RS9939609 FTO gene variant modified weight loss and insulin resistance after a partial meal-replacement hypocaloric diet.

Objective: Some studies have demonstrated that the allele A of FTO rs9939609 is related to both higher waist circumference and body mass index. Subsequently, some designs related biochemical variables and body weight changes with this genetic variant. We decide to analyze the effects of rs9939609 genetic variant of FTO gene on metabolic parameters and weight loss secondary to partial meal replacements hypocaloric diets (pMRHDs) in obese subjects.
Patients and Methods: This was a non-randomized, single-treatment study with a formula-diet in 44 obese subjects. The patients received nutritional education and a pMRHDs with two intakes of normocaloric hyperproteic formula during 12 weeks. Anthropometric parameters and biochemical profiles were measured at basal time and after 12 weeks. The variant of FTO gene rs9939609 was determined.
Results: Genotype distribution (n=44) was (16 TT (36.4%), 17 TA (38.6%) and 11 AA (25.0%)). After the pMRHD, body weight, body mass index (BMI), fat mass, waist circumference, serum leptin levels and systolic blood pressure improved in both genotypes without statistical differences in both branches. After dietary intervention with pMRHD, subjects with A allele showed a significant improvement in total cholesterol levels (TT vs. TA+AA) (-3.8±1.4 md/dL vs. -12.6±1.7 mg/dl: p=0.01), LDL-cholesterol (-0.2±1.5 md/dL vs. -10.5±1.9 mg/dl: p=0.02), insulin levels (-1.9±0.2 mU/L vs. -3.8±0.3 mU/L: p=0.02) and HOMA-IR (-0.6±0.2 units vs. -1.1±0.1 units: p=0.01).
Conclusions: Our data suggest that the genetic variant (rs9939609) of FTO gene showed better improvement of LDL-cholesterol, insulin and HOMA-IR in subjects with A allele.