Twenty-four hour ambulatory blood pressure in a population of elderly men

Sources of inaccuracy in the measurement of adult patients' resting blood pressure in clinical settings: a systematic review

BACKGROUND

To interpret blood pressure (BP) data appropriately, healthcare providers need to be knowledgeable of the factors that can potentially impact the accuracy of BP measurement and contribute to variability between measurements.

METHODS

A systematic review of studies quantifying BP measurement inaccuracy. Medline and CINAHL databases were searched for empirical articles and systematic reviews published up to June 2015. Empirical articles were included if they reported a study that was relevant to the measurement of adult patients' resting BP at the upper arm in a clinical setting (e.g. ward or office); identified a specific source of inaccuracy; and quantified its effect. Reference lists and reviews were searched for additional articles.

RESULTS

A total of 328 empirical studies were included. They investigated 29 potential sources of inaccuracy, categorized as relating to the patient, device, procedure or observer. Significant directional effects were found for 27; however, for some, the effects were inconsistent in direction. Compared with true resting BP, significant effects of individual sources ranged from -23.6 to +33 mmHg SBP and -14 to +23 mmHg DBP.

CONCLUSION

A single BP value outside the expected range should be interpreted with caution and not taken as a definitive indicator of clinical deterioration. Where a measurement is abnormally high or low, further measurements should be taken and averaged. Wherever possible, BP values should be recorded graphically within ranges. This may reduce the impact of sources of inaccuracy and reduce the scope for misinterpretations based on small, likely erroneous or misleading, changes.

Predictors of the Home-Clinic Blood Pressure Difference: A Systematic Review and Meta-Analysis

BACKGROUND

Patients may have lower (white coat hypertension) or higher (masked hypertension) blood pressure (BP) at home compared to the clinic, resulting in misdiagnosis and suboptimal management of hypertension. This study aimed to systematically review the literature and establish the most important predictors of the home-clinic BP difference.

METHODS

A systematic review was conducted using a MEDLINE search strategy, adapted for use in 6 literature databases. Studies examining factors that predict the home-clinic BP difference were included in the review. Odds ratios (ORs) describing the association between patient characteristics and white coat or masked hypertension were extracted and entered into a random-effects meta-analysis.

RESULTS

The search strategy identified 3,743 articles of which 70 were eligible for this review. Studies examined a total of 86,167 patients (47% female) and reported a total of 60 significant predictors of the home-clinic BP difference. Masked hypertension was associated with male sex (OR 1.47, 95% confidence interval (CI) 1.18–1.75), body mass index (BMI, per kg/m² increase, OR 1.07, 95% CI 1.01–1.14), current smoking status (OR 1.32, 95% CI 1.13–1.50), and systolic clinic BP (per mm Hg increase, OR 1.10, 95% CI 1.01–1.19). Female sex was the only significant predictor of white coat hypertension (OR 3.38, 95% CI 1.64–6.96).

CONCLUSIONS

There are a number of common patient characteristics that predict the home-clinic BP difference, in particular for people with masked hypertension. There is scope to incorporate such predictors into a clinical prediction tool which could be used to identify those patients displaying a significant masked or white coat effect in routine clinical practice.

Age and the difference between awake ambulatory blood pressure and office blood pressure: a meta-analysis

BACKGROUND

Ambulatory blood pressure (BP) (ABP) is a better predictor of adverse cardiovascular events than office BP (OBP). Owing to the extensive literature on the 'white coat effect', it is widely believed that ABP tends to be lower than OBP, with statements to this effect in Joint National Committee VII. However, recent evidence suggests that the difference varies systematically with age.

METHODS

We searched PubMed to identify population studies, published before April 2009, which assessed OBP and either ABP or home BP (HBP). On account of significant heterogeneity in the outcomes, random effect models were used for the meta-analyses.

RESULTS

OBP increased with age more steeply than awake ABP. OBP became higher than awake systolic/diastolic ABP at the age of 51.3/42.7 years in men (13 studies, N=3562) and 51.9/42.3 years in women (11 studies, N=2585). In the data in which OBP and HBP were measured (eight studies, N=4916), OBP was higher than HBP at all ages. In the data in which OBP, awake ABP, and HBP were all measured (two studies, N=895), awake ABP was higher than HBP at younger ages, becoming similar at the older age.

