Testosterone Screening Thresholds in Active-Duty US Male Service Members

 

1. Stephen R. Hennigar, PhD¹; Steven B. Heymsfield, MD¹; Asma S. Bukhari, PhD, RD¹
2. et al
   
   doi: 10.1001/jama.2026.19794
   
   

   Serum testosterone level is measured to evaluate suspected hypogonadism. A recent US government memorandum1 requires annual testosterone screening for all active-duty and reserve military personnel aged 30 years and older. Consequently, population estimates of prevalence of low testosterone at screening are needed. Clinical guidelines recommend against screening asymptomatic men because testosterone concentrations vary with age, time of day, obesity, illness, and physical stress.² The American Urological Association recommends a total testosterone concentration less than 300 ng/dL as a reasonable cutoff for low testosterone,³ whereas a harmonized Centers for Disease Control and Prevention reference study identified 264 ng/dL as the lower limit of normal in healthy, nonobese men aged 19 to 39 years.⁴ We estimated US Army–wide prevalence of active-duty men with testosterone concentrations below these thresholds.

   Methods

   This cross-sectional analysis used data from the Military Health and Nutrition Examination Study, a multisite survey conducted at 5 US Army installations from August 2024 through January 2026.⁵ Participants with fasting morning serum total testosterone measurements were included; 3 men receiving testosterone replacement therapy were excluded. Total testosterone and sex hormone–binding globulin levels were measured by automated immunoassay (IMMULITE 2000; Siemens) and albumin level on a Beckman UniCel DxC 600 Pro. Free testosterone level was determined by calculation.⁶ Data from women were not included because 73 of 160 (45.6%) had testosterone concentrations below the assay limit of detection (<20 ng/dL). Prevalence using a screening testosterone concentration less than 300 ng/dL and less than 264 ng/dL was estimated with 95% CIs. Poststratification calibration weights aligned estimates with the active-duty US Army population, and survey-weighted logistic regression examined associations of age and body mass index (BMI, calculated as weight in kilograms divided by height in meters squared) with testosterone level. To convert testosterone to nmol/L, multiply values by 0.0347. Participants provided written informed consent, and the study was approved by the Pennington Biomedical Research Center institutional review board and registered on ClinicalTrials.gov (NCT06380322). Additional methods are provided in the eMethods in Supplement 1.

   Results

   Men (n = 479; 1.7% were American Indian or Alaska Native, 6.3% Asian or Pacific Islander, 17.1% Hispanic, 20.5% non-Hispanic Black, and 54.4% non-Hispanic White) had a weighted mean (SE) age of 29.9 (0.6) years and BMI of 28.4 (0.2). The weighted mean morning total testosterone, sex hormone–binding globulin, and free testosterone concentrations were 405 ng/dL (95% CI, 368-442 ng/dL), 3.24 μg/mL (95% CI, 2.73-3.75 μg/mL), and 8.74 ng/dL (95% CI, 7.70-9.81 ng/dL), respectively. According to total testosterone concentrations, an estimated 100 691 active-duty US Army personnel would have a morning screening testosterone concentration less than 300 ng/dL, corresponding to a weighted prevalence of 25.7% (95% CI, 16.8%-34.5%) (Table). Using a threshold of less than 264 ng/dL, approximately 57 788 men would have a screening concentration below the threshold (weighted prevalence, 14.7%; 95% CI, 9.7%-19.7%), including 23 115 nonobese men aged 19 to 39 years (9.7%; 95% CI, 4.6%-14.8%).
   https://jamanetwork.com/journals/jama/fullarticle/2855385

   Table.  Prevalence of Total Testosterone Categories in Male Active-Duty Army Personnel^a,1