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Biomedical subjects

H S Kahn

Publications and source records attributed to H S Kahn.

At least 37 records · Page 2Linked to original sources
PubMed1997

Stable behaviors associated with adults' 10-year change in body mass index and likelihood of gain at the waist.

OBJECTIVES: The purpose of this study was to identify behaviors associated with change in body mass index or with weight gain at the waist. METHODS: A cohort of 79236 White, non-Hispanic, healthy adults was questioned in 1982 and 1992 about diet and 10 physical activities. Estimates were made of the mean effects of stable behaviors on 10-year change in body mass index and on odds ratios for gain at the waist. RESULTS: Ten-year changes in body mass index was associated positively with meat consumption and smoking cessation and inversely with vegetable consumption, vitamin E supplementation, continued smoking, and some vigorous activities (e.g., jogging/running). Women's body mass index decreased with walking 4 or more hours per week and with regular alcohol intake, but these behaviors had a smaller effect on men's body mass index. weight gain was inversely associated with high vegetable consumption, walking 4 or more hours per week, and jogging/running 1 to 3 hours per week but not with less demanding physical activities. CONCLUSIONS: Simple derivation of behaviors associated with weight loss or reduced abdominal obesity may enhance programs designed to prevent obesity and chronic diseases.

Adult↗
PubMed1996

The abdominal diameter index and sudden coronary death in men.

Alternative anthropometric indexes were compared for their ability to discriminate between 35 Atlanta men with sudden coronary death and 81 male controls. With or without adjustments for age, race, and body mass index, the abdominal diameter index (supine sagittal abdominal diameter divided by midthigh circumference) was associated with sudden coronary death more strongly than the waist/hip ratio or waist/thigh ratio of circumferences.

Abdomen↗
PubMed1996

The accumulation of visceral adipose tissue may be influenced by intra-abdominal temperature.

Despite the established link between visceral obesity and major chronic diseases, little is known about physiologic factors that directly and specifically lead to the accumulation of visceral fat. I hypothesize that reduced intra-abdominal temperature might be a physical factor underlying the partitioning of adipose tissue to the intra-abdominal region rather than the periphery. The hypothesis is supported by biochemical reports that rat and bovine lipoprotein lipase have increased activity when incubated at lower temperatures. Persons exercising in cool water have been found to preserve subcutaneous fat whereas comparable exercise without local cooling results in subcutaneous fat loss. Pima Indians, a group that commonly acquires extreme levels of visceral fat, have been found to have lower intra-abdominal temperatures during sleep than weight-matched European-Americans. In a study of four young men and four young women, I have noted that mean intra-abdominal basal temperatures were higher for women than men (36.51 +/- 0.18 degrees C vs. 35.91 +/- 0.11 degrees C; p = .0014). Since the men are more likely to acquire visceral obesity at later age, this also provides support for my hypothesis. Investigators might wish to examine further the temperature dependence of adipose-tissue lipoprotein lipase, the temperature variation between sites of adipose tissue, and the effects of foods, physical activities, smoking and drugs on localized body temperature.

Abdomen↗
PubMed1996

Simple anthropometric indices associated with ischemic heart disease.

In a case-control study of 217 hospitalized incident cases of ischemic heart disease and 261 controls we compared various anthropometric indices for the strength of their associations to the outcome event. The ratio of supine sagittal abdominal diameter to midthigh girth ("abdominal diameter index"; ADI) was the simple index that best discriminated cases from controls for both men (standardized difference, 0.65; p < 0.0001) and women (standardized difference, 0.95; p < 0.0001). The waist-to-thigh ratio of girths (WTR) (standardized difference, 0.57 and 0.90; p < 0.0001) was nearly as strong as the ADI and stronger than the traditional waist-to-hip ratio (standardized difference, 0.34 and 0.68; p < 0.005). After adjustments for age and race, the men's odds ratio for ischemic heart disease (tertile 3 vs. tertile 1) was 5.5 (95% CI, 2.9-10) using ADI and 5.1 (2.6-10) using the WTR. The women's odds ratio was 6.3 (1.9-20) using ADI and 8.7 (2.3-33) using the WTR. Further adjustments for body mass index and cardiovascular risk factors did not substantially change these risk estimates. Similar odds ratios were estimated by analyses restricted to 169 neighborhood-matched case-control pairs. In contrast, increased midthigh girth and subcutaneous fat mass (sum of three skinfolds) were associated with a protective effect against ischemic heart disease. Anthropometry using the ADI or WTR could offer a low-cost, noninvasive method for the clinical or epidemiologic evaluation of ischemic heart disease risk.

