Endocrine Abstracts

Background and aim: Low testosterone levels are known to be associated with unfavorable body composition and testosterone replacement is known to be associated with increased muscle mass and muscle strength. The aim of this cross-sectionalstudy is to evaluate the grip strength, appendicular muscle mass and physical performance and bone mineral densities of hypogonad male patients.

Method: 75 hypogonad and 45 healthy control subjects were included in this study. The etiology of hypogonadism, follow-up and replacement durations were asked. The right and left handgrip strength were measured by a hand dynomometer to assessmuscle strength. Decreased muscle strength was defined as <27 kg in men. Appendicular skeletal muscle mass was detected with bioelectrical impedance analysis and gait speed was detected with 4 meter usual walking speed test to assess physical performance if the patient was sarcopenic. Bone mineral densities of the patient group were evaluated. Serum testosterone levels measured at 10th day of testosterone propionate injection were recorded.

Results: 69 of the 75 hypogonad patients were hypogonadotrophic hypogonadism and 23 patients had panhypopituitarism. 66 of the patients were under replacement therapy but 42 of these patients had low serum testosterone levels according to reference range. The grip strength of the patient group was significantly lower than control group. 15 of the patients had muscle weakness. Appendicular skeletal muscle mass of these patients were normal. When all of the subjects were included, grip strength of the low testosterone group were lower and the BMI and Hba1c levels weresignificatly high. The total testosterone levels had a significant negative correlation with hand grip strength (r = 0.007) but no correlation with BMD levels. When the patient group was evaluated according to testosterone reference range levels, as normal or lowthere was no significant difference of grip strength and BMD levels between groups. The grip strength of the patients with panhypopituitarism were significantly low.

Conclusion: The muscle strength of the hypogonad patients are lower than healthy population but the measured low testosterone levels of the patients under regular replacement therapy may notcorrelate directly with muscle strength.