title: Carbohydrate intake and biomarkers of glycemic control among US adults: the third National Health and Nutrition Examination Survey (NHANES III).
abstract: BACKGROUND
  Recommendations for preventing and treating type 2 diabetes include consuming carbohydrates, predominantly from whole grains, fruit, vegetables, and low-fat milk. However, the quantity and type of carbohydrates consumed may contribute to disorders of glycemic control.
  
  
  OBJECTIVE
  We evaluated the association between carbohydrate intakes and biomarkers of glycemic control in a nationally representative sample of healthy US adults who participated in a cross-sectional study, the third National Health and Nutrition Examination Survey.
  
  
  METHODS
  The sample (5730 men and 6125 women aged > or = 20 y) was divided into quintiles of carbohydrate intake (as a percentage of energy). Carbohydrate intakes were examined in relation to glycated hemoglobin (Hb A(1c)), plasma glucose, serum C-peptide, and serum insulin concentrations by using logistic regression.
  
  
  RESULTS
  Carbohydrate intakes were not associated with Hb A(1c), plasma glucose, or serum insulin concentrations in men or women after adjustment for confounding variables. Carbohydrate intakes were inversely associated with serum C-peptide concentrations in men and women. Odds ratios for elevated serum C-peptide concentrations for increasing quintiles of carbohydrate intake were 1.00, 0.88, 0.57, 0.39, and 0.75 (P for trend = 0.016) in men, and 1.00, 0.69, 0.57, 0.36, and 0.41 (P for trend = 0.007) in women. When carbohydrate intakes were further adjusted for intakes of total and added sugar, the association of serum C-peptide with carbohydrate intakes was strengthened in men.
  
  
  CONCLUSIONS
  Carbohydrate intakes were not associated with Hb A(1c), plasma glucose, or serum insulin concentrations but were inversely associated with the risk of elevated serum C-peptide; this supports current recommendations regarding carbohydrate intake in healthy adults.
authors.affiliation: Food and Nutrition Database Research Center, Department of Food Science and Human Nutrition, Michigan State University, East Lansing 48824, USA.
authors.forename: Eun Ju
authors.initials: EJ
authors.lastname: Yang
authors.forename: Jean M
authors.initials: JM
authors.lastname: Kerver
authors.forename: Yi Kyung
authors.initials: YK
authors.lastname: Park
authors.forename: Jean
authors.initials: J
authors.lastname: Kayitsinga
authors.forename: David B
authors.initials: DB
authors.lastname: Allison
authors.forename: Won O
authors.initials: WO
authors.lastname: Song
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000032:analysis; D001786:Blood Glucose / Q000378:metabolism*; D002096:C-Peptide / Q000097:blood; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D007328:Insulin / Q000097:blood; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys; D009994:Osmolar Concentration; D014481:United States
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D002096:C-Peptide; D004040:Dietary Carbohydrates; D006442:Glycated Hemoglobin; D007328:Insulin