Clinical and Epidemiological Implications of 24-Hour Ambulatory Blood Pressure Monitoring for the Diagnosis of Hypertension in Kenyan Adults: A Population-Based Study

Six-month incidence of hypertension and diabetes among adults with HIV in Tanzania: A prospective cohort study

Data describing the incidence of hypertension and diabetes among people with HIV in sub-Saharan Africa remain sparse. In this study, adults with HIV were enrolled from a public clinic in Moshi, Tanzania (September 2020-March 2021). At enrollment, a survey was administered to collect information on comorbidities and medication use. Each participant's blood pressure and point-of-care glucose were measured. Baseline hypertension was defined by blood pressure ≥140/90 mmHg or self-reported hypertension at enrollment. Baseline diabetes was defined by self-reported diabetes or hyperglycemia (fasting glucose ≥126 mg/dl or random glucose ≥200 mg/dl) at enrollment. At 6-month follow-up, participants' blood pressure and point-of-care glucose were again measured. Incident hypertension was defined by self-report of new hypertension diagnosis or blood pressure ≥140/90 mmHg at follow-up in a participant without baseline hypertension. Incident diabetes was defined as self-report of new diabetes diagnosis or measured hyperglycemia at follow-up in a participant without baseline diabetes. During the study period, 477 participants were enrolled, of whom 310 did not have baseline hypertension and 457 did not have baseline diabetes. At six-month follow-up, 51 participants (95% CI: 38, 67) had new-onset hypertension, corresponding to an incidence of 33 new cases of hypertension per 100 person-years. Participants with incident hypertension at 6-month follow-up were more likely to have a history of alcohol use (90.2% vs. 73.7%, OR = 3.18, 95% CI:1.32-9.62, p = 0.008) and were older (mean age = 46.5 vs. 42.3, p = 0.027). At six-month follow-up, 8 participants (95% CI: 3, 16) had new-onset diabetes, corresponding to an incidence of 3 new cases of diabetes per 100 person-years. In conclusion, the incidence of elevated blood pressure and diabetes among Tanzanians with HIV is higher than what has been reported in high-income settings.

Prevalence and Determinants of Masked Hypertension in Nigeria: The REMAH Study

BACKGROUND

Estimating the burden of hypertension in Nigeria hitherto relied on clinic blood pressure (BP) measurement alone. This excludes individuals with masked hypertension (MH), i.e., normotensive clinic but hypertensive out-of-clinic BP.

METHODS

In a nationally representative sample of adult Nigerians, we obtained clinic BP using auscultatory method and out-of-clinic BP by self-measured home BP with semi-automated oscillometric device. Clinic BP was average of 5 consecutive measurements and home BP was average of 3 days duplicate morning and evening readings. MH was clinic BP <140 mm Hg systolic and 90 mm Hg diastolic and home BP ≥135 mm Hg systolic and/or 85 mm Hg diastolic.

RESULTS

Among 933 participants, the prevalence of sustained hypertension, MH, and white-coat hypertension was 28.3%, 7.9%, and 11.9%, respectively. Among subjects whose clinic BP were in the normotensive range (n = 558), the prevalence of MH was 13%; 12% among untreated and 27% among treated individuals. The mutually adjusted odds ratios of having MH among all participants with normotensive clinic BP were 1.33 (95% confidence interval, 1.10-1.60) for a 10-year higher age, 1.59 (1.09-2.40) for a 10 mm Hg increment in systolic clinic BP, and 1.16 (1.08-1.28) for a 10 mg/dl higher random blood glucose. The corresponding estimates in the untreated population were 1.24 (1.03-1.51), 1.56 (1.04-2.44), and 1.16 (1.08-1.29), respectively.

CONCLUSIONS

MH is common in Nigeria and increasing age, clinic systolic BP, and random blood glucose are the risk factors.

Association of neighborhood greenness exposure with cardiovascular diseases and biomarkers

AIM

Living in areas with neighborhood greenness may be associated with the incidence of cardiovascular diseases (CVDs). However, little evidence in this regard has emerged from developing countries. In the present study, we examined neighborhood greenness associated with CVDs and the lipid accumulation product (LAP) and pulse pressure (PP) in China.

METHODS

We undertook our analysis using a community cross-sectional survey conducted in Longzihu District of Bengbu from July to August 2015. We measured triglyceride levels, waist circumference, and blood pressure. To assess exposure to neighborhood greenness, we used the average normalized difference vegetation index (NDVI) at 1,000-, 1,500-, and 2,000-m buffers in the participant community. We employed generalized mixed models to determine the association among neighborhood greenness, CVDs, LAP, and PP. We conducted stratified analysis by age, gender, income, and education. We assessed the potential mediating effects of road proximity and physical activity on greenness and CVDs, PP, and LAP.

