SFEBES2021 How Do I? Sessions How do I. . .? 2 (6 abstracts)
University of Newcastle-upon-Tyne, Newcastle, UK. Newcastle-upon-Tyne Hospitals, Newcastle, UK.
Male Hypogonadism (MH) is a clinical and biochemical diagnosis, comprising pathologically low serum testosterone (T) levels and clinical features of androgen deficiency, of which low muscle mass and increased fat mass are features. The diagnosis is most secure when framed in the context of a recognised clinical syndrome, or with male factor infertility from impaired gonadal function. Testosterone levels in individual males are subject to considerable variation, according to nutritional status (both acute and chronic), sleep-wake periodicity and general state of health. Therefore, unless gonadotrophin levels are raised (signalling primary gonadal insufficiency), a low T level in the absence of corroborative clinical context is of itself insufficient to establish a verified diagnosis. Men with obesity and metabolic syndrome can represent a particular diagnostic challenge in that T and gonadotrophin levels may be low-normal for physiological, rather than pathological reasons. These comprise non-fasted or afternoon venepuncture; hyperinsulinaemic suppression of hepatic SHBG secretion giving rise to apparently low total-T with normal free-T, and suppression of gonadotrophin secretion through hyperglycaemia, hyperoestrogenaemia (mediated by aromatisation of T in adipose tissue), inflammatory adipokines and the effects of general ill health. Men with simple obesity can also exhibit clinical features that overlap with those of MH, including sexual dysfunction, fatigue and gynaecomastia, which adds to the confusion, albeit generally in the absence of key features such as anaemia, osteopaenia, or reduction in testes volume. In men with physiologically low T relating to simple obesity, the reproductive axis normalises with weight loss, whether achieved through lifestyle-change or bariatric surgery. Nevertheless, there are also clinical trial data to support a role for testosterone therapy in mitigating the risk of developing type 2 diabetes in men with simple obesity. However, this comes at the cost of an unacceptable rate of erythrocytosis that may predispose to arterial and venous thrombosis.