Renin angiotensin system gene polymorphisms modify angiotensin-converting enzyme inhibitors' effect on cognitive function: the health, aging and body composition study.

OBJECTIVES

To investigate the effect of polymorphisms in renin angiotensin system genes on the association between angiotensin-converting enzyme inhibitor (ACEI) exposure and global and executive cognitive function in the Health, Aging and Body Composition study.

DESIGN

Cohort study.

SETTING

Community.

PARTICIPANTS

Three thousand seventy-five participants: mean age 73.6, 58% Caucasian, 52% female, 15% taking ACE-Is, 8 years of follow-up.

MEASUREMENTS

The outcomes were longitudinal change in Executive Clock Drawing Test-1 (CLOX1), the Digit Symbol Substitution test, and the Modified Mini-Mental State Examination. The genetic polymorphisms included angiotensin-converting enzyme insertion deletion (ACEID) in the ACE gene and the M235T and 6AG polymorphisms in the angiotensinogen (AGT) gene.

RESULTS

For the CLOX1 outcome, there was significant interaction between 6AG and M235T polymorphisms in the AGT gene and angiotensin-converting enzyme inhibitors (ACE-Is) in Caucasian participants (P=.01 for both polymorphisms) independent of blood pressure levels. Specifically, ACE-I exposure was protective against CLOX1 score decline in carriers of the AA genotype of the 6AG and the CC genotype of the M235T (for the ACE-I vs non-ACE-I groups, P=.01 for 6AG and P=.005 for M235T) but not the other genotypes. These associations were not significant with other cognitive tests, with ACEID, or in African Americans.

CONCLUSION

ACE-Is may provide a protective effect on executive function in Caucasians with AGT gene polymorphisms known to be associated with greater renin angiotensin system activity. If confirmed in a pharmacogenetic trial, ACE-Is may be found to have additional cognitive protection in a select group of elderly individuals.