title: Association of late-night carbohydrate intake with glucose tolerance among pregnant African American women.
abstract: Obesity and late-night food consumption are associated with impaired glucose tolerance. Late-night carbohydrate consumption may be particularly detrimental during late pregnancy because insulin sensitivity declines as pregnancy progresses. Further, women who were obese (Ob) prior to pregnancy have lower insulin sensitivity than do women of normal weight (NW). The aim of this study is to test the hypothesis that night-time carbohydrate consumption is associated with poorer glucose tolerance in late pregnancy and that this association would be exacerbated among Ob women. Forty non-diabetic African American women were recruited based upon early pregnancy body mass index (NW, <25 kg m(-2) ; Ob, ≥30 kg m(-2) ). Third trimester free-living dietary intake was assessed by food diary, and indices of glucose tolerance and insulin action were assessed during a 75-g oral glucose tolerance test. Women in the Ob group reported greater average 24-h energy intake (3055 kcal vs. 2415 kcal, P < 0.05). Across the whole cohort, night-time, but not day-time, carbohydrate intake was positively associated with glucose concentrations after the glucose load and inversely associated with early phase insulin secretion (P < 0.05). Multiple linear regression modelling within each weight group showed that the associations among late-night carbohydrate intake, glucose concentrations and insulin secretion were present only in the Ob group. This is the first study to report an association of night-time carbohydrate intake specifically on glucose tolerance and insulin action during pregnancy. If replicated, these results suggest that late-night carbohydrate intake may be a potential target for intervention to improve metabolic health of Ob women in late pregnancy.
authors: Department of Nutrition Sciences, University of Alabama, Birmingham, Alabama, USA. pchandle@uab.edu.
authors: Paula C
authors: PC
authors: Chandler-Laney
authors: Department of Nutrition Sciences, University of Alabama, Birmingham, Alabama, USA.
authors: Camille R
authors: CR
authors: Schneider
authors: Department of Nutrition Sciences, University of Alabama, Birmingham, Alabama, USA.
authors: Barbara A
authors: BA
authors: Gower
authors: Department of Clinical and Diagnostic Sciences, University of Alabama, Birmingham, Alabama, USA.
authors: Wesley M
authors: WM
authors: Granger
authors: Department of Obstetrics and Gynecology, Center for Women's Reproductive Health, University of Alabama, Birmingham, Alabama, USA.
authors: Melissa S
authors: MS
authors: Mancuso
authors: Department of Obstetrics and Gynecology, Center for Women's Reproductive Health, University of Alabama, Birmingham, Alabama, USA.
authors: Joseph R
authors: JR
authors: Biggio
mesh_terms: D000293:Adolescent; D000328:Adult; D001741:Black or African American; D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D001835:Body Weight; D002096:C-Peptide / Q000097:blood; D004032:Diet; D015930:Diet Records; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D005247:Feeding Behavior; D005260:Female; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000097:blood / Q000378:metabolism; D007333:Insulin Resistance; D000078790:Insulin Secretion; D016014:Linear Models; D008659:Metabolic Diseases / Q000178:diet therapy; D015596:Nutrition Assessment; D009765:Obesity / Q000453:epidemiology*; D011247:Pregnancy; D013997:Time Factors; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D002096:C-Peptide; D004040:Dietary Carbohydrates; D007328:Insulin
keywords: diet; glycaemic; insulin sensitivity; nocturnal