title: The effects of napping on the risk of hypertension: a systematic review and meta-analysis.
abstract: OBJECTIVE
  The risk of hypertension in adults who regularly take a nap is controversial. The objective of this meta-analysis was to assess the associations between napping and hypertension.
  
  
  METHODS
  A literature search was performed using MEDLINE, EMbase and The Cochrane Database of Systematic Reviews from inception through October, 2015. Studies that reported relative risks, odd ratios or hazard ratios comparing the risk of hypertension in individuals who regularly take nap were included. Pooled risk ratios (RR) and 95% confidence interval (CI) were calculated using a random-effect, generic inverse variance method.
  
  
  RESULTS
  Nine observational studies with 112,267 individuals were included in the analysis to assess the risk of hypertension in nappers. The pooled RR of hypertension in nappers was 1.13 with 95% CI (0.98 to 1.30). When meta-analysis was limited only to studies assessing the risk of hypertension in daytime nappers, the pooled RR of hypertension was 1.19 with 95% CI (1.06 to 1.35). The data on association between nighttime napping in individuals who work night shift and hypertension were limited, only one observational study reported reduced risk of hypertension in nighttime nappers with odds ratio of 0.79 with 95% CI (0.63 to 1.00).
  
  
  CONCLUSIONS
  Our meta-analysis demonstrates a significant association between daytime napping and hypertension. Future study is needed to assess the potential benefits of HTN screening for daytime nappers.
authors.affiliation: Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA.
authors.forename: Wisit
authors.initials: W
authors.lastname: Cheungpasitporn
authors.affiliation: Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA.
authors.forename: Charat
authors.initials: C
authors.lastname: Thongprayoon
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: Narat
authors.initials: N
authors.lastname: Srivali
authors.affiliation: Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: Priya
authors.initials: P
authors.lastname: Vijayvargiya
authors.affiliation: Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: Carl A
authors.initials: CA
authors.lastname: Andersen
authors.affiliation: Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA.
authors.forename: Wonngarm
authors.initials: W
authors.lastname: Kittanamongkolchai
authors.affiliation: Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA.
authors.forename: Insara J Jaffer
authors.initials: IJ
authors.lastname: Sathick
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: Sean M
authors.initials: SM
authors.lastname: Caples
authors.affiliation: Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA.
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Erickson
mesh_terms: D006801:Humans; D006973:Hypertension / Q000209:etiology*; D017594:Publication Bias; D012306:Risk; D012890:Sleep; D013997:Time Factors
keywords: Blood pressure; hypertension; meta-analysis; nap; sleep