Variation in C-reactive protein following weight loss in obese insulin resistant postmenopausal women: is there an independent contribution of lean body mass?

Prepregnancy Fat Free Mass and Associations to Glucose Metabolism Before and During Pregnancy

OBJECTIVE

Our aim was to quantify the individual contribution of prepregnancy (PP) fat-free mass (FFM), expressed as [PP-FFM index (PP-FFMI) = FFM (kg)/height (m2)], on markers of glucose homeostasis before and during pregnancy.

METHODS

Body composition was assessed in 43 women before pregnancy using air-displacement plethysmography. Blood was drawn at PP and gestational weeks ∼8 and 30. Relationships between body composition (independent) variables and glucose homeostasis (dependent) variables were assessed using adjusted correlations and simple and multiple linear regression analyses.

RESULTS

PP-FFMI was the strongest predictor of plasma insulin concentration [squared partial correlation (Pr2) = 17, P = 0.007] and homeostasis model assessment of insulin resistance (HOMA2-IR) (Pr2 = 16, P = 0.010). At gestation week 30, PP-FFMI and gestational weight gain (GWG) were the strongest predictors of insulin concentration (PP-FFMI: Pr2 = 20, P = 0.010; GWG: Pr2 = 12, P = 0.052) and HOMA2-IR (PP-FFMI: Pr2 = 19, P = 0.012; GWG: Pr2 = 13, P = 0.045). After accounting for PP fat mass index (PP-FMI), PP-FFMI and GWG were independently associated with first-phase insulin response (PP-FFMI: Pr2 = 20, P = 0.009; GWG: Pr2 = 15, P = 0.025) and second-phase insulin response (PP-FFMI: Pr2 = 19, P = 0.011; GWG: Pr2 = 17, P = 0.016). PP-FMI was the strongest predictor of an oral glucose tolerance test‒derived estimated metabolic clearance rate of glucose (PP-FMI: Pr2 = 14, P = 0.037) and estimated insulin sensitivity index (PP-FMI: Pr2 = 13, P = 0.047).

CONCLUSIONS

PP-FFMI was a predictor of markers of glucose homeostasis before and during pregnancy. Studies assessing the effect of skeletal muscle quality on metabolic regulation during pregnancy are warranted.