Kidney stones not independently linked to chronic kidney disease, suggests study

A new study published in the Journal of American Society of Nephrology found that kidney stones were not independently linked to chronic kidney disease (CKD). Around 5 and 13% of adults suffer from kidney stones and chronic kidney disease, respectively. Renal crystal deposition, or nephrocalcinosis, can cause progressive loss of GFR and end-stage renal disease (ESRD) at a young age. Rare inherited illnesses such as primary hyperoxaluria, 2-8-hydroxyadenine crystalluria, Dent disease, and cystinuria can cause CKD which is a documented consequence of kidney stones.

Kidney stones may be a contributing factor in the development and progression of CKD even though the incidence of ESRD directly linked to kidney stones is estimated to be 3.2% among patients starting continuous hemodialysis. The precise association between previous kidney stones and increased CKD risk is yet unknown, despite observational studies suggesting such a possibility. Therefore, Zhou LT and team conducted this study to find out the intricate relationship between kidney stones and CKD.

Unbiased screening was employed to find shared comorbidities between two illnesses. Genetic association studies across a range of variables were conducted after obtaining genome-wide association study summary results from the UK Biobank (UKBB), CKDGen, and FinnGen. To identify causal relationships, bidirectional Mendelian randomization (MR) studies were carried out. Multivariable MR was also employed, which encompassed the common comorbidities such as obesity, diabetes, and hypertension. Using a UKBB subgroup and cohorts from the Mayo Clinic, observational analyses were conducted.

There was not a significant genetic association found between kidney stones and chronic kidney disease (CKD), despite the identification of 123 illnesses as shared comorbidities. Kidney stones and the risk of CKD were not significantly correlated, according to an unadjusted MR analysis. Although there was a significant correlation between kidney stones and a higher urine albumin-creatinine ratio (UACR), this correlation vanished in the multivariable MR model. Moreover, a robust regression model did not find an independent link between kidney stones and UACR or eGFR in a cross-sectional study restricted to the UKBB sample.

However, in multivariable MR models, CKD was linked to a lower the incidence of renal stones. Additionally, decreased eGFR was linked to reduced urine calcium excretion and urinary calcium oxalate/phosphate supersaturation in the Mayo Clinic cohort with accessible urinary biochemistries. Overall, kidney stones and CKD were not shown to be correlated in this study. On the other hand, CKD was linked to a lower incidence of kidney stones made of calcium, most likely as a result of altered vital signs of the urine, such as decreased excretion of calcium.

Reference:

Zhou, L.-T., Ali, A. E., Jayachandran, M., Haskic, Z., Harris, P. C., Rule, A. D., Koo, K., McDonnell, S. K., Larson, N. B., & Lieske, J. C. (2024). Association between Kidney Stones and CKD. In Journal of the American Society of Nephrology. Ovid Technologies (Wolters Kluwer Health). https://doi.org/10.1681/asn.0000000000000453