Contrast Dye Used In Diagnostic Imaging More Likely to Damage Female Kidneys

Women are more likely to experience kidney damage after undergoing a diagnostic procedure that includes injecting dye into their bodies, according to new research presented at the National Kidney Foundation's recent Spring Clinical Meetings. Click here for more on this meeting at which 3,100 kidney care professionals gathered and nearly 400 new research studies were presented.

Researchers at Henry Ford Hospital found that women were 60 percent more likely than men to develop the kidney injury known as radiocontrast-induced nephropathy (RCIN). "These findings suggest that clinicians should proceed carefully when using this procedure in female patients, particularly those with other risk factors," said Dr. Lynda Szczech, MD, MSCE, President of the National Kidney Foundation.

All 1211 study participants had recently undergone coronary angiography, in which clinicians inject dye around the heart, then take X-rays to visualize the organ and the blood vessels that supply it. Nearly 20% of women developed RCIN after the procedure, versus less than 14% of men.

The dye may injure the kidneys by causing the blood vessels of the kidney to narrow, and damaging the structures inside the kidney, said study author Dr. Javier Neyra. Why women appear to be more at risk, however, is somewhat of a mystery, he noted.

The study also found that patients were more at risk of RCIN when their doctors injected relatively large amounts of dye, and this finding may help explain why women are more likely to develop the condition, Dr. Neyra explained. Women are often smaller than men, but if they receive the same amount of dye, it's more likely to be too high of a dose in women, therefore putting them at risk of RCIN.

In some cases, RCIN can cause a fatal kidney injury. Patients who survive, however, may be more at risk of subsequent problems.

Other risk factors for RCIN include heart disease, anemia, diabetes, high blood pressure, and poor underlying kidney function.

Surprisingly, in this study, women were more likely to develop kidney injury following coronary angiography if they had healthy kidneys before the procedure.

Both women and their doctors need to understand the risks of imaging procedures that use dyes, and, if women have other risk factors for RCIN, doctors should consider whether the procedure is absolutely necessary, Dr. Neyra advised.

"We need to realize that women may represent a high-risk population when they are exposed to this dye," said Dr. Neyra.

"It is worth exploring whether this study's findings may represent a greater number of women with unrecognized early kidney disease," said Dr. Szczech.