tertiles of body mass index at age 50 years and were not significant (middle tertile RR, 0.8; CI, 0.3-1.8; high tertile RR, 0.6; CI, 0.2-1.9). CONCLUSIONS: Weight history is an important determinant of the risk of hip fracture. Weight loss beginning at age 50 years increases the risk of hip fracture in older white women, especially among those who are thin at age 50 years; weight gain of 10% or more decreases the risk of hip fracture. Physicians should include weight history in their assessment of postmenopausal older women for risk of hip fracture.     

Mortality risk by body weight and weight change in people with NIDDM. The WHO Multinational Study of Vascular Disease in Diabetes

OBJECTIVE: Care guidelines for people with non-insulin-dependent diabetes mellitus (NIDDM) emphasize the importance of weight loss in reducing mortality risk. However, existing evidence regarding the relationship between weight and mortality and the effects of weight change is conflicting. We examined these relationships in the World Health Organization Multinational Study of Vascular Disease in Diabetes. RESEARCH DESIGN AND METHODS: This was a cohort study of 1,416 men and 1,544 women. Baseline examinations were performed in 1975 through 1977, a morbidity follow-up was performed in 1983, and a mortality follow-up continued until 1988. Data were analyzed according to geographical groups: Europeans, East Asians, and Native Americans. The relationship between weight change and mortality was analyzed for Europeans only. RESULTS: Generally, body mass index (BMI) was positively associated with age, blood pressure, and cholesterol but was negatively associated with duration of diabetes, prevalence of retinopathy, and use of insulin. There was no clear relationship between BMI and mortality across the geographical groups. In Europeans, weight loss in the leanest subjects at baseline (BMI < 26 kg/m2) was associated with a threefold increase in mortality risk compared with those who had maintained a steady weight (relative risk [RR] 3.05, 95% confidence interval [CI] 1.26-7.36). Only in the most obese group was weight loss associated with a reduction in mortality risk (BMI > 29 kg/m2, RR 0.84, 95% CI 0.40-1.74). CONCLUSIONS: The positive association of BMI with age, blood pressure, and cholesterol and the negative association with duration of diabetes, retinopathy, and use of insulin may explain why there is no strong relationship between BMI and mortality in NIDDM. Weight loss, particularly in the relatively lean diabetic person, may be associated with an increased mortality risk.     

Hip fracture risk in older white men is associated with change in body weight from age 50 years to old age

BACKGROUND: Change in body weight is a potentially modifiable risk factor for hip fracture in older women but, to our knowledge, its relationship to risk in older men has not been reported previously. OBJECTIVE: To investigate the effects of weight loss and weight gain from age 50 years to old age on the risk of hip fracture among elderly men. METHODS: The association between weight change and risk of hip fracture was studied in a cohort of 2413 community-dwelling white men aged 67 years or older from 3 sites of the Established Populations for Epidemiologic Study of the Elderly. RESULTS: The older men in this study, observed for a total of 13620 person-years during the 8 years of follow-up, experienced 72 hip fractures, yielding an overall incidence rate of 5.3 per 1000 person-years. Extreme weight loss (> or =10%) beginning at age 50 years was associated in a proportional hazards model with increased risk of hip fracture (relative risk, 1.8; 95% confidence interval, 1.04-3.3). Weight loss of 10% or more was associated with several indicators of poor health, including physical disability, low mental status score, and low physical activity (P<.05). Weight gain of 10% or more beginning at age 50 years provided borderline protection against the risk of hip fracture (relative risk, 0.4; 95% confidence interval, 0.1-1.00). CONCLUSIONS: Despite differences between older men and women in the incidence of and risk factors for hip fracture, weight history is also an important determinant of the risk of hip fracture among older men. Weight loss of 10% or more beginning at age 50 years increases the risk of hip fracture in older white men; weight gain of 10% or more decreases the risk of hip fracture. The relationship between extreme weight loss and poor health suggests that weight loss is a marker of frailty that may increase the risk of hip fracture in older men. Physicians should include weight history in their assessment of the risk of hip fracture among older men.     

