Objectives: To study the interplay between serum concentrations of homocysteine, steroid hormones and vitamins B and mutations in 5,10-methylenetetrahydrofolate reductase (MTHFR) gene, in association to Alzheimer's type dementia (ATD).
Design and methods: Case-control study including 19 individuals diagnosed with ATD and 36 healthy controls. Serum concentrations of the analytes were determined and MTHFR 1298A-->C mutation was screened by PCR-RFLP.
Results: Multivariable logistic regression analysis identified homocysteine (OR=1.92, P<0.01), cholesterol (OR=1.14, P<0.001), estradiol (OR=0.728, P<0.001), uric acid (OR=2.42, P<0.02), vitamin B(12) (OR=0.984, P<0.004) and MTHFR 1298A-->C mutation (OR=6.01, P<0.04) as independent predictors of ATD. Positive interaction between homocysteine and uric acid, creatinine, urea or cortisol (P<0.02) and negative interaction between homocysteine and vitamin B(12) or MTHFR 1298A-->C mutation (P<0.03) were observed.
Conclusions: High serum concentrations of homocysteine, cholesterol and uric acid, and low concentrations of estradiol and vitamin B(12), as well as the MTHFR 1298A-->C mutation are simultaneously associated to ATD.