|ISSN No. 1606-7754 Vol.14 No.3 December 2006|
Peripheral neuropathy in type 2 diabetes mellitus in Isfahan, Iran: Prevalence and risk factors
Mohsen Janghorbani, Hasan Rezvanian, Ali Kachooei, Abbas Ghorbani, Ahmad Chitsaz, Farzad Izadi, Masoud Amini
Department of Epidemiology and Isfahan Endocrinology and Metabolism Research Centre, Isfahan University of Medical Sciences and Health Services, Isfahan, Iran
Background: To estimate the prevalence and risk factors of peripheral neuropathy (PN) in people with type 2 diabetes mellitus. Methods: 810 patients with type 2 diabetes (289 male and 521 female) from Isfahan Endocrinology and Metabolism Research Centre outpatient clinics, Iran , were examined. Part of the examination included an assessment of neurological function including neuropathic symptoms and physical signs, and nerve conduction velocity. Results: The prevalence of PN was 75.1% (95% confidence interval (CI) 72.1, 78.0). Peripheral neuropathy was associated with age, proteinuria, and duration of diabetes, insulin-treatment, and presence of retinopathy and ischaemic heart disease (IHD). The age-adjusted prevalence rate of PN was 78% higher among patients with IHD, 64% higher among patients with any retinopathy, 66% higher among insulin-treated type 2 diabetes, and greater with duration of diabetes. Using a stepwise binary logistic regression model, age, duration of diabetes and proteinuria were significant independent predictors of PN. Conclusion: PN is a common complication in this population of Iranian type 2 diabetic patients. It increases with age, duration of diabetes and proteinuria. (Int J Diabetes Metab 14: 126-133, 2006)
Key Words: Complications, diabetes mellitus, diabetic neuropathy, epidemiology, Iran, peripheral neuropathy, prevalence, risk factors.
Peripheral neuropathy is a major factor in the occurrence of foot ulcers in patients with diabetes.1 The relationship between diabetes complications and PN is well established in clinic-, hospital,2-5 and population based prevalence studies6-12 in many different populations in developed nations.2-17 The prevalence and pattern of PN vary from country to country, from as low as 1.5% to as high as 100% in patients with type 2 diabetes7,11-15 depending on the differences in screening approaches, diagnostic criteria and the study population.16 The neuropathy may be silent and go undetected. Up to 7.5% of patients with type 2 diabetes have clinical neuropathy at the time of diagnosis. This rate increases to 50% among patients with diabetes who have had diabetes for 25 years.15 However, epidemiological studies of the impact of PN on type 2 diabetes in developing countries are scarce.
Type 2 diabetes and PN are common causes of foot ulceration, gangrene, and amputation and are serious problems in Iran but to our knowledge, there have been no studies describing the prevalence or risk factors of PN in patients with diabetes.
The objective of this study was to estimate the prevalence and risk factors of PN in patients with type 2 diabetes using routinely collected data from a clinical information system for diabetes at Isfahan Endocrinology and Metabolism Research Centre, Iran.