Angiotensin I converting enzyme and angiotensinogen gene polymorphisms related to 24-h blood pressure in paediatric type I diabetes mellitus

The aim of this study was to evaluate two putative predictive genetic marke rs for hypertension in children and adolescents with diabetes mellitus. Amb ulatory blood pressure measurements were performed in 199 patients with typ e I diabetes mellitus (mean age 16.5 years, mean duration of diabetes 7.7 y ears) and compared to those of 1 141 healthy children. The local allele fre quencies were established based on a control population consisting of 181 h ealthy subjects. The allele frequencies of the angiotensinogen gene M235T polymorphism was n early identical in insulin-dependent diabetes mellitus patients (MM 33%, MT 51%, TT 16%) and controls (MM 35%, MT 49%, TT 16%). In contrast, the genot ype distribution of the angiotensin I converting enzyme gene insertion/dele tion (I/D) polymorphism was different between patients with type I diabetes mellitus (DD 26%, ID 49%, II 25%) and the control group (DD 37%, ID 44%, I I 19%) (P = 0.04). Relative nocturnal systolic and diastolic pressures in p atients with diabetes were higher than in healthy age- and height-matched c ontrols; no association was found with the angiotensinogen gene M235T polym orphism. Relative nocturnal diastolic blood pressure was higher in patients homozygous for the I allele of the angiotensin I converting enzyme gene. Conclusion Nocturnal systolic and diastolic blood pressure is higher in pat ients with type I diabetes than in healthy children. The formerly described , but controversial, association of the M235T polymorphism with arterial hy pertension could not be confirmed in this study.