Characteristics of the study population at baseline grouped according to quartiles of serum YKL-40.

*Smoking was defined as persons smoking one or more cigarettes/cigars/pipes a day; all others were classified as non-smokers.
Values are presented as.
†mean (SD),
‡median (IQR) or N (% within quartile) where not specified.
Abbreviations not mentioned in main text: BP, blood pressure; HOMA-IR, homeostasis model assessment of insulin resistance.