LAUSR

OBJECTIVE The decision whether to measure nighttime blood pressure (BP) is challenging because these values cannot be easily evaluated due to 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. DESIGN AND METHOD We divided 2,765 outpatients (mean age 63 years; hypertensives 92%) with cardiovascular risks who underwent morning, evening, and nighttime home BP (HBP) measurements (2:00, 3:00, and 4:00 a.m.) into a calibration group (n = 2,212) and validation group (n = 553). We used logistic-regression models in the calibration group to identify the predictive score for nocturnal hypertension (nighttime 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 body mass index (BMI) (> = 25 kg/m2), diabetes, elevated urine-albumin creatinine ratio (UACR) (> = 30 mg/g Cr), elevated office BP (> = 140/90 mmHg), and elevated morning and evening HBP (> = 135/85 mmHg) had positive relationships with nocturnal hypertension. The predictive scores for nocturnal hypertension were 1-point (male, BMI, diabetes, and UACR); 2-points (office BP > = 140/90 mmHg); 3-points (evening HBP > = 135/85 mmHg); 4-points (morning HBP > = 135/85 mmHg); total 13 points. Over 80% of the nocturnal hypertension cases in the validation group showed > = 10-points (AUC = 0.705, 95%CI: 0.661-0.748). We also developed a score for masked nocturnal hypertension, i.e., nocturnal hypertension despite controlled daytime HBP. CONCLUSIONS We developed a simple predictive score for nocturnal hypertension that can be used in clinical settings and for diagnoses.