title: Polymorphisms in the ghrelin gene are associated with serum high-density lipoprotein cholesterol level and not with type 2 diabetes mellitus in Koreans.
abstract: BACKGROUND
  Ghrelin is known to play a role in glucose metabolism and in beta-cell function. There are controversies regarding the role of ghrelin polymorphisms in diabetes and diabetes-related phenotypes.
  
  
  OBJECTIVE
  The objective of this study was to examine polymorphisms of the ghrelin gene in a Korean cohort and investigate associations between them and susceptibility to type 2 diabetes and its related phenotypes.
  
  
  METHODS
  The ghrelin gene was sequenced to identify polymorphisms in 24 DNA samples. Common variants were then genotyped in 760 type 2 diabetic patients and 641 nondiabetic subjects. Genetic associations with diabetes-related phenotypes were also analyzed.
  
  
  RESULTS
  Nine polymorphisms were identified, and four common polymorphisms [g.-1500C>G, g.-1062G > C, g.-994C > T, g.+408C > A (Leu72Met)] were genotyped in a larger study. The genotype distributions of these four common polymorphisms in type 2 diabetes patients were similar to those of normal nondiabetic controls. However, these four common polymorphisms were variably associated with several diabetes-related phenotypes, such as high-density lipoprotein (HDL) cholesterol, fasting plasma glucose, and homeostasis model assessment of insulin resistance. In particular, subjects harboring g.-1062C were associated with a lower serum HDL cholesterol level after adjusting for other variables (P = 0.0004 or 0.01 after Bonferroni correction for 24 tests).
  
  
  CONCLUSIONS
  The aforementioned four common polymorphisms in the ghrelin gene were not found to be significantly associated with susceptibility to type 2 diabetes mellitus in the Korean population. However, the common polymorphism g.-1062G > C in the promoter region of the ghrelin gene was found to be significantly associated with serum HDL cholesterol levels.
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, 28 Yongon-dong, Chongno-gu, Seoul 110-744, Korea.
authors.forename: Hyung Jin
authors.initials: HJ
authors.lastname: Choi
authors.forename: Young Min
authors.initials: YM
authors.lastname: Cho
authors.forename: Min Kyong
authors.initials: MK
authors.lastname: Moon
authors.forename: Hye Hun
authors.initials: HH
authors.lastname: Choi
authors.forename: Hyoung Doo
authors.initials: HD
authors.lastname: Shin
authors.forename: Hak Chul
authors.initials: HC
authors.lastname: Jang
authors.forename: Seong Yeon
authors.initials: SY
authors.lastname: Kim
authors.forename: Hong Kyu
authors.initials: HK
authors.lastname: Lee
authors.forename: Kyong Soo
authors.initials: KS
authors.lastname: Park
mesh_terms: D000368:Aged; D008076:Cholesterol, HDL / Q000097:blood*; D004268:DNA-Binding Proteins / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology* / Q000235:genetics; D005260:Female; D008040:Genetic Linkage; D054439:Ghrelin; D006801:Humans; D007723:Korea / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D036361:Peptide Hormones / Q000235:genetics*; D010641:Phenotype; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic; D017422:Sequence Analysis, DNA; D014157:Transcription Factors / Q000378:metabolism; D015533:Transcriptional Activation
chemical_list: D008076:Cholesterol, HDL; D004268:DNA-Binding Proteins; D054439:Ghrelin; D036361:Peptide Hormones; D014157:Transcription Factors