Severe Abdominal Aortic Calcification in Older Men Is Negatively Associated With DKK1 Serum Levels: The STRAMBO Study

Abstract

Experimental data show that dickkopf-1 (DKK1) may be involved in the regulation of arterial calcification. However, clinical data on the association between serum DKK1 levels and severity of abdominal aortic calcification (AAC) are scarce. Our aim was to determine the association between serum DKK1 concentration and AAC severity in men. This is a cross-sectional analysis in the STRAMBO cohort. The cohort was recruited from the general population. We examined 1139 male volunteers aged 20 to 87 years. No specific exclusion criteria were used. We collected blood samples and assessed AAC severity on the lateral spine scans obtained by a Discovery A Hologic device using the semiquantitative Kauppila score. We tested the hypothesis that low DKK1 levels are associated with AAC severity in men. In men aged 20 to 60 years, serum DKK1 levels were not associated with other variables. In men aged 60 years and older, lower DKK1 levels were associated with higher odds of severe AAC (AAC score >5). After adjustment for confounders, odds of severe AAC increased with decreasing DKK1 levels (odds ratio = 1.42, 95% confidence interval = 1.13-1.79, P < .005) and was higher below vs above the median DKK1 level (odds ratio = 2.19, 95% confidence interval = 1.37-3.49, P < .005). Heavy smoking, hypertension, ischemic heart disease, and elevated levels of fibroblast growth factor 23 were associated with severe AAC significantly, independently of DKK1 and additively with low DKK1 levels. In older men, lower serum DKK1 levels are associated with severe AAC regardless of age and other potential confounders.