title: Withdrawal of statins and risk of subarachnoid hemorrhage.
abstract: OBJECTIVE
  Vascular endothelium, which can be affected by statins, is believed to play a substantial role in subarachnoid hemorrhage (SAH). Our objective was to estimate the association between use and withdrawal of statins and the risk of SAH.
  
  
  METHODS
  We conducted a population-based case-control study within the PHARMO database. A case was defined as a person hospitalized for SAH (ICD-9-CM code 430) in the period January 1, 1998 to December 31, 2006. Ten randomly chosen controls were matched to each case on age, gender, and calendar date.
  
  
  RESULTS
  During the study period 1004 incident cases of SAH were identified. Current use of statins did not significantly decrease the risk of SAH (OR=0.77, 95% CI 0.55 to 1.07). The odds ratio for recent withdrawal compared to nonusers was 1.62 (95% CI 0.96 to 2.73). Compared to current use, recent withdrawal was associated with an increased risk of SAH (OR=2.34, 95% CI 1.35 to 4.05). Interaction analysis showed that the effect of statin withdrawal was highest in patients who had also recently stopped antihypertensive drugs (OR=6.77, 95% CI 2.10 to 21.8).
  
  
  CONCLUSIONS
  Current use of statins seems to lower the risk of SAH, although the reduction was not significant in new users. Statin withdrawal increased the risk of SAH by a factor 2, even more in patients who had also recently stopped their antihypertensive treatment.
authors.affiliation: Department of Medical Informatics, Erasmus MC, room Ee 2159, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands. r.risselada@erasmusmc.nl
authors.forename: Roelof
authors.initials: R
authors.lastname: Risselada
authors.forename: Huub
authors.initials: H
authors.lastname: Straatman
authors.forename: Fop
authors.initials: F
authors.lastname: van Kooten
authors.forename: Diederik W J
authors.initials: DW
authors.lastname: Dippel
authors.forename: Aad
authors.initials: A
authors.lastname: van der Lugt
authors.forename: Wiro J
authors.initials: WJ
authors.lastname: Niessen
authors.forename: Azadeh
authors.initials: A
authors.lastname: Firouzian
authors.forename: Ron M C
authors.initials: RM
authors.lastname: Herings
authors.forename: Miriam C J M
authors.initials: MC
authors.lastname: Sturkenboom
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D013345:Subarachnoid Hemorrhage / Q000139:chemically induced* / Q000175:diagnosis / Q000453:epidemiology; D013375:Substance Withdrawal Syndrome / Q000175:diagnosis / Q000453:epidemiology
chemical_list: D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors