건강한 내장형 비만 여성에서 혈청 호르몬과 인지질 지방산의 변화 = Relationships between Visceral-Type Obesity and Hormones and The Fatty Acid Composition of Serum Phospholipids in Korean Middle-Aged Women

다국어 초록 (Multilingual Abstract)

Background: Visceral-type obese women are known to show hyperinsulinemia, hyperandrogenicity, and low serum IGF-1 level. These endocrine perturbations with visceral fat accumulation will change the fatty acid composition of serum phapholipids(PL).
Methods: Anthropometric and computed tomographic measurements at umbilicus and thigh midway between the patella and pubis were performed in 169 middle-aged healthy women. An oral glucose tolerance test, the fatty acid composition of serum PL, fasting serum levels of lipids, IGF-1 and testosterone, and free androgen index were determined.
Results: Since visceral fat to subcutaneous fat ratio(VSR) correlated most significantly with the fatty acid composition, we devided overweight subjects into 3 groups according to their VSR. When VSR was equal to or more than 0.4, it was defined visceral-type and when VSR was less than 0.3, it was defined subcutaneous-type. Both visceral-type and subcutaneous-type groups showed similar age, body mass index, waist/hip and total abdominal fat area. An age-matched group of normal weight women served as controls. Compared with the subcutaneous-type, visceral-type group showed an increase in fasting levels and response areas of glucose and insulin, free androgen index and serum concentrations of triglyceride, LDL and total cholesterol, and a decrease in serum levels of HDL, SHBG and IGF-1. Stearic(C18:0), dihomo-γ-linolenic(C20:3ω6) acid and C20:3/18:2(Δ6-desatrase+elongation activity) in serum PL was higher in visceral-type group than the subcutaneous-type. Linoleic(C18:2ω6), arachidonic(C20:4ω6), linolenic(C18:3ω3), docosahexaenoic(C22:6ω3) acid, and C20:4/20:3(Δ5-desaturase activity) in serum PL was lower in the visceral-type than the subcutaneous-type. The averages of these parameters in the subcutaneous-type were similar to those in the normal-weight group. Δ5-desaturase activity positively correlated with the levels of SHBG(r=0.431, P$lt;0.001), IGF-1(r=0.484, P$lt;0.001) but negatively with insulin response area(r=-0.309, P$lt;0.001), testosterone level(r=-0.343, P$lt;0.001) and free androgen index (r=-0.500, P$lt;0.001). Serum IGF-1 level was negatively correlated to VSR(r=-0.440, P$lt;0.001), total saturated fatty acids(r=-0.626, P$lt;0.001), C18:0/16:0(r=-0.510, P$lt;0.001), C20:3/18:3 (r=-0.222, P$lt;0.05), but negatively to total polyunsaturated fatty acids(r=0.499, P$lt;0.001) in the serum PL fraction.
Conclusion: Our results indicate that in the visceral-type obesity, insulin resistance and hyperinsulinemia might change fatty acid desaturase activity. It is also concluded that hyperandrogenicity and low secretion of growth hormone might indirectly influence fatty acid composition because of close relationship between visceral-type obesity and endocrine abnormalities. This explains why visceral-type obesity rather than the relative body weight for height has a greater role in determining the fatty acid composition in serum PL.