#5727 THE BURDEN OF SYMPTOMS AND PROCEDURES IN PATIENTS WITH RECURRENT KIDNEY STONES – A REPORT FROM A STONE CLINIC
Authors: Tilia Rok , Skoberne Andrej 
Published: June 2023

Abstract

Background and Aims
Kidney stones (KS) are increasing in prevalence and becoming a major public health problem. The extent of the disease has been described as the stone burden, a measurement based on the size and number of stones. However, the quality of life of these patients is not affected by these parameters per se, but rather by the frequency and intensity of symptoms and the need for surgical procedures. The current data on this subject is very limited. The aim of our study was to record the frequency of symptoms and procedures in patients with recurrent KS and to evaluate possible associations with basic clinical data and common comorbidities.

Method
We report a retrospective study on 181 consecutive patients with recurrent KS who were examined at the University Medical Centre Ljubljana stone clinic for the first time during the period of 2018 – 2022. We performed a standardized questionnaire to record common KS symptoms, procedures, basic clinical data, and comorbidities. Events were defined as number of severe lumbar pain (SLP) events per year (8-10/10 on the visual analog scale – VAS) and number of surgical procedures (SP) for stone removal per year. Moderate lumbar pain (MLP) events (VAS 4-7/10) and passing of stones were quantified on a scale from 0-4. Due to the wide variety of frequencies the associations were analyzed with Chi-Square test using terciles when possible or with presence and absence of symptoms. We considered p values &lt; 0.05 as statistically significant.

Results
Mean age was 51.1 (SD 14,5) years, with 51.8% females. Arterial hypertension (AH) was present in 29.8% of patients, diabetes mellitus in 6.6%, and a family history of KS in 30%. The median frequency of SLP and SP was 0.33 (IQR 0.01-1) events/year and 0.08 (IQR 0-0.33) procedures/year, respectively; while 26.7% and 12.8% of patients had at least one SLP event or SP per year, respectively. When comparing terciles of frequency of SLP we found an association with more common SLP events in patients with a positive family history of KS compared to a negative history (17%, 63%, 20% vs. 37%, 27%, 36%; p &lt; 0.001). There was also a significant difference in the age of onset of KS in patients with and without a family history of KS. Mean decade of onset was 3 (IQR 3-5) and 4 (IQR 3-6) in patients with and without a family history of KS, respectively (p = 0.033). When comparing terciles of frequency of procedures we only found a trend towards more common procedures in patients with AH (p = 0.062). The frequency of MLP was as follows – 42.6% had it less than once per year, 11.6% had it once or twice per year, 11% three to five times per year, 12.9% every month, and 21.9% on a weekly basis. We found no statistically significant association between MLP and basic clinical data or comorbidities only a trend towards more frequent episodes in patients with AH (p = 0.096). In regards to the passing of KS we found the following frequencies – 72.4% had episodes less than once per year, 14.9% once or twice per year, 5.5% three to five times per year, 3.9% every month, and 3.3% on a weekly basis. There was statistically significant difference between passing of KS and sex, with 34.5% of males and 21.3% of females passing KS at least once per year, respectively (p = 0.047). Additionally, there was a significant difference between passing of KS and family history of KS, with 40.7% with and 21.6% of patients without a history of KS passing KS at least once per year, respectively (p = 0.008).

Conclusion
Our study showed that symptoms and surgical procedures were common in patients with recurrent KS referred to our clinic. Half of the patients had severe lumbar pain at least every three years, and a quarter had severe lumbar pain and passed KS at least once per year. About a third of patients had moderate lumbar pain at least once per month. Patients with a family history KS developed stones earlier in life and had more common severe lumbar pain and passed KS more frequently. These issues should be analyzed in greater detail, with symptom scores that would define the burden of KS in a more objective manner and help in assessing the effectiveness of KS therapies.