Role of rs490683 variant in the promoter region of the ghrelin receptor gene on body weight and metabolic syndrome after a partial meal replacement hypocaloric diet

Abstract

Background and aims: Few studies have evaluated the effect of rs490683 on weight loss. The objective of our study was to evaluate the role of this variant of GHSR gene on body weight loss and cardiovascular risk factors secondary to a partial meal replacement (pMR) hypocaloric diet. Methods: 96 individuals with a body mass index (BMI > 35 kg/m2) were enrolled. Participants consumed a normocaloric, hyperproteic formula twice daily (12-w). Measurements were taken for body weight, BMI, fat mass, waist circumference, blood pressure, lipid profile, fasting insulin levels and HOMA-IR. Results: The genotype was 70 patients (72.9 %) CC genotype, 19 patients(19.8 %) CG genotype, and 7 patients (7.3 %) GG genotype. The intake of calories, grams of carbohydrates, fats and proteins was higher at 12w in patients carrying the G allele. BMI ( 3.5 ± 0.4 kg/m2 vs 1.0 ± 0.2 kg/m2 (p = 0.01)), body weight ( 8.5 ± 1.0 kg vs 2.6 ± 1.1 kg (p = 0.01)), fat mass ( 7.7 ± 0.3 kg vs 2.6 ± 0.2 kg (p = 0.01)), waist circumference ( 7.2 ± 0.3 cm vs 2.9 ± 0.1 cm (p = 0.01)), glucose levels ( 12.1 ± 1.4 mg/dl vs 3.1 ± 1.8 mg/dl, p = 0.01), insulin ( 10.8 ± 1.2 UI/L vs 3.9 ± 1.1 UI/L, p = 0.01), HOMA-IR ( 2.1 ± 1.0 units vs 0.58 ± 0.2 units, p = 0.01), CRP ( 1.2 ± 0.1 mg/dl vs 0.7 ± 0.2 mg/dl, p = 0.01), triglycerides ( 22.1 ± 4.1 mg/dl vs 5.1 ± 3.2 mg/dl, p = 0.01), total-cholesterol ( 22.2 ± 1.3 mg/dl vs 8.8 ± 1.9 mg/dl, p = 0.01), LDL-cholesterol ( 15.2 ± 1.1 mg/dl vs 4.7 ± 1.2 mg/dl, p = 0.01), and HDL-cholesterol (6.2 ± 0.4 mg/dl vs 2.9 ± 1.2 mg/dl, p = 0.01) modifications were better in non-G allele carriers. After intervention, the odds ratio (OR) of MS in non- carrier of G allele improved OR 0.48 (95%CI: 0.31–0.73; p = 0.02). Conclusions: G allele of rs490683 have a deleterious effect on dietary restrictions, body weight and metabolic response after a pMR diet.