Body weight change and carotid artery wall thickness. The Atherosclerosis Risk in Communities (ARIC) Study

The impact of weight change in adulthood on cardiovascular disease is controversial. This study examined the association of change in body weight, from young adulthood to middle age, with average carotid artery intimal-medial wall thickness by B-mode ultrasound measured in middle age. Participants were 13,282 men and women aged 45-64 years from the baseline examination of the Atherosclerosis Risk in Communities (ARIC) Study (1987-1989). Weight change was calculated as the difference between weight at the baseline examination and self-reported weight at age 25. White men gained a mean of 9.7 kg; black men, 10.1 kg; white women, 12.0 kg; and black women, 20.8 kg. Weight change was positively, albeit modestly, associated with intimal-medial thickness in black men and white men and in white women, but not in black women. Adjusted for age, examination center, smoking, education, sports activity level, height, and body mass index at age 25, the differences in intimal-medial thickness associated with a 10-kg increment in weight change were 0.016 (95% confidence interval 0.010 to 0.022) mm in white men, 0.008 (95% confidence interval 0.001 to 0.015) mm in black men, 0.013 (95% confidence interval 0.009 to 0.017) mm in white women, and 0.002 (95% confidence interval -0.002 to 0.006) mm in black women. These findings support the hypothesis that weight gain in adulthood promotes atherosclerotic changes in white men and women and in black men.     

Body fat distribution and risk of non-insulin-dependent diabetes mellitus in women. The Nurses' Health Study

Obesity is an established risk factor for non-insulin-dependent diabetes mellitus (NIDDM). Anthropometric measures of overall and central obesity as predictors of NIDDM risk have not been as well studied, especially in women. Among 43,581 women enrolled in the Nurses' Health Study who in 1986 provided waist, hip, and weight information and who were initially free from diabetes and other major chronic diseases, NIDDM incidence was followed from 1986 to 1994. After adjustment for age, family history of diabetes, smoking, exercise, and several dietary factors, the relative risk of NIDDM for the 90th percentile of body mass index (BMI) (weight (kg)/height (m)2) (BMI = 29.9) versus the 10th percentile (BMI = 20.1) was 11.2 (95% confidence interval (CI) 7.9-15.9). Controlling for BMI and other potentially confounding factors, the relative risk for the 90th percentile of waist: hip ratio (WHR) (WHR = 0.86) versus the 10th percentile (WHR = 0.70) was 3.1 (95% CI 2.3-4.1), and the relative risk for the 90th percentile of waist circumference (36.2 inches or 92 cm) versus the 10th percentile (26.2 inches or 67 cm) was 5.1 (95% CI 2.9-8.9). BMI, WHR, and waist circumference are powerful independent predictors of NIDDM in US women. Measurement of BMI and waist circumference (with or without hip circumference) are potentially useful tools for clinicians in counseling patients regarding NIDDM risk and risk reduction.     

Rabies postexposure prophylaxis survey--Kentucky, 1994

Prompted by the recent findings that a tryptophan to arginine (Trp64Arg) mutation in the beta3-adrenergic receptor gene was associated with an earlier onset of non-insulin-dependent diabetes mellitus (NIDDM) in Pima Indians, with abdominal obesity and insulin resistance in Finns, and with an increased capacity to gain weight in French whites, we studied the prevalence of this mutation in 231 diabetic and 95 nondiabetic Japanese subjects and assessed its contribution to the development of obesity and NIDDM. The allelic frequencies of the mutation were 0.18 in diabetic and 0.23 in nondiabetic subjects, showing no significant difference between the two groups (P = .067). In nondiabetic subjects, body mass index (BMI) did not differ between those with and without the mutation (22.2 +/- 3.5 v 21.4 +/- 3.2 kg/m2, P = .252). In NIDDM subjects, BMI at the time of study and maximal BMI before the start of treatment did not differ between those with and without the mutation (22.8 +/- 2.6 v 23.2 +/- 3.7 kg/m2, P = .678, and 24.7 +/- 2.6 v 24.9 +/- 3.1 kg/m2, P = .277). Homozygotes for the mutation did not have trends to have increased BMI in either diabetic or nondiabetic subjects. The age at diagnosis of NIDDM also did not differ between the two groups (48.8 +/- 9.9 v 47.8 +/- 12.5 years, P = .796). Fasting serum cholesterol and triglyceride levels and systolic and diastolic blood pressure before the start of treatment did not differ between NIDDM subjects with and without the mutation. In conclusion, although the Trp64Arg mutation is not uncommon in Japanese, it does not appear to be associated with obesity, NIDDM, age at diagnosis of NIDDM, or dyslipidemia. Our results suggest that the mutation has minor effects, if any, on the development of obesity and NIDDM in Japanese.     

