Androgen deficiency in male patients diagnosed with ANCA-associated vasculitis: a cause of fatigue and reduced health-related quality of life?

Abstract

Introduction: Low testosterone levels in men are associated with fatigue, limited physical performance and reduced health-related quality of life (HRQOL); however, this relationship has never been assessed in patients with anti-neutrophil cytoplasmic antibodies (ANCA) -associated vasculitides (AAV). The aim of this study was to assess the prevalence of androgen deficiency and to investigate the role of testosterone in fatigue, limited physical condition and reduced HRQOL in men with AAV.

Methods: Male patients with AAV in remission were included in this study. Fatigue and HRQOL were assessed by the multi-dimensional fatigue inventory (MFI)-20 and RAND-36 questionnaires.

Results: Seventy male patients with a mean age of 59 years (SD 12) were included. Scores of almost all subscales of both questionnaires were significantly worse in patients compared to controls. Mean total testosterone and free testosterone levels were 13.8 nmol/L (SD 5.6) and 256 pmol/L (SD 102), respectively. Androgen deficiency (defined according to Endocrine Society Clinical Practice Guidelines) was present in 47% of patients. Scores in the subscales of general health perception, physical functioning and reduced activity were significantly worse in patients with androgen deficiency compared to patients with normal androgen levels. Testosterone and age were predictors for the RAND-36 physical component summary in multiple linear regression analysis. Testosterone, age, vasculitis damage index (VDI) and C-reactive protein (CRP) were associated with the MFI-20 subscale of general fatigue.

Conclusions: This study showed that androgen deficiency was present in a substantial number of patients with AAV. Testosterone was one of the predictors for physical functioning and fatigue. Testosterone may play a role in fatigue, reduced physical performance and HRQOL in male patients with AAV.

Figure 1

Mean total and free testosterone. Normal values are represented by the dashed lines, respectively, at 10 nmol/L for total testosterone and 300 pmol/L for free testosterone.

Figure 2

Mean scores in the subscales of the RAND-36 of all patients and references. A P value of P < 0.010 is shown as * and P < 0.001 as **.

Figure 3

Mean scores in the subscales of the MFI-20 of all patients and references. A P value of P < 0.010 is shown as * and P < 0.001 as **.

Figure 4

Z-scores of the RAND-36 and MFI-20 questionnaires. Grey circles represent mean and SD of patients with normal androgen levels (n = 37) and black squares represent mean and SD of patients with androgen deficiency (n = 33). Mean population score is represented by a Z-score of zero. P < 0.05 is indicated with *. Note that higher Z-scores on the MFI-20 mean more fatigue and lower Z-scores on the RAND-36 signify poorer quality of life.

Figure 5

Association between the physical component score and levels of total testosterone for patients under and above the median age of 61.3 years. Open squares represent total testosterone levels and PCS scores of patients under the median age and the blue circles represent total testosterone levels and PCS scores of patients above the median age. PCS, physical component summary.