This article is more than 5 years old. Information may no longer be current.
Lower vitamin D blood levels increased risk for contrast-induced nephropathy
In patients undergoing coronary angiography, lower blood levels of vitamin D are associated with a higher incidence of contrast-induced nephropathy, according to recent study findings.
Researchers for the prospective study evaluated 403 consecutive patients who underwent coronary angiography between Oct. 1, 2009, and Oct. 21, 2011. The researchers performed fasting blood tests on all participants and calculated their baseline estimated glomerular filtration rates.
During angiography, the researchers used iohexol (Omnipaque, GE Healthcare), a nonionic, low-osmolality contrast material, and recorded the total volume of contrast material used. Patients underwent angioplasty or stent implantation via PCI in 122 cases.
Blood levels of vitamin D and parathormone were determined before angiography, with serum vitamin D levels lower than 15 ng/mL categorized as vitamin D deficiency. Contrast-induced nephropathy was defined as a >0.5 mg/dL or >25% elevation of blood creatinine within 48 to 72 hours of contrast material use, with no other etiologic explanation.
Of the 403 patients, 18.3% developed contrast-induced nephropathy, and vitamin D deficiency was observed in 57.1% of participants. There was no significant difference in baseline estimated glomerular filtration rates (P=.14), blood urea (P=.07) or creatinine levels (P=.61) between participants in the nephropathy-positive and nephropathy-negative groups.
Vitamin D deficiency occurred significantly more frequently in the group with nephropathy (27.2% vs. 6.9%; P=.01). The nephropathy-positive group also had lower levels of vitamin D (8.5 ng/mL vs. 14.9 ng/mL, P=.01) and higher levels of parathormone (73.9 pg/mL vs. 44.2 pg/mL, P=.01) than the group without nephropathy. The association between contrast-induced nephropathy and vitamin D deficiency was not correlated with renal disease severity, as nephropathy incidence remained significantly higher among vitamin-deficient patients at all stages of renal function.
The total volume of contrast material used was higher among patients in the nephropathy group (132 ± 64 mL vs. 90 ± 41 mL; P=.01). Researchers primarily attributed this observation to more patients in this group undergoing PCI (40.5% vs. 27.9%; P=.03).
Multivariate logistic regression analysis indicated independent correlations between contrast-induced nephropathy and lower vitamin D levels (OR=1.18; 95% CI, 1.11-1.26) and increased volume of contrast material exposure (OR=1.01; 95% CI, 1.008-1.017). In a subgroup analysis of patients who underwent PCI, researchers observed an independent association between lower vitamin D levels and nephropathy onset (OR=1.31; 95% CI, 1.042-1.227), as well as increased volume of contrast material used (OR=1.025; 95% CI, 1.014-1.035).
“In our study, we have found that lower level of vitamin D was independently associated with higher incidence of [contrast-induced nephropathy],” the researchers wrote. “However, our study does not give clues regarding the pathophysiological role and possible theuropathic application of vitamin D in [contrast-induced nephropathy].”
Disclosure: The researchers report no relevant financial disclosures.