Body mass index, weight change, and risk of mobility disability in middle-aged and older women. The epidemiologic follow-up study of NHANES I

OBJECTIVE: As disability is highly prevalent among older women, is costly, and affects the quality of life, preventable causes of disability must be identified. In this study, we investigated the relationship between the body mass index (BMI), weight change, and the onset of disability in older women. DESIGN: Prospective cohort study. SETTING: The nationally representative US epidemiologic follow-up study of the National Health and Nutrition Examination Survey (NHANES) I (1971 through 1987). PATIENTS: White women classified as young-old (mean age 60 years at baseline, mean age 65 years at follow-up) and old-old (mean age 76 years at baseline, mean age 80 years at follow-up). MAIN OUTCOME MEASURES: The relative odds for the onset of mobility disability associated with tertiles of past BMI (measured 8 to 16 years prior to disability ascertainment) and current BMI (measured 2 to 5 years prior to disability ascertainment) and with weight change between the two weight measurements. RESULTS: In both cohorts, women in the high past BMI group (> 27 in the young-old and > 28.1 in the old-old cohort) had a twofold increase in the risk for disability compared with women in the low past BMI group. High current BMI was as strongly related as past BMI to risk of disability in the young-old women; it was not as strong a predictor in old-old women. In the old-old group only, women who experienced a weight loss of more than 5% had a twofold increase in risk of disability compared with weight-stable women. These results were adjusted for age, smoking, education, and study time and were not importantly modified with the addition into the models of single or multiple health conditions. CONCLUSIONS: These prospective data suggest that high BMI is a strong predictor of long-term risk for mobility disability in older women and that this risk persists even to very old age. However, the paradoxical increase in risk associated with weight loss in the old-old women requires further study. Programs to prevent overweight may have potential for decreasing disability in women.     

NIDDM in the elderly

OBJECTIVE: We conducted this study to assess the metabolic alterations in elderly patients with NIDDM. RESEARCH DESIGN AND METHODS: Healthy, lean (n = 15; age, 73 +/- 1 years; BMI, 23.8 +/- 0.5 kg/m2), and obese (n = 10; age, 71 +/- 1 years; BMI, 28.9 +/- 1.2 kg/m2) control subjects and lean (n = 10; age, 75 +/- 2 years; BMI, 24.0 +/- 0.5 kg/m2) and obese (n = 23; age, 73 +/- 1 years; BMI, 29.9 +/- 0.7 kg/m2) NIDDM patients underwent a 3-h glucose tolerance test, a 2-h hyperglycemic glucose clamp study, and a 3-h euglycemic glucose clamp study with tritiated glucose methodology to measure glucose production and disposal rates. RESULTS: Waist-to-hip ratio (WHR) was greater in both lean and obese NIDDM patients than in control subjects. Insulin responses during the oral glucose tolerance test were similar in obese subjects (control subjects: 417 +/- 64 pmol/l; NIDDM patients: 392 +/- 47 pmol/l) but were reduced in lean NIDDM patients (control subjects: 374 +/- 34 pmol/l; NIDDM patients: 217 +/- 20 pmol/l, P < 0.01). Lean and obese NIDDM patients had absent first-phase insulin responses during the hyperglycemic clamp. Second-phase insulin responses were reduced in lean (P < 0.01 vs. control subjects by analysis of variance) but not obese NIDDM patients. Hepatic glucose output was not increased in lean or obese NIDDM patients. Steady-state (150-180 min) glucose disposal rates were 16% less in lean NIDDM patients (control subjects: 8.93 +/- 0.37 mg.kg LBM (lean body mass)-1.min-1; NIDDM patients: 7.50 +/- 0.28 mg.kg LBM-1.min-1, P < 0.05) and 37% less in obese NIDDM patients (control subjects: 8.17 +/- 0.38 mg.kg LBM-1.min-1; NIDDM patients: 5.03 +/- 0.36 mg.kg LBM-1.min-1, P < 0.001). CONCLUSIONS: Lean elderly NIDDM patients have a profound impairment in glucose-induced insulin release but mild resistance to insulin-mediated glucose disposal. Obese elderly NIDDM patients have adequate circulating insulin, but marked resistance to insulin-mediated glucose disposal. Hepatic glucose output is not increased in elderly NIDDM patients.     

