Home blood pressure measurement of hypertensive patients with cognitive impairment—Is it “environmental pressure”?

The ability to use everyday technology has become important to perform daily life activities, maintain an autonomous life, and participate in society. However, understanding this issue in the elderly, especially in patients with cognitive impairment, requires more attention [1]. Difficulties using everyday technology might be a symptom of mild cognitive impairment (MCI), and can lead to Alzheimer’s disease (AD) [2].

From a conceptual view point, Lawton’s person-environment fit framework may provide the hint to understand this issue [3]. In that framework, the environmental docility hypothesis addresses the consequence of a mismatch between environmental demand and a person’s resource [4, 5]. In the elderly having difficulty operating modern devices, advanced technology increases the “environmental pressure”, which may hinder the adaptation of dementia patients [3].

In fact, people with MCI have been identified as significantly more disabled in use of modern equipment compared to cognitive healthy controls [1]. The perceived difficulty and difficulty of using the modern equipment was lowest in healthy control, followed by MCI, and highest in AD group [6]. Regarding number of errors in modern equipment use, there was significant difference between the three groups of subjective memory complaints, MCI and AD. The disability to use modern equipment begins with a stage of subjective memory complaints and continues from MCI to AD [2]. Therefore, there is a need for medical professionals to be fully aware of these points when requesting use of modern equipment such as home blood pressure (BP) (HBP) monitoring for elderly hypertensives.

In this issue of the journal, Hoshide et al. [7] reported the 303 ambulatory elderly patients in whom Montreal cognitive assessment (MoCA)-J had been assessed, who were instructed to take HBP for 5 days. After adjusting for confounders, fewer days of HBP measurements were independently associated with MoCA-J scores and cognitive impairment [7]. These results suggest that MCI, AD, and vascular dementia (VaD) were highly prevalent in elderly hypertensive patients with an average age of 77 years, and that difficulty using HBP measurement devices was an indicator of cognitive impairment (Fig. 1).

Possible mechanisms for the relationship between incompliance with home blood pressure measurement and cognitive impairment. HBPM indicates home blood pressure measurement, BP blood pressure, MCI mild cognitive impairment, MBs microbleeds, AD Alzheimer’s disease, VaD vascular dementia

In a previous study, participants with MCI made more errors using a HBP monitor than healthy controls. Frequent errors included incorrect arm position or placement of the cuff [1]. In the Three-City study, the significant relationship between HBP measurement incompliance and low mini-mental state examination score was shown in the age- and sex- adjusted model. Depression, apathy, or nonautonomous might coexist the relationship between HBP measurement incompliance and cognitive impairment [8, 9].

There is no doubt that HBP measurement is important for strict control of hypertension, but on the other hand, poor compliance to HBP measurements is also a significant problem for hypertensive patients. In Italian outpatient hypertensives [10], a total of 50% of participants rested for at least 5 min before measurement, 37% recorded BP multiple times during each measurement, and 34% took a chair or bed saddle for lumbar support. Less than 40% of the patients received some form of training by health professionals [10]. In hypertensive patients with poor HBP measurement compliance, a significant number of patients may suffer from cognitive impairment.

Recent research has begun to attempt to improve compliance through interventions for hypertensive patients who have difficulty using HBP monitoring devices. HBP measurement programs with provider feedback can be successfully implemented within daily clinical practice, and it can play an important role in BP control and cardiovascular disease risk reduction in hypertensives with poor HBP measurement compliance [11]. In a community-based nurse-led training program, a multicenter randomized controlled trial was conducted in hypertensive patients. After 1 month, compared with usual care group, the HBP measurement adherence significantly increased in the intervention group, where patients were more likely to measure BP at the same time and from the same arm, in a quiet environment, with correct posture [12]. These programs are effective in improving patients’ adherence to self-measured BP at home, and can be added to human-led hypertension management models in community.

With advances in technology, many devices have been developed in the medical field, and the opportunities for patients to use them at home are increasing. Healthcare professionals need to be cognizant about the limitations faced by patients in using modern equipment for health care purposes. Incompliance to HBP measurements may serve as a surrogate marker for cognitive impairment-related issues and help identify such patients early. Potentially, community-based interventions lead to help improve compliance with use of such equipment and also targeted strategies to improve cognitive limitations. Furthermore, the elderly hypertensives over 70 years of age also have a higher prevalence of heart failure [13]. This population will also greatly benefit from daily HBP monitoring and weight monitoring, which may ultimately contribute to the prevention of cognitive decline. The study by Hoshide et al. [7] can be further expanded in the future, to better elucidate the underlying mechanism, degree of cognitive impairment, prognosis of conversion to dementia and intervention methods in the population with low HBP measurement compliance.