SAN DIEGO – Levels of calcium, phosphorus, and parathyroid hormone are poorer in patients with heart failure at each stage of chronic kidney disease, results from a large study showed.
The finding "raises more questions than it answers," Dr. Claudine T. Jurkovitz said in an interview during a poster session at Kidney Week 2012. "The question is, are these patients less well managed for their metabolic bone disease than the patients without HF? If so, why? Is it because their HF is so severe, or is it because the nephrologists count on cardiologists or primary care physicians to treat the patients’ metabolic bone disease also? And do cardiologists identify metabolic bone disease in patients with HF?"
Dr. Jurkovitz, a physician scientist with Christiana Care Health System in Newark, Del., and her associates compared the management of CKD-associated metabolic bone disease between patients with and without HF who were treated at a local nephrology practice between 2000 and 2010. They evaluated the medical records of 11,883 patients with CKD stage 3 and above, and excluded dialysis and transplant patients. The researchers calculated average calcium, phosphorus, and intact parathyroid hormone (iPTH) by radioimmunoassay for each patient, and used multilinear regressions to determine the effects of CKD and HF on calcium, phosphorus, and iPTH after controlling for age, race, and gender.
The mean follow-up of the 11,883 patients was 4 years. Of these, nearly one-quarter (24%) had HF at baseline, while 76% had stage 3 CKD, 22% had stage 4 CKD, and 2% had stage 5 CKD. Patients with HF were slightly older, with a mean of 69 years, than were their counterparts without HF, who had a mean 66 years.
Dr. Jurkovitz and her associates found that the adjusted mean for calcium was significantly lower in patients with HF at each CKD stage. The interaction between CKD and HF was statistically significant. The adjusted means for phosphorus and iPTH were significantly higher in patients with HF at each CKD stage, while the interactions between CKD and HF were not significant.
"Physicians need to be concerned about the management of chronic kidney disease in their patients with HF, and the management of metabolic bone disease addressed on a case by case basis in a dialogue between the cardiologists, nephrologists, and primary care physicians," she concluded.
The meeting was sponsored by the American Society of Nephrology. Dr. Jurkovitz said that she had no relevant financial conflicts to disclose.