Identification of genetic loci associated with abdominal visceral adiposity in Korean populations

Abdominal obesity is characterized by accumulation of subcutaneous and visceral fat in the abdomen and has been reported to be largely responsible for many metabolic and vascular diseases. Although substantial effort has been dedicated to identification of genetic factors associated with abdominal obesity, as measured by the waist-hip ratio and waist circumference, only a few studies have explored associations with visceral fat accumulation in the abdomen. Furthermore, genetic studies of abdominal visceral adiposity conducted in Asian ethnic groups are rare. To gain insight into the genetic basis for visceral adiposity in Asian subjects, we conducted genome-wide association analysis for a pool of 1594 Korean subjects. Abdominal visceral fat area was estimated by computed tomography. After adjustment for age, linear association analysis identified three loci showing suggestive evidence of association (P < 5 × 10−6) in ASIC2, SLC35F3, and 5q14.2. Stratification by sex revealed one female-specific locus (rs17104731) located near LINC01519 with a genome-wide significant association for visceral adiposity (P = 4.66 × 10−8). Since visceral fat has been suggested to influence metabolic traits, we analyzed associations of the loci identified in this study with metabolic indicators, such as glucose, insulin, and lipid levels, and markers of kidney function. A locus (rs6699737) in SLC35F3 showed a nominal association (P < 5 × 10−2) with alanine transaminase, aspartate transaminase, and fasting plasma insulin. In addition, the linear association test using genetic risk score demonstrated that visceral adiposity loci detected in this study had a cumulative effect on abdominal visceral fat area, waist-hip-ratio, total cholesterol, and low density lipoprotein cholesterol. In summary, this study reports new loci associated with visceral adiposity and provides evidence supporting involvement of these loci in several metabolic traits in Korean populations.