The prevalence of non-insulin-dependent diabetes mellitus and the associated risk factors in a population of Mexico, D. F

Non-insulin-dependent diabetes mellitus (NIDDM) is a chronic disabling disease, that shortens length of life and implies a high burden for a community. Its prevalence goes from 0 per cent in Papua, New Guinea to 34 per cent in Pima Indians. There are very few prevalence studies in Mexico, and the strength of association of the known risk factors with the occurrence of the disease is not established. A prevalence cross sectional study was carried out with users of a first level medical care unit, with a meter measure of capillary glucose levels. Those with a previous diagnosis of diabetes or whose capillary glucose level were 200 mg or over were considered diabetics. Hyperglycemia was when the levels were recorded between 121 and 199 mg. The crude prevalence of NIDDM was 5.6 per cent (CI 95% 4.5-6.8), With almost no sex difference. Hyperglycemia prevalence was 2.9 per cent (CI 95% 2.0-3.7). Age was the main risk factor for the development of NIDDM. Those between 40 and 59 years showed a high risk (OR 10.8; CI 95% 5.4-22.0; p < 0.0001), and it was greater for the 60 years or elder (OR 20.6; CI 95% 9.8-44.1; p < 0.0001). Weight was also an important risk factor, with a 2.7 fold greater risk for obese persons (CI 95% 1.6-4.6; p < 0.0001). Other, risk factors were familiar history of diabetes (OR 1.5; CI 95% 0.9-2.3; p = 0.096), and overcrowding (OR 1.9; CI 95% 1.0-3.4; p = 0.03). In order to analyze independently each variable, a logistic regression model was applied, and a similar strength of association was observed for the crude model, but for obesity whose effect was modified by age. When only new cases were analyzed in the former model, the association with obesity was maintained. There is a need to develop prevalence studies of NIDDM in Mexico and to measure the strength of association with the known and the not jet well known risk factors of this disease in order to establish health policies according to the Mexican reality.     

Catheter ablation of atrioatrial conduction as a cure for atrial arrhythmia after orthotopic heart transplantation

