title: The relationship between red blood cell distribution width and blood pressure abnormal dipping in patients with essential hypertension: a cross-sectional study.
abstract: OBJECTIVE
  To investigate whether red blood cell distribution width (RDW) is associated with the blood pressure (BP) reverse-dipper pattern in patients with hypertension.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  Single centre.
  
  
  METHODS
  Patients with essential hypertension were included in our study (n=708). The exclusion criteria included age <18 or >90 years, incomplete clinical data, night workers, diagnosis of secondary hypertension, under antihypertensive treatment, intolerance for the 24 h ambulatory BP monitoring (ABPM) and BP reading success rate <70%.
  
  
  METHODS
  Physical examination and ABPM were performed for all patients in our study. The value of RDW was measured using an automated haematology analyser.
  
  
  METHODS
  The distribution of RDW in patients with hypertension among different circadian BP pattern groups was analyzed using analysis of variance (ANOVA). Multinomial logistic regression was applied to explore the associations of RDW and other relevant variables with ABPM results.
  
  
  RESULTS
  There was significantly increased RDW in reverse dippers (13.52 ± 1.05) than dippers (13.25 ± 0.85) of hypertension (p=0.012). Moreover, multinomial logistic regression analysis showed that RDW (OR 1.325, 95% CI 1.037 to 1.692, p=0.024) and diabetes mellitus (OR 2.286, 95% CI 1.380 to 3.788, p=0.001) were significantly different when comparing the reverse-dipper BP pattern with the dipper pattern. However, there was no difference of RDW between the non-dipper pattern and the reverse-dipper pattern (OR 1.036, 95% CI 0.867 to 1.238, p=0.693). In addition to this, RDW was negatively correlated with the decline rate of nocturnal systolic BP (r=-0.113; p=0.003) and diastolic BP (r=-0.101; p=0.007).
  
  
  CONCLUSIONS
  Our results suggested that RDW might associate with the abnormal dipper BP patterns of either reverse dipping or non-dipping homogeneously examined with 24 h ABPM.
authors.affiliation: Department of Cardiology, The Second Affiliated Hospital, Xi'an Jiaotong University, Xi'an, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Su
authors.affiliation: Department of Cardiology, The Second Affiliated Hospital, Xi'an Jiaotong University, Xi'an, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Guo
authors.affiliation: Department of Emergency Medicine, The Second Affiliated Hospital, Xi'an Jiaotong University, Xi'an, China.
authors.forename: Ya
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Department of Nephrology, The Second Affiliated Hospital, Xi'an Jiaotong University, Xi'an, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Han
authors.affiliation: Department of Emergency Medicine, The Second Affiliated Hospital, Xi'an Jiaotong University, Xi'an, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Yan
authors.affiliation: Department of Emergency Medicine, The Second Affiliated Hospital, Xi'an Jiaotong University, Xi'an, China.
authors.forename: Liyuan
authors.initials: L
authors.lastname: Peng
authors.affiliation: Department of Cardiology, The Second Affiliated Hospital, Xi'an Jiaotong University, Xi'an, China.
authors.forename: Anqi
authors.initials: A
authors.lastname: Song
authors.affiliation: Department of Hematology, The Second Affiliated Hospital, Xi'an Jiaotong University, Xi'an, China.
authors.forename: Fuling
authors.initials: F
authors.lastname: Zhou
authors.affiliation: Department of Emergency Medicine, The Second Affiliated Hospital, Xi'an Jiaotong University, Xi'an, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Wang
mesh_terms: D000704:Analysis of Variance; D001794:Blood Pressure / Q000502:physiology*; D018660:Blood Pressure Monitoring, Ambulatory; D003430:Cross-Sectional Studies; D004912:Erythrocytes / Q000502:physiology*; D000075222:Essential Hypertension; D005260:Female; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D012307:Risk Factors
keywords: blood pressure; red blood cell width