YKL‐40 Level and Hypertension Incidence: A Population‐Based Nested Case‐Control Study in China

BACKGROUND: Human cartilage glycoprotein‐39 (YKL‐40) has been suggested to be a new marker of inflammation, atherosclerosis, and endothelial dysfunction. However, whether a higher level of YKL‐40 is an independent risk factor for hypertension incidence is still unknown. METHODS AND RESULTS: In a nested case‐control study within a prospective cohort of 12 423 initially healthy Chinese adults, we measured baseline plasma concentrations of YKL‐40 among 700 new‐onset hypertension cases and 700 age‐ and sex‐matched controls. Multiple conditional logistic regression analyses were used to calculate the odds ratios (95% CIs) of hypertension associated with higher levels of YKL‐40 both in the total population and in the age‐ (>55 and ≤55 years) and sex‐matched subgroups. Among the total population, YKL‐40 levels were not associated with hypertension risk. In the subgroup older than 55 years, odds ratios (95% CIs) of hypertension for those in the two higher tertiles of YKL‐40 were 1.23 (0.77–1.97) and 1.59 (0.99–2.55) (P for linear trend=0.05). In the male subgroup, odds ratios (95% CIs) of hypertension for those in the two higher tertiles of YKL‐40 were 1.55 (0.88–2.72) and 2.09 (1.14–3.82) (P for linear trend=0.02). An interaction effect was observed between YKL‐40 and sex (P for interaction <0.01) but not between YKL‐40 and age (P for interaction=0.21). High YKL‐40 level significantly increased hypertension risk in men but decreased hypertension risk with a trend although not significant in women. CONCLUSIONS: This study suggests that YKL‐40 is associated with hypertension incidence only among men. The study findings need to be further verified by prospective cohort studies or clinical trials.