The effects of biliopancreatic diversion on type 2 diabetes mellitus in patients with mild obesity (BMI 30-35 kg/m2) and simple overweight (BMI 25-30 kg/m2): a prospective controlled study.

BACKGROUND

Beneficial effects of BPD on T2DM in BMI >35 kg/m(2) patients are far better than those in patients with BMI 25-35. This study was aimed at investigating if a similar difference exists between patients with mild obesity (OB, BMI 30-35) or simple overweight (OW, BMI 25-30).

METHODS

Fifteen OB (six M) and 15 OW (13 M), diabetic for ≥ 3 years, with HbA1c ≥ 7.5% despite medical therapy, underwent BPD. OB/OW: age 55.1 ± 8.0/57.8 ± 6.7 years, BMI 33.1 ± 1.5/28.0 ± 1.3 kg/m(2), diabetes duration 11.6 ± 8.0/11.1 ± 6.1 years, insulin therapy 4/8 p. FSG and HbA1c were determined preoperatively and up to 2 years. Insulin resistance and beta-cell function were explored by means of HOMA-IR and IVGTT (AIR). Thirty-eight diabetic patients on medical therapy served as controls.

RESULTS

Mean BMI stabilized around 27 since the 4th month in OB, and 24 since 1st month in OW. FSG in OB/OW preop, 1, 12, 24 months: 234 ± 76/206 ± 62 mg/dL, 154 ± 49/176 ± 75, 131 ± 32/167 ± 48, 134 ± 41/154 ± 41 (cross-sectional n.s. at all times); HbA1c: 9.5 ± 1.6/9.1 ± 1.3, 7.3 ± 1.1/7.3 ± 1.2, 5.9 ± 0.6/7.1 ± 1.1 (p < 0.01), 5.9 ± 0.9/6.9 ± 1.1 (p < 0.01). HOMA-IR, preoperatively 10.7 ± 5.8/7.5 ± 5.4, went below 3.0 at 1 month and remained such until 2 years in both groups. AIR, preoperatively 1.11 ± 3.17/1.27 ± 2.68 μIU/mL, in OB significantly increased at 4 months to 7.63 ± 5.79, maintained up to 2 years with 6.95 ± 3.19, whereas in OW, statistical significance was reached only at 2 years with 5.02 ± 4.87.

CONCLUSIONS

Significantly different BPD effect, thus biological severity of T2DM, also exists between mildly obese and simply overweight patients. The rise of AIR allows hoping that an increase of beta-cell mass may occur in the long run.