STUDY OBJECTIVES: Little is known about the natural development of snoring, and this survey was conducted to study the development of snoring in men over a 10-year period. DESIGN: Population-based prospective survey. SETTING: The Municipality of Uppsala, Sweden. PARTICIPANTS AND MEASUREMENTS: In 1984, 3,201 randomly selected men aged 30 to 69 years answered a questionnaire on snoring and sleep disturbances. Of the 2,975 survivors in 1994, 2,668 (89.7%) answered a new questionnaire with identical questions to those used at baseline. Questions about smoking habits, alcohol, and physical activity were also added. RESULTS: Habitual snoring was reported by 393 men (15.0%) in 1984 and by 529 (20.4%) 10 years later. In both 1984 and 1994, the prevalence of snoring increased until age 50 to 60 years and then decreased. Risk factors for being a habitual snorer at the follow-up were investigated using multiple logistic regression with adjustments for previous snoring status, age, body mass index (BMI), weight gain, smoking habits, and physical activity. In men aged 30 to 49 years at baseline, the predictors of habitual snoring at the follow-up, in addition to previous snoring status, were as follows: persistent smoking (adjusted odds ratio, 95% confidence interval) (1.4, 1.1 to 1.9), BMI 1984 (1.1, 1.02 to 1.1/kg/m2) and weight gain (1.1, 1.03 to 1.2/kg/m2). Among men aged 50 to 69 years, after adjustments for previous snoring status and age, weight gain was the only significant risk factor for developing habitual snoring (1.2, 1.05 to 1.4/kg/m2). CONCLUSIONS: In men, the prevalence of snoring increases up to the age of 50 to 60 years and is then followed by a decrease. Weight gain is a risk factor for snoring in all age groups, while smoking is mainly associated with snoring in men <60 years of age.     

Body weight and risk of nonfatal acute myocardial infarction among women: a case-control study from northern Italy

BACKGROUND: The relationship between nonfatal acute myocardial infarction (AMI) and self-reported body weight and body mass index (BMI; Quetelet index, kg/m2) has been investigated. METHODS: A case-control study was conducted between 1983 and 1992 in northern Italy on 432 women with nonfatal AMI and 867 controls in hospital for acute, noncardiovascular, nonneoplastic, nondigestive, non-hormone-related conditions. Odds ratios (OR), with their 95% confidence intervals (CI), were computed by unconditional multiple logistic regression analysis, including terms for age, education, and smoking, plus history of selected diseases. RESULTS: Women with body weight and BMI in the highest quartile had an increased risk of AMI after allowance for age, education, and smoking status (OR 1.5, 95% CI 1.0 to 2.2, and OR 1.7, 95% CI 1.2 to 2.4, respectively). Compared with leaner women, the risk was higher among women with BMI above the median, in association with a history of diabetes (OR 5.2) or hyperlipidemia (OR 6.0). Hypertensive women had similar OR in the two strata of BMI (OR 5.1 and 4.8). The association of BMI with risk of AMI was apparently stronger among women younger than 50 years and among less educated women, but was similar among smokers and never smokers. CONCLUSIONS: The results of this study confirm that AMI among women is related to excess BMI, with a population attributable risk of 17%. The excess risk was substantial among overweight women with history of diabetes or hyperlipidemia, stressing the importance of controlling body weight among these women.     

Early and late weight gain following smoking cessation in the Lung Health Study

The authors examine weight gains associated with smoking cessation in the Lung Health Study (1986-1994) over a 5-year follow-up period. A cohort of 5,887 male and female smokers in the United States and Canada, aged 35-60 years, were randomized to either smoking intervention or usual care. Among participants who achieved sustained quitting for 5 years, women gained a mean of 5.2 (standard error, 5.0) kg in year 1 and a mean of 3.4 (standard error, 5.5) kg in years 1-5. Men gained a mean of 4.9 (standard error, 4.9) kg in year 1 and a mean of 2.6 (standard error, 5.8) kg in years 1-5. In regression analyses, smoking-change variables were the most potent predictors of weight change. Participants going from smoking to quit-smoking in a given year had mean weight gains of 2.95 kg/year (3.61%) in men and 3.09 kg/year (4.69%) in women. Over 5 years, 33% of sustained quitters gained > or = 10 kg compared with 6% of continuing smokers. Also among sustained quitters, 7.6% of men and 19.1% of women gained > or = 20% of baseline weight; 60% of the gain occurred in year 1, although significant weight gains continued through year 5. The average gains and the high proportions of sustained and intermittent quitters who gained excessive weight suggest the need for more effective early interventions that address both smoking cessation and weight control.     

