Association of Metabolic Obesity Phenotypes and Total Testosterone in Middle-aged and Elderly Male Population

Abstract Objectives Obesity and metabolic syndrome have been reported to exert an impact on male reproductive system with decreasing levels of serum total testosterone (TT), however, the effect of different metabolic obesity phenotypes on testosterone has been poorly studied. We aimed to evaluate the association of metabolic obesity phenotypes and total testosterone levels in male population. Methods We performed a retrospective study based on an epidemiological investigation, a total of 4 081 middle-aged and elderly male individuals were recruited. The population was classified as metabolically healthy normal weight (MHNW); metabolically healthy obese (MHO); metabolically unhealthy normal weight (MUNW) and metabolically unhealthy obese (MUO) according to normal weight (BMI<25.0) and obesity (BMI≥25.0) with or without metabolic syndrome. Results We collected 563 hypotestosteronemia among 4 081 middle-aged and elderly male individuals. The odds ratios (ORs) (95% CIs) of hypotestosteronemia in obesity and metabolic syndrome was 3.072 (2.414-3.911) and 3.294 (2.631-4.125) respectively, after adjusting for age, luteinizing hormone, smoking status and alcohol consumption. Compared to MHNW group, male subjects in MHO, MUNW and MUO groups had a decreased serum TT levels. Additionally, MUO group have a lowest concentration of serum TT and a highest proportion of hypotestosteronemia. There was no significant difference of TT levels between MHO and MUNW group. Conclusions Obesity and metabolic syndrome are independent risk factor of hypotestosteronemia in middle-aged and elderly male populations. Our study also suggested that individuals with MHO, MUNW and MUO have a higher risk of developing hypotestosteronemia.