Objective: The prevalence of neuropathic pain in prediabetes and the associated risk factors in the general population are not known. The aim of this study was to determine the prevalence and risk factors of neuropathic pain in subjects with diabetes, impaired fasting glucose (IFG), impaired glucose tolerance (IGT), or normal glucose tolerance (NGT).
Design: Survey of neuropathic painful polyneuropathy assessed by the Michigan Neuropathy Screening Instrument using its pain-relevant questions and an examination score cutpoint >2 in a diabetic and control population. An oral glucose tolerance test was performed in the control subjects.
Setting: Population of the city of Augsburg and two surrounding counties.
Patients: Subjects with diabetes (N = 195) and controls matched for age and sex (N = 198) from the population-based MONItoring trends and determinants in CArdiovascular/Cooperative Research in the Region of Augsburg (MONICA/KORA) Augsburg Surveys S2 and S3 aged 25-74 years.
Results: Among the controls, 46 (23.2%) had IGT (either isolated or combined with IFG), 71 (35.9%) had isolated IFG, and 81 had NGT. The prevalence (95% confidence interval) of neuropathic pain was 13.3 (8.9-18.9)% in the diabetic subjects, 8.7 (2.4-20.0)% in those with IGT, 4.2 (0.9-11.9)% in those with IFG, and 1.2 (0.03-6.7)% in those with NGT (overall P = 0.003). In the entire population (N = 393), age, weight, peripheral arterial disease (PAD), and diabetes were risk factors significantly associated with neuropathic pain, while in the diabetic group, these factors were age, weight, and PAD (all P < 0.05).
Conclusions: The prevalence of neuropathic pain is two- to threefold increased in subjects with IGT and diabetes compared with those with isolated IFG. Apart from diabetes, the predominant risk factors are age, obesity, and PAD.