Ambulatory and laboratory blood pressure in individuals with negative and positive family history of hypertension.

Undertook 24-hr ambulatory blood pressure (BP) monitoring in men and women with and without family history of essential hypertension. Cardiovascular functions were also recorded in the laboratory during mental arithmetic, image star tracing, isometric exercise, and the cold pressor test. Ambulatory daytime, but not nighttime, systolic and diastolic BP as well as heart rate (HR) level and variability was higher in those with than without family history. During sleep, HR level and variability were higher among those with family history; at rest in the laboratory, however, all cardiovascular functions were similar in both groups. The strongest laboratory-based predictor of daytime BP was stress-induced BP levels. BP reactivity also significantly predicted daytime BP but with less accuracy. The best predictor of BP and HR at sleep was resting cardiovascular functions. Thus, ambulatory BP recordings add information to resting and stress-induced levels in identifying cardiovascular risk reactions.