Ambulatory blood pressure monitoring to assess the white-coat effect in an elderly East African population

Prevalence, risks factors, and control of hypertension in Guinean older adults in 2021: a cross-sectional survey

BACKGROUND

The incidence of arterial hypertension increases with the aging of the population, but its magnitude remains insufficiently assessed. The aim of this study was to investigate the prevalence of hypertension and associated factors in elderly people in Guinea.

METHODS

Data were obtained from a cross-sectional general population survey, conducted among people aged ≥ 60 years. A stratified enumeration area random sample survey was conducted in the four natural regions of Guinea from February to April 2021. This study included an interview on sociodemographic data, and a clinical examination. Hypertension was defined as systolic blood pressure ≥ 140mmHg and/or diastolic blood pressure ≥ 90mmHg or previous diagnosis of hypertension (with or without antihypertensive medication). Hypertension control was defined as blood pressure below 140/90 mmHg during treatment. Age-standardized prevalence was calculated, and logistic regression was used to examine factors associated with hypertension.

RESULTS

A total of 1698 adults (1079 men, mean age: 71.6 ± 9.4 years) had at least two blood pressure measurements. The standardized prevalence of hypertension was 61.4% [95% CI: 61.3-61.6], ranging from 52% in Middle Guinea to 67% in Upper Guinea, and was higher in women (65.2%: 65.0-65.4) than in men (59.1%:58.9-59.3). Among those with hypertension, 46.7% were unaware of their condition before the survey and 49.6% were on treatment and only 18.5% had controlled hypertension. Whatever the residence (rural or urban), increasing age, being unmarried, working as a trader or functionary, jobless, living in upper Guinea, low monthly income, intake of extra salt, known diabetic, overweight, and obesity increased the risk of hypertension. In urban area, female sex (AOR: 1.14: 1.12-1.17), living in lower Guinea (AOR: 3.08: 2.97-3.20), being Maninka (AOR: 1.26: 1.21-1.31), being Nguerze (AOR: 1.71: 1.63-1.81) increased the risk of hypertension, but living in forest Guinea (AOR: 0.88: 0.83-0.93), being Soussou (AOR: 0.88: 0.85-0.92) decreased the risk. In rural area, living in forest Guinea (AOR: 2.14: 2.03-2.26), being Soussou (AOR: 1.14: 1.12-1.17) increased the risk of hypertension, but female sex (AOR: 0.96: 0.94-0.98), living in lower Guinea (AOR: 0.87: 0.85-0.89), being Maninka (AOR: 0.94: 0.92-0.97), being Nguerze (AOR: 0.50: 0.47-0.52) decreased the risk.

CONCLUSION

Hypertension is a major problem in the elderly population in Guinea, and the level of treatment and control in elderly with known hypertension is inadequate. The place of hypertension among cardiovascular diseases and the identification of associated factors underlines the need to develop innovative approaches to control this major risk factor.

The Relationship Between the Dipping Pattern and Coronary Artery Disease Severity Assessed by the SYNTAX Score in Patients With Hypertension

Background The morbidity and mortality rates related to hypertension (HT) are still high despite the developments in this area. Nondipper hypertension (NDHT) is related to worse clinical outcomes. But the dipping pattern of HT is not still used for treatment targets. In this study, we investigated the effect of dipping patterns on coronary artery disease (CAD) complexity evaluated by the SYNTAX score (SS). Methodology Patients with stable CAD and HT were included in the study. All patients were monitored with 24-hour ambulatory monitoring, and dipping patterns were evaluated. Coronary artery complexity was determined by SS for all patients and compared along with different dipping patterns. Results A total of 331 patients with HT and stable CAD were evaluated in the study. The mean age of the patients was 62.6 ± 9.9 years, and 172 (52%) were male. The number and percentage of patients with dipper HT (DHT), NDHT, over-dipper HT (ODHT), and reverse-dipper HT (RDHT) were 89 (26%), 143 (43%), 11 (3%), and 88 (26%), respectively. When the groups were compared according to SS, the SS of the patients with RDHT were significantly higher (the SS were 6.33, 4.99, 3.09, and 2.7 for RDHT, ODHT, NDHT, and DHT, respectively, P = 0.003). The mean SS between the DHT group and the NDHT group (P = 0.03) and between the DHT group and the RDHT group (P = 0.01) was significantly different. The less decrease or increase in mean blood pressure (MnBP) values was significantly correlated with high SS. Conclusions NDHT, especially the reverse dipping pattern, is closely related to complex CAD. Meticulous consideration of dipping patterns can identify high-risk patients and improve clinical outcomes.

