Testosterone concentrations and associated predictors in men with cystic fibrosis: A retrospective, single-center study.

Background: Men with cystic fibrosis (CF) have sexual health concerns such as delayed puberty, infertility, and hypogonadism. The causes and prevalence of hypogonadism have not been well studied. The purpose of this study was to determine the prevalence of a low testosterone concentration in men with CF.

Methods: This retrospective study was approved by the Emory University Institutional Review Board (IRB). Data were extracted from the electronic medical records of adult men with CF receiving care at the Emory Cystic Fibrosis Center. A total of 129 men with CF were followed at our center from 2016 to 2023. Of these individuals, 76 men with CF (58.9%) had at least one serum total testosterone measurement. Seven individuals were excluded from this study since they were currently receiving testosterone therapy, leaving a final sample size of 69 individuals for the analysis. Demographic data, serum testosterone concentrations, and other factors associated with low testosterone concentrations were collected. Low testosterone was defined as a value below 300 ng/dL. Regression analyses were used to determine factors associated with low testosterone levels.

Results: The mean (± SD) age of the 69 eligible participants was 33.34 ± 10.98 years. The mean testosterone concentration was 421 ± 158.5 ng/dL with 27.54 percent of men with a testosterone value below 300 ng/dL. The mean hemoglobin level was 14.23 ± 2.18 g/dL. Testosterone levels were positively related to hemoglobin levels. Time of day of measurement and age were not associated with testosterone levels.

Conclusion: Roughly a quarter of men with CF demonstrated low testosterone in our sample. Low hemoglobin was associated with low testosterone levels in men with CF. Neither time of day nor age influenced testosterone concentrations in this sample.