WCE 2017: Gender Disparity in Urolithiasis – Fact or Fiction?

Vancouver, Canada (UroToday.com)  Dr. Gina Tundo, 3rd year clinical urology resident from the Dartmouth Hitchcock Medical Center, presented data comparing the urolithiasis rates of males and females. As an introduction to her poster presentation, Dr. Tundo described how the traditional belief of the disparity in the prevalence of kidney stones between men and women was that men have a higher prevalence throughout their life. However, newer studies illustrate an erosion of this gender gap. Dr. Gina Tundo and her team therefore decided to assess the relationship between the prevalence of kidney stones for men and women under the age of 50 years old. 

For this comparison, 17,658 patients were analyzed from the 2007-2012 National Health and Nutrition Examination Surveys. The research team weighed proportions and utilized multivariate logistic regression of the U.S. population to determine prevalence and odds of nephrolithiasis. Therefore, they compared the prevalence rates of men versus women of all adult ages to the prevalence rates of men versus women with an age restriction of less than 50 years of age. 

Following the analysis, Dr. Tundo discovered that for the population at all ages, men had a significantly higher stone prevalence of 9.8%, compared to the 7.7% of women. Men also had a 37% greater odd of nephrolithiasis than women when adjusting for diabetes, obesity, ethnicity, and age in multivariate logistic regression analysis. However, when only those under the age of 50 were analyzed, both with adjusted multivariate logistic regression and non-adjusted multivariate logistic regression, there was no difference in stone prevalence (p=0.98,p=0.85, respectively). 

Dr. Tundo concluded that, among working-aged U.S. adults less than 50 years of age, the much-touted gender disparity in stone prevalence is not present. She cautioned that this may simply represent prior failure to accurately assess the prevalence of stones in the economically-critical demographic or that there may be an actual change in epidemiology. Therefore, she believes her research highlights the need for continued efforts to better elucidate the pathophysiology and epidemiology of stone disease in young adults; with women equally as importantly as men. This would allow for more focused preventative efforts, improvements in the patient quality of life, and a reduction in health care costs and missed work productivity. A member of the audience commented how her findings seem to support the Nurses' Health Studies (NHS I and NHS II) where the studies illustrated how the incidence of stones in women peak at the ages of 20-40 years old, while the incidence of stones in men peak at the ages of 40-60 years old. These investigations also hinted at a large female predominance in the adolescent population nephrolithiasis prevalence rate to which Dr. Tundo responded that her team did not look at the prevalence of kidney stones per decade and will do so in the future. 

Presented by: Dr. Gina Tundo

Authors: Gina Tundo, Vernon Pais, Jr.
Affiliation: Dartmouth Hitchcock Medical Center, Lebanon N.H., Geisel School of Medicine at Dartmouth Hanover, New Hampshire

Written by: Vinay Cooper Department of Urology, University of California – Irvine at 35th World Congress of Endourology– September 12-16, 2017, Vancouver, Canada.