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

Abstract

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 5 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 % (b 5 20?138; 95 % CI 20?002, 0?278) Type 2 diabetes mellitus (T2DM) is a chronic disease mainly characterized by the disorder of glucose metabolism, which may lead to a variety of specific severe complications such as CHD, stroke, diabetic retinopathy and kidney failure (1) . T2DM and its complications have been becoming a main burden of disease around the world, particularly in developing countries (2) . Aggressive control of hyperglycaemia, either by medicine or lifestyle intervention, is crucial to decrease the incidence of diabetic complications and the related premature death (3,4) . As a biomarker reflecting an individual's average level of blood glucose over past 2-3 months, glycosylated haemoglobin A1c (HbA1c) has been associated with the risk of long-term diabetes complications (5) and used as the main indicator of glycaemic control status among diabetes patients (6) . The American Diabetes Association recommends an HbA1c level below 7?0 % as the goal of glycaemic control for diabetes patients (6) .There is sufficient evidence to support the role of dietary fibre in improving glycaemic control status in diabetes patients (7)(8)(9) . Evidence is also available for its beneficial effect on prevention of diabetes complications. By following up 7822 US women with T2DM in the Nurses' Health Study for 26 years, He et al. (10) found that *Corresponding authors: E-mail wanghong.xu@fudan.edu.cn, ruan_118@hotmail.com r The Authors 2013 the highest v. the lowest quintile of intakes of whole grains, cereal fibre, bran and germ were associated with 16 % to 31 % lower ...

Heterogeneous associations of insoluble dietary fibre intake with subsequent glycosylated Hb levels among Chinese adults with type 2 diabetes: a quantile regression approach

“…In the present study using the QR method, we observed significant associations of both insoluble dietary fibre intake and GI value with HbA 1c levels, especially among patients who did not have their blood glucose under control. Unlike the parametric logistic regression method used in our previous study ( 12 ) in which an average association was estimated among all participants without considering whether the size of the association was dependent on the level of blood glucose control, the non-parametric QR approach adopted in the present study allowed us to identify differing regression coefficients across the conditional distribution of HbA 1c and provided a more complete picture of how the dietary factors and HbA 1c levels are associated ( 14 ) .…”

“…As described in our previous study ( 12 ) , 979 prevalent patients with type 2 diabetes were recruited from the communities of Pudong New Area of Shanghai, China, and were interviewed from October to December 2006. They were followed up from May to July 2011 using a similar protocol.…”

“…In our previous study, we observed an association of insoluble dietary fibre intake with subsequent HbA 1c levels among Chinese adults with type 2 diabetes ( 12 ) . However, little is known whether and how the associations would vary in patients with different glycaemic control status.…”

Fiber in Diet Is Associated with Improvement of Glycated Hemoglobin and Lipid Profile in Mexican Patients with Type 2 Diabetes

“…Increased fiber in the diet is associated with a reduction of glycated hemoglobin (HbA1c), improved lipid profile, and loss of body weight in type 2 diabetes patients. It has been proposed that appropriate consumption of fruit in the diet may be an adequate strategy to reduce HbA1c, given the fiber content, and prevent complications from diabetes [ 1 , 2 ]. Several clinical trials have documented a positive effect of dietary fiber, [ 3 ] and in cross-sectional studies this effect has also been observed in different Asian populations [ 1 , 4 ].…”

Quantile regression reaches the parts that mean regression may not: insoluble dietary fibre and glycaemic index in type 2 diabetes

“…Generalising from these observations, no two studies examining the same issue from within or among laboratories can be assumed alike, and no two participants examined within a study can be assumed alike even when categorised similarly for clinical purposes. Such heterogeneity within and among studies is common, and failure to account for it can lead to results with an imprecise estimate of effects or associations, and failure to find truer probabilities or even any effect or association at all, as colleagues of Tan et al report in an earlier publication ( 9 ) .…”