The Angiotensin Converting Enzyme Insertion/Deletion Polymorphism Associates with Habitual Physical Activity among European-American Adults

Abstract

PURPOSE: The angiotensin converting enzyme (ACE) insertion (I) deletion (D) polymorphism (ACE DIP) (rs4340) is a 287 base pair sequence within intron 16 of chromosome 17q23 that accounts for half of the variation in plasma ACE levels. Due to its influence on cardiovascular and renal function, the ACE DIP has been examined for its association with sport performance. The literature regarding associations with habitual physical activity is limited and inconsistent. We examined associations of the ACE DIP and physical activity among 461 European-American adults. METHODS: 203 men and 258 women with a body mass index (BMI) of 24.3±4.8 kg·m2 completed the Paffenbarger Physical Activity Questionnaire to determine weekly walking distance. ACE II (n=119), ID (n=213), and DD (n=129) genotypes were determined using TaqMan allele discrimination assays. Multivariate analysis of covariance (MANCOVA) determined logtransformed differences among ACE DIP genotypes and weekly walking distance with gender as a fixed factor and age and BMI as covariates. Because a significant ACE DIPxBMI interaction was found (p=0.03), we categorized the sample into normal weight (NW:BMI≤24.9 kg·m2) and overweight (OW:BMI>24.9 kg·m2). We repeated the MANCOVA with gender and BMI groups as fixed factors and age as a covariate. Bonferroni corrections were used to control for multiple comparison testing with alpha levels at p<.05. RESULTS: For NW (BMI=21.7±1.8 kg·m2), participants with the ACE II reported walking 1.4±1.0 mi/wk, ID 1.2±0.9 mi/wk, and DD 1.6±1.2 mi/wk, with ID walking less than II and DD (p<0.05). For OW (BMI=29.6±4.4 kg·m2), participants with the ACE II reported walking 1.5±1.1 mi/wk, ID 1.2±1.0 mi/wk, and DD 0.6±0.8 mi/wk, with DD walking less than II (p=0.02). For NW vs OW, weekly walking distance was 1.0±2.2 mi/wk less among OW with the ACE DD genotype than NW with this genotype (p=0.02); there were no other genotype-physical activity differences within or between NW and OW (p>0.05). CONCLUSIONS: BMI interacted with ACE DD to modulate habitual physical activity levels such that weekly walking distance was ~1.0 mi/wk greater among NW than OW with ACE DD. Our findings may provide insight into the discrepancies of this literature, and have public health significance equating to a body weight differential of ~1.4 lb/yr.