Assessment of body composition in active and controlled acromegaly by bioelectrical impedance analysis and...

To evaluate the accuracy of bioimpedance analysis (BIA) compared to dual-energy x-ray absorptiometry (DXA) measurements of body composition in patients with active and controlled acromegaly.

BIA and DXA methods were applied to estimate body composition in patients with active acromegaly and again after disease control.

16 patients with active acromegaly were included and followed until after disease control. GH nadir decreased from 5.5 ± 5.7 μg/L to 0.2 ± 0.3 μg/L, and IGF-1 levels from 565 ± 189 ng/L to 191 ± 137 ng/L after treatment. Body weight remained stable (95.4 ± 30.0 kg and 95.5 ± 26.7 kg) throughout the study period although fat mass increased by 3.2 kg (from 34.1 ± 15.2 kg to 37.5 ± 14.6 kg) or 4.5 kg (31.5 ± 14.6 kg to 36.0 ± 16.0 kg) measured by DXA or BIA, respectively. Lean body mass measured by DXA decreased by 2.2 kg (61.6 ± 16.9 kg to 59.4 ± 14.5 kg), while fat free mass decreased by 4.2 kg (63.4 ± 19.0 kg to 59.2 ± 15.7 kg) and total body water (L) decreased by 3.1 kg (46.4 ± 13.9 kg to 43.3 ± 11.5 kg) estimated by BIA. Using Bland-Altman analysis the bias in estimates for lean mass was -1.7 kg (LOA:-10.0-6.6 kg) in active acromegaly and 0.2 kg (LOA:-10.1-10.5 kg) with hormonal control. For fat mass, bias was 2.6 kg (LOA:-3.8-9.0 kg) in active disease and 1.5 kg (LOA:-5.0-8.1 kg) in controlled disease.

A high conformity between BIA predictions and DXA scan measurements was observed in patients with acromegaly during both active disease and hormonal control. BIA provides additional important estimations of body water content.