Dear Editor,

We read with great interest the recent article by Kario et al. entitled “Peak nocturnal home blood pressure as an early and strong novel risk factor for stroke: the practitioner-based nationwide J-HOP Nocturnal BP study” published in Hypertension Research [1]. The investigators provide compelling evidence that peak nocturnal home systolic blood pressure (SBP)—defined as the average of the three highest readings across a 14-day period—is a robust predictor of stroke risk, independent of office, morning, evening, and mean nighttime BP. With a mean follow-up of 7.1 years, participants in the highest quintile (≥149 mmHg) exhibited more than fourfold higher risk of stroke compared with those in the lowest quintile, and the association strengthened when analyses were restricted to individuals with ≥6 nighttime readings. Spline regression identified 136 mmHg as a practical cut-off. These findings move risk assessment beyond mean values, highlighting the prognostic relevance of extreme nocturnal surges.