A clinical algorithm to determine target blood pressure in the elderly: evidence and limitations from a clinical perspective

As the elderly population is growing rapidly, management of hypertension in South Korea faces major challenges because the proportion of elderly hypertension patients is also increasing. The characteristics of this population are also much more complex than younger patients. Elderly hypertension is characterized by wide variations in (1) fitness or biological age, (2) white-coat effect, (3) poor functional status or frailty, (4) dependency in activities of daily living or institutionalization, (5) orthostatic hypotension, and (6) multiple comorbidities. All of these should be considered when choosing optimal target blood pressure in individual patients. Recent randomized clinical trials have shown that the benefits of intensive blood pressure control for elderly patients is greater than previously thought. For generalization of these results and implementation of the guidelines based on these studies, defining the clinician's role for individualization is critically important. For individualized decisions for target blood pressure (BP) in the elderly with hypertension, four components should first be checked. These consist of (1) the minimum requirement of functional status and capability of activities of daily living, (2) lack of harmful evidence by the target BP, (3) absence of white-coat hypertension, and (4) standing systolic BP ≥ 110 mmHg without orthostatic symptoms. Risk of decreased organ perfusion by arterial stenosis should be screened before starting intensive BP control. When the target BP differs among comorbidities, the lowest target BP should be given preference. After starting intensive BP lowering therapy, tolerability should be monitored, and the titration should be based on the mean level of blood pressure by office supplemented by out-of-office BPs. Applications of the clinical algorithms will be useful to achieve more standardized and simplified applications of target BP in the elderly.

24-hour ambulatory blood pressure monitoring and hypertension related risk among HIV-positive and HIV-negative individuals: cross sectional study findings from rural Uganda

Hypertension is diagnosed and treated based on blood pressure (BP) readings obtained in the clinic setting. Positive HIV status is associated with a higher prevalence of abnormal diurnal BP patterns, diagnosed with ambulatory BP monitoring rather than the conventional method of BP measurement. Little is known about ambulatory BP profiles in people living with HIV (PLHIV) in low-income countries, especially within sub-Saharan Africa. In this study, we compared 24-h ambulatory BP profiles of 140 HIV-positive individuals vs. profiles in 166 HIV negative individuals living in rural Uganda. HIV was well-controlled, with all HIV seropositive participants reporting use of anti-retroviral therapy, and ~123 (88%) having undetectable viral load. Most participants reported ART use duration of less than 10 years. Compared to HIV negative participants, HIV positive participants had lower median 24-h systolic BP (110.4 mmHg (IQR: 105.7, 118.7) vs 117.7 mmHg (IQR: 110.8, 129.8), p < 0.001), and 24-h diastolic BP (69.2 mmHg (IQR: 65.0, 74.9) vs. 71.9 mmHg (IQR: 67.2, 78.1), p = 0.004). Adjusted results showed greater percentage systolic nocturnal dipping among PLHIV compared to HIV negative individuals (difference = 2.70 (IQR: 0.94, 4.47), p < 0.05). Results of the adjusted Poisson regression suggested lower prevalence of 24-h and night hypertension among HIV positives compared to HIV negative, but were not statistically significant. Our data suggest that continuous 24-h BP measurements are lower in PLHIV on ART compared to HIV negative individuals.

