Association of angiotensin-converting enzyme DD genotype with blood pressure sensitivity to weight loss

The angiotensin-converting enzyme insertion/deletion polymorphism rs4340 associates with habitual physical activity among European American adults

BACKGROUND

The angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism (rs4340) (ACE DIP) accounts for half of the variability in plasma ACE concentrations. ACE has been widely studied for its influence on sports performance; however, research on its influence in physical activity is limited and inconsistent. We examined the influence of the ACE DIP on physical activity among 461 European Americans.

METHODS

Subjects completed the Paffenbarger Physical Activity Questionnaire for weekly walking distance. Multivariate analysis of covariance (MANCOVA) tested log-transformed differences in weekly walking distance among ACE DIP genotypes (II, ID, DD) with gender as a fixed factor, and age and body mass index (BMI) as covariates. Because we found a significant ACE DIPxBMI interaction (P = 0.03), we categorized the sample by normal weight (NW: BMI<25.0 kg/m²) and overweight (OW: BMI ≥25.0 kg/m²) and repeated the MANCOVA with multiple comparison adjustments.

RESULTS

NW adults with ACE II walked 15.8 ± 11.1 km/week, ID 13.2 ± 10.6 km/week, and DD 17.9 ± 13.0 km/week, with ID walking less than II (P = 0.03) and DD (P = 0.01). OW adults with ACE II walked 16.7 ± 12.6 km/week, ID 13.8 ± 11.6 km/week, and DD 9.7 ± 9.0 km/week, with DD walking less than II (P = 0.02). Weekly walking distance was 8.2 ± 2.4 km/week less among OW adults with ACE DD than NW (P = 0.02).

CONCLUSION

BMI interacted with ACE DD such that OW walked ~8.2 km/week less than NW, potentially equating to a body weight differential of ~3.5 kg annually.

Relationships between selected gene polymorphisms and blood pressure sensitivity to weight loss in elderly persons with hypertension

Salt sensitivity, the heterogeneity in the response of blood pressure (BP) to alterations in sodium intake, has been studied extensively, whereas weight sensitivity, the heterogeneity in BP response to weight change, has received scant attention. We examined the relationship of 21 gene polymorphisms previously found to be associated with hypertension, diabetes mellitus, or obesity, with weight sensitivity in the Trial of Nonpharmacologic Interventions in the Elderly, where participants with hypertension were randomized to receive intensive dietary intervention of sodium reduction, weight loss, both, or attention control, whereas pharmacological therapy was kept constant. After correcting for multiplicity, we identified significant associations of 3 polymorphisms with weight sensitivity of systolic BP (rs4646994, rs2820037, and rs1800629) and 3 polymorphisms for diastolic BP (rs4646994, rs2820037, and rs5744292). A recursive partitioning algorithm selected the combination of rs4646994, rs1800629, rs1982073, and rs1800896 as the set associated with the highest weight sensitivity. Polymorphisms related to hypertension, obesity, and diabetes mellitus are associated with weight sensitivity of BP.