Elevated serum acylated (biologically active) ghrelin and resistin levels associate with pregnancy-induced weight gain and insulin resistance

AIM: To study fasting biologically active serum ghrelin (RIA) and resistin (ELISA) levels in different trimesters of pregnancy (HP, n=45, 15 in each) and in gestational diabetes mellitus (GDM, n=30) compared to non-pregnant healthy women (NP, n=40) in correlation with TNF-alpha, soluble (s)TNF-receptor (R)-1, -2, leptin (ELISA), C-peptide (Cp, RIA) and Cp/blood glucose ratio (bg). STUDY DESIGN: Cross-sectional case control study. RESULTS: Acylated ghrelin levels were significantly increased (p<0.0001) in the 2nd (377+/-38pg/ml, X+/-S.D.) and decreased in the 3rd trimester (252+/-36) and in GDM (226+/-21) compared to NP controls (309+/-20) and HP women in the 1st trimester (314+/-41). Serum resistin levels were higher in the 1st (8.5+/-2.6ng/ml), 2nd (10.2+/-2.1) and 3rd (13.1+/-3.6) trimesters of pregnancy and in GDM (15.7+/-3.5) than in NP controls (6.5+/-2.3). Significant (p<0.01) negative linear correlations were found among fasting serum ghrelin and body mass index (BMI), the fasting C-peptide (Cp) level, C-peptide/blood glucose (Cp/bg) ratio, TNF-alpha, soluble (s)TNFR-2, leptin and resistin concentrations in both, HP and GDM groups. Significant positive correlations were observed between serum acylated ghrelin and adiponectin, and between BMI and fasting Cp, Cp/bg, TNF-alpha, sTNFR-1, -2 and leptin levels in both pregnant groups. CONCLUSION: Increased fasting serum acylated ghrelin concentrations in the 2nd trimester may associate with weight gain during pregnancy. Hyperresistinemia may also be associated with the pregnancy-induced insulin resistance. A negative regulatory feed-back mechanism between resistin, TNF-alpha and ghrelin may be hypothesized.