Factors affecting differences in supine, sitting, and standing heart rate: the Israeli CORDIS Study.
BACKGROUND
Measuring postural changes is among the simplest methods to elicit basic cardiovascular responses from patients who should not be subjected to treadmill stress testing. We attempted to clarify the individual factors that may affect these changes in resting heart rate (HR).


METHODS
In a cross-sectional study, 6016 employees in Israeli industries were screened during 1985-87 for cardiovascular disease risk factors (The CORDIS Study). Measures of resting HR (supine, sitting, and standing) were obtained from 5428 subjects. The association between the HR differences for different postures and age, sex, height, body mass index, blood pressure level, health related habits, environmental temperature, and time of the day was analyzed.


RESULTS
The difference in HR between supine and standing position was found to be greater among women than men (12.7 vs. 11.6%, p < 0.03). It was independently positively associated with height (p < 0.0001), cigarette smoking (p < 0.0001), and coffee drinking (p < 0.001), and inversely associated with age (p < 0.002), blood pressure level (p < 0.0005), and physical activity at work (p < 0.0001).


CONCLUSIONS
The interindividual variability in HR response to different postures is partially explained by individual variables such as age, sex, height, blood pressure level, and health-related habits.
D000328:Adult; D015986:Confounding Factors, Epidemiologic; D003430:Cross-Sectional Studies; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011187:Posture / Q000502:physiology*; D012737:Sex Factors; D016683:Supine Position / Q000502:physiology