Stones, Heart Disease:

The results are consistent with findings from other recent studies and suggest that nephrolithiasis may reflect a systemic vascular disorder. In fact, lead author Brian Eisner, MD, observed that stone disease may be an early marker for heart disease.

“We found at least a 15% increased risk of heart disease in patients who had a history of kidney stones,” said Dr. Eisner, a fifth-year resident in urology at Massachusetts GeneralHospital in Boston. “We believe this is important when considering the overall health care and treatment of patients with stone disease.”

The etiology of nephrolithiasis is incompletely characterized, Dr. Eisner said. He, senior author Marshall Stoller, MD, professor of urology at the University of California in San Francisco, and colleagues have theorized that the initial stone event may be vascular in origin, so they examined whether a history of nephrolithiasis was associated with sub-sequent development of coronary disease in patients.

The researchers analyzed data from the Health Professionals Follow-Up Study, which included 45,988 men whose age range at baseline was 40-75 years. Dr. Eisner and his colleagues adjusted findings for age, BMI, thiazide diuretic use, antihypertensive and cholesterol-lowering medications, tobacco use, history of gout, hypertension, diabetes mellitus, fluid intake, and other dietary factors. The primary end point was coronary heart disease, defined as MI, angina, or need for coronary artery bypass graft surgery (CABG). Stroke, including ischemic or hemorrhagic cerebrovascular events, was the secondary end point.

A total of 4,747 patients (10.3%) reported a history of nephrolithiasis at baseline. After adjusting for confounders, Dr. Eisner's team found a 15% higher risk for coronary heart disease (CHD) among subjects with a history of nephrolithiasis compared with men without nephrolithiasis. A history of nephrolithiasis was associated with a 16% increased risk for MI, a 27% increased risk for angina, and a 15% increased risk for CABG.

“These were all highly statistically significant associations. There was no increased risk of stroke in these patients,” Dr. Eisner told Renal & Urology News. “We see stone formers very early in their life. Patients tend to be in their 20s, 30s, and 40s. We should consider possible in-creased risk of coronary disease in these patients as we care for them long-term.”

Previous studies also have linked kidney stone disease with heart disease. These include a study by Japanese investigators who compared 181 calcium oxalate stone formers and 187 control subjects. The team found a history of CHD in seven (3.9%) of the stone form-ers but none of the controls, according to a report in the International Journal of Urology (2005;12:859-863).