Hypertension influences recurrent stone formation in nonobese stone formers

Objectives: To assess the influence of hypertension on urinary metabolites as well as recurrent stone formation. Recent studies have suggested that urolithiasis and hypertension are positively associated. However, the relationship between hypertension and lithogenic metabolites is inconsistent and requires further elucidation.

Methods: Based on the presence of hypertension, stone formers (SF) were classified into 2 groups, hypertensive SF (n = 121, 53.1%) and normotensive SF (n = 107, 46.9%), and differences in urinary metabolites between the groups were compared. Eighty-six patients (37.7%) who were followed for more than 36 months (median, 60.5 months; range, 7-170 months) were included in recurrence analyses. To exclude the influence of obesity on recurrent stone formation, recurrence analyses were performed with body mass index (BMI)-based stratification.

Results: Hypertensive SF had higher BMI than normotensive SF, and hypocitraturia and hyperoxaluria were more frequently observed in hypertensive SF (P <.05). In the nonobese group, hypertensive SF had a decreased time to stone recurrence (log-rank test, P = .025), whereas time to recurrence was not affected by hypertensive status in the obese group (log-rank test, P = .788). Multivariate Cox regression analysis of nonobese SF revealed that hypertension was significantly associated with stone recurrence (HR, 3.717%; 95% CI, 1.224-13.890; P = .024).

Conclusions: Hypertension is associated with hypocitraturia and hyperoxaluria. Furthermore, hypertension is an independent predictive determinant for recurrent stone formation, especially in nonobese SF.