Chronic Kidney Disease Linked to Uncontrolled Blood Pressure
Chronic kidney disease (CKD) is associated with uncontrolled blood pressure (BP), while ambulatory BP patterns are not associated with cognitive impairment or frailty in non-dialysis-dependent CKD patients, according to two studies published in the Clinical Journal of the American Society of Nephrology. For the first study, researchers compared the prevalence of BP phenotypes between 561 black patients with and without CKD taking antihypertensive medication. After multivariable adjustment, CKD was associated with increased prevalence ratios for uncontrolled versus controlled clinic BP (prevalence ratio, 1.44) and sustained uncontrolled versus sustained controlled BP (prevalence ratio, 1.66). For the second study, investigators examined the association between ambulatory BP patterns, cognitive function, physical function, and frailty among 1,502 non-dialysis-dependent CKD patients. At baseline, 129 and 275 patients had cognitive impairment and were frail, respectively; during 4 years of follow-up, 529 had incident frailty and 207 had incident cognitive impairment. The researchers found that in the fully adjusted model, participants with masked hypertension had 0.41 lower short physical performance battery scores compared with those with controlled hypertension. No association between BP or dipping patterns and incident frailty or cognitive impairment was seen after multivariable adjustment. “Future analyses should focus on exploring the association between BP and dipping patterns and change in physical functioning over time, as well as obtaining measures of cognitive function and physical functioning over a longer follow up time,” write the authors of the second study.
BP Load No Aid to Prognosis in Pediatric Chronic Kidney Disease
Blood pressure (BP) load does not provide additive value in predicting outcomes in children with chronic kidney disease (CKD), according to a study published online March 11 in the Clinical Journal of the American Society of Nephrology. Researchers used data from 533 children participating in the Chronic Kidney Disease in Children Study to determine the prevalence of normotension, isolated BP load elevation (≥25% of all readings elevated, but mean BP normal), and ambulatory hypertension. The study team found that 23% of the cohort had isolated BP load elevation, but isolated BP load elevation was not significantly associated with left ventricular hypertrophy (LVH; odds ratio [OR], 1.8) or end-stage kidney disease (ESKD; hazard ratio, 1.2). Every 10% increase in systolic BP load was associated with higher odds of LVH (OR, 1.1), but discrimination for LVH was poor. Every 10% increase in systolic BP load was associated with a 1.2-fold higher risk for ESKD, but discrimination for ESKD was also poor. Systolic BP load was not statistically significantly associated with either LVH or ESKD when adjusting for mean systolic BP. For diastolic BP load, findings were similar. “Our data suggest that the proportion of readings on a 24-hour BP test that are high may not provide additional insight beyond the average BP values surrounding a child’s risk for developing cardiac disease or worsening kidney disease,” a co-author said in a statement. “However, having a high average blood pressure on a 24-hour blood pressure test does strongly predict a child’s cardiac and kidney disease risk.”