Upper urinary tract stone compositions: the role of age and gender

ABSTRACT Objective: To analyze the compositions of upper urinary tract stones and investigate their distributions in different gender and age groups. Materials and Methods: Patients diagnosed with upper urinary tract stone disease between December 2014 and March 2018 were retrospectively reviewed. Patient's age, gender, BMI, comorbidities, stone event characteristics, and compositions were collected, and proportions of stone components in different gender and age groups were analyzed. Results: A total of 1532 stone analyses were performed (992 from males and 540 from females). The mean age was younger in males (p <0.001). Males included more cases with larger BMI, hyperuricemia, and obesity, while females had more urinary tract infections. Multiple components were present in 61.8% of stones. Calcium oxalate (CaOx) (67.0%) was the most common component, followed by uric acid (UA) (11.8%), infection stone (11.4%), calcium phosphate (CaP) (8.0%), cystine (1.1%), brushite (0.4%), and 2, 8-dihydroxyadenine (0.2%). Men contributed with more CaOx stones than women at age 30-49 years (all p <0.01) and more UA stones at 30-59 years (all p <0.05). Women contributed with more infection stones than men in age groups 30-49 and 60-69 years (all p <0.05), and more CaP stones at 30-49 years. The prevalence peak was 50-59 years in men and 60-69 years in women. Both genders had the lowest prevalence in adolescence. Prevalence of UA stones increased while that of infection stones decreased with aging in both genders. Conclusions: Age and sex had a strong association with distribution of stone compositions in this Chinese cohort.

摘要
研究目的：分析上尿路结石的成分组成，并探究其在不同性别及年龄组中的分布特征。
材料与方法：对2014年12月至2018年3月期间确诊为上尿路结石病的患者进行回顾性研究。收集患者的年龄、性别、体重指数（BMI）、合并症、结石事件特征及结石成分数据，分析不同性别与年龄组的结石成分占比情况。
结果：本研究共完成1532例结石成分检测（男性992例，女性540例）。男性患者的平均年龄显著低于女性（p<0.001）。男性中高BMI、高尿酸血症及肥胖患者占比更高，而女性中尿路感染患者占比更高。61.8%的结石为多成分混合结石。草酸钙（CaOx）为最常见的结石成分（占比67.0%），其次为尿酸（UA，11.8%）、感染性结石（11.4%）、磷酸钙（CaP，8.0%）、胱氨酸（1.1%）、透钙磷石（0.4%）及2,8-二羟基腺嘌呤结石（0.2%）。在30~49岁年龄段，男性草酸钙结石占比显著高于女性（所有组p<0.01）；30~59岁年龄段，男性尿酸结石占比更高（所有组p<0.05）。在30~49岁及60~69岁年龄段，女性感染性结石占比显著高于男性（所有组p<0.05）；30~49岁年龄段女性磷酸钙结石占比更高。男性结石患病率峰值为50~59岁，女性为60~69岁，两性在青少年时期的患病率均最低。随着年龄增长，两性的尿酸结石患病率均升高，感染性结石患病率均降低。
结论：本中国队列研究表明，年龄与性别与上尿路结石成分的分布存在显著关联。