Dietary Glycemic Index and Glycemic Load Are Associated with Metabolic Control in Type 2 Diabetes: The CAPRI Experience

Effect of Consumption of Whole-Wheat Breads on FBS, HbA1c, and Blood Lipids in Patients with Type 2 Diabetes

Whole-wheat can have positive effect on blood parameters, such as blood sugar and fat profiles, in patients with diabetic. The aim of this study was to assess the effect of whole-wheat breads on hemoglobin A1c (HbA1c) and blood lipids in patients with type 2 diabetes (T2D). The study population included men and women with T2D aged 30 years old and over in Arak, Iran. Using random sampling method, 60 patients with T2D were selected and randomly divided into control and intervention groups. After taking blood samples from the patients, the intervention group was administered 180 g of wholegrain wheat for 12 weeks. The participants were asked not to change their diets and amounts of physical activity during the study period. After 12 weeks, blood samples were taken and insulin resistance indexes, blood glucose levels, and lipid profiles were examined. The results indicated that consumption of whole-wheat bread for 12 weeks can significantly reduce body weight, and HbA1c, triglyceride, total cholesterol, and low density lipoprotein cholesterol (LDL-c) levels, and increase high density lipoprotein cholesterol (HDL-c) levels (P<0.05). However, in the control group, changes in body weight, body mass index, HbA1c, total cholesterol, HDL-c, and LDL-c levels did not significantly differ before and after the intervention period (P>0.05). As consumption of whole-wheat bread has positive effects on control of various physical and biochemical indictors in patients with diabetes, its consumption should be included in educational programs at health centers across the country.

Nutritional management of type 2 diabetes in subjects with obesity: an international guideline for clinical practice

Type 2 diabetes mellitus (T2DM) and obesity represent a global public health problem. Current nutritional recommendations focused on weight loss and overall dietary quality. However, there is no consensus on the optimal macronutrient composition of the diet, particularly for the long-term management of T2DM in subjects with obesity. An international panel of experts reviewed and critically appraised the updated literature published on the topic. This review primarily examines the evidence for areas of consensus and uncertainty about nutritional therapy in patients with T2DM and obesity. The aim of this article is to provide nutritional advice to manage these patients in clinical practice.

The association between glycemic index, glycemic load, and metabolic syndrome: a systematic review and dose-response meta-analysis of observational studies

PURPOSE

The association of glycemic index (GI) and glycemic load (GL) with metabolic syndrome (MetS) is controversial. Therefore, we conducted this first systematic review and dose-response meta-analysis of observational studies to quantify these associations.

METHODS

We searched PubMed, EMBASE, Web of Science, and the Cochrane Library for relevant studies up to 1 April 2019. Summary odds ratios (OR) and 95% confidence intervals (CI) were calculated by a random-effects model. This study was registered with PROSPERO (CRD42019131788).

RESULTS

We included eight high-quality (n = 5) or medium-quality (n = 3) cross-sectional studies in the final meta-analysis, comprising 6058 MetS events and 28,998 participants. The summary ORs of MetS for the highest versus lowest categories were 1.23 (95% CI 1.10-1.38, I² = 0, tau² = 0, n = 5) for dietary GI, 1.06 (95% CI 0.89-1.25, I² = 36.2%, tau² = 0.0151, n = 6) for dietary GL. The summary OR was 1.12 (95% CI 1.00-1.26, I² = 0, tau² = 0, n = 3) per 5 GI units, 0.96 (95% CI 0.83-1.10, I² = 33.4%, tau² = 0.0059, n = 2) per 20 GL units.

CONCLUSIONS

Dietary GI was positively associated with the prevalence of MetS. However, no significant association was found between dietary GL and the prevalence of MetS. Further studies with prospective design are needed to establish potential causal relationship between dietary GI and the MetS.

Results from a dietary survey in an Indian T2DM population: a STARCH study

OBJECTIVE

To assess the dietary total and complex carbohydrate (CHO) contents in type-2 diabetes mellitus (T2DM) participants in India.

SETTING

We enrolled 796 participants in this cross-sectional, single-visit, multicentre, two-arm, single-country survey. Participants were enrolled from 10 specialty endocrinology/dialectology centres from five regions of India.

PARTICIPANTS

A total of 796 participants (Asian) were enrolled in this study (385, T2DM and 409, non-T2DM). Key inclusion criteria-male or female ≥18 years, diagnosed with T2DM ≥12 months (T2DM), and not on any diet plan (non-T2DM).

