Endocrine Abstracts

Objective: There is little data available regarding the effects of male sex hormones on cardiac autonomic function. The aim of this study is to evaluate the association between male sex steroids and cardiac autonomic function by comparing heart rate variability (HRV) parameters of young male hypogonadotropic hypogonadism patients to those of healthy controls.

Design: The study consisted of 22 male hypogonadotropic hypogonadism patients (mean age 20.8±1.2 years) and the same number of age-matched healthy male controls (mean age 21.0±1.5 years).

Methods: A 24-hour holter monitoring was performed to assess the following HRV parameters; SDNN, SDANN, SDNN5, RMSSD, pNN50, and HRV triangular index (TRIA). Serum levels of FSH, LH, testosterone, estradiol, progesterone and prolactin were measured.

The HRV parameters of patients and control groups were compared, and possible associations between levels of tested hormones and HRV parameters were evaluated.

Results

SDNN, SDANN and SDNN5 values of patients were significantly lower compared to those of controls (147.47±56.16 vs 193.63±40.89; 138.31±57.64 vs 190.15±43.94 and 67.89±21.46 vs 84.63±24.35, respectively; P<0.05 for all). Significant negative correlations were observed between serum FSH, LH and testosterone levels and most of the HRV parameters.

Conclusions: Male sex hormone deficiency seems to adversely affect cardiac autonomic modulation with increased sympathetic and decreased parasympathetic components of HRV.