title: Non-dipping heart rate and microalbuminuria in type 2 diabetes mellitus.
abstract: OBJECTIVE
  The aim of this study was to identify factors which are independently associated with non-dipping heart rate (HR) in a type 2 diabetic population at high risk of cardiovascular disease.
  
  
  METHODS
  The study recruited 179 type 2 diabetic subjects with a mean diabetes duration of 18.3 years and with proliferative retinopathy. All underwent 24-hour blood pressure and HR monitoring, and were assessed for markers of inflammation, insulin resistance, albuminuria, presence of peripheral neuropathy and peripheral vascular disease. Subjects whose night-time HR did not decrease by more than 10% as compared to daytime readings were classified as non-dippers.
  
  
  RESULTS
  Univariate analysis revealed that non-dippers had significantly higher logarithmic albumin-creatinine ratio (ACR; p = 0.001) and higher platelet count (p = 0.014). Also, non-dippers were more likely to be on β-blockers (p = 0.037). Binary logistic regression analysis showed that logarithmic ACR (p = 0.001) and platelet count (p = 0.026) were independent predictors of non-dipping HR, even when correcting for β-blocker use.
  
  
  CONCLUSIONS
  In this high-risk type 2 diabetic population, non-dipping HR was independently associated with ACR and platelet count, suggesting that non-dipping HR might give an indication of underlying generalised atherosclerosis in diabetic patients. Also, non-dipping HR may represent a novel mechanism explaining the association of nephropathy with cardiovascular events. This merits further study.
authors: Department of Cardiac Services, Mater Dei Hospital, Msida, Malta.
authors: Caroline J
authors: CJ
authors: Magri
authors: Robert G
authors: RG
authors: Xuereb
authors: Stephen
authors: S
authors: Fava
mesh_terms: D000368:Aged; D000419:Albuminuria / Q000150:complications / Q000378:metabolism* / Q000503:physiopathology; D000704:Analysis of Variance; D002940:Circadian Rhythm / Q000502:physiology*; D003404:Creatinine / Q000378:metabolism; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000378:metabolism / Q000503:physiopathology*; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010976:Platelet Count; D012307:Risk Factors
chemical_list: D003404:Creatinine