scholarly journals Fasting Glucose State Determines Metabolic Response to Supplementation with Insoluble Cereal Fibre: A Secondary Analysis of the Optimal Fibre Trial (OptiFiT)

Nutrients ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2385 ◽  
Author(s):  
Kabisch ◽  
Meyer ◽  
Honsek ◽  
Gerbracht ◽  
Dambeck ◽  
...  

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.

Nutrients ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2726 ◽  
Author(s):  
Stefan Kabisch ◽  
Nina Marie Tosca Meyer ◽  
Caroline Honsek ◽  
Christiana Gerbracht ◽  
Ulrike Dambeck ◽  
...  

Obesity does not modulate the glycometabolic benefit of insoluble cereal fibre in subjects with prediabetes—a stratified post hoc analysis of the Optimal Fibre Trial (OptiFiT). Background: OptiFiT demonstrated the beneficial effect of insoluble oat fibres on dysglycemia in prediabetes. Recent analyses of OptiFiT and other randomised controlled trials (RCTs) indicated that this effect might be specific for the subgroup of patients with impaired fasting glucose (IFG). As subjects with IFG are more often obese, there is a need to clarify if the effect modulation is actually driven by glycemic state or body mass index (BMI). Aim: We conducted a stratified post hoc analysis of OptiFiT based on the presence or absence of obesity. Methods: 180 Caucasian participants with impaired glucose tolerance (IGT) were randomised in a double-blinded fashion to either twice-a-day fibre or placebo supplementation for 2 years (n = 89 and 91, respectively). Once a year, they underwent fasting blood sampling, an oral glucose tolerance test (oGTT) and full anthropometry. At baseline, out of 136 subjects who completed the first year of intervention, 87 (62%) were classified as OBESE (BMI >30) and 49 subjects were NONOBESE. We performed a stratified per-protocol analysis of the primary glycemic and secondary metabolic effects attributable to dietary fibre supplementation after 1 year of intervention. Results: Neither the NONOBESE nor the OBESE subgroup showed significant differences between the respective fibre and placebo groups in metabolic, anthropometric or inflammatory outcomes. None of the four subgroups showed a significant improvement in either fasting glucose or glycated haemoglobin (HbA1c) after 1 year of intervention and only OBESE fibre subjects improved 2 h glucose. Within the NONOBESE stratum, there were no significant differences in the change of primary or secondary metabolic parameters between the fibre and placebo arms. We found a significant interaction effect for leukocyte count (time × supplement × obesity status). Within the OBESE stratum, leukocyte count and gamma-glutamyl transferase (GGT) levels decreased more in the fibre group compared with placebo (adjusted for change in body weight). Comparison of both fibre groups revealed that OBESE subjects had a significantly stronger benefit with respect to leukocyte count and fasting C-peptide levels than NONOBESE participants. Only the effect on leukocyte count survived correction for multiple comparisons. In contrast, under placebo conditions, NONOBESE subjects managed to decrease their body fat content significantly more than OBESE ones. Intention-to-treat (ITT) analysis resulted in similar outcomes. Conclusions: The state of obesity does not relevantly modulate the beneficial effect of cereal fibre on major glycometabolic parameters by fibre supplementation, but leukocyte levels may be affected. Hence, BMI is not a suitable parameter to stratify this cohort with respect to diabetes risk or responsiveness to cereal fibre, but obesity needs to be accounted for when assessing anti-inflammatory effects of fibre treatments. Targeted diabetes prevention should focus on the actual metabolic state rather than on mere obesity.


2006 ◽  
Vol 155 (4) ◽  
pp. 623-632 ◽  
Author(s):  
G Neil Thomas ◽  
C Mary Schooling ◽  
Sarah M McGhee ◽  
Sai-Yin Ho ◽  
Bernard M Y Cheung ◽  
...  

Background: The use of fasting and post-prandial glucose levels in the classification of hyperglycaemic states often identifies distinct subjects, but the factors determining these intermediate-isolated glucose intolerant states are yet to be clearly elucidated in Chinese subjects. Methods: Representative subjects (n = 2769) were randomly recruited from the Hong Kong Chinese population and glycaemic status was determined using both fasting and 2h 75 g oral glucose tolerance test glucose levels. The relationship between the groups with isolated glucose intolerance and vascular risk factors was investigated using ANOVA and logistic regression analyses. Results: Using either criterion, diabetes was identified in 265 (9.6%) subjects and glucose intolerance in 568 (20.5%) subjects. Of those 568, isolated impaired glucose tolerance (IGT) using the post-load criterion was identified in 49.5% and isolated impaired fasting glucose (IFG) in 30.5%. Ageing and hyperinsulinaemia were common determinants of IGT and IFG; with small hip circumference a marker of poorer early life development and being born in China rather than Hong Kong, a possible low birth weight marker was also associated with IFG. Hypertension, hypertriglyceridaemia and poor education were also associated with IGT. When we looked for factors differentially associated with these glucose intolerant states, female sex, greater hip circumference, high triglyceride levels, low fasting insulin levels, and not being born in China were independently associated with isolated IGT compared with isolated IFG. Conclusion: Despite common antecedents to the glucose intolerant states, isolated IFG appeared to be particularly associated with early life development, and isolated IGT was more strongly associated with obesity-related determinants such as hypertriglyceridaemia.


2020 ◽  
Vol 26 (5) ◽  
pp. 529-534
Author(s):  
Juan Carlos Lizarzaburu-Robles ◽  
Lizardo Torres-Aparcana ◽  
Raúl Mansilla ◽  
José Valera ◽  
Gabriela Vargas ◽  
...  

