Simple predictive score for nocturnal hypertension and masked nocturnal hypertension using home blood pressure monitoring in clinical practice

OBJECTIVE: The decision whether to measure night-time blood pressure (BP) is challenging as these values cannot be easily evaluated because of problems with measurement devices and related stress. Using the nationwide, practice-based Japan Morning Surge-Home BP Nocturnal BP study data, we developed a simple predictive score that physicians can use to diagnose nocturnal hypertension. METHODS: We divided 2765 outpatients (mean age 63 years; hypertensive patients 92%) with cardiovascular risks who underwent morning, evening, and night-time home BP (HBP) measurements (0200, 0300, and 0400 h) into a calibration group ( n = 2212) and validation group ( n = 553). We used logistic-regression models in the calibration group to identify the predictive score for nocturnal hypertension (night-time HBP ≥120/70 mmHg) and then evaluated the score's predictive ability in the validation group. RESULTS: In the logistic-regression model, male sex, increased BMI) (≥25 kg/m 2 ), diabetes, elevated urine-albumin creatinine ratio (UACR) (≥30 mg/g Cr), elevated office BP (≥140/90 mmHg) and home (average of morning and evening) BP (≥135/85 mmHg) had positive relationships with nocturnal hypertension. The predictive scores for nocturnal hypertension were 1 point (male, BMI, and UACR); 2 points (diabetes); 3 points (office BP ≥140/90 mmHg); 6 points (home BP ≥135/85 mmHg); total 14 points. Over 75% of the nocturnal hypertension cases in the validation group showed at least 10 points [AUC 0.691, 95% CI (0.647-0.735)]. We also developed a score for masked nocturnal hypertension, that is, nocturnal hypertension despite controlled daytime HBP. CONCLUSION: We developed a simple predictive score for nocturnal hypertension that can be used in clinical settings and for diagnoses.