CONCLUSION

OBP tends to be higher than awake ABP only after the age of 50 years for systolic and after the age of 45 years for diastolic BP, but is lower than ABP at younger ages; in contrast OBP tends to exceed HBP at all ages.

Innovations in health care services: the CAALYX system

PURPOSE

This paper describes proposed health care services innovations, provided by a system called CAALYX (Complete Ambient Assisted Living eXperiment). CAALYX aimed to provide healthcare innovation by extending the state-of-the-art in tele-healthcare, by focusing on increasing the confidence of elderly people living autonomously, by building on the knowledge base of the most common disorders and respective characteristic vital sign changes for this age group.

METHODS

A review of the state-of-the-art on health care services was carried out. Then, extensive research was conducted on the particular needs of the elderly in relation to home health services that, if offered to them, could improve their day life by giving them greater confidence and autonomy. To achieve this, we addressed issues associated with the gathering of clinical data and interpretation of these data, as well as possibilities of automatically triggering appropriate clinical measures. Considering this initial work we started the identification of initiatives, ongoing works and technologies that could be used for the development of the system. After that, the implementation of CAALYX was done.

FINDINGS

The innovation in CAALYX system considers three main areas of contribution: (i) The Roaming Monitoring System that is used to collect information on the well-being of the elderly users; (ii) The Home Monitoring System that is aimed at helping the elders independently living at home being implemented by a device (a personal computer or a set top box) that supports the connection of sensors and video cameras that may be used for monitoring and for interaction with the elder; (iii) The Central Care Service and Monitoring System that is implemented by a Caretaker System where attention and care services are provided to elders, where actors as Caretakers, Doctors and Relatives are logically linked to elders. Innovations in each of these areas are presented here.

CONCLUSIONS

The ageing European society is placing an added burden on future generations, as the 'elderly-to-working-age-people' ratio is set to steadily increase in the future. Nowadays, quality of life and fitness allows for most older persons to have an active life well into their eighties. Furthermore, many older persons prefer to live in their own house and choose their own lifestyle. The CAALYX system can have a clear impact in increasing older persons' autonomy, by ensuring that they do not need to leave their preferred environment in order to be properly monitored and taken care of.

Definition of ambulatory blood pressure targets for diagnosis and treatment of hypertension in relation to clinic blood pressure: prospective cohort study

BACKGROUND

Twenty-four hour ambulatory blood pressure thresholds have been defined for the diagnosis of mild hypertension but not for its treatment or for other blood pressure thresholds used in the diagnosis of moderate to severe hypertension. We aimed to derive age and sex related ambulatory blood pressure equivalents to clinic blood pressure thresholds for diagnosis and treatment of hypertension.

METHODS

We collated 24 hour ambulatory blood pressure data, recorded with validated devices, from 11 centres across six Australian states (n=8575). We used least product regression to assess the relation between these measurements and clinic blood pressure measured by trained staff and in a smaller cohort by doctors (n=1693).

RESULTS

Mean age of participants was 56 years (SD 15) with mean body mass index 28.9 (5.5) and mean clinic systolic/diastolic blood pressure 142/82 mm Hg (19/12); 4626 (54%) were women. Average clinic measurements by trained staff were 6/3 mm Hg higher than daytime ambulatory blood pressure and 10/5 mm Hg higher than 24 hour blood pressure, but 9/7 mm Hg lower than clinic values measured by doctors. Daytime ambulatory equivalents derived from trained staff clinic measurements were 4/3 mm Hg less than the 140/90 mm Hg clinic threshold (lower limit of grade 1 hypertension), 2/2 mm Hg less than the 130/80 mm Hg threshold (target upper limit for patients with associated conditions), and 1/1 mm Hg less than the 125/75 mm Hg threshold. Equivalents were 1/2 mm Hg lower for women and 3/1 mm Hg lower in older people compared with the combined group.

