Dietary and Lifestyle Risk Factors Associated with Incident Kidney Stones in Men and Women

Abstract

Purpose

Several dietary and lifestyle factors are associated with a higher risk of developing kidney stones. We estimated the population attributable fraction (PAF) and number needed to prevent (NNTP) for modifiable risk factors including body mass index (BMI), fluid intake, DASH-style diet, dietary calcium intake and intake of sugar-sweetened beverages.

Materials and methods

We used data from the Health Professionals Follow-up Study (HPFS) and the Nurses’ Health Studies (NHS) I and II cohorts. Information was obtained from validated questionnaires. Poisson regression models adjusted for potential confounders were used to estimate the association of each risk factor with development of incident kidney stones and to compute PAF and NNTP.

Results

The study included 192,126 participants who contributed a total of 3,259,313 person-years of follow-up, during which 6,449 participants developed an incident kidney stone. All the modifiable risk factors were independently associated with incident stones in each of the cohorts. The PAF ranged from 4.4% for higher sugar-sweetened beverages intake to 26.0% for lower fluid intake; the PAF for all the five risk factors combined was 57.0% in HPFS, 55.2% in NHS I and 55.1% in NHS II. NNTP over 10 years ranged from 67 for lower fluid intake to 556 for lower dietary calcium intake.

Conclusions

Five modifiable risk factors accounted for more than 50% of incident kidney stones in three large prospective cohorts. Assuming a causal relation, our estimates suggest that preventive measures aimed at reducing those factors could substantially reduce the burden of kidney stones in the general population.