C-reactive protein levels and ageing male symptoms in hypogonadal men treated with testosterone supplementation.

C-reactive protein (CRP) is a marker of systemic low-grade inflammation, and may be associated with subjective symptoms of androgen deficiency. We studied the effects of normalisation of plasma testosterone levels in an open, nonrandomised study. Hypogonadal men (T levels: 5.9-12.1 nmol l(-1), aged 34-69 years) were treated for 15 months with parenteral testosterone undecanoate (1000 mg per 12 weeks). In 100 men, plasma CRP and Aging Male Symptom (AMS) self-report data were available at baseline, of 91 men at 6 months, of 59 men at 12 months and of 60 men at 15 months. Testosterone administration resulted in a profound decline in CRP levels and AMS scores (both P < 0.001). There was a positive association between CRP levels and AMS scores over time (r = 0.22; P < 0.001), while adjusting for smoking, alcohol use, age, and body mass index. Low-grade inflammation may be involved in the pathogenesis of subjective symptoms of androgen deficiency in ageing men.