Dietary fiber intakes and insulin requirements in pregnant women with type1 diabetes

Objective To determine whether higher dietary fiber intake (water soluble a nd insoluble) is associated with lower insulin requirements and better glyc emic control in pregnant women with type 1 diabetes consuming a self-select ed diet. Design A longitudinal, observational study. Subjects Pregnant women (n = 141) with type 1 diabetes participating in an interdisciplinary program examining the effects of glycemic control on preg nancy outcome (Diabetes and Pregnancy Program, University of Cincinnati Med ical Center). Measurements We determined total, water soluble and insoluble fiber intakes from 3-day food records kept each trimester during pregnancy. Outcome meas ures were insulin dose, pre-meal blood glucose, and glycated hemoglobin con centrations. Statistical analyses Correlation coefficients, multiple regression, mixed-m odel analysis of variance. Results Mean intakes (g/day) of total, water soluble fiber, and insoluble f iber were 14.0 (range, 1.8-33.1), 4.8 (range, 0.6-10.5) and 9.0 (range, 1.1 -24.0), respectively. In the second and third trimesters of pregnancy, insu lin requirements were inversely associated with total, water soluble, and i nsoluble fiber intakes; the correlation coefficients ranged from -0.22 to - 0.17 (P = .02 to .08). Insulin requirements associated with a higher fiber intake (20.5 g/day) were 16% to 18% lower than for a lower fiber intake (8. 1 g/day). These relations remained after adjustment for body weight, diseas e severity and duration, insulin type, and study year in the second (P = .0 3 to .10) but not in the third trimester. Pre-meal blood glucose and glycat ed hemoglobin concentrations were riot associated with fiber intake. Conclusions Among pregnant women with type 1 diabetes, higher fiber intake is associated with lower daily insulin requirements. Dietary fiber intake s hould be considered when counseling patients about the management of blood glucose concentrations.