title: Nonlinear relation between alcohol intake and high-density lipoprotein cholesterol level: results from the Copenhagen City Heart Study.
abstract: BACKGROUND
  It has been suggested that the level of high-density lipoprotein cholesterol (HDL-C) in the blood can be used as a marker of recent alcohol intake. However, before using HDL-C as a predictor of alcoholism, the relation between alcohol intake and HDL-C in the entire range of consumption must be explored. Most studies model the relation between alcohol intake and HDL-C linearly, although a threshold effect is expected. The objective of this study was to evaluate the shape of the relation between intake of alcohol and HDL-C and to determine whether there are differential effects of beer, wine, and spirits on HDL-C and whether they remain after adjusting for total alcohol.
  
  
  METHODS
  The relation between alcohol intake and HDL-C was investigated by means of generalized additive models using data from the Copenhagen City Heart Study.
  
  
  RESULTS
  A nonlinear effect of alcohol improved the model fit significantly, and the nonlinearity of alcohol was highly significant in both men and women. The relation was concave: HDL-C was stable in men and women who drank more than approximately 35 and 20 drinks per week, respectively. We found a significant nonlinear term of wine on HDL-C in men after adjustment for total alcohol intake.
  
  
  CONCLUSIONS
  There was a concave relation between alcohol intake and HDL-C, indicating a threshold effect of alcohol on HDL-C. The association between wine and HDL-C in men after adjusting for total alcohol intake may be due to residual lifestyle confounding.
authors.affiliation: Danish Epidemiologic Science Centre at the Institute of Preventive Medicine, Copenhagen University Hospital, Copenhagen, Denmark. dj@ipm.hosp.dk
authors.forename: Ditte
authors.initials: D
authors.lastname: Johansen
authors.forename: Per K
authors.initials: PK
authors.lastname: Andersen
authors.forename: Majken K
authors.initials: MK
authors.lastname: Jensen
authors.forename: Peter
authors.initials: P
authors.lastname: Schnohr
authors.forename: Morten
authors.initials: M
authors.lastname: Grønbaek
mesh_terms: D000328:Adult; D000428:Alcohol Drinking / Q000097:blood*; D000434:Alcoholic Beverages / Q000706:statistics & numerical data*; D008076:Cholesterol, HDL / Q000097:blood*; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017711:Nonlinear Dynamics; D011159:Population Surveillance; D018709:Statistics, Nonparametric
chemical_list: D008076:Cholesterol, HDL