Fasting glucose state determines metabolic response to supplementation with insoluble cereal fibre: A secondary analysis of the Optimal Fibre Trial (OptiFiT)

TY - JOUR

T1 - Fasting glucose state determines metabolic response to supplementation with insoluble cereal fibre

T2 - A secondary analysis of the Optimal Fibre Trial (OptiFiT)

AU - Kabisch, Stefan

AU - Meyer, Nina M T

AU - Honsek, Caroline

AU - Gerbracht, Christiana

AU - Dambeck, Ulrike

AU - Kemper, Margrit

AU - Osterhoff, Martin A

AU - Birkenfeld, Andreas L

AU - Arafat, Ayman M

AU - Hjorth, Mads Fiil

AU - Weickert, Martin O

AU - Pfeiffer, Andreas F H

N1 - CURIS 2019 NEXS 326

PY - 2019/10

Y1 - 2019/10

N2 - Background: High intake of cereal fibre is associated with reduced risk for type 2 diabetes and long-term complications. Within the first long-term randomized controlled trial specifically targeting cereal fibre, the Optimal Fibre Trial (OptiFiT), intake of insoluble oat fibre was shown to significantly reduce glycaemia. Previous studies suggested that this effect might be limited to subjects with impaired fasting glucose (IFG).Aim: We stratified the OptiFiT cohort for normal and impaired fasting glucose (NFG, IFG) and conducted a secondary analysis comparing the effects of fibre supplementation between these subgroups.Methods: 180 Caucasian participants with impaired glucose tolerance (IGT) were randomized to twice-a-day fibre or placebo supplementation for 2 years (n = 89 and 91, respectively), while assuring double-blinded intervention. Fasting blood sampling, oral glucose tolerance test and full anthropometry were assessed annually. At baseline, out of 136 subjects completing the first year of intervention, 72 (54 %) showed IFG and IGT, while 64 subjects had IGT only (labelled "NFG"). Based on these two groups, we performed a stratified per-protocol analysis of glycometabolic and secondary effects during the first year of intervention.Results: The NFG group did not show significant differences between fibre and placebo group concerning anthropometric, glycometabolic, or other biochemical parameters. Within the IFG stratum, 2-h glucose, HbA1c, and gamma-glutamyl transferase levels decreased more in the fibre group, with a significant supplement x IFG interaction effect for HbA1c. Compared to NFG subjects, IFG subjects had larger benefits from fibre supplementation with respect to fasting glucose levels. Results were robust against adjustment for weight change and sex. An ITT analysis did not reveal any differences from the per-protocol analysis.Conclusions: Although stratification resulted in relatively small subgroups, we were able to pinpoint our previous findings from the entire cohort to the IFG subgroup. Cereal fibre can beneficially affect glycemic metabolism, with most pronounced or even isolated effectiveness in subjects with impaired fasting glucose.

AB - Background: High intake of cereal fibre is associated with reduced risk for type 2 diabetes and long-term complications. Within the first long-term randomized controlled trial specifically targeting cereal fibre, the Optimal Fibre Trial (OptiFiT), intake of insoluble oat fibre was shown to significantly reduce glycaemia. Previous studies suggested that this effect might be limited to subjects with impaired fasting glucose (IFG).Aim: We stratified the OptiFiT cohort for normal and impaired fasting glucose (NFG, IFG) and conducted a secondary analysis comparing the effects of fibre supplementation between these subgroups.Methods: 180 Caucasian participants with impaired glucose tolerance (IGT) were randomized to twice-a-day fibre or placebo supplementation for 2 years (n = 89 and 91, respectively), while assuring double-blinded intervention. Fasting blood sampling, oral glucose tolerance test and full anthropometry were assessed annually. At baseline, out of 136 subjects completing the first year of intervention, 72 (54 %) showed IFG and IGT, while 64 subjects had IGT only (labelled "NFG"). Based on these two groups, we performed a stratified per-protocol analysis of glycometabolic and secondary effects during the first year of intervention.Results: The NFG group did not show significant differences between fibre and placebo group concerning anthropometric, glycometabolic, or other biochemical parameters. Within the IFG stratum, 2-h glucose, HbA1c, and gamma-glutamyl transferase levels decreased more in the fibre group, with a significant supplement x IFG interaction effect for HbA1c. Compared to NFG subjects, IFG subjects had larger benefits from fibre supplementation with respect to fasting glucose levels. Results were robust against adjustment for weight change and sex. An ITT analysis did not reveal any differences from the per-protocol analysis.Conclusions: Although stratification resulted in relatively small subgroups, we were able to pinpoint our previous findings from the entire cohort to the IFG subgroup. Cereal fibre can beneficially affect glycemic metabolism, with most pronounced or even isolated effectiveness in subjects with impaired fasting glucose.

KW - Faculty of Science

KW - Diabetes mellitus type 2

KW - Prediabetes

KW - Diabetes prevention

KW - Impaired fasting glucose

KW - Stratification

KW - Impaired glucose tolerance

KW - Insoluble dietary fibre

KW - Insulin sensitivity

U2 - 10.3390/nu11102385

DO - 10.3390/nu11102385

M3 - Journal article

C2 - 31590438

SN - 2072-6643

VL - 11

JO - Nutrients

JF - Nutrients

IS - 10

M1 - 2385

ER -