Angiotensin-converting enzyme insertion/deletion polymorphism and the longitudinal progression of Alzheimer's disease

Aim: The angiotensin-converting enzyme gene (ACE) insertion (0/deletion (D) polymorphism is considered a biologically plausible gene for Alzheimer's disease (AD) in cross-sectional studies. The present study aimed to investigate the longitudinal effect of ACE UD polymorphism on AD progression. Methods: This 3-year observational study investigated the longitudinal effect of ACE UD polymorphism on AD progression. Clinically diagnosed AD patients with a clinical dementia rating (CDR) of 0.5 or 1 were enrolled in the study. The Mini-Mental State Examination (MMSE), Cognitive Assessment Screening Instrument (CAS]) and the CDR scale were carried out for all patients on the date of the initial interview and 36 6 months after the initial evaluation. Results: A total of 177 patients with sporadic AD were enrolled in this study. Among all patients, those with the UI genotype showed a higher risk of CDR deterioration (UI versus I/D + D/D: adjusted OR 2.103, 95% CI 1.113-3.972; adjusted P = 0.022). Among 74 AD patients without hypertension, those with the 1/1 genotype showed significantly greater differences in the MMSE, CASI and the CDR-sum of box scores, and a higher risk of CDR deterioration (UI versus UD + D/D: adjusted OR 3.255, 95% CI 1..099-9.639; adjusted P = 0.033) after adjustment for possible confounders during the 3-year follow up. Conclusions: Patients with AD who were homozygous for the I allele presented with a more rapid AD deterioration than did those who had other ACE genotypes, particularly those patients without hypertension.