Associations of Free Fatty Acids With Insulin Secretion and Action Among African‐American and European‐American Girls and Women
Open Access
- 1 February 2010
- Vol. 18 (2), 247-253
- https://doi.org/10.1038/oby.2009.248
Abstract
Ethnic differences in insulin secretion and action between African Americans (AAs) and European Americans (EAs) may influence mobilization of free fatty acids (FFAs). We tested the hypotheses that FFA concentrations would be associated with measures of insulin secretion and action before and during a glucose challenge test. Subjects were 48 prepubertal girls, 60 premenopausal women, and 46 postmenopausal women. Fasting insulin (insulin0), the acute insulin response to glucose (AIRg), the insulin sensitivity index (SI), basal and nadir FFA (FFA0, FFAnadir), and nadir time (TIMEnadir) were determined during an intravenous glucose tolerance test (IVGTT). Stepwise multiple linear regression (MLR) analysis was conducted to identify associations of FFA0, FFAnadir, and TIMEnadir with ethnicity, age group, insulin measures, indexes of body composition from dual‐energy X‐ray absorptiometry, and measures of fat distribution from computed tomography scan. In this population, insulin0 and AIRg were higher among AAs vs. EAs, whereas SI was lower, independent of age group. MLR analyses indicated that FFA0 was best predicted by lean tissue mass (LTM), leg fat mass, ethnicity (lower in AAs), SI, and insulin0. FFAnadir was best predicted by FFA0, age group, and intra‐abdominal adipose tissue (IAAT). TIMEnadir was best predicted by leg fat mass, AIRg, and SI. In conclusion, indexes of insulin secretion and action were associated with FFA dynamics in healthy girls and women. Lower FFA0 among AAs was independent of insulin0 and SI. Whether lower FFA0 is associated with substrate oxidation or risk for obesity remains to be determined.Keywords
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