Background: Sex hormone-binding globulin (SHBG) is the major sex steroid carrier protein. Its production is negatively regulated by insulin and monosaccharides. The concentration of SHBG increases between 16 and 27 weeks gestation and is negatively associated with pre-gestational BMI and weight gain during pregnancy. The link of SHBG with cardiovascular risk is poorly understood.
Objective and hypotheses: In obese pregnant women, we aimed to study the association of circulating SHBG with cardiovascular risk factors independently of endocrinemetabolic parameters.
Method: Fasting serum SHBG levels were quantified between 24 and 28 weeks of gestation in 160 healthy pregnant women (87 with normal weight and 73 with pre-pregnancy obesity and/or gestational obesity, as defined by international references). Cardiovascular risk parameters (C-reactive protein (CRP) and blood pressure (BP)), metabolic parameters (HbA1c), pre- and post-load glucose, C-peptide, insulin (and insulin resistance index (HOMA-IR)), triglycerides, and high molecular weight adiponectin (HMW)), and endocrine parameters (total testosterone and estradiol) were also assessed.
Results: As expected, lower concentrations of SHBG were associated with increased BMI, HbA1c, pre- and post-load glucose, C-peptide, HOMA-IR, triglycerides and less HMW adiponectin; lower SHBG was also associated with more CRP and BP (P<0.01P<0.0001 for all comparisons). These associations were more robust in women with obesity, who had lower SHBG concentrations compared to normal-weight women (P<0.0001). In multivariate analysis in obese women, SHBG showed independent associations with CRP (β=−0377, P<0.001, R2=16.7) and BP (β=−0.255, P=0.030, R2=6.4) independently of metabolic (HOMA-IR and HbA1c) and endocrine (testosterone and estradiol) parameters.
Conclusion: SHBG is decreased in obese pregnant women in association with a less favorable cardiovascular profile. We suggest that SHBG can integrate the cardiovascular risk and metabolic dysfunction of gestational obesity.
20 - 22 Sep 2014
European Society for Paediatric Endocrinology