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.

Adipose tissue located in the viscera is considered to be functionally and metabolically different from that found in the subcutaneous depot. However, subcutaneous adipose tissue in generalized regions is considered to be homogeneous in nature. Affymetrix GeneChip Human Exon 1.0 ST Arrays were used to determine differential gene expression in four subcutaneous adipose depots (upper abdomen, lower abdomen, flank and hip) in normal weight women. A total of 2890/24,409 transcripts were differentially expressed between all sites. When comparing the hip and flank to the lower abdomen, 248 and 83 genes were differentially expressed, respectively. When comparing the hip and flank to the upper abdomen, 2480 and 79 genes were differentially expressed, respectively. No genes were significantly different when the lower abdomen was compared to the upper abdomen and the hip to the flank. Genes involved in the complement and coagulation cascades and immune responses showed increased expression in the lower abdomen compared to the flank. In addition, two genes involved in the complement and coagulation cascade, CR1 and C7, were expressed more highly in the lower abdomen compared to the hip. Genes involved in basic biochemical metabolism including insulin signaling, the urea cycle, glutamate metabolism, arginine and proline metabolism and aminosugar metabolism had higher expression in the lower abdomen compared to the hip. These results in normal weight healthy women provide a new perspective on regional differences in subcutaneous adipose tissue biology that may have pathophysiologic implications when adiposity increases.

Femoral subcutaneous adipose tissue (SAT) appears to be cardioprotective compared with abdominal SAT, possibly through better triglyceride (TG) sequestration. We hypothesized that removal of femoral SAT would increase postprandial TG through a reduction in dietary fatty acid (FA) storage. Normal-weight (means ± SD; BMI 23.9 ± 2.6 kg/m(2)) women (n = 29; age 45 ± 6 yr) were randomized to femoral lipectomy (LIPO) or control (CON) and followed for 1 yr. Regional adiposity was measured by DEXA and CT. A liquid meal labeled with [(14)C]oleic acid was used to trace the appearance of dietary FA in plasma (6-h postprandial TG), breath (24-h oxidation), and SAT (24-h [(14)C]TG storage). Fasting LPL activity was measured in abdominal and femoral SAT. DEXA leg fat mass was reduced after LIPO vs. CON (Δ-1.4 ± 0.7 vs. 0.1 ± 0.5 kg, P< 0.001) and remained reduced at 1 yr (-1.1 ± 1.4 vs. -0.2 ± 0.5 kg, P < 0.05), as did CT thigh subcutaneous fat area (-39.6 ± 36.6 vs. 4.7 ± 14.6 cm(2), P < 0.05); DEXA trunk fat mass and CT visceral fat area were unchanged. Postprandial TG increased (5.9 ± 7.7 vs. -0.6 ± 5.3 × 10(3) mg/dl, P < 0.05) and femoral SAT LPL activity decreased (-21.9 ± 22.3 vs. 10.5 ± 26.5 nmol·min(-1)·g(-1), P < 0.05) 1 yr following LIPO vs. CON. There were no group differences in (14)C-labeled TG appearing in abdominal and femoral SAT or elsewhere. In conclusion, femoral fat remained reduced 1 yr following lipectomy and was accompanied by increased postprandial TG and reduced femoral SAT LPL activity. There were no changes in storage of meal-derived FA or visceral fat. Our data support a protective role for femoral adiposity on circulating TG independent of dietary FA storage and visceral adiposity.