High Nighttime Blood Pressure May Warn of Faster Kidney Disease Progression in Kids

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Elevated nighttime blood pressure may be a warning sign that a child with kidney disease is at risk of faster progression, according to an abstract presented at Kidney Week.

Hypertension is a risk factor for kidney disease, and is linked to faster progression. Typically, physicians monitor blood pressure with readings during clinic visits. However, use of 24-hour ambulatory blood pressure monitoring is increasing, and emerging data suggest that high nighttime blood pressure may be a particularly important risk factor in kidney disease. For example, a recent study in adults with kidney disease suggested that elevated nighttime blood pressure may lead to worse organ damage (Wang C, et al. PLoS One 2015; 10:e0131546).

Now, Mónica Guzmán-Limón, MD, a nephrology and hypertension fellow at the McGovern Medical School at the University of Texas Health Science Center, and her colleagues show that nighttime hypertension is also an important risk factor for children with CKD. They analyzed results from 1195 24-hour blood pressure monitoring studies from 693 children ages 1 to 16 enrolled in the Chronic Kidney Disease in Children (CKiD) study. Children who had nocturnal only hypertension experienced faster kidney decline than children with normal blood pressure, and children who had elevated blood pressure both day and night had the fastest progression. For children with nonglomerular kidney disease, high nocturnal blood pressure was associated with worsening outcome with a Hazard Ratio (HR) of 1.80 compared to normotensive children (p=0.02), and those who had high blood pressure around the clock had a HR of 2.37 (p=0.001).

“Our study highlights the importance of normal nighttime blood pressure in children with chronic kidney disease,” said Guzmán-Limón. “This study highlights the importance of ambulatory blood pressure monitoring to aid in the management of patients with chronic kidney disease.”

The findings confirm the baseline data out of the CKiD study that nocturnal hypertension is more common than daytime hypertension, said Janis Dionne, MD, a clinical associate professor and pediatric nephrologist at the University of British Columbia, and show that having both high daytime and nighttime blood pressure is most strongly linked to the risk of progression.

“It reinforces that we need to use [24-hour ambulatory blood pressure monitoring] in pediatric hypertension and pediatric kidney disease,” Dionne said. But she noted that payers poorly reimburse such monitoring, if it is reimbursed at all.

“Physicians need to advocate to get them done in their patients,” she said.

Why nocturnal high blood pressure is associated with worse outcomes isn’t yet clear. It might be a cause or marker of renal or systemic vascular changes, Dionne noted.

Guzmán-Limón suggested nighttime control of blood pressure may be an important means to delay kidney disease progression.

There is definitely room for improvement in hypertension treatment in this population, said Dionne, as many children with CKD and hypertension are not currently taking antihypertensive medication. But she noted that additional research is needed to determine if such treatment improves patient outcomes and, if so, what are the best treatment options.

“Nocturnal hypertension is common and is associated with CKD progression in chronic kidney disease” (Abstract 2756651)