Login to Access Video or Poster Abstract: MP95-06
Sources of Funding: none

Introduction

Urolithiasis has been reported to be a cause of decreased bone marrow density. Decreased bone marrow density has also been found to be closely linked to fracture. It is interesting and also important to know whether there is a relevant association between urinary stone and fracture.

Methods

We used data sourced from Longitudinal Health Insurance Database, which consists of one million randomly selected subjects from the National Health Insurance Research Database of Taiwan. Health Insurance System of Taiwan covers approximately 23 million people (98% of population). From 1997 to 2001, a total of 27237 subjects, 16346 males and 10891 females, with age 18-year-old or older were diagnosed with upper urinary track stone. All subjects did not have previous diagnosis of fracture. A cohort of 136185 (5 for each subject with upper urinary track stone) age and gender matched subjects without the diagnosis of upper urinary track stone in anytime of follow-up were enrolled as the control group. All subjects were followed up to the end of 2009 with a minimal follow-up of 8 years. A Cox shared frailty regression model was used to calculate the risk of fracture between study and control groups.

Results

At the end of follow-up, 5252 (19.3%) of the 27237 study subjects and 22018 (16.2%) of the 136185 control subjects developed fractures. Upper urinary track stone was associated with a significantly increased risk of fracture (hazard ratio 1.20, 95% confidence interval, 1.16 - 1.24, p < 0.0001) when metabolic syndrome was not taken into account. After adjusting for age, gender and metabolic syndrome status, the Cox shared frailty regression analysis still showed that patients with upper urinary track stone were more likely to develop fracture than the patients without urinary stone (hazard ratio 1.18, 95% confidence interval, 1.14 - 1.21, p < 0.0001).

Conclusions

The findings of this study indicate that urolithiasis is an independent risk factor for fracture. Patients, especially elderly, with urolithiasis should be advised about appropriate steps to take with respect to fracture prevention.

Funding

none