Jeong CW, Lee S, Byun S-S, Lee DH, Lee SE. No increase in risk of microscopic hematuria with aspirin use by asymptomatic healthy people. JAMA Intern Med. Published online April 22, 2013. doi:10.1001/jamainternmed.2013.567
eTable. Logistic Regression Analysis to Estimate the Risk of Microscopic Hematuria
Jeong CW, Lee S, Byun S, Lee DH, Lee SE. No Increase in Risk of Microscopic Hematuria With Aspirin Use by Asymptomatic Healthy People. JAMA Intern Med. 2013;173(12):1145-1146. doi:10.1001/jamainternmed.2013.567
Author Affiliations: Department of Urology, College of Medicine, Seoul National University, Seoul, Korea (Drs Jeong, S. Lee, Byun, and S. E. Lee); and Department of Urology (Drs Jeong, S. Lee, Byun, and S. E. Lee), Health Promotion Center (Dr D. H. Lee), and Department of Internal Medicine (Dr D. H. Lee), Seoul National University Bundang Hospital, Seongnam, Korea.
The daily use of aspirin in low doses (75-325 mg) is a well-known preventive therapy for cardiovascular disease.1 Approximately 35% of adults in the United States are estimated to take aspirin regularly for this purpose.2 Furthermore, the regular use of aspirin seems to reduce the risk of several types of cancer and distant metastasis.3,4 However, aspirin can increase the risk of bleeding, especially risk for bleeding of the gastrointestinal tract and hemorrhagic stroke.5,6 Nevertheless, the correlation between the daily use of low-dose aspirin and microscopic hematuria in the asymptomatic general population is unknown. We evaluated whether the daily use of aspirin increases the risk of hematuria in a large sample of healthy individuals.
Data were obtained from asymptomatic healthy adults (≥20 years old) who underwent general health screening during the period August 2005 through December 2010 at the Health Promotion Center in our institution. After exclusions for missing data, 56 632 participants were included in the analysis. This study was approved by the institutional review board of Seoul National University Bundang Hospital (Seongnam, Republic of Korea).
We prospectively collected data regarding medication use, medical history, and smoking history using a standardized questionnaire. The routine use of drugs including aspirin was checked with a response of either “yes” or “no.” Microscopic hematuria was defined as the presence of more than 4 red blood cells per high-power field at urine microscopic analysis. The primary outcome was the relative prevalence of hematuria in aspirin users and nonusers.
We also calculated the relative risk of developing microscopic hematuria among those who did not have hematuria at the initial screening and underwent at least 1 additional health screening during the study period (9199 participants; 17.3%). Finally, we calculated the relative risk of persistent hematuria among those with hematuria at the initial screening who had a second urinalysis within 12 months (1619 participants; 46.0%).
The characteristics of the participants are presented in the Table. There were 4254 participants (7.5%) who used aspirin daily. Microscopic hematuria was identified in 3517 participants (6.2%) by means of urine microscopy. Use of low-dose aspirin was not significantly associated with hematuria: prevalence was 6.1% (258 of 4254) in aspirin users and 6.2% (3259 of 52 378) in nonusers (P = .71). Aspirin use also did not influence the degree of hematuria. The prevalence of microscopic hematuria increased with age (20-29 years, 4.1%; 30-39 years, 5.0%; 40-49 years, 5.9%; 50-59 years, 6.6%; 60-69 years, 7.8%; and ≥70 years, 9.1%; P < .001). After adjustment for other factors using multivariate logistic regression, aspirin use did not increase the risk of microscopic hematuria (odds ratio, 1.0 [95% CI, 0.9-1.2]; P = .79). Female sex, older age, chronic renal failure, and current smoking significantly increased the odds of having microscopic hematuria, whereas diabetes mellitus decreased the risk (eTable).
Of those who did not have hematuria at baseline, 9199 (17.3%) underwent at least 1 follow-up screening at a median (range) of 13 (4-64) months after initial screening. At the second screening, the incidence of microscopic hematuria in these participants was 4.4% (27 of 614) in aspirin users and 4.1% (348 of 8585) in nonusers (P = .67).
Among 1619 participants with microscopic hematuria at baseline who underwent a second urinalysis within 12 months, 911 (56.3%) showed persistent microscopic hematuria; these rates were not different between aspirin users (60.6% [57 of 94]) and nonusers (56.0% [854 of 1525]; P = .39).
In a large study of asymptomatic persons, we found no association of low-dose aspirin use with microscopic hematuria in either cross-sectional or longitudinal analyses. Previously, 1 study suggested that low-dose aspirin use does not increase risk of hematuria; however, it was a small study including only 69 patients.7 Our results suggest that clinicians should use the same approach to evaluation of the causes of microscopic hematuria in persons using low-dose aspirin as in those who are not taking aspirin.
Correspondence: Dr S. E. Lee, Department of Urology, Seoul National University Bundang Hospital, 82, Gumi-ro 173 Beon-gil, Bundang-gu, Seongnam-si, Gyeonggi-do, 463-707, Republic of Korea (firstname.lastname@example.org).
Published Online: April 22, 2013. doi:10.1001/jamainternmed.2013.567
Author Contributions: Dr S. E. Lee had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. Study concept and design: Jeong and S. E. Lee. Acquisition of data: Jeong, S. Lee, Byun, and D. H. Lee. Analysis and interpretation of data: Jeong and S. Lee. Drafting of the manuscript: Jeong. Critical revision of the manuscript for important intellectual content: S. Lee, Byun, D. H. Lee, and S. E. Lee. Statistical analysis: Jeong and S. Lee. Administrative, technical, and material support: Byun. Study supervision: D. H. Lee and S. E. Lee.
Conflict of Interest Disclosures: None reported.
Additional Contributions: Soyeon Ahn, PhD (Medical Research Collaboration Center, Seoul National University Bundang Hospital), provided statistics consultation and support.