STUDY OUTCOME

Primary outcome was to find out the percentage of total energy intake as simple and complex CHO from total CHO. Secondary outcomes were to find the differences in percentage of total energy intake as simple CHO, complex CHO, proteins and fats between T2DM and non-T2DM groups. The percentage of T2DM participants adhering to diet plan and showing glycaemic controls were also examined.

RESULTS

The mean (SD) of total calorie intake per day (Kcal) was 1547 (610, 95% CI 1486 to 1608) and 2132 (1892, 95% CI 1948 to 2316), respectively, for T2DM and non-T2DM groups. In the T2DM group (n=385), the mean (SD) percentage of total energy intake as total CHO, complex CHO and simple CHO was 64.1±8.3 (95% CI 63.3 to 64.9), 57.0±11.0 (95% CI 55.9 to 58.1) and 7.1±10.8 (95% CI 6.0 to 8.2), respectively. The mean (SD) percentage of complex CHO intake from total CHO was 89.5±15.3 (95% CI 88.0 to 91.1). The mean (SD) total protein/fat intake per day (g) was 57.1 (74.0)/37.2 (18.6) and 57.9 (27.2)/55.3 (98.2) in T2DM and non-T2DM groups, respectively.

CONCLUSIONS

Our study shows that CHO constitutes 64.1% of total energy from diet in T2DM participants, higher than that recommended in India. However, our findings need to be confirmed in a larger epidemiological survey.

TRIAL REGISTRATION NUMBER

NCT01450592 & Clinical Trial Registry of India: CTRI/2012/02/002398.

Effect of a low dose whey/guar preload on glycemic control in people with type 2 diabetes--a randomised controlled trial

OBJECTIVE

Large preloads of protein and fat have been shown to lower glucose after a carbohydrate-rich meal in people with type 2 diabetes but add a considerable energy burden. Low calorie preloads [<5% of daily energy intake] have been tested in this study in people with prediabetes and with type 2 diabetes.

RESEARCH DESIGN AND METHODS

This was an unblinded randomised crossover study with two placebo days and two active treatment days. Glucose was measured for 3 hours with fingerprick samples as well as continuous glucose monitoring [CGMS]. Twenty-four subjects with pre-diabetes or moderately controlled type 2 diabetes [fasting glucose < 10 and HbA1c < 8.5%] were recruited. The preload contained 17 g whey protein plus 3 g lactose and 5 g guar, and 1 g flavour material [including sucralose] dissolved in 150 ml cold water or 150 ml cold water with no additives. The breakfast test meal consisted of 2 slices of bread, margarine and jam [3 slices for men] with the test drink 15 minutes beforehand.

RESULTS

Peak fingerprick glucose was reduced by 2.1 mmol/L at 45 min [p < 0.0001]. Average fingerprick glucose over 3 hours was reduced by 0.8 mmol/L [p = 0.0003]. There was no difference between those with diabetes or prediabetes or those on medication or not on medication.

CONCLUSIONS

An 80 kcal whey protein/fibre preload can lower average glucose over 3 hours by 0.8 mmol/L. If used long term before at least two carbohydrate-rich meals/day this preload could lower HbA1c by up to 1%.

TRIAL REGISTRATION

The trial was registered with the Australian New Zealand Clinical Trials Registry number ACTRN12612001251819.

Long-term effect of dietary fibre intake on glycosylated haemoglobin A1c level and glycaemic control status among Chinese patients with type 2 diabetes mellitus

OBJECTIVE

Dietary fibre has been linked to lower levels of glycosylated haemoglobin A1c (HbA1c) among diabetes patients. The present study aimed to evaluate the long-term effect of dietary fibre on HbA1c levels among Chinese patients with type 2 diabetes mellitus.

DESIGN

Two cross-sectional surveys were conducted in 2006 and 2011, with the second one being a repeat survey on a sub-sample from the initial one. In both surveys, an in-person interview was conducted to collect information on demographic characteristics and lifestyles following a similar protocol. Dietary intake was assessed with a validated FFQ. Anthropometric measures and biochemical assays were performed at the interview.

SETTING

Communities in Pudong New Area of Shanghai, China.

SUBJECTS

Chinese patients (n 934) with type 2 diabetes mellitus.

