Silent ischemia of lower extremities in patients with diabetic peripheral polyneuropathy without pathosis of large arteries

Aim ? to study the prevalence of lower limb tissue ischemia among patients with diabetic neuropathy and preserved blood flow of large arteries and determine its relation with the duration of disease, the level of control of diabetes and smoking. Materials and methods. We examined 178 patients with type 2 diabetes mellitus and severe diabetic peripheral polyneuropathy. Patients with other possible causes of neuropathy : metabolic disorders other than diabetes were excluded. Patients were investigated to exclude the presence of occlusions of the large arteries of the lower extremities. Transcutaneous oximetry(TсPO2) was performed in all the patients. A total of 178 patients (82 men and 96 women) aged 39 to 62 years were investigated. The average age of men was (48,56±9,23) years, women (51,58±8,35) years. The average level of glycated hemoglobin in men 8.97+2.53%, women 8.39+1.87%. The duration of diabetes was up to 7 years in 28 men and 34 women, 7-10 years ? 36 men and 44 women, more than 12 years ? 18 men and 18 women. Smokers at the time of the survey were 33 men and 13 women. Results and discussion. TcPO2 in tissues of the foot was reduced in comparison with the norm in 139 (78%) patients. In 39 cases this index was in the range 55-63 mmHg. Statistical relationship of TcPO2 with the level of glycated hemoglobin was not found, except for the fact that in all six patients with levels of glycosylated hemoglobin >10.0% TcPO2 level did not exceed 30 mmHg., which indicates critical ischemia of the lower limbs. However, the BPI in all the patients was within 0,87-1,04, that is, there were no signs of angiopathy of large vessels. Due to the small sample significant difference between smoking and non-smoking group was not established. Also no significant difference between men and women was seen , both in general and within the groups of the study. A clear difference was seen in TcPO2 values depending on the duration of diabetes, with a reliable trend towards decreased oxygenation of the lower extremities directly proportional to the duration of the disease. We found a direct statistically significant relation between the degree of tissue ischemia of the lower limbs and the duration of diabetes, with the worst figures of TcPO2 in patients with diabetes for more than 12 years. Conclusions. Due to the absence of instrumentally confirmed occlusion of the large and medium leg arteries we concluded that the cause of silent ischemia of foot tissues is the development arteriolovenular shunts.