Abstract
Previous cross-sectional and longitudinal studies have described decreasing testosterone levels with age in men, without consideration of acquired comorbidities in aging males.
We evaluated the longitudinal association between age and testosterone levels as well as the impact of several comorbidities on this relationship using multivariate panel regression analysis.
Participants were selected from the Baltimore Longitudinal Study of Aging. Data were obtained on the presence of several comorbidities and total testosterone level during each follow-up visit. A multivariate panel regression analysis was performed to determine the impact of age on testosterone level while controlling for individual comorbidities.
The primary outcomes were strength of association between age and various comorbidities, and testosterone level.
A total of 625 men were included in this study, with a mean age of 65 years and a mean testosterone level of 463 ng/dL. On multivariable-adjusted panel regression analysis, age was not significantly associated with testosterone decline, while anemia, diabetes mellitus, heart failure, obesity, peripheral artery disease, and stroke were inversely associated with total testosterone level. We report no association between cancer and total testosterone.
This study indicates that a decline in testosterone levels over time may be due to the presence of various comorbidities, which affects the medical management of hypogonadism in aging men.
The strengths of this study include the standardized acquisition of testosterone tests and uniform collection of variables, while limitations include the lack of follow-up data from 205 patients and the limited racial/ethnic diversity in the cohort.
In this large longitudinal study, we found that when adjusted for the presence of concomitant comorbidities, age does not predict a significant decline in testosterone level. With the overall increase in life expectancy and the simultaneous rise in the incidence of comorbidities such as diabetes and dyslipidemia, our findings may help optimize screening and treatment for late-onset hypogonadism in patients with multiple comorbidities.
