Endocrine Abstracts

Background: Testosterone (T) levels decline gradually with increasing age in men. However, age-related decline in several functional domains (e.g. frailty, cognitive deficits, osteoporosis) accelerates in the eighth decade. It is not known if the loss of function in the oldest old is related to a more precipitous fall in T.

Objective: To determine if total testosterone (TT) declines more rapidly in men in the eighth compared to those in the sixth and seventh decade and determine, if factors influencing T levels among octogenarians are different from earlier decades.

Methods: One thousand three hundred and twenty men, mean age, 73 (range 65–95) yrs who responded to invitation letters to participate in a clinical trial of testosterone replacement therapy were included in this study. Total testosterone (TT), sex hormone binding globulin (SHBG), follicle stimulating hormone (FSH), and luteinizing hormone (LH) were measured.

Results: The cohort was divided into 4 age bands: B1 (65–69 years, n=510), B2 (70–74 years, n=357), B3 (75–79 years, n=258) and B4 (80–95 years, n=195). There was no significant difference in TT in B4, compared to other age bands (13.4 nmol/L vs.13.9, 13.7, 13.9 nmol/L for B1, B2 and B3 respectively, P=0.63). Over 60% of men in B4 had a TT >12 nmol/L, not significantly different from other age bands. There was no difference in the number of comorbidities or prevalence of individual comorbidities among age bands except cerebrovascular disease, which was higher in B4 (P=0.01). Men in B4 were more likely to be exsmokers (P<0.05) and less likely to be current smokers, P<0.01). BMI was associated with TT in all age groups. Chronic obstructive airways disease was associated with falling TT only in B2 (β=−1.72, P=0.04). Cancer was associated with TT (β=−4.82 and −4.53) for B3 and B4 respectively.

Conclusions: TT does not fall at a faster rate in men in the eighth decade and older. Most factors influencing TT do not differ in octogenarians compared to younger men.