Endocrine deficiencies, like GH and estrogen deficiencies, are likely candidates to explain increased visceral to subcutaneous fat ratio in patients with pituitary insufficiency. However, recent reports pointed to cranial radiotherapy (CRT) as an additional determinant of an unfavorable fat distribution. Therefore, we determined the effect of CRT on abdominal fat distribution in men with treated pituitary insufficiency.
Thirty-five consecutive male subjects (16 men with and 19 men without CRT aged 62±12 and 56±14 years respectively, P=0.175) visiting our Endocrine Outpatient Clinic for pituitary insufficiency were invited to participate in this study. A standardized single-slice abdominal CT scan at the level of fourth lumbar vertebra was performed to determine visceral fat area, subcutaneous fat area, and visceral to subcutaneous fat ratio. In addition, we assessed body mass index, total fat percentage with bioelectrical impedance analysis, resting energy expenditure with indirect calorimetry, calorie intake using a diary, and serum hormone concentrations.
Subjects with CRT had a smaller subcutaneous fat area (225.1 (71.1–480.7) vs 269.0 (133.2–59.9) cm2, P=0.022) and a higher visceral to subcutaneous fat ratio (0.79 (0.39–1.55) vs 0.63 (0.23–0.88), P=0.001) than subjects without CRT. Both the groups were comparable for body mass index, waist–hip ratio, resting energy expenditure, and calorie intake. Importantly, serum hormone concentrations were similar.
In men treated for pituitary insufficiency, previous CRT is associated with a higher visceral to subcutaneous fat ratio.