Abstract and Introduction
Abstract
Objective: Testosterone replacement therapy (TRT) is recommended for the treatment of symptomatic hypogonadism in men. Data on prescription behaviours are, however, limited and conflicting. The objective of this study was to investigate clinical characteristics associated with the likelihood of being prescribed TRT by general practitioners (GP) in North-West London (NWL).
Design: Retrospective cohort study using Discover database of GP-registered patients in NWL between 2015 and 2019.
Patients: We identified 20,299 men aged ≥18 years with serum total testosterone measurement (TT) and without prior TRT prescription records.
Measurements: We determined whether TRT was subsequently commenced, while analysing clinical characteristics related to hypogonadism.
Results: Of all men having TT measurement, 19,583 (96.4%) were not commenced on TRT (Group A) and 716 (3.5%) men were commenced on TRT (Group B). Men prescribed TRT (Group B) had higher mean age, body mass index (BMI) and higher risks of hypertension, depression type 2 diabetes and ischaemic heart disease; conversely, men in Group B had lower mean pretreatment TT and were less likely to have prostate cancer. Four-hundred and thirty-six men (24.3%) with TT < 8 nmol/L and symptoms of low libido were not prescribed TRT.
Conclusions: Our study highlights several factors which may influence the decisions made by clinicians when initiating TRT in primary care. Clearer guidance for clinicians may help to improve the consistency of treatment of men with hypogonadism.
Introduction
Testosterone is an essential hormone for sexual function, muscle growth and bone mineralisation, and has important behavioural effects in men. Hypogonadism (symptomatic low testosterone) results in significant morbidity and adversely affects the quality of life. Incidence of hypogonadism increases with advancing male age such that levels of circulating testosterone decline annually by approximately 1% from the age of 40 years according to the European Male Ageing Study.[1] This has contributed to a worldwide increase in the prescription of testosterone therapy.[2]
The benefits of testosterone replacement therapy (TRT) including increased libido, improved bone density, strength and muscle mass are well-documented. Some studies have reported an increased risk of myocardial infarction and stroke associated with testosterone use.[3,4] In contrast, other studies have observed that TRT was associated with either lower or unchanged risk of cardiovascular disease in men with hypogonadism.[5] Furthermore, there exist several clinical guidelines for TRT[6–9] each with differing advice which may create a lack of clarity for practitioners treating men with hypogonadism. Taken together, clinicians face a myriad of conflicting considerations when making the decision whether to initiate TRT in men. It is likely that there exists substantial variability in the prescribing habits of clinicians with regard to TRT for men with symptoms of hypogonadism.[10]
To better understand the factors associated with prescribing (or not prescribing) TRT, we analysed a primary healthcare database to profile the clinical characteristics and comorbidities of men who had at least one serum total testosterone level (TT) measured from a population of over 2.5 million patients registered with a general practitioner (GP) in North-West London (NWL), UK.