Ambulatory Blood Pressure Monitoring and Postprandial Hypotension in Elderly Patients with Isolated Systolic Hypertension
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Journal of Human Hypertension (1998) 12, 161–165 1998 Stockton Press. All rights reserved 0950-9240/98 $12.00 ORIGINAL ARTICLE Ambulatory blood pressure monitoring and postprandial hypotension in elderly patients with isolated systolic hypertension T Grodzicki1, M Rajzer2, R Fagard3, ET O’Brien4, L Thijs3, D Clement5, C Davidson6, P Palatini7, G Parati8, J Kocemba1 and JA Staessen3, on behalf of the Systolic Hypertension in Europe (SYST-EUR) Trial Investigators 1Department of Gerontology and Family Medicine, Jagiellonian University, Cracow, Poland; 21st Department of Cardiology, Jagiellonian University, Cracow, Poland; 3Syst-Eur Coordinating Office, Universitaire Ziekenhuizon UZ Gasthuisberg, Leuven, Belgium; 4Blood Pressure Unit, Beamont Hospital, Dublin, Ireland; 5Department of Cardiology and Angiology, University Hospital, Gent, Belgium; 6Royal County Hospital, Brighton, UK; 7Policlinico, Padua, Italy; 8Centro di Fisiologia Clinica e Ipertensione, Ospedale Maggiore, Milan, Italy The present analysis was undertaken to evaluate post- in the 2 h before and after the meal, both SBP and DBP prandial (PP) changes in blood pressure (BP) assessed decreased significantly (respectively −6.6 mm Hg, −5.4 with ambulatory BP monitoring (ABPM) in elderly sub- mm Hg; P Ͻ 0.001). In 67.6% of all patients a decrease jects with isolated systolic hypertension (ISH) on con- in SBP was observed and in 24.1% it exceeded 16 ventional measurement. A total of 530 patients (335 mm Hg. The corresponding values for DBP were 71.3% women and 195 men, aged 60–100 years, median 70 and 24.5% (DBP decreased more than 12 mm Hg). A years) who performed an ABPM during the placebo run- greater fall in DBP was associated with a greater in period of the Syst-Eur trial were included into the decrease in HR (r = 0.20, P Ͻ 0.001), while changes in analysis. The PP changes in BP and heart rate (HR) were SBP and HR were not interrelated. Regression analysis calculated by subtracting the mean systolic BP (SBP), did not identify any significant covariate of PPH. Group diastolic BP (DBP) and HR in the 2 h preceding the main means of PPH could be reproduced without significant meal from the corresponding means covering the 2 h changes in their values, but the within-subject repro- after the meal. The reproducibility of the postprandial ducibility of the PP changes was low. There were no dif- fall in BP and heart rate (PPH) was assessed by con- ferences in PPH according to the place of residence of trasting the first and second ABPM in a subgroup of 147 the patients. In conclusion, the descriptive analysis of patients who performed two ABPM’s during the placebo the meal-induced changes in ABPM in elderly subjects run-in period. The mean SBP and DBP decreased and with ISH showed that in every day circumstances most reached the nadir 2 h after the main meal while HR did of them experience falls in both SBP and DBP within 2 h not change. When PPH was assessed by comparing BP after the meal. Keywords: postprandial hypotension; isolated systolic hypertension; elderly; ambulatory blood pressure monitoring; SYST- EUR Introduction suggested as a reason of this phenomenon.1,4 Age- associated cardiovascular changes such as arterial Significant reductions in blood pressure (BP) after stiffness and left ventricular diastolic dysfunction mixed-meals or oral glucose have been observed in may cumulatively produce alterations in BP regulat- elderly healthy, hypertensive or diabetic patients, ory mechanisms that impair an older person’s and in patients with Parkinson’s disease or auto- 5 1–3 ability to adapt to hypotensive stress. Moreover, the nomic insufficiency. Although the underlying blunted baroreceptor reaction in elderly hyper- mechanisms are not well established, the increase tensive patients may be partially responsible for in concentration of vasoactive gastrointestinal pep- profound postprandial hypotention. It has been tides or insulin-related vasodilatation have been demonstrated that patients with a history of falls or syncope present with a more distinct BP decrease after meals.6 Correspondence: Dr Tomasz Grodzicki, Dept of Gerontology and Family Medicine, School of Medicine, Jagiellonian University, Isolated systolic hypertension (ISH) remains an Wielicka 267, 30-663 Cracow, Poland important feature of aging associated with a dimin- Received 3 May 1997; revised and accepted 13 October 1997 ished baroreceptor function and susceptibility to ABPM and postprandial BP in isolated systolic hypertension T Grodzicki et al 162 orthostatic hypotention.7 Nowadays, 24-h ambulat- ory BP monitoring (ABPM) is used widely in research and everyday clinical practice and remains the