CONCLUSIONS

Our study provides daytime ambulatory blood pressure thresholds that are slightly lower than equivalent clinic values. Clinic blood pressure measurements taken by doctors were considerably higher than those taken by trained staff and therefore gave inappropriate estimates of ambulatory thresholds. These results provide a framework for the diagnosis and management of hypertension using ambulatory blood pressure values.

Low ambulatory blood pressure is associated with lower cognitive function in healthy elderly men

INTRODUCTION

Low blood pressure (BP) has been found to be associated with cerebrovascular damage in the elderly. Studies of the relation of ambulatory BP to cognitive function in elderly persons aged 80 years or above is lacking, however.

METHODS

Ninety-seven 81-year-old men from the population study 'Men born in 1914' underwent ambulatory BP monitoring and were given a cognitive test battery, 79 subjects completing all six tests. Low ambulatory systolic blood pressure (SBP) was defined as <130 mmHg and low ambulatory diastolic blood pressure (DBP) as <80 mmHg (corresponding in terms of office BP to approximately <140 and <90 mmHg, respectively). Odds ratios (OR) for lower cognitive function were calculated using a forward stepwise logistic regression model, controlling for confounding factors.

RESULTS

Subjects with ambulatory SBP <130 mmHg had higher OR values for daytime (OR 2.6; P=0.037), nighttime (OR 3.6; P=0.032) and 24h (OR 2.6; P=0.038) BP measurements. A lower cognitive function was associated with lower nighttime SBP and DBP levels and lower 24-h mean SBP compared to subjects with higher cognitive function. OR values connected to low nocturnal SBP, had a tendency to be particularly high among subjects on anti-hypertensive drugs (OR 9.1; P=0.067, n.s.).

CONCLUSION

Ambulatory SBP levels <130 mmHg and lower nighttime SBP and DBP were associated with lower cognitive function in healthy elderly men. Further investigation is needed to ascertain the effects of the presently recommended treatment goal of <140 mmHg for office SBP also on elderly over 80 years of age.

Myocardial delayed contrast enhancement in patients with arterial hypertension: initial results of cardiac MRI

PURPOSE

In arterial hypertension left ventricular hypertrophy comprises myocyte hypertrophy, interstitial fibrosis and structural alterations of the coronary microcirculation. MRI enables the detection of myocardial fibrosis, infarction and scar tissue by delayed enhancement (DE) after contrast media application. Aim of this study was to investigate patients with arterial hypertension but without known coronary disease or previous myocardial infarction to detect areas of DE.

METHODS AND MATERIAL

Twenty patients with arterial hypertension with clinical symptoms of myocardial ischemia, but without history of myocardial infarction and normal coronary arteries during coronary angiography were investigated on a 1.0 T superconducting magnet (Gyroscan T10-NT, Intera Release 8.0, Philips). Fast gradient-echo cine sequences and T2-weighted STIR-sequences were acquired. Fifteen minutes after injection of Gadobenate dimeglumine inversion recovery gradient-echo sequences were performed for detection of myocardial DE. Presence or absence of DE on MRI was correlated with clinical data and the results of echocardiography and electrocardiography, respectively.

RESULTS

Nine of 20 patients showed DE in the interventricular septum and the anteroseptal left ventricular wall. In 6 patients, DE was localized intramurally and in 3 patients subendocardially. There was a significant correlation between myocardial DE and ST-segment depressions during exercise and between DE and left-ventricular enddiastolic pressure. Patients with intermittent atrial fibrillation showed a myocardial DE more often than patients without atrial fibrillation.

CONCLUSION

In our series, 45% of patients with arterial hypertension showed DE on cardiac MRI. In this clinical setting, delayed enhancement may be due to coronary microangiopathy. The more intramurally localization of DE, however, rather indicates myocardial interstitial fibrosis.

The period of hypotension following orthostatic challenge is prolonged in dementia with Lewy bodies

OBJECTIVES

To determine whether orthostatic hypotension (OH) is more common in patients with dementia than in older people without cognitive impairment and to identify key differences in the profile of the orthostatic response and the pulse drive during orthostatic challenge between Alzheimer's disease (AD) and dementia with Lewy bodies (DLB).

