ACE gene insertion/deletion polymorphism associated with 1998 World Health Organization definition of metabolic syndrome in Chinese type 2 diabetic patients

OBJECTIVE: Because ACE insertion/deletion (I/D) polymorphism has been shown to be associated with diabetes, hypertension, coronary artery diseases, and diabetic nephropathy, and because plasma ACE concentration has been found to be associated with plasma triglyceride and total cholesterol levels in patients with type 2 diabetes, the goal of this study was to investigate whether ACE gene I/D polymorphism is associated with metabolic syndrome in Chinese subjects with type 2 diabetes. RESEARCH DESIGN AND METHODS: A total of 711 patients with type 2 diabetes and 750 control subjects were studied. The ACE I/D polymorphism was determined by PCR. The definition and criteria of metabolic syndrome used in this study matched those proposed in the 1998 World Health Organization classification. RESULTS: Of 711 patients with type 2 diabetes, 534 (75.1%) fulfilled the criteria for metabolic syndrome. The prevalence of metabolic syndrome in control subjects with II, ID, and DD genotype was 9.4, 11.5, and 15.4%, respectively, and in patients with type 2 diabetes, it was 68.6, 79.2, and 86.1%, respectively. The ACE I/D polymorphism was significantly associated with the syndrome in patients with type 2 diabetes (P = 0.001). When pooling the control subjects with diabetic patients, the prevalence of metabolic syndrome in the whole study group with II, ID, and DD genotype was 37.9, 44.5, and 51.0%, respectively, and ACE I/D polymorphism was still significantly associated with metabolic syndrome (P = 0.003). Diabetic patients with DD genotype were also found to have a higher prevalence of dyslipidemia (II/ID/DD = 43.1/53.1/65.8%, P < 0.001) and albuminuria (36.0/44.6/50.6%, P = 0.018) and to have higher serum triglyceride levels (II, ID, and DD = 155 +/- 114, 170 +/- 140, and 199 +/- 132 mg/dl, respectively, P < 0.05). Control subjects with DD genotype were also found to have a higher prevalence of albuminuria or more advanced nephropathy (II/ID/DD = 5.7/14.0/15.4%, P = 0.001), whereas the prevalence of dyslipidemia was not found to be statistically different in the control group. When pooling control with diabetic subjects, ACE genotype could still be significantly associated with dyslipidemia (II/ID/DD = 34.7/41.3/52.2%, P < 0.001) and albuminuria or more advanced nephropathy (20.3/28.9/33.1%, P < 0.001). Diabetic patients with metabolic syndrome were found to have higher serum uric acid levels than those without metabolic syndrome (6.4 +/- 1.8 vs. 5.3 +/- 1.4 mg/dl, P < 0.01). CONCLUSIONS: The ACE I/D polymorphism was found to be associated with metabolic syndrome in Chinese patients with type 2 diabetes. This finding may provide genetic evidence to explain the clustering of metabolic syndrome and suggests that the renin-angiotensin system is involved in the pathophysiology of metabolic derangement in patients with type 2 diabetes.