Evaluation of the effect of dpp-4 inhibitors on cognitive function and levels of bdnf and pentraxin-3 in patients with type-2 diabetes

Type-2 Diabetes Mellitus is an important risk factor for neurodegenerative diseases such as cognitive impairment and dementia. Independent from glycemic control, the effect of antidiabetic drugs in preventing central nervous system-related complications of diabetes is one of the most important current research topics. Our study aimed to evaulate the effect of DPP-4 inhibitors on cognitive functions, serum BDNF levels and serum pentraxin-3 levels in patients with type-2 diabetes. A total of 50 patients with type-2 diabetes who have HbA1c levels at ≤ 7.5% were included. Participants were classified into two groups: patients received DPP-4 inhibitors (n=25) and patients received only metformin treatment as the control group (n=25). Patients received antidiabetic treatments other than DPP-4 inhibitors and metformin were not included in the study. Serum BDNF and serum pentraxin-3 levels were measured using ELISA. MMSE test was used to evaluate the cognitive functions. The routine laboratory parameters of the patients were retrospectively reviewed from the last one month of electronic health records, if available. There was no significantly difference between the two groups in regards to age, gender, disease duration of type-2 diabetes, blood glucose levels, HbA1c levels, sysctolic and diastolic blood pressure levels (p>0.05). The MMSE scores (p=0,041) and serum BDNF levels (p=0,001) were significantly higher in the DPP-4 inhibitors treatment group compared to the control group. When the serum pentraxin-3 levels were compared between the study groups, the difference did not reach a significant level (p=0.055). A significant positive correlation was observed between MMSE scores and serum BDNF levels (r=0,316, p=0,025). Additionally, a significant invers correlation was observed between HbA1c and serum BDNF levels (r=-0,354, p=0,012). The findings in this study suggest that the use of DPP-4 inhibitor in patients with type-2 diabetes may be associated with increased BDNF levels and higher MMSE scores. Further clinical studies on larger populations are needed to thoroughly evaluate the potential protective effects of DPP-4 inhibitor use in patients with type-2 diabetes against neurodegenerative diseases such as cognitive impairment and dementia.