Impact of female gender on frequency of contrast medium-induced nephropathy: post hoc analysis of dialysis versus diuresis trial.

BACKGROUND

Of patients exposed to contrast medium (CM), 10% will develop contrast medium-induced nephropathy (CIN). Many studies have assessed potential risk factors for CIN. There are limited date concerning the influence of gender on frequency of CIN.

METHODS

From January 2001 to July 2004, a prospective trial was performed to compare different treatments for CIN prevention. Creatinine levels (72 hours) were assessed, as well as in-hospital and long-term outcome. CIN was defined as in an increase of > or =25% or >0.5 mg/dL compared with baseline creatinine. The frequency of CIN in women and men was determined retrospectively.

RESULTS

Four hundred twelve patients (67.1 +/- 10.2 years, 68 women) were randomized for different treatment strategies. Univariate analyses identified higher age (p = 0.031), diabetes (p = 0.03), decreased estimated glomerular filtration rate (eGFR) (p < 0.001), lower hemoglobin levels (p = 0.001), use of angiotensin-converting enzyme inhibitors (ACEI) (p = 0.004) and loop diuretics (p = 0.011), the amount of CM given (p < 0.001), and female gender to be associated with the occurrence of CIN within 72 hours. The frequency of CIN within 72 hours after CM administration was significantly higher in women than in men (p = 0.016). When CIN-associated factors were compared between women and men, women were older (69.8 vs. 66.5 years, p = 0.014) and had lower hemoglobin levels (12.6 vs. 13.8 g/dL, p < 0.001) and eGFR (35 vs. 49 mL/min, p < 0.001), suffered more often from diabetes (37% vs. 29%, p = 0.09), and had medication more frequently with loop diuretics (50% vs. 36%, p = 0.036) but not ACEI (56% vs. 57%, ns). The amount of CM given was identical (189 vs. 189 mL, ns). Multivariate analysis found female gender not to be an independent predictor of CIN (odds ratio [OR] 1.48, 95% confidence interval [CI] 0.72-3.02).

CONCLUSIONS

Women are significantly more likely than men to suffer from CIN. This higher rate of CIN was confounded by unfavorable comorbidities, as found by univariate and multivariate analyses.