한국인의 체지방 및 제지방 무게에 미치는 유전적 영향 분석

Abstract

Objective: Obesity is a well-known risk factor for cardiovascular disease. The body composition, especially fat mass, is determined by complex phenotype in which multiple genetic and nongenetic factors are involved. Here we applied the regressive model to fat mass (FM) and fat free mass (FFM) to investigate the major gene hypothesis for obesity in Korean population.

Methods: The sample consisted of 745 members of 135 families from Cardiovascular Genome Study. Proband was diagnosed as hypertension or coronary artery disease. FM and FFM were assessed by bioelectrical impedance TBF 105 analyzer. The data were adjusted for age, gender, height, BMI, drinking, exercise status prior to analysis. Body mass index (BMI) was calculated as a ratio of weight in kg to height in meters squared.

Results: Adjusted factor FM, FFM, BMI showed a strong familial aggregation with estimated sibling correlations of 0.33, 0.29, 0.42 and parents-offspring correlations of 0.14, 0.24, 0.16, respectively. For FM, the most parsimonious model was a Mendelian codominant model and the major putative gene explained 30% of variance for adjusted FM. The estimated heritability of FM is 45%. For FFM, the segregation analysis did not provide any statistical evidence for a major gene effect. These results suggest that FFM is more affected by various environmental factors than FM.

Conclusion: Our results demonstrated the major gene effect in determining the FM in Korean population. Linkage analyses using the genetic markers should be followed for identification of major genes.