RESULTS

The highest tertiles of NDVI_1500-m were steadily and significantly associated with lower odds of CVDs prevalence: the adjusted OR of such prevalence was 0.612 (95% CI, 0.462-0.811); higher NDVI was significantly associated with lower PP levels. The NDVI was strongly associated with CVDs prevalence among participants who were male and had high income. Ambient road proximity significantly mediated 9.7% of the estimated association between greenness and PP, there was no evidence of mediation effects for physical activity.

CONCLUSIONS

Higher neighborhood greenness could have a beneficial effect on CVDs and biomarkers. There were higher associations between residential greenness and CVDs among male and higher-income individuals; road proximity partially mediated the observed association between greenness and PP.

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.

Diagnostic performance of clinic and home blood pressure measurements compared with ambulatory blood pressure: a systematic review and meta-analysis

BACKGROUND

Clinic blood pressure measurement (CBPM) is currently the most commonly used form of screening for hypertension, however it might have a problem detecting white coat hypertension (WCHT) and masked hypertension (MHT). Home blood pressure measurement (HBPM) may be an alternative, but its diagnostic performance is inconclusive relative to CBPM. Therefore, this systematic review aimed to estimate the performance of CBPM and HBPM compared with ambulatory blood pressure measurement(ABPM) and to pool prevalence of WCHT and MHT.

METHODS

Medline, Scopus, Cochrane Central Register of Controlled Trials and WHO's International Clinical Trials Registry Platform databases were searched up to 23rd January 2020. Studies having diagnostic tests as CBPM or HBPM with reference standard as ABPM, reporting sensitivity and specificity of both tests and/or proportion of WCHT or MHT were eligible. Diagnostic performance of CBPM and HBPM were pooled using bivariate mixed-effect regression model. Random effect model was applied to pool prevalence of WCHT and MHT.

RESULTS

Fifty-eight studies were eligible. Pooled sensitivity, specificity, and diagnostic odds ratio (DOR) of CBPM, when using 24-h ABPM as the reference standard, were 74% (95% CI: 65-82%), 79% (95% CI: 69%, 87%), and 11.11 (95% CI: 6.82, 14.20), respectively. Pooled prevalence of WCHT and MHT were 0.24 (95% CI 0.19, 0.29) and 0.29 (95% CI 0.20, 0.38). Pooled sensitivity, specificity, and DOR of HBPM were 71% (95% CI 61%, 80%), 82% (95% CI 77%, 87%), and 11.60 (95% CI 8.98, 15.13), respectively.

CONCLUSIONS

Diagnostic performances of HBPM were slightly higher than CBPM. However, the prevalence of MHT was high in negative CBPM and some persons with normal HBPM had elevated BP from 24-h ABPM. Therefore, ABPM is still necessary for confirming the diagnosis of HT.

Mapping the Current and Future Noncommunicable Disease Burden in Kenya by Human Immunodeficiency Virus Status: A Modeling Study

BACKGROUND

The noncommunicable disease (NCD) burden in Kenya is not well characterized, despite estimates needed to identify future health priorities. We aimed to quantify current and future NCD burden in Kenya by human immunodeficiency virus (HIV) status.

METHODS

Original systematic reviews and meta-analyses of prevalence/incidence of cardiovascular disease (CVD), chronic kidney disease, depression, diabetes, high total cholesterol, hypertension, human papillomavirus infection, and related precancerous stages in Kenya were carried out. An individual-based model was developed, simulating births, deaths, HIV disease and treatment, aforementioned NCDs, and cancers. The model was parameterized using systematic reviews and epidemiological national and regional surveillance data. NCD burden was quantified for 2018-2035 by HIV status among adults.

RESULTS

Systematic reviews identified prevalence/incidence data for each NCD except ischemic heart disease. The model estimates that 51% of Kenyan adults currently suffer from ≥1 NCD, with a higher burden in people living with HIV (PLWH) compared to persons not living with HIV (62% vs 51%), driven by their higher age profile and partly by HIV-related risk for NCDs. Hypertension and high total cholesterol are the main NCD drivers (adult prevalence of 20.5% [5.3 million] and 9.0% [2.3 million]), with CVD and cancers the main causes of death. The burden is projected to increase by 2035 (56% in persons not living with HIV; 71% in PLWH), with population growth doubling the number of people needing services (15.4 million to 28.1 million) by 2035.

CONCLUSIONS

NCD services will need to be expanded in Kenya. Guidelines in Kenya already support provision of these among both the general and populations living with HIV; however, coverage remains low.