Energy intake and net weight gain in pregnant women according to body mass index (BMI) status

OBJECTIVE: To investigate whether body mass index (BMI) is related to energy intake during pregnancy, and whether BMI, energy intake and other factors are related to net weight gain. DESIGN: Longitudinal, duration of pregnancy. SUBJECTS: 156 healthy pregnant women residing in Quedlinburg county, Germany. METHODS: Weighed 7 d food records and standardized anthropometric measures in the first, second and third trimester. The analysis of variance (ANOVA) statistical technique was used to analyze differences in energy intake, net weight gain and birthweight across BMI groups, and the Cochran-Mantel Haenszel test was used to analyze food group intake by BMI group. RESULTS: Women at the highest level of BMI were significantly less often in the high energy intake category than women at the medium or low level of BMI (15% vs 36% and 48%). Net weight gain during pregnancy was independently influenced by BMI status and energy intake. Women at the highest level of BMI gained significantly less weight (4.2 kg) from first to third trimester than women at the medium or low levels of BMI (weight gains of 6.2 kg and 5.9 kg, respectively). Women with a low daily energy intake gained 4.6 kg during pregnancy, while women with medium and high energy intakes gained 6.0 kg and 6.1 kg, respectively. Examination of net weight gain simultaneously across BMI and parity groups revealed a much lower net weight gain among multigravid women at the highest BMI level (3.3 kg). Primigravid high BMI women, in contrast, gained 6.9 kg, whereas multigravid and primigravid women at medium and low BMI levels gained average of 4.8 kg and 6.5 kg, respectively. The mean birth weight in the three BMI groups did not differ and was not influenced by age, marital status, education, parity or smoking. CONCLUSION: Because other studies have shown that weight gain during pregnancy increases the risk of subsequent overweight, multigravid high BMI women may prevent an increased weight retention after pregnancy due to lower weight gain in the current gestation. A lower caloric diet may help to accomplish a lower weight gain during pregnancy in overweight women without increased risk of low birth weight infants. These findings indicate further investigation of the associations between BMI, parity and caloric intake during pregnancy are needed to increase understanding of factors affecting subsequent weight gain.     

Risk factors for incident radiographic knee osteoarthritis in the elderly: the Framingham Study

OBJECTIVE: Knee osteoarthritis (OA) is highly prevalent, especially in the elderly. Preventive strategies require a knowledge of risk factors that precede disease onset. The present study was conducted to determine the longitudinal risk factors for knee OA in an elderly population. METHODS: A longitudinal study of knee OA involving members of the Framingham Study cohort was performed. Weight-bearing knee radiographs were obtained in 1983-1985 (baseline) and again in 1992-1993. Incident disease was defined as the occurrence of new radiographic OA (Kellgren and Lawrence grade > or = 2 on a 0-4 scale) in those without radiographic OA at baseline. Risk factors assessed at baseline and in the interim were tested in univariate and multivariate equations to evaluate their association with incident knee OA. RESULTS: Of 598 patients without knee OA at baseline (mean age 70.5 years, 63.7% women), 93 (15.6%) developed OA. After adjustment for multiple risk factors, women had a higher risk of OA than did men (adjusted odds ratio [OR] = 1.8, 95% confidence interval [95% CI] 1.1-3.1). Higher baseline body mass index increased the risk of OA (OR = 1.6 per 5-unit increase, 95% CI 1.2-2.2), and weight change was directly correlated with the risk of OA (OR = 1.4 per 10-lb change in weight, 95% CI 1.1-1.8). Physical activity increased the risk of OA (for those in the highest quartile, OR = 3.3, 95% CI 1.4-7.5). Smokers had a lower risk than did nonsmokers (for those who smoked an average of > or = 10 cigarettes/day, OR = 0.4, 95% CI 0.2-0.8). Factors not associated with the risk of OA included chondrocalcinosis and a history of hand OA. Weight-related factors affected the risk of OA only in women. CONCLUSION: Elderly persons at high risk of developing radiographic knee OA included obese persons, nonsmokers, and those who were physically active. The direction of weight change correlated directly with the risk of developing OA.     

