Lack of association of angiotensin-converting enzyme (DID/II) and angiotensinogen M235T gene polymorphism with renal function among Chinese patients with type II diabetes

The prevalence of diabetic nephropathy is greater in nonwhite patients with type II diabetes, including the Chinese, and genetic variation appears to have a role. We examined angiotensin-converting enzyme (ACE) DD/II and angi otensinogen (Atg) M235T polymorphism in a cohort of Chinese patients with t ype II diabetes with an average duration of diabetes of 14 years. Group A ( n = 88) did not have significant diabetic nephropathy (creatinine levels le ss than or equal to 130 mu mol/L [less than or equal to 1.48 mg/L], without macroalbuminuria), and group B (n = 80) had significant diabetic nephropat hy (macroalbuminuria or creatinine level > 130 mu mol/L [> 1.48 mg/d], and those undergoing dialysis). The two groups were matched in different aspect s, including age, duration of diabetes, blood pressure, and glycemic contro l. The results showed: (1) no difference of genotype distribution between g roups A and B (DD:DI:II, 14%:45%:41% v 8%:38%:54%; P = 0.20; TT:TM/MM, 70%: 30% v 76%:24%; P = 0.43), (2) no evidence of synergistic effect of ACE (DD/ II) and Atg M235T gene polymorphisms, (3) no difference of allele frequenci es between groups A and B (D:I, 36%:64% v 27%:73%; P = 0.20 and I:RA, 86%:1 6% v 86%:14%; P = 0.73), and (4) ACE activity was greatest in patients with DD genotype and least in those with II genotype (DD:DI:II = 66.9 +/- 13.3 U/L:61.5 +/- 19.9 U/L:45.0 +/- 17.0 U/L; P < 0.005). The data do not suppor t a role of ACE (DD/II) or Atg M235T polymorphism in the development of dia betic nephropathy in Chinese patients with type II diabetes, and no synergi stic effect was found between them. Greater ACE activity was associated wit h DD genotype, and its role in diabetic nephropathy remains to be elucidate d. (C) 1999 by the National Kidney Foundation, Inc.