Abstract
Background: Diabetes mellitus is a global health concern as many people are getting diagnosed in the early stages of its development. The advancements in the treatment of diabetes have increased life span and prevented complications. However, early detection of cognitive impairment and vascular dementia still poses a great challenge as these conditions are conventionally not addressed as regularly as nephropathy, peripheral neuropathy, and retinopathy. As indicators of various degrees of systemic inflammation, the neutrophil-lymphocyte ratio (NLR) has been found to be closely related to cardiovascular diseases and diabetic microvascular concurrent diseases.

Aims and Objectives: The objectives of this study were as follows: (1) To assess the prevalence of cognitive impairment in patients with type 2 diabetes mellitus (T2DM) at a tertiary care center and (2) to study the association between NLR and cognitive impairment in T2DM.

Materials and Methods: A case–control design was used in the study. Thirty cases and 30 controls satisfying the inclusion and exclusion criteria were recruited after obtaining informed written consent. Semi-structured, pretested questionnaires consisting of sociodemographic details of the study population, questions based on health profile and treatment were administered. Cognitive function was assessed using the Mini-Mental State Examination (MMSE) questionnaire. The NLRs were analyzed from blood investigations. Data were analyzed using MS Excel, SPSS version 17. The study was undertaken after obtaining clearance from the Institutional Ethical Committee.

Results: Majority of the cases (15) were in the age group of 56–70 years and controls (15) were in the age group of 40–55 years. Majority of the cases (18) were in the age group of 40–55 years when diagnosed with T2DM. Most of the cases (29) were diagnosed with T2DM for the duration of 10–20 years. The NLR was <3.5 in 24 cases and 27 controls and >3.5 in six cases and three controls. About 30% (9) of cases showed mild cognitive impairment (MCI) and 23% (7) showed severe cognitive impairment. NLR was 2.79 ± 1.5 (mean ± standard deviation [SD]) and 1.85 ± 0.8 (mean ± SD) in cases and controls, respectively. NLR was significantly increased among diabetics (P = 0.004). There was no statistically significant association between NLR and cognitive impairment in diabetics (P > 0.05).

Conclusion: The present study showed 30% prevalence of MCI as per MMSE scores in the first 20 years of diagnosis with T2DM. NLR was significantly elevated in T2DM patients. There was no statistically significant association between NLR and cognitive impairment in T2DM.

Key words: Cognitive Impairment; Neutrophil-Lymphocyte Ratio; Type 2 Diabetes Mellitus