Association of ANGPTL8 (Betatrophin) Gene Variants with Components of Metabolic Syndrome in Saudi Adult population

Angiopoietin-like protein 8 (ANGPTL8) has a role in lipid metabolism, beta-cell proliferation and diabetes progression, however, the association between different variants in the ANGPTL8 gene and metabolic syndrome (MetS) components has not been studied widely especially in Arab ethnic groups. In this study, the associations of ANGPTL8 variants on MetS risk in Saudi Arab adults were investigated. A total of 905 unrelated Saudi adults (580 healthy controls and 325 MetS) were included. MetS was screened based on the International Diabetes Federation (IDF) criteria. The genotype and allele frequency distribution of rs737337 (T/C) and rs2278426 (C/T) polymorphism in ANGPTL8 gene was studied. Participants with MetS were significantly older, had higher BMI, and rs737337 polymorphism frequency was significantly lower than in control. Furthermore, the TC+CC genotype and C allele of rs737337 (T/C) was associated with decreased risk of hypercholesterolemia and hyperglycemia [odds ratio (OR) 0.61, 95%CI 0.40-0.93, p=0.016 and OR 0.58, 0.39-0.86, p=0.007 respectively for hypercholesterolemia; and OR 0.66, 0.45-0.97, p=0.032 and OR 0.65, 0.46-0.93; p=0.016 respectively for hyperglycemia]. Similarly, CT, CT+TT genotype and T allele of rs2278426 (C/T) were associated with decreased risk of hyperglycemia (p<0.05). In conclusion, the study suggests that the gene variants in SNPs rs 737337 (T/C) and rs 2278426 (C/T) are associated with lower risk of hypercholesterolemia and hyperglycemia. These findings supplement the growing literature supporting the role of ANGPTL8 in lipid and glucose metabolism.