Association between weight gain and sarcopenic obesity in patients treated with androgen deprivation therapy.

Abstract

189 Background: Weight gain in response to androgen deprivation therapy (ADT) can be a marker for adverse effects of ADT. However, a concomitant decrease in lean mass in response to ADT may decrease the utility of weight gain in terms of sarcopenia. Therefore, the goal of the present study was to analyze the relationship among weight gain, obesity, and sarcopenia in patients undergoing ADT. Methods: Patients with prostate cancer who were hormone-naïve and scheduled to receive long-term ADT were recruited between 2011 and 2013. Body weight and results from blood tests of lipid and glucose metabolism were recorded every 3 months during 1 year of ADT. Computed tomography (CT) was performed to measure areas of subcutaneous and visceral fat and the psoas muscle before and after 1-year of ADT. ADT was limited to a luteinizing hormone-releasing hormone agonist with or without bicalutamide. Results: CT was performed in 72 patients before and after 1 year of ADT. Median age was 74 years (49-83). Median prostate-specific antigen before ADT was 21.9 ng/ml (0.3-3316). Clinical stage was B (43.1%), C (26.4%), and D (29.2%). Mean increase in weight was 2.7% after 1 year of ADT. Mean increase in the area of subcutaneous and visceral fat was 31.3% and 20.7%, respectively. Mean change in the area of the psoas muscle was -8.4%. When patients were divided into two groups according to weight change during 1 year of ADT (Group A (n = 34): weight gain < 3.0%, Group B (n = 38): weight gain ≥ 3.0%), an increase in subcutaneous and visceral fat was significantly more frequent in Group B, whereas the frequency of a decrease in psoas muscle area was not significantly different between the two groups (Group A: -9.5%, Group B: -7.5%, P = 0.11). Pearson correlation coefficients showed a moderate relationship between weight gain and fat accumulation (r = 0.44-0.52), but little relationship between weight gain and a decrease in psoas muscle area (r = 0.18). Conclusions: Fat accumulation tended to increase in patients who gained weight during ADT, whereas a decrease in psoas muscle area was not related to weight change. Sarcopenia could occur despite weight change during ADT. Clinical trial information: UMIN000018478.