Evaluation of a low-resource screening strategy for ophthalmic pathologies and associated neurological morbidity in an older Tanzanian HIV-positive population

Globally, 43 million people are living with HIV, 90% in developing countries. Increasing life expectancy with combination antiretroviral therapy (cART) results in chronic complications, including HIV-associated neurocognitive disorders (HAND) and eye diseases. HAND screening is currently challenging. Our aim was to evaluate clinical utility of retinopathy as a screening measure of HAND in older cART-treated individuals in Tanzania and feasibility of smartphone-based retinal screening in this low-resource setting. A cross-sectional systematic sample aged ≥ 50-years attending routine HIV follow-up in Tanzania were comprehensively assessed for HAND by American Academy of Neurology criteria and received ophthalmic assessment including smartphone-based retinal imaging. HAND and ophthalmic assessments were independent and blinded. Diagnostic accuracy was evaluated by AUROC curves. Of 129 individuals assessed, 69.8% were visually impaired. Thirteen had retinopathy. HAND prevalence was 66.7%. Retinopathy was significantly associated with HAND but HIV-disease factors (CD4, viral load) were not. Diagnostic accuracy of retinopathy for HAND was poor (AUROC 0.545-0.617) but specificity and positive predictive value were high. We conclude that ocular pathology and HAND appear highly prevalent in this low-resource setting. Although retinal screening cannot be used alone identify HAND, prioritization of individuals with abnormal retinal screening is a potential strategy in low-resource settings.

Ambulatory Blood Pressure Profiles and Correlation with Cardiovascular Risk Factors in a Sample of 390 University Employees in Tanzania

Background

Hypertension is a major risk factor for cardiovascular morbidity and mortality. Increasingly, evidence suggests that 24-hour ambulatory blood pressure (BP) monitoring (ABPM) is more accurate than clinic BP in predicting cardiovascular risk. However, this association has not been widely studied in subSaharan Africa, especially in Tanzania.

Aim

To explore the relationship between 24-hour ABPM profiles and cardiovascular risk factors in comparison with clinic BP among Muhimbili University of Health and Allied Sciences (MUHAS) employees.

Methods

A descriptive cross-sectional study was conducted from October 2018 to February 2019. Socio-demographic and cardiovascular risk information was gathered. We used an automated ABPM device to record 24-hour ambulatory BP. Correlation between BP profiles and cardiovascular risk factors was done using Pearson’s correlation coefficient, and independent factors for hypertension were determined using logistic regression analysis. P-value of <0.05 was considered statistically significant.

Results

In total, 390 employees participated. Their mean age was 40.5 ± 8.9 years, and 53.6% were men. The mean office systolic and diastolic BP were 126±12 mmHg and 78±13 mmHg, respectively, while the corresponding values for mean 24-hour ABPM were 122±14 and 75±10 mmHg. The prevalence of hypertension was 23.1%. The prevalence of white coat hypertension was 16.2%, while masked hypertension and nocturnal non-dipping were present in 11.5 and 66.7%, respectively. Overall, the mean 24-hour systolic BP showed the strongest correlations with cardiovascular risk factors while mean office systolic BP showed least. Independent associated factors of hypertension were male gender, age ≥40 years, family history of hypertension, central obesity, raised cholesterol and uric acid levels, all p<0.01.

Conclusion

Compared to office BP, ABPM measurements had stronger correlations with cardiovascular risk factors in this population, and therefore likely to reflect true BP. ABPM has revealed high proportion of masked, white coat and nocturnal non-dipping, supporting use of ABPM to detect these clinically important BP profiles.