Anthropometry↗
PubMed1994

Abdominal obesity and mortality risk among men in nineteenth-century North America.

The health consequences of an adverse body-fat distribution (e.g., android, upper-body, visceral) have only recently concerned the medical community. Ninety years ago, however, actuarial study demonstrated the relationship of body-fat distribution to the mortality experience of insured, North American men. Thirty-four insurance companies pooled their data on males issued life policies between 1870 and 1899. Special classes of risk were defined by weight for height at baseline or by the observation that abdominal girth exceeded the girth of the expanded chest (abdominal obesity). The mortality experience of each risk class was compared to an age-stratified, actuarial table of the period. We present new analyses of these historical data relating specifically to the mortality impact of abdominal obesity. Among 163,567 overweight men, the prevalence of abdominal obesity increased with age and with degree of overweight. Among moderately overweight men, those with abdominal obesity experienced 133% of the expected mortality rate compared to 112% of the expected mortality for those who were not abdominally obese. Severely overweight men with abdominal obesity experienced 152% of the expected mortality compared to 135% of the expected mortality for severely overweight men who were not abdominally obese. We believe this nineteenth-century, acturial study of waist and chest girths was the first demonstration that body-fat distribution can influence longevity. These early actuarial findings, taken with more recent reports, establish that abdominal enlargement, but not necessarily an 'upper-body' fat distribution, constitutes a major health hazard. Future research must establish which abdominal-obesity index best predicts disease outcomes.

Abdomen↗
PubMed1993

Dental disease and risk of coronary heart disease and mortality.

OBJECTIVE: To investigate a reported association between dental disease and risk of coronary heart disease. SETTING: National sample of American adults who participated in a health examination survey in the early 1970s. DESIGN: Prospective cohort study in which participants underwent a standard dental examination at baseline and were followed up to 1987. Proportional hazards analysis was used to estimate relative risks adjusted for several covariates. MAIN OUTCOME MEASURES: Incidence of mortality or admission to hospital because of coronary heart disease; total mortality. RESULTS: Among all 9760 subjects included in the analysis those with periodontitis had a 25% increased risk of coronary heart disease relative to those with minimal periodontal disease. Poor oral hygiene, determined by the extent of dental debris and calculus, was also associated with an increased incidence of coronary heart disease. In men younger than 50 years at baseline periodontal disease was a stronger risk factor for coronary heart disease; men with periodontitis had a relative risk of 1.72. Both periodontal disease and poor oral hygiene showed stronger associations with total mortality than with coronary heart disease. CONCLUSION: Dental disease is associated with an increased risk of coronary heart disease, particularly in young men. Whether this is a causal association is unclear. Dental health may be a more general indicator of personal hygiene and possibly health care practices.

Adult↗
PubMed1993

Choosing an index for abdominal obesity: an opportunity for epidemiologic clarification.

Despite numerous reports that abdominal obesity is related to disease risk, the study of body-fat distribution remains a largely empirical science. Elucidation of the pathophysiologic linkage between abdominal obesity and disease would be better served by generating hypotheses and testing them--the process of deductive science. Physiologists have proposed that adipose tissue of the intra-abdominal compartment (that drained by the portal vein) contributes strongly to atherosclerosis. If this is so, then the volume of the intra-abdominal fat depot might be better correlated with disease states than a less specific anthropometric index such as the waist-to-hip girth ratio. Alternative abdominal-obesity indices (e.g. sagittal abdominal diameter divided by thigh girth) could be tested in epidemiologic studies to improve our pathophysiologic understanding of how body-fat distribution is related to atherosclerosis and other diseases.

