title: Effect of Serum Cholesterol on Insulin Secretory Capacity: Shimane CoHRE Study.
abstract: OBJECTIVE
  Previous studies indicate that, in addition to the blood glucose level, the lipid level in the blood may affect functions of pancreatic beta cells. In this study, we aimed to examine whether there was a relationship between the serum level of total cholesterol (TC) and the insulin secretory capacity in healthy subjects.
  
  
  METHODS
  In participants of health examinations conducted from 2006 to 2010, we analyzed data from a total of 2,499 subjects (1,057 men and 1,442 women) after exclusion of individuals with dyslipidemia, thyroid dysfunction, diabetes, HbA1c≥6.5%, or fasting blood glucose≥126 mg/dL. Homeostasis model assessment for beta cell function (HOMA-beta) was utilized as a model representing the pancreatic beta cell function.
  
  
  RESULTS
  Although the serum TC level had a positive correlation with HOMA-beta in a univariate correlation analysis, after adjustment by confounding factors in a multiple regression analysis, HOMA-beta had a negative correlation with TC. This was further confirmed in a multiple logistic regression analysis, showing that higher TC was an independent risk factor for decreased insulin secretory capacity (defined as HOMA-beta≤30%) together with higher age, lower BMI, lower TG, male sex and regular alcohol intake. After the participants were stratified by BMI into three groups, the effect of TC on HOMA-beta increased along with the increase in BMI, and it was highly significant in the highest tertile.
  
  
  CONCLUSIONS
  This cross-sectional study indicated that increased serum TC level might be related to the decrease of insulin secretory capacity in aged healthy population and that reduction of TC is more necessary in obese subjects to prevent diabetes.
authors.affiliation: Department of Internal Medicine, Okuizumo Municipal Hospital, Shimane, Japan.|Department of Medical Education and Research, Shimane University Faculty of Medicine, Shimane, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Wada
authors.affiliation: Department of Laboratory Medicine, Shimane University Faculty of Medicine, Shimane, Japan.|The Center for Community-based Health Research and Education (CoHRE), Shimane, Japan.
authors.forename: Shozo
authors.initials: S
authors.lastname: Yano
authors.affiliation: The Center for Community-based Health Research and Education (CoHRE), Shimane, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Hamano
authors.affiliation: The Center for Community-based Health Research and Education (CoHRE), Shimane, Japan.|Department of Functional Pathology, Shimane University Faculty of Medicine, Shimane, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Nabika
authors.affiliation: Department of Medical Education and Research, Shimane University Faculty of Medicine, Shimane, Japan.
authors.forename: Shunichi
authors.initials: S
authors.lastname: Kumakura
mesh_terms: D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D002784:Cholesterol / Q000097:blood*; D003153:Community Health Services; D003710:Demography; D003924:Diabetes Mellitus, Type 2 / Q000097:blood; D005260:Female; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D007333:Insulin Resistance; D000078790:Insulin Secretion; D016014:Linear Models; D008297:Male; D015999:Multivariate Analysis
chemical_list: D001786:Blood Glucose; D007328:Insulin; D002784:Cholesterol