Association of Serum Myostatin with Body Weight, Visceral Fat Volume, and High Sensitivity C-Reactive Protein But Not With Muscle Mass and Physical Fitness in Premenopausal Women.

Background: The myokine myostatin regulates muscle mass and has been linked to insulin resistance and metabolic syndrome. However, data on its role in humans is still limited. We, therefore, investigated the associations of serum myostatin with muscle mass, physical fitness, and components of the metabolic syndrome in a cohort of premenopausal women.

Methods: We undertook a cross-sectional analysis of 233 women from the monocenter study PPSDiab, conducted in Munich, Germany. Participants had recently completed a pregnancy with or without gestational diabetes. Our analysis included medical history, anthropometrics, oral glucose tolerance testing, laboratory chemistry, cardiopulmonary exercise testing, and magnetic resonance imaging (n=142) of visceral fat volume, left quadriceps muscle mass, and muscle fat content. Serum myostatin was quantified by a competitive enzyme-linked immunosorbent assay.

Results: We observed positive correlations of serum myostatin with body mass index (ρ=0.235; p=0.0003), body fat percentage (ρ=0.166; p=0.011), waist circumference (ρ=0.206; p=0.002), intraabdominal fat volume (ρ=0.182; p=0.030) and high-sensitivity C-reactive protein (ρ=0.175; p=0.008). These correlations were reproduced in linear regression analyses with adjustment for age and time after delivery. We saw no correlations with muscle mass, physical fitness, insulin sensitivity, triglycerides, HDL cholesterol, and blood pressure.

Conclusions: Our observation of elevated serum myostatin in women with a higher body fat percentage, visceral obesity, and elevated c-reactive protein suggests that this myokine contributes to the altered muscle-adipose tissue crosstalk in metabolic syndrome. Elevated myostatin may advance this pathophysiologic process and could also impair the efficacy of exercise interventions. Further mechanistic studies, therefore, seem warranted.