Long-term effects of bariatric surgery in patients with obesity and chromosome 16 p11.2 microdeletion.

Background: Chromosome 16 p11.2 microdeletion is associated with early-onset obesity. Information is limited about the effect of bariatric surgery in patients with genetic obesity.

Objective: To examine the effects of bariatric surgery in obese patients with chromosome 16 p11.2 microdeletion.

Setting: Academic research institution.

Methods: The Swedish Obese Subjects study is a prospective study with 2010 participants receiving bariatric surgery. DNA was available for 1843 participants. Multiplex ligation-dependent probe amplification was used to identify 16 p11.2 microdeletion carriers. Follow-up time was 10 years. In carriers and noncarriers, follow-up rate was 86% and 82%, respectively, at 10 years.

Results: Nine carriers of the chromosome 16 p11.2 microdeletion (9/1843, .49%) were found. At baseline, most risk factors were similar; however, carriers had higher body mass index (BMI), insulin levels, and systolic blood pressure compared to noncarriers. At the 1-year examination, the percent excess BMI lost (%EBMIL) in carriers and noncarriers was 71.9 and 62.2, respectively; P = .031 (37.9 and 30.6 kg). This was followed by partial weight regain in both groups, and after 10 years %EBMIL was 25.5 and 41.5 (15.7 and 21.3 kg), respectively (P = .377). Changes in risk factors were similar in the carriers and noncarriers. Two carriers who had type 2 diabetes at baseline were both in remission at 2-year follow-up but relapsed at 10-year follow-up. Perceived health status was similar in carriers and noncarriers during follow-up (overall P = .198).

Conclusions: Despite a small sample size, our results indicate that bariatric surgery is a treatment option for obese patients with chromosome 16 p11.2 microdeletion.