Sex disparities and the risk of urolithiasis: a large cross-sectional study

Abstract

Background: Urolithiasis is one of the most common diseases in urology, with a lifetime prevalence of 14% and is more prevalent in males compared to females. We designed to explore sex disparities in the Chinese population to provide evidence for prevention measures and mechanisms of stone formation.

Materials and methods: A total of 98232 Chinese individuals who had undergone a comprehensive examination in 2017 were included. Fully adjusted odds ratios for kidney stones were measured using restricted cubic splines. Multiple imputations was applied for missing values. Propensity score matching was utilised for sensitivity analysis.

Results: Among the 98232 included participants, 42762 participants (43.53%) were females and 55470 participants (56.47%) were males. Patients' factors might cast an influence on the development of kidney stone disease distinctly between the two genders. A risk factor for one gender might have no effect on the other gender. The risk for urolithiasis in females continuously rises as ageing, while for males the risk presents a trend to ascend until the age of around 53 and then descend.

Conclusions: Patients' factors might influence the development of kidney stones distinctly between the two genders. As age grew, the risk to develop kidney stones in females continuously ascended, while the risk in males presented a trend to ascend and then descend, which was presumably related to the weakening of the androgen signals.Key messagesWe found that patients' factors might cast an influence on the development of kidney stone disease distinctly between the two sexes.The association between age and urolithiasis presents distinct trends in the two sexesThe results will provide evidence to explore the mechanisms underlying such differences can cast light on potential therapeutic targets and promote the development of tailored therapy strategies in prospect.

Keywords: China; Urolithiasis; age; cross-sectional study; sex difference.

Figure 1.

Flow of study participants in the study. After excluding 1627 participants who were lack of ultrasonography outcome (n = 1267), under 18 years old (n = 351), or had kidney deformity (n = 14), kidney transplantation (n = 23), solitary kidney (n = 205), those who completed a health examination were recruited (n = 98232).

Figure 2.

Association between age and urolithiasis. Adjusted as model 2 (see Methods-Statistical Analyses section for a description of model 2), restricted cubic splines were applied (details can be found in the Methods-Statistical Analyses section). (A) Odds ratio (OR) with 95% confidence interval (95%CI) was indicated by the red line and shade; blue histogram illustrated the distribution of the whole participants. The dashed line demonstrated the inflection point where the OR for urolithiasis reversed the trend. (B) Stratified by sex, the red and blue line and shade presented OR and 95%CI of urolithiasis in females and in males, respectively. The risk for urolithiasis in females continuously rose as ageing, while for males the risk indicated a trend to ascend until the age of around 53 and then descend.

Figure 3.

Subgroup analyses on the OR of sex (male vs. female). Abbreviations: CI, confidence interval; BP, blood pressure; eGFR, estimated glomerular filtration rate; HDL, high-density lipoprotein; LDL, low-density lipoprotein; UpH, Urine pH. Adjusted as model 2 (see Methods-Statistical Analyses section for descriptions of model 2). P for interaction was calculated applying the Wald test. Except for those who are older than 75 years old or absent of CHD, the risk of males developing kidney stones is significantly higher than that of females. *p < .05; **p < .01; ***p < .001.