RESULTS

An inverse association was observed between dietary fibre and glycaemic status indicated by HbA1c level in both surveys, although it was significant only in the first survey. Among 497 patients participating in both surveys, dietary fibre intake at the first survey was inversely associated with uncontrolled glycaemic status at the second survey, with adjusted odds ratios across the tertiles of intake being 1·00, 0·72 (95 % CI 0·43, 1·21) and 0·58 (95 % CI 0·34, 0·99; P trend = 0·048). The change in fibre intake was slightly associated with glycaemic status, with each increase in tertile scores of intake linked to a 0·138 % (β = -0·138; 95 % CI -0·002, 0·278) decrease in HbA1c value and a 19 % (OR = 0·81; 95 % CI 0·65, 1·02) reduced risk of uncontrolled glycaemic status at the second survey.

CONCLUSIONS

Dietary fibre may have a long-term beneficial effect on HbA1c level among Chinese diabetes patients.

Impact of behavioral interventions in the management of adults with type 2 diabetes mellitus

Research on the role of behavior change as an efficacious intervention for adults with type 2 diabetes is evolving. Searching PubMed and Ovid Medline, we identified and reviewed primarily randomized controlled trials from 2010 to 2013 of adults managing type 2 diabetes without insulin. All studies are evaluated in terms of the rigor of their design and their impact on glycosylated hemoglobin. The most efficacious interventions appear to be low-carbohydrate/glycemic load diets, combined aerobic and resistance training, and self-monitoring of blood glucose, which educates patients about the impact of their food selections and physical activity on their blood glucose.

Dietary fiber intake is associated with HbA1c level among prevalent patients with type 2 diabetes in Pudong New Area of Shanghai, China

BACKGROUND

Dietary factors play an important role in glycemic control in diabetic patients. However, little is known about their effects among Chinese diabetic patients, whose diets are typically abundant in fiber and high in glycemic index (GI) values.

METHODOLOGY/PRINCIPAL FINDINGS

934 patients with type 2 diabetes and 918 healthy volunteers from Pudong New Area, Shanghai, China, were interviewed during the period of Oct-Dec, 2006 to elicit demographic characteristics and lifestyle factors. Dietary habits were assessed using a validated food frequency questionnaire. Anthropometric measurements, bio-specimen collection and biochemical assays were conducted at the interview according to a standard protocol. In this population, diabetic patients consumed lower levels of energy and macronutrients but had higher levels of fasting plasma glucose (FPG), glycolated hemoglobin A1c (HbA1c), triglyceride and body mass index than healthy adults. While the average consumption levels of the nutrients among diabetic patients did not vary along duration of the disease, the average levels of FPG and HbA1c increased with increasing duration. Regardless of diabetes duration, HbA1c level was observed lower in patients having a higher fiber or lower GI intake. Compared with those with the lowest tertile intake of fiber, the adjusted odds ratios (ORs) for poor glycemic control reduced from 0.75 (95%CI: 0.54-1.06) to 0.51 (95%CI: 0.34-0.75) with increasing tertile intake (P for trend <0.001).

CONCLUSIONS

Dietary fiber may play an important role in reducing HbA1c level. Increasing fiber intake may be an effective approach to improve glycemic control among Chinese diabetic patients.

Dietary effects on incretin hormone secretion

The delivery of nutrients from the stomach into the duodenum and their subsequent interaction with the small intestine to stimulate incretin hormone release are central determinants of the glycemic response. The incretin effect has hitherto been attributed to the secretion of glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) from enteroendocrine cells in the intestinal epithelium. A number of recent studies have yielded fundamental insights into the influence of individual nutrients on incretin release and the mechanisms involved in the detection of carbohydrates, fats, and proteins by enteroendocrine cells, including the K(ATP) channel, sodium-glucose cotransporter 1 (SGLT1), sweet taste receptors, G-protein-coupled receptors (GPRs), and oligopeptide transporter 1 (PepT1). Dietary modification, including modifying macronutrient composition or the consumption of "preloads" in advance of a meal, represents a novel approach to manipulate the incretin response and thereby regulate glucose homeostasis in patients with type 2 diabetes. This review focuses on the effects of individual nutrients on incretin hormone secretion, our current understanding of the signaling mechanisms that trigger secretion by enteroendocrine cells, and the therapeutic implications of these observations.