Effect of poor glycemic control in cognitive performance in the elderly with type 2 diabetes mellitus: The Mexican Health and Aging Study.

Background: Cognitive impairment is twice more frequent in elderly with type 2 diabetes mellitus (DM). This study was conducted to determine the association between glycemic control and cognitive performance among community-dwelling elderly persons in Mexico.
Methods: Cross-sectional study conducted in individuals aged 60 years or elderly participating in the 2012 Mexican Health and Aging Study. Type 2 DM participants were classified in 3 groups according to their glycated hemoglobin levels (Hb _A1c ): < 7% (intensive control), 7-7.9% (standard control) or ≥ 8% (poor control), and cognitive performance: low (CCCE ≤44 points), intermediate (44.1-59.52 points), or high (≥59.53 points). Multinomial logistic regression models were constructed to determine this association.
Results: Two hundred sixteen community-dwelling adults aged 60 and older with type 2 diabetes were selected. Subjects in the low cognitive performance group were older (69.7 ± 6.6 vs 65.86 ± 5.18 years, p < .001) and had a lower educational level (2.5 ± 2.6 vs 7.44 ± 4.15 years, p < .000) when compared to the high cognitive performance participants. Hb _A1c  ≥ 8% was associated with having low (Odds Ratio (OR) 3.17, 95% CI 1.17-8.60, p = .024), and intermediate (OR 3.23, 95% CI 1.27-8.20, p = .014) cognitive performance; this trend was not found for Hb _A1c 7.0-7.9% group. The multinomial regression analysis showed that the presence of Hb _A1c  ≥ 8% (poor glycemic control) was associated with low (OR 3.17, 95% CI = 1.17-8.60, p = .024), and intermediate (OR 3.23, 95% CI = 1.27-8.20, p = .014) cognitive performance. After adjusting for confounding variables.
Conclusions: Glycemic control with a Hb _A1c  ≥ 8% was associated with worse cognitive performance.