Measures of body fat and related factors in normal adults—I

488

111

A B S T R A C T Considerable controversy exists over the purported role of obesity in causing hyperglycemia, hyperlipemia, hyperinsulinemia, and insulin resistance; and the potential beneficial effects of weight reduction remain incompletely defined. Hypertriglyceridemia is one of the metabolic, abnormalities proposed to accompany obesity, and in order to help explain the mechanisms leading to this abnormality we have proposed the following sequential hypothesis: insulin resistance > hyperinsulinemia > accelerated hepatic triglyceride (TG) production > elevated plasma TG concentrations. To test this hypothesis and to gain insight into both the possible role of obesity in causing the above metabolic abnormalities and the potential benefit of weight reduction we studied the effects of weight loss on various aspects of carbohydrate and lipid metabolism in a group of 36 normal and hyperlipoproteinemic subjects. Only weak to absent correlations (r = 0.03 -0.46) were noted between obesity and the metabolic variables measured. This points out that in our study group obesity cannot be the sole, or even the major, cause of these abnormalities in the first place. Further, we have observed marked decreases after weight reduction in fasting plasma TG (mean value: pre-weight reduction, 319 mg/l00 ml; post-weight reduction, 180 mg/100 ml) and cholesterol (mean values: pre-weight reduction, 282 mg/100 ml; post-weight reduction, 223 after weight reduction were also measured and the overall post-weight reduction decrease in insulin response was 48% while the glucose response was relatively unchanged. In a subgroup of patients we studied both the degree of cellular insulin resistance and the rate of hepatic very low density (VLDL) TG production before and after weight reduction. These subjects demonstrated significant decreases after weight reduction in both degree of insulin resistance (33% decrease) and VLDL-TG production rates (40% decrease). Thus, weight reduction has lowered each of the antecedent variables (insulin resistance, hyperinsulinemia, and VLDL-TG production) that according to the above hypothesis lead to hypertriglyceridemia, and we believe the overall scheme is greatly strengthened. Furthermore, the consistent decreases in plasma TG and cholesterol levels seen in all subjects lead us to conclude that weight reduction is an important therapeutic modality for patients with endogenous hypertriglyceridemia.

Section: Methodsmentioning

confidence: 99%

“…To emphasize the dramatic effects of weight loss, we summarized (Table VII) (27), while most of the above authors use relative weight. However, using relative weight as the estimate of obesity did not alter any of our findings (Table III) reduction decrements in plasma TG and cholesterol concentrations in both percentage and absolute terms.…”

Section: Methodsmentioning

confidence: 99%

Effects of Weight Reduction on Obesity STUDIES OF LIPID AND CARBOHYDRATE METABOLISM IN NORMAL AND HYPERLIPOPROTEINEMIC SUBJECTS

Olefsky¹,

Reaven²,

Farquhar³

1974

488

111

“…Volunteers responded to a notice asking for assistance in a research project which would furnish their living expenses during a 2 wk hospital stay. The percentage of total body weight as adipose tissue (per cent adiposity) was calculated by the method of Steinkamp and coworkers (26,27) which they found superior to other estimates of adiposity based on measures such as single skinfold thickness, relative weight, or ponderal index. Multiple series of anthropometric measurements were made by one observer, whose repeat data agreed within a +5%o coefficient of variation.…”

Section: Methodsmentioning

confidence: 99%

Comparison of impedance to insulin-mediated glucose uptake in normal subjects and in subjects with latent diabetes

Shen¹,

Reaven²,

Farquhar³

1970

482

252

“…There was no serial change during the second half as all kinetic measures fluctuated widely (Fig. SB & D) secretion rate [12] divided by the pool size) was not affected by the ovulatory cycle, but there were fewer cycles per hour (and per day) in the pregnant subjects (P < 0.001). Since there was no difference among patients in different stages of pregnancy (Table IV) data from all pregnant subjects were combined.…”

mentioning

confidence: 97%

“…All measurements were made by radioimmunoassay by Endocrine Sciences, Tarzana, Calif. (11). § Calculated by the anthropometric method of Steinkamp et al (12).…”

mentioning

confidence: 99%

Biliary lipids, bile acids, and gallbladder function in the human female. Effects of pregnancy and the ovulatory cycle.

Kern¹,

Everson²,

DeMark³

et al. 1981

240

A B S T R A C T To study the events that might lead to an increased risk of cholesterol gallstones, we examined biliary lipid composition and secretion and bile acid composition and kinetics at different stages of pregnancy or ovulation in young, nonobese, healthy women.Lipid composition and bile acid distribution were determined in duodenal fluid obtained in percentage of cholic acid. The pool size of each major bile acid increased in the first trimester. Chenodeoxycholic acid and deoxycholic acid pools, but not cholic acid pools, subsequently decreased. The fractional turnover rate of both primary bile acids was slower during pregnancy. The synthesis rate of chenodeoxycholic but not cholic acid decreased in a linear manner during the first 20 wk of pregnancy. The rate of enterohepatic cycling of the bile acid pool was reduced throughout pregnancy.The volume of the fasting gallbladder and the residual volume after a physiologically stimulated contraction were directly correlated with bile acid pool size. The residual volume was also directly related to total bile acid synthesis.