Asbjørn Høegholm

24-h ambulatory blood pressure in 352 normal Danish subjects, related to age and gender

UNLABELLED The study was conducted to determine age and sex stratified normal values for 24-h ambulatory blood pressure. A sample of 352 healthy subjects (all white) were randomly selected from the community register and stratified by sex and age groups in decades from 20 to 79 years of age. Persons with a history of hypertension, cerebral apoplexy, diabetes, myocardial or renal disease, and who were taking blood pressure-influencing medication were excluded. Ambulatory blood pressure was recorded over 24 h, with measurements taken every 15 min from 07:00 to 22:59, and every 30 min from 23:00 to 6:59. Systolic blood pressure increased only slightly with age and was significantly higher in men than in women. The diastolic blood pressure increased only slightly with age in both sexes until the 50 to 59 years age group and declined thereafter. The diastolic blood pressure was not different for the two sexes. Both systolic and diastolic blood pressure were approximately 15% lower during the night regardless of age or sex. Ambulatory blood pressure during the daytime was on an average of 5 mm Hg lower than office blood pressure, but the mean difference between the two measurements increased with age. The variability of the difference also increased with age. IN CONCLUSION Normal values for ambulatory blood pressure are presented in a randomly selected age- and gender-stratified population. Differences between office blood pressure and ambulatory blood pressure increased with age suggesting that the previously observed higher blood pressure seen in the elderly partly might be explained by a greater impact of white coat hypertension in older people.

No impact of blood pressure variability on microalbuminuria and left ventricular geometry: analysis of daytime variation, diurnal variation and ‘white coat’ effect

ObjectiveTo investigate the influence of blood pressure variability on target organ involvement. MethodsUsing a cross‐sectional study of a hypertension clinic at a district general hospital, 420 patients with newly diagnosed untreated essential hypertension referred on a consecutive basis from general practice and 146 normal subjects drawn at random from the Danish National Register underwent a variety of measurements which included: echocardiography with determination of left ventricular mass index and relative wall thickness and early morning urine albumin/creatinine ratio. Mean, standard deviation and coefficient of variation of automated clinic values; daytime, night‐time and full 24‐h period were extracted from 24‐h ambulatory blood pressure (ABP) monitoring. ‘White coat’ effect and dip were calculated. Hypertensives were classified into subjects with high or low variability, into ‘white coat’ hypertensives or established hypertensives and into dippers or non‐dippers. ResultsStandard deviation of daytime blood pressure (BP) was positively associated with target organ damage and BP level, which was not the case when variability was expressed as a coefficient of variation. Patients with high variability exhibited no more significant target organ damage than patients with low variability, but patients with established hypertension had significantly more target organ damage than the ‘white coat’ hypertensives. The ‘white coat’ effect as such was not associated with increased target organ involvement. Non‐dippers had significantly more cardiac target organ damage than dippers, but the difference disappeared after correction for different 24‐h BP level. ConclusionBP variability data obtained by non‐invasive ABP monitoring does not seem to improve the information inherent in the BP level.

White coat hypertension and blood pressure variability

The objective of this cross-sectional study was to investigate blood pressure variability and pulse pressure in white coat hypertensives in comparison to established hypertensives and normal subjects. Four hundred and twenty patients were referred consecutively from general practice with newly diagnosed untreated essential hypertension. One hundred and forty-six control subjects were drawn at random from the Danish national register. Seventy-six patients from the former group were considered white coat hypertensive using a normalcy cutoff level of 135/90 mm Hg. Mean, standard deviation, and coefficient of variation of the blood pressures from the automated clinic readings, daytime, nighttime, and full 24-h periods were extracted from 24-h ambulatory blood pressure monitorings. Mean arterial pressure, pulse pressure, white coat effect, and dip were calculated in all three groups of subjects. The main findings were that white coat hypertensives did not differ significantly from normotensives regarding variability data except for the white coat effect. However, the white coat hypertensives had a significantly lower pulse pressure than the established hypertensives, according to clinic blood pressure and ambulatory readings. We conclude that white coat hypertension evaluated with indirect ambulatory blood pressure monitoring is not a state with a generally higher blood pressure variability than normotension or established hypertension. The patients with white coat hypertension have pulse pressure at the same level as normal controls, but significantly lower than established hypertensives.