Differential effects of BMI on diabetes risk among black and white Americans

OBJECTIVE: To determine whether the associations of BMI and fat distribution with diabetes risk are modified by race. RESEARCH DESIGN AND METHODS: Data from the National Health and Nutrition Examination Survey, Epidemiologic Follow-up Study (1971-1992), were used to investigate potential interactions of BMI and fat distribution with race. Incident diabetes was defined by self-report of physician-diagnosed diabetes, hospital and nursing home discharge records, and death certificates. RESULTS: Among the 1,531 black and 9,852 white subjects who were nondiabetic at baseline, 1,139 (10.0%) developed diabetes during 20 years of follow-up. Although the cumulative risk of diabetes increased with baseline BMI in all four race-sex groups, the sex-specific odds ratios (ORs) for black:white subjects decreased with increasing BMI. In particular, for BMI of 22 kg/m2, the OR of diabetes for black:white individuals was 1.87 and 1.76 (P < 0.01) for men and women, respectively; for BMI of 32 kg/m2, the OR decreased to 0.99 and 1.20 (NS) for men and women, respectively. Skinfold ratio was also associated with increased diabetes risk in all race-sex groups, but did not modify the association between race and diabetes. CONCLUSIONS: These findings suggest that the effect of BMI on diabetes risk is different for black and white Americans, with a larger risk for blacks than whites at low BMI and an equivalent risk for both groups at high BMI. A lower degree of visceral adiposity among blacks at higher BMI or a greater impact of visceral adiposity among blacks at low BMI may help explain the interaction of race and BMI on diabetes risk.     

NIDDM incidence in a tri-ethnic population of diagnosed hypertensives

OBJECTIVE: Significant racial/ethnic differences exist in the prevalence of hypertension (HTN) and non-insulin dependent diabetes mellitus (NIDDM). The purpose of this study was to determine if ethnicity (African-American, Hispanic and non-Hispanic white) was related to NIDDM incidence over a maximum follow-up period of 10 years. DESIGN: Retrospective cohort study. SETTING: A large, urban public health care system serving over 200,000 predominantly minority persons. The system includes nine primary care health centers. PATIENTS: African-American, Hispanic and non-Hispanic white patients with diagnosed hypertension who received primary care in the study setting. METHODS: Medical records of 2,941 hypertensives free of NIDDM at their baseline visit were reviewed to document incident NIDDM during follow-up. Sociodemographic characteristics and physiologic covariates consistently available in the medical record (blood pressure, height, weight, and blood glucose) were also abstracted. RESULTS: The mean age of patients at the baseline visit was 56 years; 67% were female, 63% were African-American. 17% Hispanic, and 20% non-Hispanic white. Two hundred thirty-six incident cases of NIDDM were identified in the cohort. In Cox proportional hazards analysis, the risk of developing NIDDM was not related to ethnicity either in univariate analysis or after adjusting for age, baseline blood glucose, and body mass index (adjusted RR for African Americans compared with whites = .82, 95% CI = .57-1.18; adjusted RR for Hispanics compared with whites = .84, 95% CI = .51-1.38). CONCLUSION: The lack of association between ethnicity and NIDDM risk among hypertensives is unexpected, and may indicate differences in the pathogenetic mechanisms that underlie the development of hypertension and NIDDM in these three ethnic groups.     