Ambulatory blood pressure monitoring and management of hypertension at a cardiac clinic in Kumasi Metropolis, Ghana

Ambulatory blood pressure monitoring (ABPM) is considered a good intervention strategy to avoid misdiagnosis of hypertension and allow for targeted treatment of patients with hypertension. This study sought to assess the contribution of ABPM to blood pressure (BP) control and antihypertensive therapy at a cardiac clinic in Ghana. Medical records of 97 patients, aged 18-85 years (mean 55), were reviewed. Among patients with clinic BP (CBP) and ambulatory BP recorded on the same day, we assessed for the different hypertension phenotypes, CBP control 6 months following ABPM, and changes to antihypertensive therapy after review of the ABPM records in patients with controlled and uncontrolled ambulatory BP. From the clinic and ambulatory BP records measured at baseline, the proportion of patients with white-coat uncontrolled hypertension (WUCH) was 19.5% (17/87) and those with masked uncontrolled hypertension (MUCH) was 16.1% (n = 14). A significant reduction in average systolic CBP in the overall cohort (-6.2 mm Hg, P < .01) and in the uncontrolled subgroup (-8.8 mm Hg, P < .001) at follow-up was observed. After review of the ABPM records, 51.7% of the patients on treatment had changes made in their antihypertensive therapy. Antihypertensive therapy was deintensified or left unchanged in majority of the patients with WUCH and sustained controlled hypertension. In patients with MUCH and true uncontrolled hypertension (TUCH), therapy was intensified. In conclusion, ABPM improved clinical decision-making for antihypertensive therapy and BP control. ABPM should therefore be used more often in hypertension and cardiac clinics in low/middle-income countries for optimal care.

Hypertension in older adults in Africa: A systematic review and meta-analysis

BACKGROUND

Hypertension is the leading driver of cardiovascular disease deaths in Africa. Its prevalence is highest in older populations. Yet, this group has received little attention in many African countries. We conducted a systematic review and meta-analysis (PROSPERO registration: CRD42017056474) to estimate the prevalence of hypertension in older adults living in Africa.

METHODS

We searched grey literature and major electronic databases including PubMed and Embase for population-based studies and published between 1 January 1980 to 28 May 2018 reporting the prevalence of hypertension for adults aged ≥50 years living in Africa. We employed a random effects model to estimate the pooled prevalence across included studies.

FINDINGS

We screened 10,719 articles and retrieved 103 full-text articles to evaluate for inclusion in the review. Thirty-four unique studies providing 37 data points on 43,025 individuals in 15 African countries were analyzed. The prevalence of hypertension ranged from 22.3% to 90.0% from the individual studies while the overall pooled prevalence was 57.0% (95% CI 52%-61%). The prevalence was not statistically significantly different by sex, residence, or African sub-region. In individual studies, older age and overweight/obesity were independently associated with hypertension. Twenty-nine (78%) data points were deemed to be of low- or moderate-risk of bias. Eliminating high-risk bias studies made little difference to the pooled estimate of hypertension. Sensitivity analyses, omitting one study at a time, identified three studies with significant but relatively small impact on the pooled estimate. We observed substantial heterogeneity (I2 = 98.9%) across the studies which was further explored by meta-regression analyses. Overall, the GRADE assessment suggested moderate quality evidence in the results.

CONCLUSION

The persistent high prevalence of hypertension among older adults in Africa, even in rural populations warrants more attention to the cardiovascular health of this group by public health authorities.

Retinal imaging to identify target organ damage in older Africans: A pilot study

By 2030, sub-Saharan Africa is forecast to see the steepest rise in the number of people with hypertension of any world region. Hypertensive retinopathy is known to be a common complication of hypertension in developed countries and some studies suggest it is associated with the presence of other hypertension-related end-organ damage (EOD) such as stroke and cardiovascular disease. In Tanzania hypertension is relatively more common than in other parts of sub-Saharan Africa, especially in the older population; however, the prevalence of hypertensive retinopathy and its association with EOD remain unknown. The authors conducted a cross-sectional study of elderly, community-dwelling, rural Tanzanians to determine the prevalence of hypertensive retinopathy and its association with hypertension and other forms of EOD. Hypertensive retinopathy was diagnosed based on retinal imaging. In a cohort of 61 patients with gradable images, the authors found the overall prevalence of hypertensive retinopathy to be 64% (n = 39), which was strongly associated with hypertension (X² [1] = 4.207, P = .004), with a significant trend towards more severe retinopathy with more severe hypertension (r = .377, P = .003). The authors did not find hypertensive retinopathy to be associated with other forms of EOD. Hypertensive retinopathy is highly prevalent in this population and is associated in most but not all cases with hypertension. These findings do not suggest that it could be used as a screening tool for EOD, but it is important to identify and educate patients with retinopathy about possible complications of the condition.

