Among people with chronic kidney disease (CKD), nocturnal stage I hypertension significantly increases the risk for CKD progression, results of a new retrospective cohort study showed.
These findings “stress the role of out-of-office blood pressure measurements, including nocturnal blood pressure,” said senior author of the study, Xinying Jiang, MD, of the Division of Nephrology, Department of Medicine, The Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai, China.
“Clinicians should avoid dismissing nocturnal stage I hypertension in non-dialysis CKD patients, since it is associated with renal outcomes,” Jiang told Medscape Medical News.
With the known bidirectional relationship between CKD and hypertension, blood pressure management is essential in CKD, and studies have underscored that nocturnal blood pressure, measured with ambulatory blood pressure monitoring, can provide a fuller picture vs daytime-only office measurements in determining the risk for adverse outcomes.
To further investigate the risks, Jiang and colleagues enrolled 2418 participants with CKD stage I through stage IV at two centers in China between August 2010 and December 2024, who were not receiving dialysis. The results of the study were published in JAMA Network Open.
Study Details
The participants (58.4% male; mean age, 45.4 years) were categorized per 2025 American College of Cardiology/American Heart Association guidelines into the following groups: no nocturnal hypertension (blood pressure, < 110/65 mm Hg; n = 436 [18%]), stage I (nocturnal blood pressure, 110-120/65-70 mm Hg; n = 345 [14.3%]), or stage II (nocturnal blood pressure, > 120/70 mm Hg; n = 1637 [67.7%]).
Over a median follow-up of 3.9 years, there were 394 cases of the composite outcome of kidney failure requiring replacement therapy (203) and worsening kidney function (235) overall.
The incidence rates for the composite kidney failure outcome were 29.1 and 28.6 per 1000 person-years in the non-hypertension and stage I hypertension groups, respectively, and a higher rate of 63.7 per 1000 person-years among those with stage II hypertension.
For the primary outcome, after a multivariate adjustment for age and sex, nocturnal stage I hypertension was associated with a significantly increased risk for the composite kidney outcome (hazard ratio [HR], 2.49), kidney failure requiring replacement therapy (HR, 2.37), and worsening kidney function (HR, 3.79) compared with nocturnal non-hypertension.
In a further propensity score matching analysis, involving 292 patients with stage I hypertension vs non-hypertension patients and 363 patients with stage II hypertension vs non-hypertension patients (1:1 matching for each group), those with stage I and stage II hypertension remained at a significantly higher risk for the composite kidney outcome (P = .03 and P = .01, respectively).
Patients with stage I nocturnal hypertension remained at a significantly higher risk than those with no hypertension after adjustment for daytime systolic blood pressure (HR, 2.10).
In a further analysis, 13.4% of patients had nocturnal isolated diastolic hypertension (NIDH), 2.7% had nocturnal isolated systolic hypertension (NISH), and 65.9% had nocturnal systolic and diastolic hypertension (NSDH).
After adjusting for age, sex, and BMI, the HR for the composite kidney outcome was 2.88 for the patients with NIDH, 3.34 for those with NISH, and 5.61 for those with NSDH.
Lower Nocturnal Blood Pressure a Problem in Older Patients?
In contrast with the overall results, patients aged 65 years or older showed a higher risk for the composite CKD outcome when their nocturnal blood pressure was lower (< 110/65 mm Hg) than with stage I hypertension (HR, 5.50; P = .04) and also had a higher risk of worsening kidney function (HR, 5.65; P = .05).
“This suggests that excessively low nocturnal blood pressure may be detrimental and increase the risk of adverse events in older patients with CKD,” Jiang and his colleagues wrote.
But Jiang cautioned that the small sample size and low event rates prevent any firm conclusions regarding nocturnal non-hypertension and older patients.
Of note, however, previous research indicated that in older patients with CKD, office systolic blood pressure < 120 mm Hg is associated with increased mortality. And studies have also shown that in older and frail patients in particular, intensive blood pressure reductions are associated with a higher risk for adverse events, including acute kidney injury and hypotension.
Commenting on the study, Peter W. de Leeuw, MD, PhD, of Maastricht University Medical Center, Maastricht, Netherlands, agreed that the findings in older patients should be cautiously interpreted.
“This was a retrospective study in patients not on dialysis,” he told Medscape Medical News.
“It may very well be that younger patients had already started on replacement therapy and that the older group comprised patients in whom the decision to start dialysis was postponed for whatever reason,” he said. “In that case, you end up with a population with a worse prognosis regardless of the nocturnal pressure.”
The study also is limited by the Chinese-only population; however, de Leeuw noted that even when evaluated in non-Chinese populations, “I do not think that this will lead to fundamentally different results.”
The study ultimately underscores that “we should pay more attention to nocturnal pressure,” he said.
“The role of nocturnal pressure was already known but is further strengthened by this study.”
The Need for Better Home Blood Pressure Monitoring
While home blood pressure monitoring is recommended among patients with CKD in Kidney Disease: Improving Global Outcomes guidelines, another recent study, published in JAMA Cardiology, found low rates of home-based monitoring, even among higher-risk patients with CKD and other risk factors, despite being provided with personal support.
The study included 3390 patients with a median age of 61 years with uncontrolled hypertension and other comorbidities, including nearly 30% with diabetes. Only 34.8% had high engagement with home blood pressure monitoring, and 32.7% had no engagement at all — not transmitting a single home blood pressure reading.
“Engagement was not meaningfully higher among patients with CKD, diabetes, or other comorbidities associated with elevated cardiovascular risk,” first author Ozan Unlu, MD, of the Accelerator for Clinical Transformation, Brigham and Women’s Hospital, Boston, told Medscape Medical News.
While the overall degree of low engagement was surprising, the lack of a difference between at-risk subgroups was not, Unlu noted.
“Hypertension is largely asymptomatic, and the perceived immediate benefit of repeated blood pressure measurements is often low for patients, even when long-term risk is high,” he explained.
Importantly, traditional home blood pressure monitoring protocols impose a burden that is not trivial, he said, requiring frequent, repeated measurements over sustained periods. “For patients with CKD or diabetes, this burden is layered on top of already complex treatment regimens, polypharmacy, and multiple competing health priorities,” he added.
The findings overall “highlight the need for monitoring strategies that are less burdensome, more patient-centered, and better integrated into routine care, especially for patients already managing complex, high-intensity treatment regimens,” Unlu said.
Jiang, Unlu, and de Leeuw reported having no disclosures.
<
Leave a Reply