Leisure time physical activity, smoking and risk of recent symptomatic urolithiasis: Survey of stone clinic patients

Introduction: We explore relationships between selected lifestyle factors and recent (<= 6 months) symptomatic urolithiasis (RSU). Methods: Surveys querying socio-demographic, medical history, physical activity, diet and smoking were administered to a convenience sample of stone clinic patients at a tertiary care hospital. Leisure time physical activity (LTPA) was assessed with the International Physical Activity Questionnaire (long form). Multivariate logistic regression was used to identify associations between risk factors and RSU. Results: Of the 163 participants, most were male (64%) and white (78%), with a mean (standard deviation) age of 56.3 (14.2) years. The mean body mass index (BMI) was 27.3 (5.4) kg/m(2) and 57 (35%) patients reported RSU. No significant (p < 0.05) differences were observed between participants with and without RSU in age, sex, ethnicity, BMI, or diet. Of the cohort, 52 (35%) participants met physical activity guidelines for walking (29%), moderate (27%) or vigorous activity (29%). LTPA did not differ significantly by RSU status. Compared to those without RSU, participants with RSU had higher rates of smoking (7% vs. 21%, p = 0.02 and had 8.5 (95% confidence interval 2.2-32.2) times the odds of being current smokers after controlling for sex, diet, and LTPA. Conclusions: Physical inactivity and smoking are common among stone clinic patients, though LPTA was not associated with RSU. Study limitations include its small sample size, selection bias, and reliance on self-reported RSU (recall bias). In addition, participants may have already been following dietary recommendations to prevent urolithiasis recurrence. Nonetheless, current smoking was a potent predictor of RSU. When desired, smokers should be referred for smoking cessation.