Adipocyte fatty acid-binding protein is associated with markers of obesity, but is an unlikely link between obesity, insulin resistance, and hyperandrogenism in polycystic ovary syndrome women.
OBJECTIVE
Many polycystic ovary syndrome (PCOS) women suffer from adiposity and insulin resistance (IR), which play an important role in the development and maintenance of PCOS. Adipocyte fatty acid-binding protein (A-FABP) is mainly expressed in adipocytes, and circulating A-FABP has been associated with markers of obesity and IR. Thus, as observed with other adipose tissue derived factors, secreted A-FABP might be involved in the pathogenesis of obesity-associated disorders such as PCOS.


METHODS
Plasma A-FABP concentrations were measured in 102 non-diabetic PCOS women, and associations with markers of obesity, IR, inflammation, and hyperandrogenism were investigated by correlation and multiple linear regression analyses. The effect of lifestyle intervention on A-FABP was studied in a second cohort of 17 obese PCOS women.


RESULTS
A-FABP correlated with body mass index (BMI; R = 0.694, P < 0.001), dual-energy X-ray-absorptiometry (DEXA) fat mass (R = 0.729, P < 0.001), DEXA lean body mass (R = 0.399, P = 0.001), HOMA %S (R = -0.435, P < 0.001), hsCRP (R = 0.355, P = 0.001), and free testosterone (fT; R = 0.230, P = 0.02). Adjusted for age, smoking, and glucose metabolism the association of A-FABP with HOMA %S was still significant (P < 0.001), whereas the associations with fT (P = 0.09) and hsCRP (P = 0.25) were not. Inclusion of BMI into the model abolished the impact of A-FABP on HOMA %S. In BMI-matched PCOS women (n = 20 pairs), neither HOMA %S (P = 0.3) nor fT (P = 0.6) were different despite different A-FABP levels (P < 0.001), and in 17 obese PCOS women undergoing a lifestyle intervention, changes in IR were not paralleled by changes in A-FABP.


CONCLUSIONS
Circulating A-FABP was correlated with markers of obesity, but had no major impact on IR, inflammation, or hyperandrogenemia in PCOS women.
Department of Endocrinology, Diabetes and Nutrition, Charité-University Medicine Berlin, Campus Benjamin Franklin, 12200 Berlin, Germany. mmoehlig@dife.de
Matthias
M
Möhlig
Martin O
MO
Weickert
Elham
E
Ghadamgadai
Andrea
A
Machlitt
Bettina
B
Pfüller
Ayman M
AM
Arafat
Andreas F H
AF
Pfeiffer
Christof
C
Schöfl
D000328:Adult; D015415:Biomarkers; D001823:Body Composition / Q000502:physiology; D015992:Body Mass Index; D015331:Cohort Studies; D050556:Fatty Acid-Binding Proteins / Q000235:genetics* / Q000378:metabolism*; D005260:Female; D006801:Humans; D017588:Hyperandrogenism / Q000209:etiology / Q000235:genetics* / Q000378:metabolism*; D007333:Insulin Resistance / Q000235:genetics / Q000502:physiology*; D008598:Menstruation / Q000502:physiology; D009765:Obesity / Q000378:metabolism*; D011085:Polycystic Ovary Syndrome / Q000150:complications / Q000235:genetics* / Q000378:metabolism*
D015415:Biomarkers; D050556:Fatty Acid-Binding Proteins