Genetic polymorphisms of the renin-angiotensin system and obesity-related metabolic changes in response to low-energy diets in obese women.

OBJECTIVE

Genetic polymorphisms of the renin-angiotensin system have been implicated in cardiovascular and metabolic diseases. The purpose of this study was to investigate whether the insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) gene and 3123C/A polymorphism of the angiotensin II type 2 receptor (AT(2)R) gene affect blood pressure and other obesity-related metabolic changes in response to low-energy diets using meal replacement shakes for weight loss.

METHODS

Clinical, metabolic, and biochemical profiles were measured before and after a 2-mo intervention in 32 obese women (age 49.9 ± 8.4 [SD] y; BMI 28.4 ± 3.3 kg/m²) restricted to 1200 kcal/d (5021 kJ/d). The polymorphisms were determined with an intercalater-mediated FRET probe assay system.

RESULTS

Although weight loss and nutrient intake levels did not differ among the genotypes, the reduction in body fat after weight loss was significantly less in the ACE deletion/deletion (D/D) genotype than insertion/insertion (I/I) plus I/D genotype (-2.25 ± 1.40% versus -0.80 ± 1.57%, P < 0.05). The AT₂R A/A group had significantly less improved levels of systolic blood pressure (-7.23 ± 8.50 versus 2.50 ± 12.6 mmHg, P < 0.05), low-density lipoprotein-cholesterol (-0.36 ± 0.29 versus -0.09 ± 0.25 mmol/L, P < 0.05), carbohydrate (-54.4 ± 27.2 versus -31.8 ± 16.3 mg/min, P < 0.05) and fat oxidation (8.31 ± 11.86 versus 0.05 ± 9.99 mg/min, P < 0.05) than the C/C plus C/A genotypes.

CONCLUSION

The present findings suggest that the homozygous form of the ACE gene may hinder the improvement of body fat and that the homozygous form of the AT₂R gene may make improving systolic blood pressure and some obesity-related metabolic parameters through a dietary intervention difficult among obese women.