FTO variant RS 1121980 interact with metabolic response after weight loss with a meal replacement hypocaloric diet in Caucasian obese subjects.

Objective: One genetic variant (rs1121980) of FTO gene has been related with body mass index and visceral adiposity. The objective of our study was to investigate the role of rs1121980 genetic variant of FTO gene on weight loss and metabolic changes secondary to a partial meal replacement (pMR) hypocaloric diet.
Patients and Methods: We conducted an interventional study on 219 obese Caucasian subjects with body mass index (BMI) > 30 kg/m2. The subjects received two intakes per day of a normocaloric hyperproteic formula for 12 weeks. Adiposity and biochemical parameters (lipid profile, insulin, homeostasis model assessment (HOMA-IR) and glucose) were determined.
Results: After the pMR diet, body weight, BMI, fat mass, waist circumference, blood pressure, total-cholesterol, LDL-cholesterol, triglyceride, fasting insulin levels and HOMA-IR decreased in both genotype groups. The improvements in adiposity parameters and some biochemical parameters (insulin, HOMA-IR, triglyceride levels) were bigger in non-T allele carriers than in T allele carriers. The percentage of patients who achieved 7.5% weight loss was higher in the non-T carriers (76.7% vs. 48.4%), also with a different average of weight loss (-12.3±0.3 kg vs. -5.9±0.5 kg: p=0.01). The odds ratio to achieve 7.5% of weight loss was (OR= 2.22, 95% CI=1.24-4.01; p=0.02).
Conclusions: Non-T allele carriers of rs1121980 show a higher magnitude of weight loss and improvement in adiposity parameters, insulin, HOMA-IR and triglyceride levels resulting from a pMR diet than T allele carriers.