title: Dietary fibre consumption and insulin resistance - the role of body fat and physical activity.
abstract: The present study was conducted to determine the association between fibre intake and insulin resistance in 264 women using a cross-sectional design. Insulin resistance was indexed using homeostasis model assessment of insulin resistance (HOMA-IR) (US formula: fasting insulin (μU/ml) × fasting glucose (mg/dl)/405 international formula: fasting glucose (mmol/l) × fasting insulin (μU/l)/22.5). Fibre and energy consumption were assessed using 7 d weighed food records. Fibre was expressed as g/4184 kJ (1000 kcal). Body fat percentage (BF%) was measured using the BOD POD, and physical activity (PA) was ascertained using Actigraph accelerometers (Health One Technology) worn for seven consecutive days. Women with high total fibre intakes (F= 4·58, P= 0·0332) or high soluble fibre intakes (F= 7·97, P= 0·0051) had significantly less insulin resistance than their counterparts. Participants with high insoluble fibre intakes did not differ from their counterparts (F= 0·7, P= 0·6875). Adjusting for either PA or BF% weakened the relationships significantly. Controlling for BF% nullified the total fibre–HOMA-IR link (F= 1·96, P= 0·1631) and attenuated the association between soluble fibre and HOMA-IR by 32 % (F= 6·86, P= 0·0094). To create dichotomous variables, fibre intake and HOMA-IR were each divided into two categories using the median (low and high). In women who had high soluble fibre intake (upper 50 %), the OR of having an elevated HOMA-IR level was 0·58 (95 % CI 0·36, 0·94) times that of women with low soluble fibre intake (lower 50 %). After controlling for all of the potential confounding factors simultaneously, the OR was 0·52 (95 % CI 0·29, 0·93). High fibre intake, particularly soluble fibre, is significantly related to lower levels of insulin resistance in women. Part of this association is a function of differences in PA and BF%.
authors.affiliation: Department of Exercise Sciences, Brigham Young University, Provo, Utah 84602, USA. c.b.breneman@gmail.com
authors.forename: Charity B
authors.initials: CB
authors.lastname: Breneman
authors.forename: Larry
authors.initials: L
authors.lastname: Tucker
mesh_terms: D056044:Actigraphy; D000273:Adipose Tissue / Q000502:physiology*; D000328:Adult; D001823:Body Composition; D016001:Confidence Intervals; D003430:Cross-Sectional Studies; D004043:Dietary Fiber / Q000494:pharmacology*; D002149:Energy Intake; D015444:Exercise / Q000502:physiology*; D005247:Feeding Behavior; D005260:Female; D005947:Glucose / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance / Q000502:physiology*; D008875:Middle Aged; D009043:Motor Activity; D016017:Odds Ratio
chemical_list: D004043:Dietary Fiber; D007328:Insulin; D005947:Glucose