Department of Internal Medicine, Division of Cardiology, William Beaumont Hospital, Royal Oak, Michigan 48073, USA.
Metab Syndr Relat Disord. 2010 Feb;8(1):15-20. doi: 10.1089/met.2009.0012.
Bariatric surgery has become a common treatment for morbid obesity. The relative changes in body tissue that comprise the substantial weight loss over time are not completely understood.
We evaluated the differential rates of fat and lean tissue losses in morbidly obese patients who underwent Roux-en-Y gastric bypass surgery. Body composition was assessed using whole-body dual energy X-ray absorptiometry (DXA) performed at two timepoints in the postoperative period. Patients were stratified by the tertile of rapidity of weight loss expressed as percent reduction in body mass index per month.
Thirty two patients (25 women, 7 men) with a mean age of 46.7 +/- 10.4 years and an average initial body weight of 141.4 +/- 29.4 kg experienced a 52.3 +/- 16.6 kg (36.5 +/- 5.5%) weight loss over 13.9 +/- 6.0 months. The incremental rates of lean body mass loss by tertiles were 0.3 +/- 0.6, 0.5 +/- 0.2, and 1.0 +/- 0.8 kg/month (P = 0.02), whereas the rates of fat loss were 1.2 +/- 0.9, 1.8 +/- 0.4, and 2.9 +/- 1.0 kg/month (P = 0.0001). The ratios for lean to fat loss among the respective tertiles were 1:4.0, 1:3.6, and 1:3.0. The correlation between rates of lean and fat mass loss was r = 0.37 (P = 0.04). Only three of the 32 patients (9.4%) patients maintained or gained lean mass following Roux-en-Y gastric bypass surgery.
After bariatric surgery, those patients losing weight at the greatest rate appear to have accelerated losses of both lean and fat mass. Few patients maintain lean body mass after bariatric surgery, despite self-reported participation in conventional exercise programs. These data suggest the need for more aggressive interventions to preserve lean body mass during the weight loss phase after Roux-en-Y gastric bypass surgery.
减重手术已成为治疗病态肥胖的常用方法。但对于随着时间推移导致体重显著减轻的身体组织的相对变化，我们仍未完全了解。
我们评估了接受 Roux-en-Y 胃旁路手术的病态肥胖患者的体脂和去脂体重的差异丢失率。在术后的两个时间点，使用全身双能 X 射线吸收法（DXA）评估身体成分。患者按体重指数每月降低百分比的体重减轻的三分位数来分层。
32 名患者（25 名女性，7 名男性）的平均年龄为 46.7 ± 10.4 岁，平均初始体重为 141.4 ± 29.4kg，13.9 ± 6.0 个月后体重减轻了 52.3 ± 16.6kg（36.5 ± 5.5%）。按三分位数分层，瘦体重丢失的增量率分别为 0.3 ± 0.6、0.5 ± 0.2 和 1.0 ± 0.8kg/月（P = 0.02），而脂肪丢失率分别为 1.2 ± 0.9、1.8 ± 0.4 和 2.9 ± 1.0kg/月（P = 0.0001）。相应三分位数之间的瘦体重与脂肪丢失的比例分别为 1:4.0、1:3.6 和 1:3.0。瘦体重和脂肪质量丢失率之间的相关性为 r = 0.37（P = 0.04）。32 名患者中只有 3 名（9.4%）患者在 Roux-en-Y 胃旁路手术后保持或增加了瘦体重。
减重手术后，体重减轻最快的患者似乎同时加速了瘦体重和脂肪质量的丢失。尽管有自我报告的参与常规运动计划，但许多患者在减重手术后仍无法保留瘦体重。这些数据表明，在 Roux-en-Y 胃旁路手术后的减肥阶段，需要更积极的干预措施来保留瘦体重。
