Obesity research · 2000
Ethnic differences in the responsiveness of adipocyte lipolytic activity to insulin.
Сравнительное исследованиеСтатьяПоддержка исследования: вне правительства СШАНазвание и аннотация: Перевод пока не подготовлен
Обработка статьи · этапы, ошибки и управление
Загрузка состояния…
Ошибки и ограничения
История · было → стало
Состояние обновляется каждые 5 секунд, пока блок открыт. Процент показывается только там, где известен объём работы. Пауза останавливает продолжение этапа; текущий запрос к источнику может завершиться.
Buthelezi E P, van der Merwe M T, Lönnroth P N, Gray I P, Crowther N J
Аннотация
OBJECTIVE: The goal of this study was to quantify differences in lipid metabolism and insulin sensitivity in black and white subjects to explain ethnic clinicopathological differences in type 2 diabetes.
RESEARCH METHODS AND PROCEDURES: The in vitro lipolytic activity of adipocytes isolated from obese black and white women was measured in the presence of insulin and isoproterenol. Insulin resistance was assessed in vivo using the euglycemic hyperinsulinemic clamp technique.
RESULTS: Fasting plasma levels of insulin and nonesterified fatty acid (NEFA) in black and white women were 67 +/- 5 pM vs. 152 +/- 20 pM (p < 0.01) and 863 +/- 93 microM vs. 412 +/- 34 microM (p < 0.01), respectively. Euglycemic hyperinsulinemic clamp studies showed that obese black subjects were more insulin-resistant than their white counterparts (glucose infusion rates: 1.3 +/- 0.2 vs. 2.2 +/- 0.3 mg/kg per min; p < 0.05). Isolated adipocytes from white women were more responsive to insulin than those from black women with 0.7 nM insulin causing a 55 +/- 4% inhibition of isoproterenol-stimulated lipolysis compared with 27 +/- 10% in black women (p < 0.05).
DISCUSSION: The low responsiveness of adipocyte lipolytic activity to insulin in black women in the presence of a relative insulinopenia may account for the high plasma NEFA levels seen in these women, which may, in turn, account for their higher in vivo insulin resistance. High NEFA levels may also contribute to the low insulin secretory activity observed in the obese black females. These data suggest that the pathogenesis of insulin resistance and type 2 diabetes within the black obese community is strongly influenced by their adipocyte metabolism.
RESEARCH METHODS AND PROCEDURES: The in vitro lipolytic activity of adipocytes isolated from obese black and white women was measured in the presence of insulin and isoproterenol. Insulin resistance was assessed in vivo using the euglycemic hyperinsulinemic clamp technique.
RESULTS: Fasting plasma levels of insulin and nonesterified fatty acid (NEFA) in black and white women were 67 +/- 5 pM vs. 152 +/- 20 pM (p < 0.01) and 863 +/- 93 microM vs. 412 +/- 34 microM (p < 0.01), respectively. Euglycemic hyperinsulinemic clamp studies showed that obese black subjects were more insulin-resistant than their white counterparts (glucose infusion rates: 1.3 +/- 0.2 vs. 2.2 +/- 0.3 mg/kg per min; p < 0.05). Isolated adipocytes from white women were more responsive to insulin than those from black women with 0.7 nM insulin causing a 55 +/- 4% inhibition of isoproterenol-stimulated lipolysis compared with 27 +/- 10% in black women (p < 0.05).
DISCUSSION: The low responsiveness of adipocyte lipolytic activity to insulin in black women in the presence of a relative insulinopenia may account for the high plasma NEFA levels seen in these women, which may, in turn, account for their higher in vivo insulin resistance. High NEFA levels may also contribute to the low insulin secretory activity observed in the obese black females. These data suggest that the pathogenesis of insulin resistance and type 2 diabetes within the black obese community is strongly influenced by their adipocyte metabolism.