method of choice to evaluate fluctuations in BP in hypertensive and normotensive subjects. As to the best of our knowledge the literature describing the influence of meals on the 24-h BP profile is scarce, it seemed interesting to undertake the present analysis to evaluate changes in BP in patients with ISH in relation to the main meal. Patients and methods The protocol of the multicentre SYST-EUR trial and its side-project on ABPM has been published else- where.8,9 After discontinuation of all anti-hyperten- sive drugs, the participants (у60 years) first entered a single-blind period on placebo, during which eli- gible patients maintained a sitting systolic BP (SBP) of 160–219 mm Hg and a diastolic BP (DBP) below 95 mm Hg on conventional measurement. Ambulat- ory pressure was recorded non-invasively at inter- vals not greater than 30 min. A total of 578 patients included into the SYST-EUR (on August 1995) had their ABPM measured at least once during the pla- cebo run-in period phase. Of these 48 were excluded from the analysis because their ABPM recordings were incomplete (n = 26), the time of the main meal was missing (n = 18) or BP measurements during 1 h Figure 1 Means of SBP, DBP and heart rate before and after preceding or after meal were missing (n = 4). The main meal. ABPM recordings of the remaining 530 patients were included into analysis. In a subgroup of 147 Results patients ABPM had been repeated during the base- line period on placebo. The ABPM recordings of 530 patients were included The postprandial change in BP and heart rate (HR) into analysis. This group consisted of 335 women was calculated by subtracting the mean SBP, DBP and 195 men, aged 60–100 years (median 70 years), and HR in the 2 h preceding the main meal with mean body mass index of 26.9 ± 4.2 kg/m2 (according to the patients’ diaries) from the corre- (women) and 26.2 ± 3.4 kg/m2 (men). Cardiovascular sponding means from the 2 h after the main meal. complications were present in 27% of the patients. All analyses were performed in the entire group of The main meal was taken between 10.30 am and patients (n = 530) and separately in subjects taking 11.00 pm, but 95% of patients took their main meal their main meal between 11.00 am and 2.00 pm (n between 11.45 am and 7.00 pm. = 296), and between 5.00 pm and 8.00 pm (n = 130). In the entire group SBP and DBP decreased after the main meal reaching a minimum 1–2 h after the main meal. Heart rate was similar before and after Statistical analysis the main meal (Figure 1). When the postprandial change in BP was assessed by comparing the average Database management and statistical analyses were BP in the 2 h before and after the meal both SBP performed with the SAS software (The SAS institute and DBP decreased significantly but HR remained Inc, Cary, NC, USA). Unless otherwise indicated the unchanged (Table 1). The analysis of these changes standard deviation (s.d.) was used to report the according to the time of the main meal did not reveal spread of the results. In order to identify factors that any differences between subjects who had their may contribute to the postprandial BP fall, a sub- main meal in the afternoon or in the evening. The group and single and multiple linear regression analyses were performed. For multiple means com- parisons Ducan’s test was used. The reproducibility Table 1 Postprandial changes in systolic (SBP), diastolic (DBP) of the postprandial changes in BP was assessed by blood pressure and heart rate (HR) contrasting the first and second BP monitoring. The repeatability coefficients were calculated as 2 s.d. of Mean ± s.d. Confidence the differences between repeated measurements. To interval allow comparisons between various measurements SBP (mm Hg) −6.6 ± 13.8*** −7.77; −5.43 the repeatibility coefficients were expressed as per- DBP (mm Hg) −5.4 ± 10.9*** −6.33; −4.47 centages of nearly maximal biological variation, ie, Pulse rate (bpm) −0.1 ± 8.7 −0.84; +0.64 four times the s.d. of the averaged duplicate measurements. ***P Ͻ 0.001. ABPM and postprandial BP in isolated systolic hypertension T Grodzicki et al 163 Table 2 Reproducibility of the postprandial changes in blood pressure and pulse rate Change Consistency Repeatability (mm Hg) (mm Hg) (mm Hg) (%) SBP −0.5 9.3 (0.6–31.3) 29 (68%) DBP −1.0 7.2 (0.7–28.1) 25 (70%) Heart rate −1.6 5.7 (0.8–23.1) 24 (79%) Change = mean difference between duplicate recordings taking into account the sign of the difference. Consistency = median difference between duplicate recordings, disregarding the sign of the difference (5th and 95th percentile range in parentheses). Repeatability = twice the standard deviation of the changes between repeated recordings (percent of maximal variation in parentheses). litus, R-wave amplitude in aVL and the Sokolov + Figure 2 Histogram of the postprandial changes in SBP.