METHODS

The orthostatic response was evaluated in 235 patients with AD, 52 patients with DLB and 62 elderly controls. The blood pressure and pulse rate were measured in supine position, immediately after standing up and after 1, 3, 5 and 10 min of standing. OH was defined as a reduction of systolic blood pressure (SBP) of at least 20 mm Hg or a reduction of diastolic blood pressure (DBP) of at least 10 mm Hg.

RESULTS

OH occurred in 69% of the DLB patients and in 42% of the AD patients, but only in 13% of the controls (p<0.001 controls vs AD and controls vs DLB, p=0.001 AD vs DLB) The DLB patients had a greater drop in SBP than the other study groups during orthostatic challenge and had a more prolonged period of orthostasis. The pulse drive on orthostatic challenge was similar in between groups. However, in the DLB group it was not adequate to restore the blood pressure to supine values.

CONCLUSIONS

Patients with DLB react different to orthostatic challenge than patients with AD or controls, with important clinical implications for key disease symptoms and treatment.

hUNC-93B1, a novel gene mainly expressed in the heart, is related to left ventricular diastolic function, heart failure morbidity and mortality in elderly men

AIMS

The hUNC-93B1 gene has the highest expression in the heart. We aimed to explore relationships between the hUNC-93B1 gene and cardiac function, morbidity and mortality in elderly men.

METHODS AND RESULTS

Two sub-samples of the population-based ULSAM-cohort (n=330, mean age 71 years and n=152, mean age 75 years, respectively) were used to explore and validate relationships between genotypes of the hUNC-93B1 gene and cardiac phenotypes (ejection fraction, E/A-ratio, left ventricular mass index and relative wall thickness). In the two samples, subjects homozygous for haplotype H3 had 34% and 35% higher level of E/A-ratio compared to non-carriers (p=0.0002 and 0.017, respectively) independent of cardiovascular disease and medication. Using national cause-of-death and hospital-discharge register data with 29 years of follow-up, no heart failure patients homozygous for haplotype H3 were hospitalised for heart failure before the age of 75 years, compared to 25% for heterozygous and 55% for non-carriers (p<0.03). No homozygous subjects died during follow-up while 17% of the heterozygous and 15% of the non-carriers died (p=0.01).

CONCLUSION

Haplotype H3 of the hUNC-93B1 gene seems related to E/A-ratio in elderly men. The relationship between the hUNC-93B1 gene and the age at onset of heart failure and mortality support a view of a clinically relevant impact of the gene.

Use of a mild sedative helps to identify true non-dippers by ABPM: a study in patients with diabetes mellitus and hypertension

BACKGROUND

The interplay between the continuity or quality of sleep and diurnal variation in blood pressure has not been directly examined before. We examined the influence of a mild, non-hypotensive sedative on nocturnal dipping.

DESIGN

This was a randomized, single-blind study.

SETTING

The study took place in an out-patient clinic in an academic hospital.

INTERVENTION

Zolpidem 10 mg or placebo was given randomly for the first or second night, and ambulatory blood pressure monitoring was instigated for 48 h.

PATIENTS

The population under study comprised 96 male patients with type 2 diabetes mellitus and hypertension (mean age 54 +/- 6 years, mean blood pressure 158/94 +/- 9/6 mmHg).

MAIN OUTCOME MEASURE

Nocturnal dipping (nocturnal blood pressure >/= 10% lower than daytime pressure) was found in 71% of the patients taking the sedative compared with 27% of those on placebo (P=0.001).

RESULTS

On placebo, non-dippers and dippers had similar profiles of cardiovascular risk parameters. In contrast, non-dippers taking zolpidem had significantly higher values for most cardiovascular risk parameters compared with dippers: higher systolic blood pressure, higher low-density lipoproteins, lower high-density lipoproteins, higher serum creatinine, a higher urinary albumin:creatinine ratio, higher serum insulin and insulin resistance.

CONCLUSION

The use of a mild sedative during ambulatory blood pressure monitoring may help to identify the patients with a very high cardiovascular risk. These are the patients with a blunted nocturnal hypotension despite sedation.

Twenty-four-hour ambulatory blood pressure in community-dwelling elderly men and women, aged 60-102 years

OBJECTIVE

To investigate ambulatory blood pressure in elderly people, including 'old elderly' subjects, aged over 80 years.

