Circadian blood pressure variation in normotensive type 2 diabetes patients and angiotensin converting enzyme polymorphism

Background/aims: Loss of circadian blood pressure (BP) variation (i.e., lack of nocturnal BP dip by at least 10 mmHg, 'non-dipping') is associated with increased mortality rate in subjects with diabetes. We studied whether angiotensin converting enzyme (ACE) insertion/deletion (VD) gene polymorphism may play a role in 24-h BP rhythm control. Methods: The study group was 38 normotensive normoalbuminuric type 2 diabetes patients with impaired BP variation, the controls were 51 well-matched type 2 diabetes subjects with normal 24-h BP rhythm. ACE I/D polymorphism, endothelial function and subclinical inflammation parameters (serum endothelin-1, sE-selectin, intercellular and vascular cell adhesion molecules, tumor necrosis factor-alpha.) were assessed. Results: ACE DD genotype was found in 20 (53%), ID genotype in 16 (42%), and II genotype in 2 (5%) study group subjects, while 5 (10%) control subjects had DD genotype, 30 (59%) - ID genotype, and 16 (31%) - II genotype (p < 0.0001). Study group subjects presented with marked endothelial dysfunction. Conclusion: impaired circadian blood pressure variation in normotensive normoalbuminuric type 2 diabetes patients is associated with ACE DD genotype and marked endothelial dysfunction when compared to diabetic subjects with normal blood pressure rhythm. (c) 2008 Elsevier Ireland Ltd. All rights reserved.