Can kidney stones lead to heart problems?

Having kidney stones seems associated with a greater risk for cardiovascular disease and stroke, but whether or not kidney stones are actually the cause of this higher risk remains uncertain.

That’s the caution from Dr. Darshika Chhabra, a nephrologist and medical director of kidney transplantation at Advocate Christ Medical Center, following the publication of a major study of kidney stones this month in the American Journal of Kidney Diseases. She says that kidney stone formation and development of cardiovascular disease are linked to similar risk factors – obesity, high cholesterol, diabetes and hypertension.

“Kidney stones may be associated with cardiovascular disease and stroke simply because these diseases all share the same lifestyle risk factors. On the other hand, kidney stones may prove to be an independent risk factor for cardiovascular disease,” Dr. Chhabra says.  “We just don’t know the answer yet.”

Led by scientist, Yanqiong Liu, of the First Affiliated Hospital of Guangxi Medical University in China, a research team conducted comprehensive analyses of the methodology, characteristics and findings of six major kidney stone studies undertaken previously by other researchers.

Combined, the studies involved nearly 50,000 patients with kidney stones and more than 3.5 million participants serving as controls. In comparing the results of these studies, the group reported finding an overall 19 percent increase in risk for coronary heart disease, a 40 percent increase in risk for stroke and a higher risk for heart attack (29 percent) in patients with kidney stones.

The association between kidney stones and heart attack seemed confined to women. However, the evidence was only “suggestive, but not conclusive,” the researchers said

Kidney stones are made of mineral and acid salts.  Stones can form when these minerals become too concentrated in a person’s urine and begin to crystallize and clump together. Approximately 80 percent of patients form stones composed of calcium minerals. The remainder develops stones with uric acid or other substances. Although extremely painful when they move, kidney stones cause no permanent damage and oftentimes pass on their own through the urinary tract. About 13 percent of men and 7 percent of women in the United States will develop a kidney stone at some time during their lives.

“This study raises so many questions,” Dr. Chhabra says. “As health care professionals, should we be cautioning patients with kidney stones that they have a higher risk for cardiovascular disease?  Perhaps, kidney stone patients should be given a more thorough cardio assessment and evaluation.”