ABSTRACT
Sasang constitutional medicine (SCM), a Korean tailored medicine, categorizes human beings into four types through states of physiological imbalances and responsiveness to herbal medicine. One SCM type susceptible to obesity seems sensitive to energy intake due to an imbalance toward preserving energy. Common variants of fat mass and obesity associated (FTO) and melanocortin 4 receptor (MC4R) genes have been associated with increased body mass index (BMI) by affecting energy intake. Here, we statistically examined the association of FTO and MC4R polymorphisms with BMI in two populations with 1370 Koreans before and after SCM typing, and with the lowering of BMI in 538 individuals who underwent a 1-month lifestyle intervention. The increased BMI replicated the association with FTO haplotypes (effect size ≃ 1.1 kg/m(2)) and MC4R variants (effect size ≃ 0.64 kg/m(2)). After the lifestyle intervention, the carriers of the haplotype represented by the minor allele of rs1075440 had a tendency to lose more waist-to-hip ratio (0.76%) than non-carriers. The constitutional discrepancy for the accumulation of body mass by the effects of FTO and/or MC4R variants seemed to reflect the physique differences shown in each group of SCM constitutional types. In conclusion, FTO and MC4R polymorphisms appear to play an important role in weight gain, while only FTO variants play a role in weight loss after lifestyle intervention. Different trends were observed among individuals of SCM types, especially for weight gain. Therefore, classification of individuals based on physiological imbalance would offer a good genetic stratification system in assessing the effects of obesity genes.
ABSTRACT
It has been newly reported in recent studies that single-nucleotide polymorphisms (SNPs) in the first intron of the FTO gene have been associated with BMI in whites. To determine whether the gene is associated with BMI in Asians also, we performed a replication study of the association of the gene with BMI in a Korean population. Two SNPs in the FTO gene (rs1421085 and rs17817449) were genotyped using the TaqMan method in a Korean population (n = 1,733). The two SNPs were then used for an association study with BMI through statistical analyses. The rs1421085 C allele (P = 0.0015, effect size = 0.0056) and rs17817449 G allele (P = 0.0019, effect size = 0.0053) were found to be significantly associated with increased BMI. Our results suggest that FTO may be one of the worldwide obesity-risk genes.
