Association between polymorphism c.1-765G>C of the COX2 gene and cognitive impairment in individuals 65 years or more with diabetes from a Geriatric Service in Monterrey, Mexico.

BACKGROUND AND OBJECTIVE: Cognitive impairment and dementia are common geriatric syndromes in diabetic patients. Inflammation plays a crucial role in the pathophysiology of Alzheimer's disease and cognitive impairment. Cyclooxygenases (COX) 1 and 2 participate in inflammation. The polymorphism c.1-765G>C of the COX2 gene might be protective against cognitive decline in Mexicans with diabetes mellitus through its reduced promotor activity. To determine the association between polymorphism c.1-765G>C of the COX2 gene and cognitive impairment in elderly adults with diabetes.

PATIENTS AND METHODS: Case-control study. We included diabetic patients from the Geriatric Clinic of General Hospital No. 17 who were over 65 years and accepted to participate. Cases were patients with a score of 24 or less on the Mini Mental Status Examination (MMSE) and with DSM IV criteria for dementia. Controls were those with MMSE scores of 25 or greater. Results We included 97 patients (50 cases and 47 controls). There were no differences regarding clinical and laboratory characteristics between cases and controls. The frequency of the C allele and the CG genotype was higher in controls than in cases and this difference remained significant in a multivariate analysis with an odds ratio of 0.012 (95% CI 0.001-0.091) and 0.009 (95% CI 0.001-0.076) in the bivariate and multivariate analysis, respectively, using the GG genotype frequency as a reference.

CONCLUSION: Cognitive impairment in Mexican patients with diabetes is associated with less exposure to the CG genotype of the c.1-765G>C polymorphism of COX2.