Glycaemic control for painful diabetic peripheral neuropathy is more than fasting plasma glucose and glycated haemoglobin

Abstract

BackgroundThe relationship between postprandial hyperglycaemia and diabetic peripheral neuropathy (DPN), whether painful or painless, has yet to be determined. Thus, the aim of this study was to investigate the relationship in patients with type 2 diabetes (T2D). MethodsThis cross-sectional study was conducted in adults with T2D between January and October 2013. Blood samples were collected after overnight fasting every 3 months prior to enrolment. For this study, increased postprandial glycaemic exposure was defined as high glycated haemoglobin (HbA1c) and near-normal mean fasting plasma glucose (FPG) levels. Both painless and painful DPN were evaluated using two validated tools, the Michigan Neuropathy Screening Instrument (MNSI) and Douleur Neuropathique 4 (DN4) questionnaire. ResultsThis study included 1040 participants with mean FPG levels<140mg/dL, 535 of which were<126mg/dL. Of these patients, 200/1040 (19.2%) and 105/535 (19.6%) had DPN. Multivariate analysis demonstrated that higher HbA1c levels (≥7%) did not increase risk of painless DPN, but did significantly increase risk of painful DPN in T2D patients with FPG<140mg/dL and<126mg/dL, with corresponding odds ratios of 2.49 and 3.77 (95% confidence intervals: 1.09–5.71 and 1.20–11.79), respectively, after adjusting for demographic factors, diabetes-related variables and comorbidities. ConclusionThis study is the first to reveal that increased postprandial glycaemic exposure, as assessed by high HbA1c and near-normal FPG levels, is associated with an increased risk of painful DPN in adults with T2D.