Washington: Higher levels of phosphate in the blood are linked with increased calcium levels in coronary arteries - a key indicator of atherosclerosis and future cardiovascular risk.

"Phosphate levels... could help identify people for whom modifiable (cardiovascular risk) factors could be screened and managed," comments Robert N. Foley, Managing Director of University of Minnesota.

Foley and colleagues studied the relationship between phosphate levels and coronary artery calcium in 3,015 healthy young adults from a long-term study of risk factors for coronary artery disease.

At an average age of 25 years, the subjects underwent measurement of their serum phosphate level. The phosphate level reflects the mineral phosphorus, which plays an important role in bone metabolism.

A special computed tomography (CT) scan was used 15 years later to measure the level of calcium in the coronary arteries. Coronary artery calcium is an early sign of atherosclerosis, or "hardening of the arteries".

After adjustment for other factors, blood phosphate levels at age 25 were significantly related to coronary artery calcium levels at age 40.

Subjects with higher phosphate levels were about 50 percent more likely to be at the highest level of coronary artery calcium, compared to those with lower phosphate levels.

The relationship was strongest at higher phosphate levels - however, phosphate levels were within range of normal for nearly all of the young adults studied, according to a Minnesota release.

Patients with kidney disease have increased phosphate levels, which are associated with an increased risk of heart disease.

If higher phosphate levels play a role in causing cardiovascular disease, then a link between phosphate level and early atherosclerosis might be found even in healthy people without kidney disease.

These finding will appear in the February 2009 issue of the Journal of the American Society of Nephrology (JASN). IANS