Testosterone deficiency has been linked with autoimmune disease and an increase in inflammatory markers, such as C-reactive protein (CRP), tumor necrosis factor, and interleukin-6 (IL-6). However, no large-scale longitudinal studies have examined this association. We examined whether untreated hypogonadism was associated with an increased risk of rheumatic autoimmune disease in a large nationally representative cohort. Using one of the nation's largest commercial insurance databases, we conducted a retrospective cohort study in which we identified 123,460 men diagnosed with hypogonadism between January 1, 2002 and December 31, 2014 and with no prior history of rheumatic autoimmune disease. We matched this cohort to 370,380 men without hypogonadism, at a 1 to 3 ratio, on age and index/diagnosis date. All patients were followed until December 31, 2014 or until they lost insurance coverage or were diagnosed with a rheumatic autoimmune disease. Cox proportional hazards regression was used to calculate adjusted hazard ratios (aHRs). Untreated hypogonadism was associated with an increased risk of developing any rheumatic autoimmune disease (HR = 1.33, 95 % CI = 1.28, 1.38), rheumatoid arthritis (HR = 1.31, 95 % CI = 1.22, 1.44), and lupus (HR = 1.58, 95 % CI = 1.28, 1.94). These findings persisted using latency periods of 1 and 2 years. Hypogonadism was not associated with the control outcome, epilepsy (HR = 1.04, 95 % CI = 0.96, 1.15). Patients diagnosed with hypogonadism who were not treated with testosterone had an increased risk of developing any rheumatic autoimmune disease, rheumatoid arthritis, and lupus. Future research should further examine this association, with particular attention to underlying mechanisms.
Keywords: Androgen; Autoimmune disease; Rheumatic disease; Testosterone replacement therapy.