Research reportAngiotensin converting enzyme serum activities: Relationship with Alzheimer's disease

- Serum ACE activity may be a potential risk factor for the development of AD.
- A higher ACE activity were at worse a orientation and immediate recall in AD.
- The higher ACE activity was associated with the severity of the development of AD.
- ACE might be used as potential biomarker for the status of moderate-severe AD.
- Moreover, patients with aMCI and AD could take ACEI to retard cognitive decline.

ObjectiveTo determine serum activities of angiotensin-converting enzyme (ACE) as a marker in diagnosis and determine the severity of Alzheimer's disease (AD),MethodsWe measured serum ACE activities in 59 moderate-severe AD, 19 mild AD, 45 amnestic mild cognitive impairment (aMCI) and 39 controls.ResultsWe found that patients in moderate-severe AD stages showed significantly higher ACE in comparison to aMCI and controls (ANOVA, LSD post hoc test: p: 0.02 and p: 0.01, respectively). Logistic regression analysis showed that if ACE activities added 200 U/L, the superiority of AD risk was 1.18 times higher than before compared with the control group (OR 1.18, 95% CI 1.01-1.74; P=0.49). By means of multivariate linear regression analysis, we found that age (β coefficient: 7.77; P: 0.01) was significantly associated with ACE activities. However, ACE activities were found to be significantly negatively associated with measures of orientation and immediate recall among the AD patients (r<0, P<0.05), whereas ACE activities were not associated with any MMSE scores among the non-AD groups (P > 0.05).uuuuConclusionsACE serum activity that correlates with age is likely to constitute a potential risk factor for the development of AD. ACE serum activity might be a useful biomarker for disease status with increasingly high ACE from mild stage to moderate-severe stage. Moreover, patients with aMCI could take ACE inhibitor (ACEI) to decrease the incidence of AD, and patients with AD could take ACEI to retard cognitive decline in early AD.