Nocturnal Dialysis Improves Kidney Patients' Heart Function

A new study shows that compared with conventional hemodialysis (CHD), in-hospital nocturnal dialysis (INHD) is associated with a significant reduction in the thickness of the heart wall.

Researchers at St. Michael’s Hospital (Toronto, ON, Canada) conducted a prospective cohort study involving 67 prevalent CHD recipients at two medical centers in Canada, of whom 37 were converted to INHD and 30 remained on CHD. The primary outcome was change in left ventricular mass (LVM) after one year, as assessed by cardiac magnetic resonance imaging. Secondary outcomes included changes in serum phosphate concentration, phosphate binder burden, hemoglobin, erythropoiesis stimulating agent usage, and blood pressure.

The results showed that conversion to INHD was associated with a 14.2 gram reduction in LVM, as compared with continuation on CHD. A trend toward a larger drop in systolic blood pressure among INHD recipients was also evident, with a concomitant significant reduction in the number of prescribed antihypertensive agents. Serum phosphate also declined among INHD recipients without any difference in calcium-based phosphate binder requirements, as compared with those who remained on CHD. The study was published on July 9, 2015, in the Canadian Journal of Cardiology.

“This study is good news in several ways; it suggests there is a cardiovascular benefit for people who are receiving in-hospital nocturnal dialysis and it may encourage other kidney patients to switch to this more intense form of dialysis,” said lead author nephrologist Ron Wald, MD. “In addition to the potential health benefits, nighttime dialysis may free up patients' daytime hours to do the things that hemodialysis treatments typically disrupt such as employment, child care, and household chores.”

Patients with end-stage renal disease (ESRD) who receive chronic dialysis have high rates of CVD and resulting death, with about 15%–20% of them dying each year from CVD. Interventions that reduce the risk of CVD in the general population have less success with dialysis patients, suggesting there may be unique mechanisms driving CVD in patients with advanced kidney disease. The dialysis procedure itself, especially when performed on a conventional schedule of 12 hours a week, may also promote or exacerbate CVD.

INHD is long, slow, gentle, and generally self-performed dialysis, usually undertaken at home, but can also be provided in “sleep-over” centers. It can be performed from every alternate night and up to 6–7 nights per week. As a result, INHD delivers up to four times the amount of dialysis compared to CHD. Advantages include minimal fluid or dietary restrictions, and no need for phosphate binding or blood pressure medication for most patients.

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