title: Insulin sensitivity and secretion in Arab Americans with glucose intolerance.
abstract: BACKGROUND
  This study examined the pathophysiological abnormalities in Arab Americans with impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT).
  
  
  METHODS
  Homeostasis model assessment of insulin resistance (HOMA-IR), homeostasis model assessment of insulin secretion (HOMA-%β), and the Matsuda Insulin Sensitivity Index composite (ISIcomposite) were calculated from the fasting and stimulated glucose and insulin concentrations measured during the oral glucose tolerance test in a population-based, representative, cross-sectional sample of randomly selected Arab Americans.
  
  
  RESULTS
  In total, 497 individuals (42±14 years old; 40% males; body mass index [BMI], 29±6 kg/m(2)) were studied. Multivariate linear regression models were performed to compare HOMA-IR, HOMA-%β, and ISIcomposite among individuals with normal glucose tolerance (NGT) (n=191) versus isolated IFG (n=136), isolated IGT (n=22), combined IFG/IGT (n=43), and diabetes (n=105). Compared with individuals with NGT (2.9±1.6), HOMA-IR progressively increased in individuals with isolated IFG (4.8±2.7, P<0.001), combined IFG/IGT (6.0±4.3, P<0.001), and diabetes (9.7±8.3, P<0.001) but not in those with isolated IGT (3.0±1.7, P=0.87). After adjustment for sex and BMI, these associations remained unchanged. Whole-body insulin sensitivity as measured by ISIcomposite was significantly lower in individuals with isolated IFG (3.9±2.3, P<0.001), isolated IGT (2.8±1.5, P<0.001), combined IFG/IGT (1.9±1.1, P<0.001), and diabetes (1.6±1.1, P<0.001) compared with those with NGT (6.1±3.5). HOMA-%β was significantly lower in diabetes (113.7±124.9, P<0.001) compared with NGT (161.3±92.0). After adjustment for age, sex, and BMI, isolated IFG (146.6±80.2) was also significantly associated with a decline in HOMA-%β relative to NGT (P=0.005).
  
  
  CONCLUSIONS
  This study suggests that differences in the underlying metabolic defects leading to diabetes in Arab Americans with IFG and/or IGT exist and may require different strategies for the prevention of diabetes.
authors.affiliation: 1 Department of Pharmacy Practice, Wayne State University Eugene Applebaum College of Pharmacy and Health Sciences , Detroit, Michigan.
authors.forename: Francine D
authors.initials: FD
authors.lastname: Salinitri
authors.forename: Nicole R
authors.initials: NR
authors.lastname: Pinelli
authors.forename: Emily T
authors.initials: ET
authors.lastname: Martin
authors.forename: Linda A
authors.initials: LA
authors.lastname: Jaber
mesh_terms: D000328:Adult; D018912:Arabs / Q000706:statistics & numerical data; D001786:Blood Glucose / Q000378:metabolism*; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000208:ethnology* / Q000378:metabolism / Q000517:prevention & control; D054242:Emigrants and Immigrants / Q000706:statistics & numerical data; D005215:Fasting / Q000097:blood; D005260:Female; D018149:Glucose Intolerance / Q000208:ethnology* / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D007333:Insulin Resistance; D000078790:Insulin Secretion; D008297:Male; D008875:Middle Aged; D014481:United States / Q000453:epidemiology
chemical_list: D001786:Blood Glucose; D007328:Insulin