Research and Development of Information and Communication Technology-based Home Blood Pressure Monitoring from Morning to Nocturnal Hypertension

Abstract

Asians have specific characteristics of hypertension (HTN) and its relationship with cardiovascular disease. The morning surge in blood pressure (BP) in Asians is more extended, and the association slope between higher BP and the risk for cardiovascular events is steeper in this population than in whites. Thus, 24-hour BP control including at night and in the morning is especially important for Asian patients with HTN. There are 3 components of "perfect 24-hour BP control": the 24-hour BP level, adequate dipping of nocturnal BP (dipper type), and adequate BP variability such as the morning BP surge. The morning BP-guided approach using home BP monitoring (HBPM) is the first step toward perfect 24-hour BP control. After controlling morning HTN, nocturnal HTN is the second target. We have been developing HBPM that can measure nocturnal BP. First, we developed a semiautomatic HBPM device with the function of automatic fixed-interval BP measurement during sleep. In the J-HOP (Japan Morning Surge Home Blood Pressure) study, the largest nationwide home BP cohort, we successfully measured nocturnal home BP using this device with data memory, 3 times during sleep (2, 3, and 4 am), and found that nocturnal home BP is significantly correlated with organ damage independently of office and morning BP values. The second advance was the development of trigger nocturnal BP (TNP) monitoring with an added trigger function that initiates BP measurements when oxygen desaturation falls below a variable threshold continuously monitored by pulse oximetry. TNP can detect the specific nocturnal BP surges triggered by hypoxic episodes in patients with sleep apnea syndrome. We also added the lowest heart rate-trigger function to TNP to detect the "basal nocturnal BP," which is determined by the circulating volume and structural cardiovascular system without any increase in sympathetic tonus. This double TNP is a novel concept for evaluating the pathogenic pressor mechanism of nocturnal BP. These data are now collected using an information and communication technology (ICT)-based monitoring system. The BP variability includes different time-phase variability from the shortest beat-by-beat, positional, diurnal, day-by-day, visit-to-visit, seasonal, and the longest yearly changes. The synergistic resonance of each type of BP variability would produce great dynamic BP surges, which trigger cardiovascular events. Thus, in the future, the management of HTN based on the simultaneous assessment of the resonance of all of the BP variability phenotypes using a wearable "surge" BP monitoring device with an ICT-based data analysis system will contribute to the ultimate individualized medication for cardiovascular disease.

An overview of hypertension and cardiac involvement in Asia: Focus on heart failure

“…There are significant ethnic differences in the determinants of hypertension and the risk of hypertension‐related demographics of CVD . In Asian countries, stroke and nonischemic HF are more common than in the Western countries.…”

Understanding short-term blood-pressure-variability phenotypes: from concept to clinical practice

“… 58 Various causes for the absence of dipping have been proposed including sleep disturbance, depression, obesity, obstructive sleep apnea, orthostatic hypotension, autonomic dysfunction, chronic kidney disease, diabetic neuropathy, and old age. 23 , 59 – 61…”

“…Nocturnal hypertension is defined as having an average of nocturnal BP values of ≥ 120/70 mmHg and is generally caused by a failure in nocturnal dipping and hence usually observed in nondippers or reverse dippers. 59 It is especially important to control nocturnal BP, as it is more likely to represent the patient’s actual BP more closely, as it is often not influenced by the pressor effects of physical, emotional, and other environmental factors that occur during the day. 14 Moreover, patients with nocturnal hypertension have been found to be at significantly higher risk of organ damage and cardiovascular events, independently of OBP or morning BP values.…”

“… 14 Moreover, patients with nocturnal hypertension have been found to be at significantly higher risk of organ damage and cardiovascular events, independently of OBP or morning BP values. 59 , 64 , 80 – 82 Nocturnal BP has also been found to be a superior predictor of cardiovascular disease than daytime BP. 45 , 83 Previously, nocturnal hypertension was able to be detected only by ABPM.…”

Systemic Hemodynamic Atherothrombotic Syndrome and Resonance Hypothesis of Blood Pressure Variability: Triggering Cardiovascular Events

“… 16) There is growing evidence that variability of each of these types of BP is associated with organ damage and cardiovascular disease. 15) 16) 23) 24) 25) 26) 27) 28) 29) 30) 31) 32) 33) 34) 35) 36) 37) 38) 39) 40) 41) 42) 43) 44) 45) Each type of BP variability increases with aging due to baroreflex dysfunction and small artery remodeling. Although most of these phenotypes of BP variability are partly correlated with each other, 18) 46) 47) 48) the degree of augmentation of each type of BP variability differs from person to person.…”