title: Selenium status and blood lipids: the cardiovascular risk in Young Finns study.
abstract: BACKGROUND
  Concern has been recently raised about possible adverse cardio-metabolic effects of high selenium status, such as increased risks of diabetes and hyperlipidaemia. However, most of the evidence comes from selenium-replete populations such as that of the United States.
  
  
  OBJECTIVE
  To examine cross-sectional and longitudinal associations of serum selenium with cardiovascular risk factors in Finland where selenium levels were amongst the lowest in the world until the early 1980s before the implementation of a nationwide selenium fertilization programme.
  
  
  METHODS
  Serum selenium was measured in 1235 young Finns aged 3-18 years at baseline in 1980 (prefertilization) and in a subgroup (N = 262) at the 6-year follow-up (1986, postfertilization). During the 27-year follow-up, serum lipids, blood pressure, body mass index and smoking were assessed five times (1980, 1983, 1986, 2001 and 2007).
  
  
  RESULTS
  Mean (±SD) serum selenium concentrations were 74.3 ± 14.0 ng mL(-1) in 1980 and 106.6 ± 12.5 ng mL(-1) in 1986 (average increase 32.3 ng mL(-1); 95% CI: 30.3 to 34.3, P < 0.0001). In univariate and multivariable cross-sectional models in 1980 and 1986, increased serum selenium levels were consistently associated with increased total, HDL and Low-density lipoprotein (LDL) cholesterol. However, the average longitudinal changes in lipids were -0.20 mmol L(-1) (95% CI: -0.30 to -0.10, P < 0.0001) for total cholesterol, 0.06 mmol L(-1) (95% CI: 0.03 to 0.10, P < 0.0001) for HDL cholesterol, and -0.23 mmol L(-1) (95% CI: -0.31 to -0.14, P < 0.0001) for LDL cholesterol. Selenium measured in 1986 was not associated with lipids assessed in 2001 and 2007.
  
  
  CONCLUSIONS
  Cross-sectional findings from the Young Finns study corroborate positive associations of selenium status with serum lipids. However, longitudinal evidence does not support the causality of this link.
authors.affiliation: Health Sciences Research Institute, University of Warwick Medical School, Coventry, UK. S.Stranges@warwick.ac.uk
authors.forename: S
authors.initials: S
authors.lastname: Stranges
authors.forename: A G
authors.initials: AG
authors.lastname: Tabák
authors.forename: E
authors.initials: E
authors.lastname: Guallar
authors.forename: M P
authors.initials: MP
authors.lastname: Rayman
authors.forename: T N
authors.initials: TN
authors.lastname: Akbaraly
authors.forename: M
authors.initials: M
authors.lastname: Laclaustra
authors.forename: G
authors.initials: G
authors.lastname: Alfthan
authors.forename: H
authors.initials: H
authors.lastname: Mussalo-Rauhamaa
authors.forename: J S A
authors.initials: JS
authors.lastname: Viikari
authors.forename: O T
authors.initials: OT
authors.lastname: Raitakari
authors.forename: M
authors.initials: M
authors.lastname: Kivimäki
mesh_terms: D000293:Adolescent; D002318:Cardiovascular Diseases / Q000097:blood* / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D008076:Cholesterol, HDL / Q000097:blood*; D008078:Cholesterol, LDL / Q000097:blood*; D003430:Cross-Sectional Studies; D005260:Female; D005387:Finland / Q000453:epidemiology; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D012307:Risk Factors; D012643:Selenium / Q000097:blood*; D014280:Triglycerides / Q000097:blood*
chemical_list: D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D014280:Triglycerides; D012643:Selenium