Reproductive and metabolic hormone associations in adult Samoan males with and without obesity

Abstract Background Obesity is a global health challenge prevalent in Samoa. However, the influence of obesity on adult male reproductive health in Samoa is poorly understood. Objectives To determine if reproductive hormone levels differed between adult Samoan males with and without obesity. Methodology Reproductive hormones (follicle stimulating hormone [FSH], luteinizing hormone [LH], inhibin b) and sex hormone binding globulin (SHBG) were compared between non-diabetic adult males in Samoa with and without obesity to test the hypothesis that obesity is associated with compromised reproductive function in this population. Metabolic hormones (insulin, leptin, adiponectin), fasting glucose, age, and anthropometrics were assessed and included in multivariable models. Results Males with obesity exhibited higher FSH (P = 0.002), lower inhibin b (P = 0.004) and lower SHBG (P < 0.0001). LH levels were similar (P = 0.43). Significant associations were evident between LH and FSH (obesity: r2 = 0.19, P = 0.003; without obesity: r2 = 0.24, P = 0.001), inhibin b and FSH (obesity: r2 = 0.21, P = 0.002; without obesity: r2 = 0.02, P = 0.41), and LH and SHBG (obesity: r2 = 0.25, P = 0.0005; without obesity: r2 0.01, P = 0.49). Multivariable models revealed insulin as an important contributor to inhibin b levels in all males. Conclusions Obesity status is an important factor in variation in male reproductive hormone profiles in adult Samoan males. Implications Obesity has potentially negative effects on male reproductive hormone function in Samoa. While the effects on male fertility remain unclear, further research is merited.