Seasonal variation in diurnal blood pressure pattern

Aims To explore the relationship between diurnal blood pressure (BP) pattern and season. Methods A total of 6765 eligible patients (average age 57.35 +/- 15.53 years; male 51.8%; hypertensives 68.8%) from 1 October 2016 to 6 April 2022 were enrolled, who were divided into four dipper groups, dipper, non-dipper, riser, and extreme-dipper, according to the diurnal BP pattern calculated using their ambulatory BP monitoring data. The season which the patient was in was determined by the time of ambulatory BP monitoring examination. Results Among the 6765 patients, 2042 (31.18%) were grouped into dipper, 380 (5.6%) into extreme-dipper, 1498 (22.1%) into riser and 2845 (42.1%) into non-dipper. Only the dipper subjects showed age difference among seasons, with the average age significantly lower in winter. There was no seasonal difference in age for the other types. No seasonal difference was revealed in gender, BMI, hypertension or not. Diurnal BP patterns significantly differed among seasons (P < .001). Post hoc tests with Bonferroni correction indicated the significantly different diurnal BP pattern between any two seasons (P < .001), but not between spring and autumn (P = .257), and the significance of the P value was assessed at 0.008 (0.05/6) after Bonferroni correction. Multinomial logistic regression suggested season as an independent contributor to diurnal BP pattern. Conclusion Diurnal BP pattern is influenced by season.