Investigation of PER3 of the circadiene rhythm genes in diabetic neuropathy

Diabetes (Diabetes Mellitus- Diabetes) is a health problem that is observed with increasing frequency all over the world and in Turkey today. This disease is a chronic disease characterized by hyperglycemia, manifested by a defect in insulin secretion (Type I), the mechanism of action of insulin (Type II), or both of these functions. When diabetes was diagnosed in diabetic patients, it was observed that 10% of the patients developed diabetic neuropathy due to microvascular complications, while at the end of the 20th year, it was observed that around 50% of the patients with neuropathy were detected. The circadian rhythm is a system that regulates the timing of cellular processes to optimize and adapt physiology and metabolism to the time of day, as a result of the Earth's rotation around its axis, as a result of which organisms are exposed to environmental changes associated with day and night (for example, light-dark and temperature cycles). The basic molecular mechanisms behind the circadian rhythm are controlled by clock genes. In this thesis, the effects of the VNTR polymorphism of PER3, one of the first circadian rhythm genes in the literature, on the development of diabetic neuropathy were investigated. For this purpose, 84 patients diagnosed with only diabetes and 220 patients diagnosed with diabetic neuropathy, who applied to Tokat Gaziosmanpaşa University Faculty of Medicine Research and Practice Hospital, Department of Internal Medicine, and 218 healthy individuals as the control group were examined. PER3 gene VNTR polymorphism was detected by classical PCR method using DNAs isolated from peripheral blood samples of volunteers. When the data obtained in our study were examined, no statistically significant difference was observed between diabetic neuropathy patients, control and diabetes groups in terms of PER3 VNTR polymorphism. However, a significant difference was found between the control group and the diabetes group, especially in terms of 5/5 genotype and 5 alleles, between the patient group and the control group (p<0.05). In conclusion, first in the world, the relationship between PER3 gene VNTR polymorphism and diabetic neuropathy and diabetes, was investigated. Our results showed that PER3 may be associated with diabetes but not with diabetic neuropathy.