title: Statin adherence and the risk of Parkinson's disease: A population-based cohort study.
abstract: BACKGROUND
  While experimental data provided some compelling evidence on the benefits of statins on dopaminergic neurons, observational studies reported conflicting results regarding the potential of statins to effect the risk of Parkinson's disease (PD).
  
  
  OBJECTIVE
  To evaluate the association between changes in statin adherence over time and PD risk.
  
  
  METHODS
  A population-based cohort of new statin users (ages 40-79, years 1999-2012) was derived from a large Israeli healthcare services organization. Data included history of statin purchases and low density lipoprotein cholesterol (LDL-C) levels. Personal statin adherence was measured annually by the proportion of days covered (PDC). PD was detected employing a drug-tracer approach. Stratified (by sex, LDL-C levels at baseline and age) Cox proportional hazards models with time-dependent covariates were used to compute adjusted Hazard Ratio (HR) with 95%CI.
  
  
  RESULTS
  The cohort included 232,877 individuals, 49.3% men. Mean age at first statin purchase was 56.5 (±9.8) years for men and 58.7 (±9.2) years for women. PDC distribution for the whole follow up period differed between men and women: medians 58.3% and 54.1% respectively. During a mean follow up of 7.6 (±3.4) years, 2,550 (1.1%) PD cases were identified. In a 1-year lagged analysis, we found no association between annual statin adherence and PD risk in all age-groups regardless of statin type and potency. Age-pooled HR (95%CI) for men and women with LDL-C levels at baseline ≤160mg/dL were: 0.99 (0.99-1.01), 1.01 (1.00-1.02); and for men and women with LDL-C >160mg/dL levels: 0.99 (0.98-1.01), 0.97 (0.98-1.01).
  
  
  CONCLUSIONS
  Our findings suggest that statin adherence over time does not affect PD risk. Future studies should use large-scale cohorts and refining assessments of long-term profiles in statin adherence.
authors.affiliation: Department of Epidemiology, School of Public Health, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Violetta
authors.initials: V
authors.lastname: Rozani
authors.affiliation: Neurological Institute, Tel Aviv Medical Center, Tel Aviv, Israel.|Sagol School of Neuroscience, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Nir
authors.initials: N
authors.lastname: Giladi
authors.affiliation: Maccabi Healthcare Services, Tel Aviv, Israel.
authors.forename: Baruch
authors.initials: B
authors.lastname: El-Ad
authors.affiliation: Neurological Institute, Tel Aviv Medical Center, Tel Aviv, Israel.|Sagol School of Neuroscience, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Tanya
authors.initials: T
authors.lastname: Gurevich
authors.affiliation: Maccabi Healthcare Services, Tel Aviv, Israel.
authors.forename: Judith
authors.initials: J
authors.lastname: Tsamir
authors.affiliation: Maccabi Healthcare Services, Tel Aviv, Israel.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Hemo
authors.affiliation: Department of Epidemiology, School of Public Health, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Chava
authors.initials: C
authors.lastname: Peretz
mesh_terms: D000328:Adult; D000368:Aged; D000924:Anticholesteremic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D008078:Cholesterol, LDL / Q000097:blood; D015331:Cohort Studies; D005260:Female; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000009:adverse effects / Q000627:therapeutic use*; D015994:Incidence; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000453:epidemiology*; D010349:Patient Compliance; D012307:Risk Factors
chemical_list: D000924:Anticholesteremic Agents; D008078:Cholesterol, LDL; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors