title: Insulin, but not estrogen, correlated with indexes of desaturase function in obese women.
abstract: This study determined the associations of serum insulin and estrogen with fatty acid composition, fatty acid product/substrate ratios used as indexes of desaturase enzyme function, and platelet aggregation in obese and lean women. Thirty women were classified as obese (n = 8) or lean (n = 21) based on body mass index. Obese women were characterized by higher insulin levels (p < 0.05) but fasting glucose levels did not differ (p > 0.05) from lean women. Insulin positively correlated with increased C20:4n6/C18:3n6 (index of delta 5-desaturase) (p < 0.05) and C20:4n6/C18:2n6 (index of overall n6 pathway activity) (p < 0.01) in serum, and the n5 pathway in platelets (p < 0.01), but there was no correlation for insulin with platelet C18:3n6/C18:2n6 (index of delta 6-desaturase activity). Insulin was also positively related (p < 0.01) to aggregation as measured by impedance and negatively related to lag time (p < 0.05). Platelets of obese women aggregated more (p < 0.05) compared to lean women and began aggregating faster (p < 0.05), suggesting the possibility that the obese women were at greater risk for enhanced blood clotting. Plasma estrogen was correlated with age (p < 0.05) but not for other variables studied (p > 0.05). Insulin, but not estrogen, appears to influence desaturase activity, as demonstrated by increased desaturase function associated with hyperinsulinemia in obese women.
authors.affiliation: Department of Human Nutrition and Food Management, Ohio State University, Columbus, USA.
authors.forename: L C
authors.initials: LC
authors.lastname: Medeiros
authors.forename: Y W
authors.initials: YW
authors.lastname: Liu
authors.forename: S
authors.initials: S
authors.lastname: Park
authors.forename: P H
authors.initials: PH
authors.lastname: Chang
authors.forename: A M
authors.initials: AM
authors.lastname: Smith
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D004967:Estrogens / Q000097:blood*; D044943:Fatty Acid Desaturases / Q000502:physiology*; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood*; D008875:Middle Aged; D009765:Obesity / Q000097:blood*; D010743:Phospholipids / Q000097:blood
chemical_list: D001786:Blood Glucose; D004967:Estrogens; D007328:Insulin; D010743:Phospholipids; D044943:Fatty Acid Desaturases