DESIGN

Cross-sectional study of community-dwelling, elderly subjects.

METHODS

Subjects were healthy, self-caring, and living independently. Those who were taking medication affecting blood pressure were excluded. Conventional blood pressure was the mean of two measurements. Ambulatory blood pressure monitoring was performed using the SpaceLabs 90207 device. Daytime and night-time blood pressure were defined by fixed clock intervals.

RESULTS

Seventy-five 'young elderly', aged 60-79 years, (39 men, 36 women) and 81 'old elderly' aged 80 years and older (37 men, 44 women) underwent 24-h ambulatory blood pressure monitoring. Systolic blood pressure (SBP) was related to age, correlation coefficients between age and SBP were 0.31, 0.25 and 0.31, respectively, for conventional SBP, daytime SBP and night-time SBP (P < 0.01 for all). There was no correlation between age and diastolic blood pressure. Blood pressure levels were similar in men and women. Mean conventional blood pressure, daytime blood pressure and night-time blood pressure were found to be 149/81, 138/82 and 119/69 mmHg, respectively, in the 'young elderly' and 162/82, 147/83, and 133/71 mmHg, respectively, in the 'old elderly (P < 0.01 for SBP). The night : day SBP ratio was significantly higher in the 'old' elderly compared with the 'young' elderly (0.90 versus 0.86, respectively; P < 0.01).

CONCLUSIONS

Ambulatory blood pressure levels in healthy, community-dwelling 'old elderly' are higher than those reported for younger adults and reflect the prominent age-related rise in SBP associated with advanced old age. Advanced old age is associated with a diminished nocturnal dip in blood pressure.

Isolated ambulatory hypertension predicts cardiovascular morbidity in elderly men

BACKGROUND

Little is known about isolated ambulatory hypertension, a state with elevated ambulatory but normal office blood pressure (BP). This study aimed to investigate the prognostic significance of isolated ambulatory hypertension for cardiovascular morbidity in a population of elderly men.

METHODS AND RESULTS

At baseline, 24-hour ambulatory BP and metabolic and cardiac risk profiles were evaluated in 578 untreated 70-year-old men, participants of a population-based cohort. Subjects with isolated ambulatory hypertension (office BP <140/90 and daytime BP > or =135/85) and sustained hypertension (office BP > or =140/90 and daytime BP > or =135/85) had increased plasma glucose, body mass index, and echocardiographically determined left ventricular relative wall thickness compared with normotensive subjects (office BP <140/90 and daytime BP <135/85). Seventy-two cardiovascular morbid events (2.37 per 100 person-years at risk) occurred over 8.4 years of follow-up. The prognostic value of isolated ambulatory and sustained hypertension was assessed with Cox proportional hazard regression. Multivariate models adjusting for serum cholesterol, smoking, and diabetes demonstrated that both isolated ambulatory hypertension (hazard ratio [HR], 2.77; 95% CI, 1.15 to 6.68) and sustained hypertension (HR, 2.94; 95% CI, 1.49 to 5.82) were independent predictors of cardiovascular morbidity. In a multivariate model with continuous BP variables, ambulatory daytime systolic BP (HR for 1 SD increase, 1.47; 95% CI, 1.09 to 1.97) was associated with an adverse outcome independently of office systolic BP.

CONCLUSIONS

In the present study, isolated ambulatory hypertension as well as sustained hypertension predicted cardiovascular morbidity. The findings suggest that 24-hour ambulatory BP monitoring may disclose important prognostic information also in subjects characterized as normotensive according to office BP.