Prevalence of white coat and masked hypertension in Africa: A systematic review and meta-analysis

Data on masked hypertension (MH) and white-coat hypertension (WCH) in African populations are needed to estimate the true prevalence of hypertension in these populations because they have the highest burden of the disease. We conducted the first systematic review and meta-analysis that summarized available data on the prevalence of WCH and MH in Africa. We searched PubMed and Scopus to identify all the articles published on MH and WCH in populations living in Africa from inception to November 30, 2017. We reviewed each study for methodological quality. A random-effects model was used to estimate the prevalence of WCH and MH across studies. Eleven studies were included, all having a low-risk of bias. The prevalence of masked hypertension was 11% (95% CI: 4.7-19.3; 10 studies) in a pooled sample of 7789 individuals. The prevalence of WCH was 14.8% (95% CI: 9.4-21.1; 8 studies) in a pooled sample of 4451 individuals. There was no difference on the prevalence of WCH and MH between studies in which participants were recruited from the community and the hospital. The prevalence of MH was higher in urban areas compared to rural ones; there was no difference for WCH. WHC and MH seem to be frequent in African populations, suggesting the importance of out-of-clinic BP measurement in the diagnosis and management of patients with hypertension in Africa, especially in urban areas for MH.

Hypertension in a resource-limited setting: Is it associated with end organ damage in older adults in rural Tanzania?

Few data from sub-Saharan Africa exist on the effects of hypertension on the organs of the human body. We aimed to establish the prevalence of hypertensive end organ damage (EOD) in an elderly cohort of Tanzanians. The population aged 70 years and over of 2 villages in northern Tanzania (n = 246), had blood pressure (BP) data available from 2010 and 2013, and underwent in-depth follow-up for markers of hypertensive EOD in 2016. Assessment included ankle-brachial pressure index, lying-standing BP, electrocardiogram, and mid-stream urine dip. Sustained hypertension (those with hypertension at all 3 assessments) was found in 129 (52.4% subjects). Of the entire cohort, 13.9% had left ventricular hypertrophy and 26.4% had peripheral arterial disease, both of which were associated with sustained hypertension, although orthostatic hypotension, stroke, proteinuria, and arterial stiffening were not. Further investigation, particularly in younger age groups, is merited if hypertension-associated morbidity is to be controlled.

Rates and predictors of three-year mortality in older people in rural Tanzania

BACKGROUND

There are few data on mortality rates in the general elderly living in sub-Saharan Africa. We aimed to detail three-year mortality rates in a population of rural community-dwelling older adults in northern Tanzania.

METHODS

We performed a community-based study of 2232 people aged 70 years and over living in Hai district, Tanzania. At baseline, participants underwent clinical assessment for disability, neurological disorders, hypertension, atrial fibrillation and memory problems. At three-year follow-up mortality data were collected. Mortality rates were compared to UK estimates.

RESULTS

At follow-up, data were available for 1873 subjects (83.9%). Of those, 208 (11.1%, 95% CI 9.7-12.5) had died. The age-standardised mortality rate was 10.2% (95% CI 8.8-11.6). Age-standardised mortality rates were lower than estimated for the UK (13.9%). In Cox regression analysis, greater age, higher levels of functional disability, use of a walking aid, subjective report of memory problems, being severely underweight and being normotensive were significant predictors of mortality.

CONCLUSIONS

Those who survive to old age in Tanzania appear to have relatively low mortality rates. Physical and cognitive disabilities were strongly associated with mortality risk in this elderly community-dwelling population. The association between blood pressure and mortality merits further study.