The emergence of sarcopenia as an important entity in older people

Editor – The informative article by Offord et al highlights the detrimental impact of age-related frailty and sarcopenia on mobility, fracture risk, quality of life, and NHS resources.¹ We were, however, surprised to find no mention of hypogonadism among the recognised causes of sarcopenia (and anaemia) in older males. The anabolic benefits of androgens on skeletal muscle mass are well-documented, albeit also observable with supraphysiological levels achieved by athletes as well as in the context of medically justifiable T replacement.² The European Male Ageing study found that hypogonadism affects 2–5% of community-dwelling older men.³

Hypogonadism is either caused by deficient testicular function (ie primary hypogonadism) or reduced pituitary luteinising hormone (LH) and follicle stimulating hormone (FSH) secretion (ie secondary hypogonadism). Secondary hypogonadism (low LH, FSH and T) is challenging to diagnose, particularly in the acute setting, as similar biochemical results may be observed in relation to non-gonadal illness, and in healthy men in the evening or post-prandially (T levels have diurnal variation and are suppressed acutely by food intake).⁴ By contrast, the biochemical fingerprint of primary hypogonadism is unambiguous, even in the setting of an acute medical or geriatric-rehabilitation ward; serum levels of LH and FSH are elevated, and serum T is low or low-normal. Furthermore, it is important to consider that patients may also present with microcytic anaemia caused by reduced T-dependent haematopoeisis.

T treatment may be given topically or by depot injection. T treatment is not recommended for men with physiological suppression of T secretion as a result of either frailty or obesity of old age.^3–5 However, for older men with true hypogonadism, T replacement is an inexpensive, safe and effective therapy that can reverse sarcopaenia, osteopaenia and anaemia, with expert consensus defining no upper age limit for the initiation of therapy in these individuals.⁶

Thus, when diagnosing sarcopaenia in older men, we urge physicians not to reflexively ascribe this to ‘old age’, and to also recognise that unexplained anaemia may sign-post hypogonadism. If the patient is subsequently found to have elevated LH and FSH, a trial of T replacement should be considered following an expert review.