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Assessment of age-dependent changes in circadian blood pressure rhythm in patients with essential hypertension
1Second Department of Medicine, Tohoku University School of Medicine, Sendai, Japan.
Insights
Age impacts circadian blood pressure rhythms in hypertensive patients, with younger hypertensives showing altered systolic and diastolic blood pressure acrophases compared to older hypertensives and normotensive individuals.
Area of Science:
- Cardiology
- Chronobiology
- Hypertension Research
Background:
- Essential hypertension is a common cardiovascular condition.
- Circadian rhythms play a crucial role in blood pressure regulation.
- Age-related changes in circadian blood pressure patterns are not fully understood.
Purpose of the Study:
- To investigate the influence of age on the circadian blood pressure rhythm in patients with untreated essential hypertension.
- To compare these age-related patterns with those observed in normotensive subjects.
Main Methods:
- 24-hour ambulatory blood pressure monitoring was performed on 133 hypertensive and 91 normotensive subjects.
- Subjects were categorized into young (<40), adult (40-59), and old (≥60) age groups.
- The single cosinor method was employed to analyze circadian rhythm parameters (amplitude, acrophase).
Main Results:
- Circadian blood pressure rhythm amplitude showed no significant age-related differences in either hypertensive or normotensive groups, though it was wider in hypertensives.
- Circadian heart rate rhythm amplitude decreased with age in both groups.
- Younger hypertensives exhibited a significantly different acrophase for systolic and diastolic blood pressure compared to older hypertensives and young normotensives.
Conclusions:
- Age-related alterations in circadian blood pressure rhythm acrophase are specific to hypertensive individuals.
- Younger hypertensive patients display distinct circadian blood pressure patterns compared to their older counterparts and normotensive individuals.
- These findings highlight potential age-specific chronobiological dysregulation in essential hypertension.
Abstract:
The effects of age on the circadian blood pressure rhythm of patients with untreated essential hypertension (n = 133, World Health Organization stage I or II) were compared with those of normotensive subjects (n = 91). Subjects were classified into three groups by age: young (less than 40 years old), adult (40-59 years old) and old (greater than or equal to 60 years old). Blood pressure was monitored every 5 min for 24 h, using a finger volume oscillometric device under fixed external conditions. The single cosinor method was used to evaluate circadian rhythm. There was no difference in the amplitude of circadian systolic or diastolic blood pressure rhythm among the different normotensive and essentially hypertensive age groups although a wide distribution of amplitude was noted within each group. The distribution of amplitude was wider in the hypertensive than in the normotensive groups. The amplitude of circadian blood pressure rhythm was independent of the mesor level. On the other hand, the amplitude of circadian heart rate rhythm decreased with increasing age both in normotensive subjects (P less than 0.05, young versus adult or old) and hypertensive patients (P less than 0.01, young and old versus adult). The acrophase of circadian systolic blood pressure rhythm in young hypertensives was greater than that in adult or old hypertensives (P less than 0.05, for both). Such age-dependent changes were not observed in the normotensive groups. Consequently, the acrophase of circadian systolic or diastolic blood pressure rhythm in young hypertensives was larger than that in young normotensives (P less than 0.05, for both systolic and diastolic blood pressure).(ABSTRACT TRUNCATED AT 250 WORDS)