There is growing evidence of a relationship between kidney stones and cardiovascular risk. The precise pathophysiological basis for this association is, at present, unknown, but some evidence exists that patients with kidney stones might have abnormalities in vessel wall as suggested by increased carotid intima-media thickness and pulse-wave velocity in these patients. The relationship between kidney stones and endothelial function has never been investigated.
We retrospectively investigated the presence of a history of kidney stones in a cohort of patients with peripheral vascular disease who underwent the study of endothelial function (flow-mediated dilation [FMD] of the brachial artery). Information on history of kidney stones was collected with a standardized questionnaire administered by phone. Patients with a diagnosis of kidney stones were individually matched on age (±5 years), sex and estimated glomerular filtration rate (eGFR, ±5 mL/min/1.73 m2) with patients without history of kidney stones and the percent changes in FMD in the two groups were compared.
Out of 149 patients constituting the original sample, 21 (14%) had a history of kidney stones. Of these, 3 lacked data on eGFR and were excluded. The individual matching yielded an homogeneous distribution of average age (68±8 vs 69±9 years, p = 0.92), proportion of males (39% in both groups, p > 0.99) and average eGFR (79±17 in both groups, p = 0.95). The average values of FMD percent change for patients with and without a history of stones were 5.9±3.4 and 8.1±5.2, respectively, and the difference was statistically significant (p = 0.02). Further adjustment for other covariates did not change the finding.
In a cohort of patients with peripheral vascular disease, a history of kidney stones was associated with reduced values of FMD percent change, suggesting that endothelial function might be impaired in these patients.
