title: Non-Dipping Pattern and Subclinical Cardiac Damage in Untreated Hypertension: A Systematic Review and Meta-Analysis of Echocardiographic Studies.
abstract: OBJECTIVE
  The association of non-dipping (ND) pattern with cardiac damage is debated. We performed a meta-analysis in order to provide comprehensive information on subclinical cardiac alterations in untreated ND hypertensives.
  
  
  METHODS
  A computerized search was performed using PubMed, OVID, EMBASE, and Cochrane library databases from 1 January 1990 up to 31 October 2014. Full articles published in English language providing data on subclinical cardiac damage in ND as compared to dipper (D) hypertensives, as assessed by echocardiography, were considered.
  
  
  RESULTS
  A total of 3,591 untreated adult subjects (1,291 ND and 2,300 D hypertensives) included in 23 studies were considered. Left ventricular (LV) mass index (LVMI) was higher in ND than in D hypertensives (122±3.8 g/m2 vs. 111±3.3 g/m2, standardized mean difference, SMD: 0.40±0.07, confidence interval (CI): 0.26-0.53, P < 0.001); relative wall thickness (RWT) and left atrium (LA) diameter were greater (SMD: 0.14±0.005, CI: 0.05-0.23, P = 0.002; 0.36±0.10, CI: 0.16-0.56, P < 0.001, respectively), while mitral E/A ratio was lower in ND than in D counterparts (SMD: -0.23±0.08, CI: -0.39 to -0.08, P = 0.003). After assessing data for publication bias, the difference between groups was still significant, with the exception of E/A ratio.
  
  
  CONCLUSIONS
  Our meta-analysis supports an association between ND pattern and increased risk of LV structural alterations in untreated essential hypertensives. This observation supports the view that an effective BP control throughout the entire 24-hour cycle may have a key role in preventing or regressing subclinical cardiac damage associated to ND pattern.
authors.affiliation: Department of Health Science, University of Milano-Bicocca, Milano, Italy; Istituto Auxologico Italiano, Milano, Italy; cesare.cuspidi@unimib.it.
authors.forename: Cesare
authors.initials: C
authors.lastname: Cuspidi
authors.affiliation: Department of Clinical Sciences and Community Health, University of Milano and Fondazione Ospedale Maggiore Policlinico di Milano, Milano, Italy;
authors.forename: Carla
authors.initials: C
authors.lastname: Sala
authors.affiliation: University Clinical Hospital Centre "Dragisa Misovic", Belgrade, Serbia;
authors.forename: Marijana
authors.initials: M
authors.lastname: Tadic
authors.affiliation: Department of Clinical Sciences and Community Health, University of Milano and Fondazione Ospedale Maggiore Policlinico di Milano, Milano, Italy;
authors.forename: Marta
authors.initials: M
authors.lastname: Rescaldani
authors.affiliation: Department of Health Science, University of Milano-Bicocca, Milano, Italy; Istituto di Ricerche a Carattere Scientifico Multimedica, Sesto San Giovanni, Milan, Italy.
authors.forename: Guido
authors.initials: G
authors.lastname: Grassi
authors.affiliation: Istituto Auxologico Italiano, Milano, Italy;
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Mancia
mesh_terms: D001794:Blood Pressure; D004452:Echocardiography; D006801:Humans; D006973:Hypertension / Q000000981:diagnostic imaging* / Q000503:physiopathology*
keywords: blood pressure; essential hypertension; hypertension; non-dipping; subclinical cardiac damage.