Determinants of poor pregnancy outcomes among teenagers in Sweden

OBJECTIVE: To study pregnancy outcomes among teenagers and to determine whether age-related increases in risk are due to differences in socioeconomic conditions, maternal smoking, or anthropometric status. METHODS: All single births during 1990-1991 to mothers aged less than 25 years recorded in the Swedish Medical Birth Registry were studied (n = 62,433). The pregnancy outcomes analyzed were late fetal death, infant mortality, preterm birth, low birth weight, small for gestational age, and low Apgar scores. Information on maternal age, parity, family situation, maternal smoking, maternal height, and weight gain during pregnancy was recorded in the Medical Birth Registry. Information on socioeconomic characteristics was obtained from the Population Census. Logistic regression analysis was used to define the determinants of the adverse outcomes among teenagers. RESULTS: Compared with women aged 20-24 years, girls of 17 years or less were at higher risk for preterm birth (odds ratio [OR] 1.6), and this increased risk remained essentially unchanged after controlling for major confounding factors (OR 1.5). Teenagers also had a crude 50% higher risk of late fetal death and infant mortality, but this risk was reduced after controlling for the effect of socioeconomic characteristics (adjusted OR 1.2). CONCLUSIONS: The increase in risk of late fetal death and infant mortality associated with low maternal age is substantially an effect of teenagers' poorer socioeconomic situation. However, the increase in preterm birth among younger teenagers suggests that young maternal age may be a biologic risk factor for preterm birth.     

Weight change and glycemic control in a population-based sample of adults with older-onset diabetes

BACKGROUND: Numerous clinic-based studies have observed improved glycemic control with even moderate weight reductions, for periods up to 1 year, in obese subjects with noninsulin-dependent diabetes mellitus (NIDDM). Similar benefits of weight loss have not been well documented in free-living populations, particularly in older persons with NIDDM of long duration. METHODS: Relations between weight change and glycosylated hemoglobin were evaluated in a population-based sample of persons with older-onset diabetes. Persons participating in baseline (1980-1982, n = 1370) and two follow-up examinations (1984-1986, n = 987; 1990-1992, n = 550) were included. Mean glycosylated hemoglobin levels among those losing, gaining, or remaining within 5 kg were compared in all subjects combined and stratified by insulin use, using ordinary least-squares regression to adjust for confounding variables. RESULTS: Subjects who lost weight had higher mean glycosylated hemoglobin compared to those who gained weight (baseline to second exam only). This pattern remained in those not using insulin. Weight change was not related to glycosylated hemoglobin in persons using insulin. CONCLUSIONS: Associations suggest that in older persons not using insulin, moderate weight loss over periods of 4-6 years has little beneficial impact on glycosylated hemoglobin. Weight loss may be reflecting disease processes that also result in poor glycemic control. Intentional weight loss achieved over a shorter time period and maintained through the later years in older diabetic persons remains to be evaluated.     

An evaluation of various indices of body weight change and their relationship with coronary risk factors

OBJECTIVE: To compare interrelationships between different indices and their relationship with cardiovascular disease risk factors. METHOD: Longitudinal comparison among weight change indices in the observation of a fixed population from age 21-40. SUBJECTS: 215 non-obese blue-collar workers in a steel company. MEASUREMENTS: Systolic blood pressure, diastolic blood pressure, serum cholesterol, serum uric acid, past history of illness, present illness, body mass index (BMI: weight/height2 (kg/m2)), indices of weight change (the intrapersonal standard deviation of BMI (ISD), the coefficient of variation of BMI (CV), the root mean square error of variation (RMSE) around the slope of BMI vs age, weight change categories (cycler, weight gainer, no changer, etc.), and number of weight cycles (NWC: one cycle is defined as 5% weight loss and 5% weight gain)). Indices were calculated using yearly and five-yearly measurements of weight for analyses. RESULTS: The average RMSE distinguished large cyclers from other weight change categories, while ISD and CV did not. The correlation between ISD and CV was strong and significant. That between RMSE and ISD (or CV) was moderate and significant. Among the weight change categories, no weight change group included many actual weight cyclers. As for the relationship with coronary risk factors, no significant change in risk was noted in cyclers as determined by NWC or weight change category. The top one third of ISD and the top one third of CV was related with elevated risk of "any risk factor,' but at a lower level of significance. CONCLUSION: ISD and CV reflect almost the same aspects of weight change, but the other indices reflect different aspects. When investigating the relationship between coronary risk factors and weight variability (especially, weight cycling) among young adult non-obese men, it is preferable to use weight change patterns such as NWC and weight change categories, or RMSE in conjunction with or in place of CV (or ISD).