Incidental renal artery calcifications: a study of 350 consecutive abdominal computed tomography scans.

BACKGROUND

Calcifications in arteries are thought to represent atherosclerosis.

METHODS

Consecutive abdominal tomographic scans performed during a 4-month period were evaluated and assessed for renal artery calcifications (RAC). Scans that showed calcifications were evaluated for renal artery narrowing and for various characteristics of the atherosclerotic plaque.

RESULTS

Of 350 consecutive examinees, 43% were men, 40% had hypertension and 38% had hypercholesterolaemia. The age was 61 +/- 13 years. Aortic calcifications were found in 54% and RAC in 102 (29%), of whom 53 had bilateral calcifications. Subjects with RAC were older, 72 +/- 6 versus 55 +/- 12 years. Adjusted odds ratios of RAC were 2.2 (95% CI 1.1-4.6) for male gender, 2.4 (1.2-4.8) for hypertension and 2.9 (1.4-5.8) for hypercholesterolaemia, whereas family history of hypertension was protective with 0.5 (0.3-0.9). All patients with calcified renal arteries had aortic calcifications, versus 35% of those without RAC. A significant correlation was found between the severity of calcifications and the degree of renal artery narrowing (r = 0.7), and also between the presence of bilateral calcifications and a high-grade narrowing.

CONCLUSIONS

RAC strongly relates to atherosclerosis. Calcifications and artery narrowing may have a role in the pathogenesis of hypertension. Bilateral calcifications suggest atherosclerotic renal artery stenosis.