Vitamin D ‘does not improve’ cardiac outcomes in CKD
MedWire News: Vitamin D therapy does not improve cardiac structure, function, or left ventricular mass in patients with chronic kidney disease (CKD), researchers say.
Although primarily recommended for improving bone health, treatment with vitamin D has recently been suggested for cardiovascular disease (CVD), explain Ravi Thadhani (Massachusetts General Hospital, Boston, USA) and co-authors in JAMA.
In the current study, they investigated whether 48-week therapy with the vitamin D compound paricalcitol would alter ventricular mass index or improve certain measures of diastolic dysfunction in patients with chronic kidney disease.
The randomized controlled trial was conducted between July 2008 and September 2012. It involved 227 patients with CKD (estimated glomerular filtration rate [eGFR] of 15-60 mL/min/1.73 m2), mild to moderate left ventricular hypertrophy (LVH; septal wall thickness of 1.1-1.7 cm in women, 1.2-1.8 cm in men), and preserved left ventricular ejection fraction (<50%).
All participants were randomly allocated to receive treatment with either oral paricalcitol 2 µg per day (n=115) or matching placebo (n=112).
Overall, 85.7% of the paricalcitol group and 16.5% of the placebo group demonstrated a reduction in intact parathyroid hormone (iPTH) level of more than 30% by week 48 (p<0.001).
The primary endpoint of the study - change in left ventricular mass index - did not differ significantly between the two groups.
Doppler measures of diastolic function, including peak early diastolic lateral mitral annular tissue velocity, also did not differ significantly between the paricalcitol and placebo groups.
However, there were significantly fewer hospitalizations for CVD events in the paricalcitol group, at 1.1 compared with 8.8 hospitalizations per 100 person-years in the placebo group (p=0.04).
Although plasma B-natriuretic peptide level was increased in both groups at 48 weeks, it was attenuated in the paricalcitol group compared with the placebo group, at respective increases of 21% and 41%. This association persisted after adjusting for changes in eGFR.
Hypercalcemia was significantly more common in paricalcitol- than placebo-treated patients (22.6 vs 0.9%; p<0.001).
Editorialists Stefan Anker and Stephan von Haehling from Charité Campus Virchow-Klinikum in Berlin, Germany, say that paricalcitol cannot be recommended for CKD patients at this time, adding that a larger trial powered for clinical endpoints must be conducted.
"Considering the competition for public funding of clinical trials in CKD, the provitamin D research groups may face an uphill battle to keep this treatment option viable for patients with CKD."
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By Piriya Mahendra