Chronic kidney disease (CKD) represents a significant global health burden [1]. In Asian populations, CKD may increase the lifetime risk for stroke, particularly in young individuals, highlighting the importance of early prevention and appropriate management [2]. While blood pressure (BP) levels, especially nighttime BP, have been associated with the incidence of CKD in the general Asian populations [3,4,5,6], further research is needed on the relationship between time-specific BP patterns and prognosis in patients with CKD. Due to factors, including impaired natriuresis during the daytime or volume overload, attenuated baroreflex sensitivity, dysregulated damaged sympathetic modulation of nighttime BP, or sleep disorders, patients with CKD commonly exhibit abnormal circadian BP rhythms, characterized primarily by the absence of nocturnal BP dipping [3, 6].

Recent research by Li et al. provided compelling evidence for the prognostic value of nocturnal BP in patients with CKD [7]. Their cohort study of 1051 patients with CKD showed that nighttime systolic BP was superior to other BP parameters in predicting clinical outcomes. Their findings demonstrated a linear relationship between nocturnal systolic BP and multiple outcomes, including all-cause mortality, cardiovascular disease (CVD) mortality, CVD events, and renal events. Notably, maintaining nighttime systolic BP below 124 mmHg was associated with a lower cardiovascular risk, whereas levels below 110 mmHg corresponded to better renal outcomes. The association between nighttime BP and these outcomes persisted after adjusting for 24-h BP measurements, suggesting that elevated nighttime BP, which reflects altered circadian variation, may independently predict adverse outcomes.

A previous multicenter study by Minutolo et al. focusing on patients with CKD suggested that nighttime BP control might be more strongly associated with the risks of cardiovascular and renal outcomes than daytime BP control in an Italian population [8]. Their study population (n = 436) was characterized by high antihypertensive medication use (91%), hypertensive nephropathy (42%), diabetic nephropathy (20%), and glomerulonephritis (8%) as the primary underlying conditions [8]. In contrast, the Asian CKD patient study by Li et al. presented a different demographic profile: 46% were on antihypertensive therapy, and the primary etiology was glomerulonephritis (65%), followed by diabetic kidney disease (18%), and hypertensive nephropathy (4%) [7]. Despite these demographic and clinical differences, the superior prognostic value of nighttime BP over daytime BP has been confirmed [7], which is consistent with a previous study [8]. Although diabetes mellitus and hypertension are the leading causes of CKD worldwide [1], glomerulonephritis is also a prevalent concern in low- and middle-income countries [9]. Li et al. [7] highlighted the growing importance of nighttime BP monitoring in these regions. However, these findings [7, 8] do not negate the importance of daytime measurements in CKD populations. Daytime BP also correlates well with various outcomes, although its predictive power may be relatively weaker [7, 8]. Another small study in a CKD population demonstrated that daytime and nighttime BP appeared to be similarly associated with composite outcomes [10].

Despite the clinical significance of nighttime BP measurements [6, 11,12,13], practical challenges persist. First, nighttime BP measurements generally require patients to visit specialized clinics using ambulatory BP monitoring (ABPM) devices. Few officially approved devices are available to consumers. Second, patients face a considerable burden of wearing an ABPM device throughout the day and night. Sleep disruption during measurement remains a major concern limiting ABPM frequency. Third, even with accurate nighttime measurements, definitive evidence regarding optimal therapeutic strategies is lacking. The clinical significance of specifically targeting nighttime BP, particularly in addressing impaired nocturnal dipping, remains unclear. This may represent a critical gap in translating nighttime BP measurements into practical therapeutic interventions.

In this commentary, we attempt to assess ABPM usage in Japan by summarizing the National Database Open Data (1st–9th) of the Ministry of Health, Labour, and Welfare [14]. Since ABPM is covered by medical insurance in Japan, we can track annual ABPM claims [14]. As shown in Fig. 1, our summary indicates that the annual number of 24-h ABPM insurance claims has decreased over the past decade. Although further investigation is required to determine the cause of this decrease, ABPM utilization appears to be declining, at least in Japanese clinical practice. Addressing the aforementioned ABPM challenges helps resolve this situation.

Fig. 1
figure 1

Annual Number of Insurance Claims for 24-h ABPM in Japan. The graph shows the annual number of insurance claims for 24-h ambulatory blood pressure monitoring (ABPM) in Japan by fiscal year. Data represent the total number of ABPM procedures performed under medical insurance, regardless of the number of unique patients. The data were obtained from the National Database Open Data (1st–9th) of the Ministry of Health, Labour and Welfare in Japan [14]

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Home BP measurement has an established clinical value in BP management [3, 15]. Some home BP devices can measure nighttime BP, which is associated with a higher cardiovascular risk, and could serve as a provisional alternative to nighttime BP using ABPM [16,17,18]. Although wrist-type cuff devices for home BP measurement may reduce sleep disturbance during nighttime BP measurement, their measurement accuracy requires careful evaluation [19, 20]. However, evidence on the utility of nighttime home BP measurements in patients with CKD remains scarce and requires further investigation. Cuffless devices using optical or microelectromechanical systems show potential for minimal sleep disruption; however, their accuracy is currently unproven and awaits technological advancement [21].

The findings of Li et al. [7] reinforced the significance of nighttime BP measurements in patients with CKD. Investigation of population-specific differences in nighttime BP outcome associations may help refine risk assessments and treatment strategies across diverse geographic and demographic contexts. Concurrent priorities include implementing nighttime BP monitoring in clinical practice, evaluating whether home BP device-based nighttime measurements improve health outcomes in patients with CKD, and establishing evidence for therapeutic strategies targeting nighttime BP based on patient characteristics.