Risk Factors Associated With Diabetic Peripheral Neuropathy Analysis

Backgrounds and objectives:With the change of lifestyle and the increase of population aging, the prevalence of diabetes in China is rising rapidly. Diabetic peripheral neuropathy (DPN) is one of the most common chronic complications of diabetes, which affects sensory nerve, motor nerve and autonomic nerve, mostly in sensory nerve. The UKPDS study found that among the patients with a diabetes durations more than 12 years,71% of men and 51% of women had been in the clinical stage of diabetic neuropathy. Due to the weak symptoms, DPN often onset occult, however, an advanced stage of DPN can cause muscle atrophy, nerve pain, lossofsensation,and even amputation (toe). Diabetic neuropathy The 5-10 year mortality in patients with DPN is up to 50% now, which has been one of the most causes leading to increased morbidity and mortality in patients with diabetes. DPN is not only seriously affects the life quality of patients, increase the burden of the family, but also bring complex and medical related social, psychological and economic problems. Therefore, early screening and early treatment of DPN is very important, and the correct analysis and control of risk factors of peripheral neuropathy are of clinical significance.Presently, the pathogenesis of DPN is not yet fully understood, however, it has been considered as a disease caused by multiple factors, which including long-term hyperglycemia, oxidative stress, glycosylation product accumulation, active polyol pathway, lack of neurotrophic factors and genetic factors such as multiple factors. In addition, in the 2014 European diabetes annual meeting, professor Tesfaye reported that atherosclerosis and the blood vessel arteriovenous shunt can reduce nerve blood flow, leading to DPN, which emphasized the important role of vascular factors in the development of neuropathy. In addition, a survey carried out in 20 cities of China found that 78.51% of the patients with type 2 diabetes mellitus accompanied with dyslipidemia, which is a well-established risk factor of atherosclerosis. Therefore, this research is aimed to observe, apart from "glucotoxicity", whether "lipotoxicity" and "vascular factors" also play important roles in the development of DPN.Methods:According to the 1999 WHO diagnosis standard of diabetes, this cross-sectional study included 268 patients with type 2 diabetes in the department of endocrinology of Qilu Hospital of Shandong University from the January 2013 to June 2014, among which 112 were male,156 were female. The following measurements were conducted to all subjects:height, weight, waist circumference, blood pressure and ankle brachial index (ABI). All enrolled patients with cardiac, carotid, lower extremity vascular Doppler ultrasound, color fundus examination and reflection sheet 24-hour ambulatory blood pressure monitoring.ZET-100 digital cardio-cerebral emg instrument was used to detect the nerve conductive velocity. The conductive velocity of median nerve< 50 mm/s or the conductive velocity of nervus peroneus communis < 40 mm/s was defined as slowering of nerve conductive velocity. According to the nerve conductive velocity, all the subjects were divided into two groups:DPN and non-DPN. Fasting blood of all the subjects were collected for the measurement of plasma glucose, fasting insulin (FINS), alanine aminotransferase (ALT), aspertate aminotransferase (AST), triglycerides (TG), total cholesterol (TC), high-density lipoprotein (HDL-C), low density lipoprotein (LDL)-c) and uric acid (UA). The continuous variables are expressed as the mean ± standard deviation (SD), and the categorical variables are presented as numbers (%). Between-group differences were detected using Student’s t-test or chi-squared test (categorical variables). The associations of different metabolic markers with the risk of DPN were estimated using binary logistic regression analysis. P< 0.05 was considered to be statistically significant. The data were analyzed using the SPSS 16.0 software.Results:1.Compared with non-DPN group, the proportion of male, waist circumference, pulse pressure, fasting plasma glucose, HbAlc, LDL-C and UA were significantly higher in DPN group. Meanwhile, the value of ABI was significant lower in DPN group.2.After adjusting for age and gender, or further adjusting for waist circumference, pulse pressure, ABI, TG、TC、ALT and UA, HbAlc but fasting insulin was the risk factor of DPN.3. After adjusting for multiple factors,increased LDL-C was the risk factor of DPN.4.After adjusting for multiple factors, the elevated pulse pressure or decreased ABI was associated with increased risk of DPN.5.When unjusted, waist circumference was closely related to DPN. However, after adjusting for multiple factors, waist circumference was not significantly associated with DPN any more.6. After adjusting for multiple factors,UA was also associated with increased risk of DPN.7. Increased pulse wave velocity and thickening of the carotid intima-media thickness are both risk factors of DPN.8. DPN is usually accompanied by diabetic retinopathy, the heavier of diabetic retinopathy is, the greater probability of DPN occur9. Lower limb artery intima-media occurred more often in thickening, plaque formation, luminal stenosis and occlusion in pathents with DPN.Conclusion:1. Apart from hyperglycemia, dyslipidemia is also an independent risk factor of DPN.2. Besides, other metabolic disorders, such as obesity-related chronic inflammation and hyperuricemia, are also closely associated with the development of DPN.3. The decrease of ABI and the increase of pulse pressure are both risk factors for DPN. The sclerosis degree and embolism degree of double lower limb vascular are heavier in patients with DPN. Further more, by evaluating the blood vessels of color doppler ultrasonic testing index, we verify thata the vascular elasticity and atherosclerosis (narrow) are independent risk factors of DPN.