BERKELEY, CA (UroToday.com) - Several risk factors of coronary heart disease (CHD) including hypertension, metabolic syndrome, diabetes, gout, and chronic kidney disease have recently been linked to kidney stones (nephrolithiasis).[1, 2, 3, 4, 5, 6] Recently, a study by Liu et al.[7] and our study[1] showed that patients with a history of nephrolithiasis are at significantly higher risk of CHD, particularly female patients with kidney stones.
We recently conducted a meta-analysis of 7 study populations from 4 cohort studies and one cross-sectional study which found that a history of nephrolithiasis was correlated with a significant 1.43-fold increased CHD risk in females. However, the association was not significant in males (RR, 1.14 (95% CI, 0.94-1.38)).
The underlying pathophysiology of the increased risk of CHD in females remains unclear. The prevalence of nephrolithiasis is higher in males than females (10.6% vs 7.1%, respectively).[8] Also, CHD is more prevalent in males than in females (7.8% vs 4.6%).[9, 10] Thus, it is surprising that we found that females with nephrolithiasis were more likely to have CHD. Females with kidney stones may also be exposed to unknown factors that could increase their risk of CHD. Further studies are required to identify the possible risk factors of CHD in females with nephrolithiasis, for example, hormonal factors (estrogen/progesterone), dietary, genetic factors, pregnancy, and muscle to fat composition.
Our study is a meta-analysis of observational studies with inherent limitations. Thus, at best, it can reveal an association but not a causal relationship. In addition, observational studies require multivariable adjustments that may fail to adjust for unanticipated confounders. Future studies are needed to elucidate the mechanisms underlying this potential causal relationship of the kidney stone and its association with CHD, especially in female gender.
In summary, the findings from our meta-analysis suggest that a history of nephrolithiasis is a risk factor of CHD in females and may impact future clinical practice.
References:
- Cheungpasitporn W, Thongprayoon C, Mao MA, et al. The Risk of Coronary Heart Disease in Patients with Kidney Stones: A Systematic Review and Meta-analysis. N Am J Med Sci. 2014;6(11):580-5.
- Rivers E, Nguyen B, Havstad S, et al. Early goal-directed therapy in the treatment of severe sepsis and septic shock. N Engl J Med. 2001;345(19):1368-77.
- Cheungpasitporn W, Thongprayoon C, O'Corragain OA, et al. The risk of kidney cancer in patients with kidney stones: a systematic review and meta-analysis. QJM. 2015;108(3):205-12.
- Cheungpasitporn W, Erickson SB. Medullary sponge kidneys and the use of dual-energy computed tomography. Urol Ann. 2015;7(1):129.
- Thongprayoon C, Cheungpasitporn W. Recent Literatures and Updated Guidelines on Kidney Stones. Journal of Nature and Science. 2015;1(1):30.
- Charat Thongprayoon WC. Epidemiological evidence and future perspective in kidney diseases. Journal of Nature and Science. 2015;1(1):28.
- Liu Y, Li S, Zeng Z, et al. Kidney stones and cardiovascular risk: a meta-analysis of cohort studies. Am J Kidney Dis. 2014;64(3):402-10.
- Scales CD, Jr., Smith AC, Hanley JM, Saigal CS. Prevalence of kidney stones in the United States. Eur Urol. 2012;62(1):160-5.
- Prevalence of coronary heart disease--United States, 2006-2010. MMWR Morb Mortal Wkly Rep. 2011;60(40):1377-81.
- Goldfarb DS. Kidney stones and the risk of coronary heart disease. Am J Kidney Dis. 2013;62(6):1039-41.
Written by:
Charat Thongprayoon, MD and Wisit Cheungpasitporn, MD as part of Beyond the Abstract on UroToday.com. This initiative offers a method of publishing for the professional urology community. Authors are given an opportunity to expand on the circumstances, limitations etc... of their research by referencing the published abstract.
Division of Nephrology and Hypertension, Department of Internal Medicine, Mayo Clinic, Rochester, MN USA