title: Relation of cumulative low-level lead exposure to depressive and phobic anxiety symptom scores in middle-age and elderly women.
abstract: BACKGROUND
  Different lines of evidence suggest that low-level lead exposure could be a modifiable risk factor for adverse psychological symptoms, but little work has explored this relation.
  
  
  OBJECTIVE
  We assessed whether bone lead--a biomarker of cumulative lead exposure--is associated with depression and anxiety symptoms among middle-age and elderly women.
  
  
  METHODS
  Participants were 617 Nurses' Health Study participants with K-shell X-ray fluorescence bone lead measures and who had completed at last one Mental Health Index 5-item scale (MHI-5) and the phobic anxiety scale of the Crown-Crisp Index (CCI) assessment at mean ± SD age of 59 ± 9 years (range, 41-83 years). With exposure expressed as tertiles of bone lead, we analyzed MHI-5 scores as a continuous variable using linear regression and estimated the odds ratio (OR) of a CCI score ≥ 4 using generalized estimating equations.
  
  
  RESULTS
  There were no significant associations between lead and either outcome in the full sample, but associations were found among premenopausal women and women who consistently took hormone replacement therapy (HRT) between menopause and bone lead measurement (n = 142). Compared with women in the lowest tertile of tibia lead, those in the highest scored 7.78 points worse [95% confidence interval (CI): -11.73, -3.83] on the MHI-5 (p-trend = 0.0001). The corresponding OR for CCI ≥ 4 was 2.79 (95% CI: 1.02, 7.59; p-trend = 0.05). No consistent associations were found with patella lead.
  
  
  CONCLUSIONS
  These results provide support for an association of low-level cumulative lead exposure with increased depressive and phobic anxiety symptoms among older women who are premenopausal or who consistently take postmenopausal HRT.
authors.affiliation: Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts 02215, USA.
authors.forename: Ki-Do
authors.initials: KD
authors.lastname: Eum
authors.forename: Susan A
authors.initials: SA
authors.lastname: Korrick
authors.forename: Jennifer
authors.initials: J
authors.lastname: Weuve
authors.forename: Olivia
authors.initials: O
authors.lastname: Okereke
authors.forename: Laura D
authors.initials: LD
authors.lastname: Kubzansky
authors.forename: Howard
authors.initials: H
authors.lastname: Hu
authors.forename: Marc G
authors.initials: MG
authors.lastname: Weisskopf
mesh_terms: D000367:Age Factors; D001842:Bone and Bones / Q000737:chemistry; D003863:Depression / Q000139:chemically induced / Q000453:epidemiology*; D004781:Environmental Exposure / Q000706:statistics & numerical data*; D015914:Estrogen Replacement Therapy / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D007854:Lead / Q000633:toxicity*; D016014:Linear Models; D008593:Menopause / Q000523:psychology; D016017:Odds Ratio; D010698:Phobic Disorders / Q000139:chemically induced / Q000453:epidemiology*; D012307:Risk Factors; D013052:Spectrometry, X-Ray Emission; D014481:United States / Q000453:epidemiology
chemical_list: D007854:Lead