Figures
Abstract
In men with obesity, a low serum testosterone concentration in the absence of pathology of the hypothalamic-pituitary-testicular axis is termed functional hypogonadism and is mostly due to obesity. Such a finding should prompt a comprehensive assessment for underlying chronic disease and cardiometabolic risk.
Key Points
- Ageing in men is not inherently associated with a significant decrease in serum testosterone concentrations until the process is very well advanced (>80 years).
- Obesity, where the excess fat is stored in viscerally located adipose tissue and associated with insulin resistance, dyslipidaemia and inflammation, decreases serum testosterone concentration by both central and peripheral mechanisms.
- The low serum testosterone concentration resulting from obesity is reversible with weight loss and is therefore best thought of as obesity-associated functional hypogonadism.
- Men with visceral obesity, the metabolic syndrome and low serum testosterone concentrations are at increased risk for type 2 diabetes.
- Other causes of functional hypogonadism include medication (opioids), smoking cessation, excess alcohol consumption, inflammatory processes and subtypes of depression.
- A low serum testosterone concentration caused by a definable abnormality in the hypothalamus, pituitary or testes is termed pathological hypogonadism.
- The finding of a low serum testosterone concentration requires a thorough clinical and endocrinological assessment to establish the reason it is low, and treatment instituted accordingly.