Objective: The aim of this study was to evaluate the association between the 1-hour oral glucose tolerance test (OGTT) (≥155 mg/dL) and metabolic syndrome (MS) in a sample with previous impaired fasting glucose (IFG). Methods: Three hundred and twenty four Peruvian subjects with a history of IFG ≥100 mg/dL were selected for a cross-sectional study. They underwent a 75 g OGTT and were assigned to different groups according to the result. We evaluated the association between 1-hour OGTT and MS. Results: The mean age was 56.5 ± 12.6 years and 191 (61.5%) were female. During the OGTT, we found 28 (8.6%) subjects with diabetes, 74 (22.8%) with IGT, and 222 (68.5%) with a normal glucose tolerance test with a 2-hour glucose <140 mg/dL (NGT). In the NGT group, 124 (38.3%) had 1-hour glucose levels <155 mg/dL, while 98 (30.2%) had 1-hour glucose levels ≥155 mg/dL. Evaluating the association between the 1-hour value in the OGTT and MS, we found that subjects with a 1-hour glucose ≥155 mg/dL were more than twice as likely to have MS as those with a 1-hour glucose <155 mg/dL (odds ratio = 2.64, 95% confidence interval: 1.52 to 4.57). In addition, body mass index, fasting glycemia, triglycerides, and waist circumferences were significantly higher in subjects with 1-hour glucose levels ≥155 mg/dL compared to those with 1-hour glucose levels <155 mg/dL ( P<.05). Conclusion: Among subjects with IFG, performing an OGTT was helpful to identify subjects with 1-hour glucose levels ≥155 mg/dL and NGT who were significantly more likely to have MS and a worse cardiometabolic risk profile. Abbreviations: AST = aspartate aminotransferase; BMI = body mass index; CI = confidence interval; IFG = impaired fasting glucose; IGT = impaired glucose tolerance; LDL = low-density lipoprotein; MS = metabolic syndrome; NGT = normal glucose tolerance; OGTT = oral glucose tolerance test; OR = odds ratio; T2DM = type 2 diabetes; TG = triglycerides


Nutrients ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 2126
Author(s):  
Masanobu Hibi ◽  
Sayaka Hari ◽  
Tohru Yamaguchi ◽  
Yuki Mitsui ◽  
Sumio Kondo ◽  
...  

Effects of meal frequency on blood glucose levels and glucose metabolism were evaluated over 3 days in adult males with normal glucose tolerance (NGT, n = 9) or impaired fasting glucose (IFG, n = 9) in a randomized, crossover comparison study. Subjects were provided with an isocaloric diet 3 times daily (3M) or 9 times daily (9M). Blood glucose was monitored on Day 3 using a continuous glucose monitoring system, and subjects underwent a 75-g oral glucose tolerance test (OGTT) on Day 4. Daytime maximum blood glucose, glucose range, duration of glucose ≥180 mg/dL, and nighttime maximum glucose were significantly lower in the NGT/9M condition than in the NGT/3M condition. Similar findings were observed in the IFG subjects, with a lower daytime and nighttime maximum glucose and glucose range, and a significantly higher daytime minimum glucose in the 9M condition than in the 3M condition. The OGTT results did not differ significantly between NGT/3M and NGT/9M conditions. In contrast, the incremental area under the curve tended to be lower and the maximum plasma glucose concentration was significantly lower in the IFG/9M condition than in the IFG/3M condition. In IFG subjects, the 9M condition significantly improved glucose metabolism compared with the 3M condition. Higher meal frequency may increase glucagon-like peptide 1 secretion and improve insulin secretion.


2019 ◽  
Vol 104 (9) ◽  
pp. 4024-4032 ◽  
Author(s):  
Miguel Bigotte Vieira ◽  
João Sérgio Neves ◽  
Lia Leitão ◽  
Rute Baeta Baptista ◽  
Rita Magriço ◽  
...  

Abstract Purpose Diabetes mellitus is a risk factor for the development and progression of chronic kidney disease (CKD). However, the association of prediabetes with adverse kidney outcomes is uncertain. Methods We performed a secondary analysis of the Systolic Blood Pressure Intervention Trial (SPRINT), including 9361 participants without diabetes at baseline. We categorized participants according to fasting glucose level as having impaired fasting glucose [≥100 mg/dL (≥5.6 mmol/L)] or normoglycemia [&lt;100 mg/dL (&lt;5.6 mmol/L)]. Unadjusted and adjusted proportional hazards models were fitted to estimate the association of impaired fasting glucose (vs normoglycemia) with a composite outcome of worsening kidney function [≥30% decrease in estimated glomerular filtration rate (eGFR) to &lt;60 mL/min/1.73 m2 in participants without baseline CKD; ≥50% decrease in eGFR or need for long-term dialysis/kidney transplantation in participants with CKD] or incident albuminuria (doubling of urinary albumin/creatinine ratio from &lt;10 mg/g to &gt;10 mg/g). These outcomes were also evaluated separately and according to CKD status at baseline. Results Participants’ mean age was 67.9 ± 9.4 years, 35.5% were female, and 31.4% were black. The median follow-up was 3.3 years, and 41.8% had impaired fasting glucose. Impaired fasting glucose was not associated with higher rates of the composite outcome [hazard ratio (HR): 0.97; 95% CI: 0.8 to 1.16], worsening kidney function (HR: 1.02; 95% CI: 0.75 to 1.37), or albuminuria (HR: 0.98; 95% CI: 0.78 to 1.23). Similarly, there was no association of impaired fasting glucose with outcomes according to baseline CKD status. Conclusions Impaired fasting glucose at baseline was not associated with the development of worsening kidney function or albuminuria in participants of SPRINT.


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