Study Title:

Fat Comes Back Following Liposuction

Study Abstract

No randomized studies in humans have examined whether fat returns after removal or where it returns. We undertook a prospective, randomized-controlled trial of suction lipectomy in nonobese women to determine if adipose tissue (AT) is defended and if so, the anatomic pattern of redistribution. Healthy women with disproportionate AT depots (lower abdomen, hips, or thighs) were enrolled. Baseline body composition measurements included dual-energy X-ray absorptiometry (DXA) (a priori primary outcome), abdominal/limb circumferences, subcutaneous skinfold thickness, and magnetic resonance imaging (MRI) (torso/thighs). Participants (n = 32; 36 ± 1 year) were randomized to small-volume liposuction (n = 14, mean BMI: 24 ± 2 kg/m2) or control (n=18, mean BMI: 25 ± 2) following baseline. Surgery group participants underwent liposuction within 2–4 weeks. Identical measurements were repeated at 6 weeks, 6 months, and 1 year later. Participants agreed not to make lifestyle changes while enrolled. Between-group differences were adjusted for baseline level of the outcome variable. After 6 weeks, percent body fat (%BF) by DXA was decreased by 2.1% in the lipectomy group and by 0.28% in the control group (adjusted difference (AD): −1.82%; 95% confidence interval (CI): −2.79% to −0.85%; P = 0.0002). This difference was smaller at 6 months, and by 1 year was no longer significant (0.59% (control) vs. −0.41% (lipectomy), AD: −1.00%; CI: −2.65 to 0.64; P = 0.23). AT reaccumulated differently across various sites. After 1 year the thigh region remained reduced (0.77% (control) vs. −1.83% (lipectomy), AD: −2.59%; CI: −3.91 to −1.28; P = 0.0001), but AT reaccumulated in the abdominal region (0.64% (control) vs. 0.42% (lipectomy), AD: −0.22; CI: −2.35 to 1.91; P = 0.84). Following suction lipectomy, BF was restored and redistributed from the thigh to the abdomen.

From press release:

Liposuction has become one of the most popular plastic surgeries in the United States. It has been around since 1974 and there are now more than 450,000 operations a year. But does the fat come back? A recent study by Teri L. Hernandez, PhD, RN and Robert H. Eckel, MD, at the University of Colorado School of Medicine have found that the fat eventually returns within one year, and is redistributed to other areas of the body, especially the upper abdomen. There was further redistribution around the shoulders and triceps of the arms.

"The fact that fat returned is of great interest to us as scientists. It supports the idea that levels of body fat are very tightly regulated by mechanisms we have yet to uncover," said Eckel. "This was the hypothesis we were testing and it was confirmed. In rodents when fat is removed it returns, and after weight loss in humans most everyone regains the weight. We think the brain somehow knows how much fat is on board and responds in a manner to regulate that weight. That's why preventing obesity is so important."

The study was a difficult one to execute because fat must be measured precisely with expensive scans that require multiple resources and considerable manpower. The University of Colorado is one of a handful of institutions that could facilitate this type of highly controlled study. Obesity researchers said that they are not surprised the fat came back. Data in animal models have shown that after surgical removal of fat, it tends to return to other areas. The liposuction study performed at the University of Colorado is the first randomized controlled trial in humans.

"We must emphasize that liposuction surgery is not a weight loss procedure. Our research participants are wonderful women who sought to change their shape through liposuction. Despite fat returning, their cosmetic shape benefit was retained and they have been very happy with their surgery results," said Hernandez.

Study Information

Teri L. Hernandez, John M. Kittelson, Christopher K. Law, Lawrence L. Ketch, Nicole R. Stob, Rachel C. Lindstrom, Ann Scherzinger, Elizabeth R. Stamm, Robert H. Eckel.
Fat Redistribution Following Suction Lipectomy: Defense of Body Fat and Patterns of Restoration
2011 April
University of Colorado School of Medicine

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