Context: Despite recognition that androgen deficiency in men should be defined according to biochemical and clinical criteria, most prevalence estimates are based on low testosterone levels alone.
Objective: The objective of this study was to examine the association between symptoms of androgen deficiency and low total and calculated free testosterone levels and estimate the prevalence of symptomatic androgen deficiency in men.
Design: This study was a population-based, observational survey.
Participants: A total of 1,475 Black, Hispanic, and white men, between the ages of 30-79 yr, with complete data on testosterone, SHBG, and symptoms of androgen deficiency, and who are not taking medications that impact sex steroid levels were randomly selected from the Boston Area Community Health Survey.
Outcome: Outcomes were measured as symptomatic androgen deficiency, defined as low total (<300 ng/dl) and free (<5 ng/dl) testosterone plus presence of low libido, erectile dysfunction, osteoporosis or fracture, or two or more of following symptoms: sleep disturbance, depressed mood, lethargy, or diminished physical performance.
Results: Mean age of the sample was 47.3 +/- 12.5 yr. Approximately 24% of subjects had total testosterone less than 300 ng/dl, and 11% of subjects had free testosterone less than 5 ng/dl. Prevalence of symptoms were as follows: low libido (12%), erectile dysfunction (16%), osteoporosis/fracture (1%), and two or more of the nonspecific symptoms (20%). Low testosterone levels were associated with symptoms, but many men with low testosterone levels were asymptomatic (e.g. in men 50+ yr, 47.6%). Crude prevalence of symptomatic androgen deficiency was 5.6% (95% confidence interval: 3.6%, 8.6%), and was not significantly related to race and ethnic group. Prevalence was low in men less than 70 yr (3.1-7.0%) and increased markedly with age to 18.4% among 70 yr olds. Projection of these estimates to the year 2025 suggests that there will be as many as 6.5 million American men ages 30-79 yr with symptomatic androgen deficiency, an increase of 38% from 2000 population estimates.
Conclusions: Prevalence of symptomatic androgen deficiency in men 30 and 79 yr of age is 5.6% and increases substantially with age. The aging of the U.S. male population will cause a large increase in the burden of symptomatic androgen deficiency. Future work should address the clinical significance of low testosterone levels in asymptomatic men.