The relationship between calcium kidney stones, arterial stiffness and bone density: unraveling the stone-bone-vessel liaison

Kidney stone disease is associated with a higher incidence of cardio-vascular (CV) events for still unclear reasons. Reduced bone density is also a frequent finding in calcium kidney stones. The association of reduced bone density with increased vascular stiffness and calcification has been discovered in a number of conditions. We investigated the hypothesis that patients with calcium kidney stones have increased arterial stiffness, which would be associated with reduced bone density and higher CV risk. We compared measures of arterial stiffness [carotid-radial pulse-wave velocity (CR-PWV), carotid-femoral pulse-wave velocity (CF-PWV) and augmentation index (AI)] and of bone density (T-scores determined at lumbar spine, neck and hip) among 42 idiopathic calcium stone formers compared with 42 age- and sex-matched healthy volunteers. Stone formers had higher values of CR-PWV, CF-PWV and AI, and lower values of all T-scores. Furthermore, the prevalence of abnormal arterial stiffness and reduced bone density was significantly higher among stone formers. Statistical adjustment for age, sex, body mass index and other covariates did not change the results. Our study confirms that stone formers have increased arterial stiffness and reduced bone density. Abnormal arterial stiffness appears to be independent of reduced bone density and may explain the higher CV risk observed in stone formers.