Assessment of cognitive status in patients with type 2 diabetes through the mini-mental status examination: a cross-sectional study

BACKGROUND: Diabetes is considered an independent risk factor for cognitive impairment and some studies observed through neuropsychological tests that cognitive disfunction affects both elderly and younger patients with diabetes. The aims of this study were to evaluate the cognitive status of outpatients with type 2 diabetes and to evaluate factors associated with impaired function. METHODS: A cross-sectional study was conducted in a group of type 2 diabetic outpatients. They were asked to undergo the Mini-Mental State Examination (MMSE) during routine ambulatory visits between April 2006 and January 2007, with the highest pontuation of the test being 30 points. Patients were classified as having possible dementia according to years of study. Exclusion criteria were blindness, illiterately, stroke, Alzheimer disease and psychiatric disorder. Results are presented as median (interquartile range) or mean ± SD. RESULTS: The study group was composed of 346 type 2 diabetic outpatients (216 females), aged 58,6 ± 12,1 years and with duration of diabetes of 12,3 ± 9,1 years. Hypertension was present in 77,2%. The total MMSE score achieved was 26 points (16 - 30) and was correlated with years of study (R(2 )= 0,39, p < 0,001) and 'per capita' income (R(2 )= 0,22, p < 0,0001) and duration of diabetes (R2 = - 0,13, p = 0,01). Patients who needed help to take their medications obtained worst performance in the MMSE (23,16 ± 3,55 vs 25,7 ± 2,84, p < 0,01) and were more likely to present possible dementia (p < 0,01). Forty two subjects (12.1%) had diagnosis of possible dementia and this was also associated with years of study (p = 0,045). No association was observed between possible dementia and total MMSE scores with A1C levels. CONCLUSIONS: We conclude that patients with type 2 diabetes should be regularly evaluated for their cognitive function, because duration of disease could be associated with decline in cognition. The early implementation of mini mental which is a simple method of execution can be done to detect early stages of dementia. This test could be an important tool to access the ability of patient to understand their disease and treatment.