Blood pressure response to hyperventilation test reflects daytime pressor profile

Recent studies show that healthy subjects and patients with moderate hypertension have different pressor responses to hyperventilation, depending on their sympathoadrenergic reactivity. In the present study, we investigated whether a different response to the hyperventilation test is related to differences in the daily blood pressure profiles recorded with noninvasive ambulatory monitoring. Forty-five healthy subjects and 67 patients with essential hypertension of grades 1 and 2 (Joint National Committee VI and World Health Organization) were investigated. Healthy subjects and hypertensive patients responding to hyperventilation with an increase in systolic blood pressure had, during daytime ambulatory blood pressure assessment, peak systolic blood pressure values (146.0+/-5.0 mm Hg, 182.2+/-9.0 mm Hg, respectively) similar to the hyperventilation peak systolic blood pressure values (147.2+/-3.5 mm Hg, 183.0+/-4.7 mm Hg, respectively). Hypertensive patients responding to hyperventilation with a decrease in blood pressure showed clinic systolic blood pressure values (178.4+/-3.2 mm Hg) higher than daytime average ambulatory systolic blood pressure (155.2+/-7.1 mm Hg; P<0.01). Our results indicate that a hyperventilation test yields information on daily peak blood pressure values in healthy subjects and hypertensive patients when it induces a pressor increase and can identify hypertensive patients with the so-called "white coat effect" when it induces a pressor decrease.

The majority of nondipping men do not have increased cardiovascular risk: a population-based study

OBJECTIVE

To investigate whether nondipping and diabetes are independently related to metabolic risk profile and prevalence of target organ damage in a population setting.

METHODS

A population-based cohort of 70-year-old men (n = 1057) was examined with 24-h ambulatory blood pressure monitoring, euglycemic hyperinsulinemic clamp and lipid and glucose determinations. We defined nondipping as a night-day systolic blood pressure ratio >or= 1 (n = 66). Urinary albumin excretion rate and echocardiographically determined left ventricular geometry were used as indices of target organ damage.

RESULTS

Nondipping was not related to hypertension, but diabetes was more common in nondippers (26%) than in dippers (14%, P < 0.05). Nondiabetic nondippers did not differ from dippers regarding insulin sensitivity, plasma glucose or lipids. However, nondipping in diabetic subjects was associated with the most pronounced impairments in body mass index, serum triglycerides and fasting plasma glucose. Measures of target organ damage did not differ between nondippers and dippers in the whole population, but an interaction (P < 0.05) between nondipping and diabetes contributed to an increased left ventricular mass in diabetic nondippers. The urinary albumin excretion rate was independently related to diabetes.

CONCLUSIONS

In this population study, an interaction between diabetes and nondipping was demonstrated regarding fasting plasma glucose, lipid levels and left ventricular mass, indicating that nondipping is a marker of risk in diabetic subjects. However, in the nondiabetic majority of the population, nondipping was not associated with either metabolic disturbances or target organ damage.

Different metabolic predictors of white-coat and sustained hypertension over a 20-year follow-up period: a population-based study of elderly men

BACKGROUND

The clinical significance of white-coat hypertension is still unclear. Moreover, no study has examined metabolic predictors of white-coat versus sustained hypertension.

METHODS AND RESULTS

We investigated men (n=602) in a longitudinal population-based cohort who at age 70 years were identified as normotensive, white-coat hypertensive (office blood pressure [BP] > or =140/90 and daytime ambulatory BP <135/85 mm Hg), and sustained hypertensive (office BP > or =140/90 and daytime ambulatory BP > or =135/85 mm Hg). At baseline, when the subjects were aged 50 years, blood glucose, insulin, lipids, and fatty acid composition of the serum cholesterol esters were analyzed. The investigations at age 70 years included determination of insulin sensitivity and target organ damage. At age 50 years, individuals who 20 years later were identified as white-coat hypertensive or sustained hypertensive showed significantly elevated BP, heart rate, and impaired glucose tolerance compared with normotensive subjects but white coat hypertensive subjects were leaner and had a more favorable serum cholesterol ester fatty acid profile than did sustained hypertensive subjects. At age 70 years, both white-coat and sustained hypertensive subjects showed an impaired insulin sensitivity, elevated blood glucose, and increased serum insulin and heart rate compared with normotensive subjects, but left ventricular mass and urinary albumin excretion were increased only in sustained hypertensive subjects.

CONCLUSIONS

These findings indicate that although metabolic abnormalities and elevated heart rate were consistent over time in both hypertensive groups, a lower body mass index and more favorable dietary fat composition predicted the development of white-coat as opposed to sustained hypertension over 20 years.