Opposite seasonal variation in nighttime and morning blood pressure: a longitudinal study of patients with hypertension.

In 30 seconds

This longitudinal study examined seasonal variations in nighttime and morning blood pressure (BP) among 419 hypertensive patients using home blood pressure monitoring. Results indicated that nighttime systolic BP was significantly higher in summer than in winter, with an adjusted mean difference of 8.3 mmHg. Conversely, morning systolic BP was lower in summer.

Key findings

• Nighttime systolic BP was elevated in summer compared to winter, with an adjusted mean difference of 8.3 mmHg.
• Among winter-to-summer participants, nighttime systolic BP increased by 5.1 mmHg.
• Morning systolic BP decreased by 3.8 mmHg in summer among winter-to-summer participants.
• Seasonal variations in room temperature correlated positively with nighttime BP changes (r = 0.43).

Why it matters

Understanding seasonal variations in blood pressure can help clinicians better manage hypertension, particularly in adjusting treatment strategies during warmer months when nighttime BP may be elevated.