Assessment of body composition in active and controlled acromegaly by bioelectrical impedance analysis and dual-energy x-ray absorptiometry.

GH nadir and IGF-1 levels decreased significantly after treatment for acromegaly.

• GH nadir decreased from 5.5 ± 5.7 μg/L to 0.2 ± 0.3 μg/L after treatment.
• IGF-1 levels decreased from 565 ± 189 ng/L to 191 ± 137 ng/L after treatment.
• 16 patients with active acromegaly were included and followed until after disease control.

Body weight remained stable throughout the study period despite significant changes in body composition.

• Body weight was 95.4 ± 30.0 kg during active disease and 95.5 ± 26.7 kg after disease control.
• Fat mass increased by 3.2 kg (from 34.1 ± 15.2 kg to 37.5 ± 14.6 kg) as measured by DXA.
• Fat mass increased by 4.5 kg (from 31.5 ± 14.6 kg to 36.0 ± 16.0 kg) as measured by BIA.
• Lean body mass measured by DXA decreased by 2.2 kg (from 61.6 ± 16.9 kg to 59.4 ± 14.5 kg).

BIA-estimated fat-free mass and total body water decreased after hormonal control of acromegaly.

• Fat free mass measured by BIA decreased by 4.2 kg (from 63.4 ± 19.0 kg to 59.2 ± 15.7 kg).
• Total body water decreased by 3.1 kg (from 46.4 ± 13.9 L to 43.3 ± 11.5 L) as estimated by BIA.
• These changes occurred despite stable body weight, indicating a shift from lean/fluid mass to fat mass following treatment.

Bland-Altman analysis showed relatively small bias between BIA and DXA estimates of lean mass in both active and controlled acromegaly.

• Bias in lean mass estimates was -1.7 kg (limits of agreement: -10.0 to 6.6 kg) in active acromegaly.
• Bias in lean mass estimates was 0.2 kg (limits of agreement: -10.1 to 10.5 kg) with hormonal control.
• The bias improved (moved toward zero) after disease control, though limits of agreement widened.

Bland-Altman analysis showed a positive bias between BIA and DXA estimates of fat mass in both active and controlled acromegaly.

• Bias for fat mass was 2.6 kg (limits of agreement: -3.8 to 9.0 kg) in active disease.
• Bias for fat mass was 1.5 kg (limits of agreement: -5.0 to 8.1 kg) in controlled disease.
• BIA tended to overestimate fat mass relative to DXA in both disease states, though the bias decreased after hormonal control.

BIA demonstrated high conformity with DXA measurements for body composition assessment in acromegaly patients during both active disease and hormonal control.

• The study applied both BIA and DXA methods to the same 16 patients at two time points: active disease and after disease control.
• BIA was found to provide additional important estimations of body water content not available from DXA.
• The study concludes that BIA is a valid tool for body composition assessment in acromegaly across disease states.