Abdomen↗
PubMed1993

Recreational physical activity and ten-year weight change in a US national cohort.

Clinical research has established that increases in physical activity cause weight loss among the obese, but less is known about the influence of physical activity on longer-term weight change in the general population. Data from the NHANES-I Epidemiologic Follow-up Study (1971-1975 to 1982-1984) were used to examine the relationship between self-reported recreational physical activity level (low, medium, high) and measured weight change after ten years among 3515 men and 5810 women aged 25-74 years. Cross-sectional analyses at both the baseline and follow-up surveys revealed that recreational physical activity was inversely related to body weight. Low recreational physical activity reported at the follow-up survey was strongly related to major weight gain (> 13 kg) that had occurred during the preceding ten years. The estimated relative risk of major weight gain for those in the low activity level at the follow-up survey compared to those in the high activity level was 3.1 (95% Cl = 1.6-6.0) in men and 3.8 (2.3-6.5) in women. In addition, the relative risk for persons whose activity level was low at both the baseline and follow-up surveys was 2.3 (0.9-5.8) in men and 7.1 (2.2-23.3) in women. However, no relationship was found between baseline physical activity level and subsequent weight gain among either men or women. The lack of a relationship may be due to mis-specification of physical activity because of changes in activity over time. These findings suggest that low physical activity may be both a cause and a consequence of weight gain.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

The 10-y incidence of obesity and major weight gain in black and white US women aged 30-55 y.

Although the prevalence of obesity in US women is well-described, data are limited on the incidence of major weight gain and obesity. We used data from the First National Health and Nutrition Examination Survey Epidemiologic Follow-up Study to estimate the 10-y incidence of major weight gain (greater than or equal to 10 kg) and obesity [body mass index (BMI, in kg/m2) greater than or equal to 29] in a cohort of US women aged 30-55 y (n = 535 blacks and 2976 whites). In women not obese at baseline, blacks were 60% more likely to become obese than whites [incidence in blacks = 15.5%, 95% confidence interval (CI) = 11.2-19.7; incidence in whites = 9.7%, 95% CI = 8.6-10.8]. This higher incidence of obesity in blacks was largely due to their higher average BMI at baseline. The incidence of major weight gain was 50% higher in blacks than in whites (in blacks, 17.3%; 95% CI = 13.6-21.0; in whites, 11.7%; 95% CI = 10.3-13.1). We estimate that in black and white women, respectively, 16% and 12% of coronary heart disease is attributed to major weight gain whereas 35% and 21% is attributed to being obese.

Adult↗
PubMed1991

Is race associated with weight change in US adults after adjustment for income, education, and marital factors?

We examined the 10-y change in body mass index (BMI, in kg/m2) of black and white adults who entered the First National Health and Nutrition Examination Survey Epidemiologic Followup Study at ages 25-44 y. In women the mean change in BMI was greater for blacks than for whites despite multiple adjustments. However, the risk of major weight gain (MWG; BMI change greater than or equal to + 5) was nearly identical in black and white women. Womens' MWG was independently associated with low income [odds ratio (OR) = 1.7] and with becoming married (OR = 1.8). The risk of major weight loss (MWL; BMI change less than or equal to -2.5) was lower in black women than in white women (OR = 0.6). In men mean BMI change, MWG (BMI change greater than or equal to + 4) and MWL (BMI change greater than or equal to -2) were not associated with race, but there were effects associated with low income, low education, and marital changes. Black race does not increase the risk of weight gain; in women it may be associated with a reduced likelihood of weight loss.

Adult↗
PubMed1991

A major error in nomograms for estimating body mass index.

The Surgeon General's Report on Nutrition and Health and Diet and Health include a nomogram for determining body mass index (BMI, in kg/m2) when the subject's weight and height are known. I regret to report that the BMI in nomograms in these books are highly inaccurate when compared with direct calculations of BMI. Anyone wishing to use a nomogram for the rapid estimation of BMI should be cautioned against relying on the versions that appear in these books.

Anthropometry↗