Greater Concentrations of IGF Binding Protein-2 after Bariatric Surgery Compared with Diet

TL;DR

Bariatric surgery leads to higher levels of a metabolic marker (IGFBP-2) compared to diet, even after similar weight loss.

Contribution

The study identifies IGFBP-2 as a marker that increases more after bariatric surgery than diet, independent of weight loss.

Findings

IGFBP-2 levels increased more after bariatric surgery than after a low-calorie diet.

Weight loss alone does not fully explain the metabolic benefits of bariatric surgery.

The adiponectin/leptin ratio improved similarly after both interventions.

Abstract

Bariatric surgery causes greater sustained weight loss (WL) and metabolic improvements compared to lifestyle modification. It remains unclear which metabolic changes are solely attributable to WL and which also involve WL-independent changes.

The objective of this study was to quantify changes in the adiponectin/leptin ratio and IGF binding protein 2 (IGFBP-2), both markers of metabolic disease.

Adults with body mass index ≥35 kg/m2 underwent a 12-week 800 kcal/day low-calorie diet (LCD; n = 20), sleeve gastrectomy (n = 18), or Roux-en-Y gastric bypass (n = 10) and were studied at baseline [time 1(T1)], early weight loss [time 2 (T2)], and 1 year [time 3 (T3)]. As outcomes were similar between surgeries, the groups were combined for analysis.

The LCD and surgery groups had similar median WL of 15% at T2 (P = .72), achieved in 90 vs 48 days, respectively. The LCD group maintained WL at T3 whereas WL was 30% after surgery. At T2, the adiponectin/leptin ratio increased similarly; however, IGFBP-2 increased to a greater extent after surgery, 203 ng/mL (169-259) vs LCD, 153 (110-181; P = .028). Further WL after surgery at T3 resulted in a more marked increase in the adiponectin/leptin ratio, yet IGFBP-2 levels remained the same.

IGFBP-2 levels and the adiponectin/leptin ratio improve after WL. The greater increase in IGFBP-2 levels after surgery compared with LCD may have long-term beneficial effects that appear to be partly independent of the degree of weight reduction.

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