Background

The leptin-melanocortin pathway (LMP) is key for food intake regulation. LMP gene variants result in severe obesity. Bariatric surgery is the most effective treatment for obesity, however, its efficacy in carriers of LMP gene variants is unknown. We aim to examine weight loss outcomes after sleeve gastrectomy (SG) in patients with heterozygous gene variants of the LMP.

Methods

This retrospective cohort study included genotyped adult patients with severe obesity and a LMP gene variant who underwent SG. Patient medical information was abstracted starting before surgery and for the next 2 years. Total body weight loss percentage (%TBWL) was calculated from pre-surgery weight and followed up at 3, 6, 12, 18, and 24 months. Continuous data was summarized as mean +- standard deviation. Multiple linear regression analysis adjusted for age, sex, diabetes-diagnosis and BMI was used to evaluate the difference in %TBWL between patients with (carriers) and without (non-carriers) a heterozygous variant.

Results

Forty-five patients (48+-12 years, 44+-9kg/m2 and 80% females) had a SG and were genotyped, 10 carriers and 35 non-carriers. Carriers were 10 years older at baseline. Carriers had a %TBWL of -19.7 compared with -26.1 in non-carriers (Δ6.4, 95%[CI], -12.3 - -0.5) at 24 months. There were no significant differences in %TBWL after adjusting for baseline characteristics.

Conclusions

In this small sample size, the LPM integrity is not essential for weight loss after SG when adjusting for age, sex and BMI. Further studies are needed to understand the differences in weight loss among the two groups.