Blood pressure, T cells, and mortality in people with HIV in Tanzania during the first 2 years of antiretroviral therapy

Cardiovascular disease is now a leading cause of mortality in people with HIV (PWH). High blood pressure is the major driver of cardiovascular disease. Despite this, little is known about blood pressure in PWH during the early years of antiretroviral therapy (ART). In this prospective cohort study in Tanzania, the authors conducted unobserved blood pressure measurements at enrollment, 3, 6, 12, 18, and 24 months in 500 PWH initiating ART and 504 HIV-uninfected adults. The authors excluded measurements taken on antihypertensive medications. Although PWH had a significantly lower blood pressure before ART initiation, they had a significantly greater increase in blood pressure during the first 2 years of ART compared to HIV-uninfected controls. Blood pressure correlates in PWH differed from HIV-uninfected controls. In PWH, lower baseline CD4⁺ T-cell counts were associated with lower blood pressure, and greater increases in CD4⁺ T-cell counts on ART were associated with greater increases in blood pressure, both on average and within individuals. In addition, PWH with a systolic blood pressure (SBP) <90 mm Hg at the time of ART initiation had ~30% mortality in the following 3 months due to occult infections. These patients require careful investigation for occult infections, and those with tuberculosis may benefit from corticosteroids.

Hypertension, white-coat hypertension and masked hypertension in Australia: findings from the Australian Diabetes, Obesity, and Lifestyle Study 3

BACKGROUND AND METHOD

The Australian Diabetes, Obesity, and Lifestyle Study is a national, population-based examination of ∼11 000 adults with a third follow-up phase at 12 years. The aim was to use ambulatory blood pressure monitoring (ABPM) in a subsample (n = 508) of the main Australian Diabetes third follow-up cohort to determine the proportion with established, masked or white-coat hypertension in city and regional centers and the effectiveness of diagnosis and treatment.

RESULTS

Mean age was 58.9 years, BMI was 27.6 kg/m with 53% women. The mean clinic BP was 127/73 mmHg and mean 24-h BP was 121/73 mmHg. Using regression analysis estimations, the predicted ABPM daytime equivalent for the hypertension threshold values of 140/90 mmHg were 136/90 mmHg. There were 43% classified as hypertensive due to either ABPM 24-h more than 130/80 mmHg (17%) or taking antihypertensive therapy (25%). Ambulatory SBP/DBP were higher in men (24-h + 6.4/4.9 mmHg, P < 0.001) compared with women. There was only 3% with white-coat but 21% with masked hypertension indicating 24% misdiagnosis. Based on ABPM, 9% were treated and still hypertensive, which was three times more common in men (14%) than women (4%). Thus 36% had not reached target. There were no differences between urban and rural participants. Based on ABPM, nearly half the participants were hypertensive while only a quarter were taking antihypertensive therapy.

CONCLUSION

The findings highlight the importance of out-of-office BP assessments and the considerable gaps in effectively diagnosing and treating hypertension.

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.

Evaluation of the Accuracy of a New Cuffless Magnetoplethysmography Blood Pressure Monitor in Hypertensive Patients

OBJECTIVE

There is a growing demand for cuffless blood pressure (BP) measurement as an easy alternative to cuff-occlusion-based BP measurement. We assessed the accuracy of a new cuffless, watch-style BP monitor with a magnetoplethysmography (MPG) sensor compared to two standard auscultatory and oscillatory BP monitors.

SUBJECTS AND METHODS

A total of 34 patients with uncontrolled hypertension (systolic BP ≥150 mm Hg or diastolic BP ≥95 mm Hg) were enrolled in the study. BP was measured by two conventional monitors and the new device during the pre-exercise phase, during isometric handgrip exercise, and during the recovery phase (5 min after exercise). The correlation between monitors was assessed using intraclass correlation coefficient (ICC) and Bland-Altman plots.

RESULTS

Although two reference monitors produced highly correlated BP measurements, each was differentially correlated with BP measurements obtained by the new MPG monitor. During exercise, the mean difference between systolic BP obtained by the MPG and oscillatory monitors was >7 mm Hg with an ICC of 0.549 (95$ CI 0.264-0.746) in systole and 0.737 (95$ CI 0.534-0.859) in diastole. The ICC between the auscultatory monitor and the MPG monitor was 0.753 (95$ CI 0.559-0.868) in systole and 0.841 (95$ CI 0.706-0.918) in diastole after exercise. Bland-Altman plots also indicated that the performance of the new MPG device was very similar to that of the auscultatory monitor.

CONCLUSION

Although the performance of the new MPG monitor was comparable to that of the reference monitors used in this study, improved stability and accuracy are necessary for accurate BP evaluation during dynamic activity.