Endocrine Abstracts

Background: Late-onset central hypogonadism (LOH), whose prevalence is high among dysmetabolic males, impairs quality of life and increases cardiovascular risk. Although lifestyle modification is the first-line therapeutic strategy, it often fails in clinical practice, probably due to socio-cultural, economic and organisational barriers, as well as the lack of effective and sustainable intervention programs.

Aim: To delineate sustainable physical exercise programs and to assess the effects of such programs mainly on endocrine-metabolic and neurovegetative outcomes in a cohort of men with metabolic syndrome-related central LOH.

Methods: 18-80-year-old men, consecutively referred to IRCCS Istituto Auxologico Italiano due to dysmetabolic central LOH, will be enrolled in this prospective study. Participants will undergo a structured and personalised exercise program (accompanied by an adequate nutrition program). After 6 months they will be subdivided into two groups, according to the weekly physical activity volume actually performed (above or below 600 MET·minutes/week). Changes in endocrine-metabolic and neurovegetative outcomes (e.g., gonadal axis function, glucose and lipid profile, body composition, cardiac autonomic regulation (CAR)) will be compared between the two groups. In particular, Autonomic Nervous System Index (ANSI), being extracted from the autoregressive spectral analysis of heart rate variability by combining the three most informative variables, will be used for non-invasive assessment of CAR¹. Besides, genetic investigations will be performed to explore the potential role of genetic predisposition in the development of dysmetabolic LOH.

Preliminary results and discussion: Seven patients have been hitherto enrolled. As expected, they presented low percentages of fat free mass in the face of increased fat mass, and low SHBG levels. An impairment in both autonomic function (ANSI) was observed in comparison with reference populations from other studies. This is the first study assessing neurovegetative control by means of ANSI in hypogonadal men. Indeed, obesity/insulin resistance is associated with neurovegetative dysfunction, and lifestyle interventions have been shown to improve CAR in dysmetabolic patients. In this context, it will be interesting to explore the possible crosstalk between metabolic syndrome-related hypogonadism, autonomic dysfunction, and physical exercise. Notably, exercise prescription requires the clear definition of modality, intensity, frequency, duration and progression of exercise, tailored on patient’s clinical conditions and goals. Intervention programs should be sustainable in economic and organisational terms, with a view to embedding behavioural changes in patient’s everyday life.

Reference: 1. Sala R, et al. A Composite Autonomic Index as Unitary Metric for Heart Rate Variability: A Proof of Concept. Eur. J. Clin. Invest. 2017, 47, 241–249.