The Risk of Nephrolithiasis Among Patients With Ankylosing Spondylitis: a Population-Based Cohort Study

Mu Tsun SHIH1, Shou Hung TANG1, Tai Lung CHA1, Sheng Tang WU1, Jen Huai CHIANG2, Wen Chi CHEN2,3

1Division of Urology, Department of Surgery, Tri-service General Hospital, National Defence Medical Center, Taipei City, Taiwan
2Graduate Institute of Integrated Medicine, College of Chinese Medicine, College of Medicine, Research Center for Chinese Medicine & Acupuncture, China Medical University, Management Office for Health Data, China Medical University Hospital, Taichung City, Taiwan
3Sex Hormone Research Center, Departments of Obstetrics and Gynecology, Urology, and Medical Research, China Medical University Hospital, Taichung City, Taiwan

Abstract

Objectives: This study aims to investigate the correlation of ankylosing spondylitis (AS) with nephrolithiasis by performing a nationwide population- based cohort study.
Patients and methods: The data used in this retrospective cohort study were collected from the Taiwan National Health Insurance Research database. The study included a total of 3,334 AS patients (1,914 males, 1,420 females; mean age 44.51±16.83 years; range 22 to 79 years) and 13,336 non-AS patients (7,656 males, 5,680 females; mean age 44.27±17.01 years; range 21 to 78 years) who had been followed-up on an average of 6.78 years and 6.75 years, respectively, between January 2000 and December 2008.
Results: The percentage of newly diagnosed nephrolithiasis was 4.8% in all study subjects. However, the percentages of newly diagnosed nephrolithiasis were 5.76% and 4.58% in the AS and non-AS cohorts, respectively. After adjusting the patients’ sex, age, urbanization level, and comorbidities, the hazard ratio obtained from our multivariable Cox model was 1.19.
Conclusion: Our study findings indicate that patients with AS are more likely to develop nephrolithiasis than non-AS patients.

Conflict of Interest

The authors declared no conflicts of interest with respect to the authorship and/or publication of this article.

Financial Disclosure

This study is supported by Taiwan Ministry of Health and Welfare Clinical Trial and Research Center of Excellence (MOHW105-TDU-B-212-133019), China Medical University Hospital, Academia Sinica Taiwan Biobank Stroke Biosignature Project (BM10501010037), NRPB Stroke Clinical Trial Consortium (MOST 104- 2325-B-039 -005), Tseng-Lien Lin Foundation, Taichung, Taiwan, Taiwan Brain Disease Foundation, Taipei, Taiwan, and Katsuzo and Kiyo Aoshima Memorial Funds, Japan.