Differential associations of testosterone, dihydrotestosterone and oestradiol with physical, metabolic and health-related factors in community-dwelling men aged 17-97 years from the Busselton Health Survey.

OBJECTIVES: Lower testosterone (T) levels are associated with poorer health outcomes in older men, but associations in younger or middle-aged men are uncertain, and data for dihydrotestosterone (DHT) and oestradiol (E2) are limited. We assessed the associations of circulating T, DHT and E2 with physical and health-related factors in a cohort comprising men aged 17-97 years. PARTICIPANTS AND METHODS: Serum from 2143 community-dwelling men from the 1994/95 Busselton Health Survey was assayed for T, DHT and E2 using liquid chromatography-tandem mass spectrometry. Men receiving hormonal therapy or reporting the use of testosterone, or with prostate cancer or orchidectomy were excluded.
RESULTS: Of the men, 43% had never smoked, 6·1% had diabetes and 16·8% cardiovascular disease (CVD). Mean (±SD) age was 50·3 ± 17·0 years. Total T was moderately correlated with DHT (r = 0·56), E2 (r = 0·35) and sex hormone-binding globulin (r = 0·53). In age-, smoking-, body mass index (BMI)- and sex hormone-binding globulin (SHBG)-adjusted analyses, T was inversely associated with metabolic syndrome score, while DHT and E2 were not associated. In multivariable models, higher total T was associated with lower age, BMI and C-reactive protein, and with higher creatinine and haemoglobin, independently of SHBG. Higher DHT was associated with lower age, BMI and glucose level, and higher creatinine and haemoglobin. E2 was positively associated with age, BMI and haemoglobin.
CONCLUSIONS: In men spanning younger, middle and older ages, circulating androgens are more related to age and metabolic factors than CVD or chronic disease. Further investigation is required to clarify whether androgens and oestrogens have contrasting roles as risk predictors for CVD.