Risk factors and outcomes of hospitalized stroke patients in Lusaka, Zambia

Kigelia africana fruit fractions inhibit in vitro alpha-glucosidase activity: a potential natural alpha-glucosidase inhibitor

BACKGROUND

Diabetes affects 75% of people in low-income countries, where conventional drugs like metformin are available, but newer drugs like alpha-glucosidase inhibitors are not accessible to most Southern African patients.

AIM

To evaluate the α-glucosidase and α-amylase inhibitory activities of fractionated aqueous extracts of Kigelia africana fruit (KAFE) and their phytochemical fingerprints using gas chromatography-mass spectrometry (GC-MS).

MATERIALS AND METHODS

We studied K. africana fruit fractions' inhibitory effects on alpha-glucosidase and alpha-amylase using bioassay-guided fractionation, and analyzed their phytochemical profiles with GC-MS.

KEY FINDINGS

Both the aqueous extract and ethyl acetate fraction of the aqueous extract exhibited a low dose-dependent inhibition of alpha-amylase activity (p < 0.0001). At a concentration of 500 μg/mL, the aqueous extract caused an alpha-glucosidase inhibition of 64.10 ± 2.7%, with an estimated IC50 of 193.7 μg/mL, while the ethyl acetate fraction had an inhibition of 89.82 ± 0.8% and an estimated IC50 of 10.41 μg/mL. The subfraction G, which had the highest alpha-glucosidase inhibitory activity at 85.10 ± 0.7%, had significantly lower activity than the ethyl acetate fraction. The most bioactive fraction was found to contain 11"(2-cyclopenten-1-yl) undecanoic acid, ( +)- and cyclopentane undecanoic acid as well as the indole alkaloids Akuammilan-17-ol-10-methoxy, N-nitroso-2-methyl-oxazolidine and epoxide Oxirane2.2″ -(1.4-butanediyl) bis-.

CONCLUSION

The K. africana fruit fraction demonstrated significant alpha-glucosidase inhibitory activity, while its alpha-amylase inhibitory activity was limited. This study suggests a potential natural alpha-glucosidase inhibitor and phytocompounds that could serve as leads for developing antidiabetic agents.

Stroke characteristics and outcomes in urban Tanzania: Data from the Prospective Lake Zone Stroke Registry

BACKGROUND

Stroke is a second leading cause of death globally, with an estimated one in four adults suffering a stroke in their lifetime. We aimed to describe the clinical characteristics, quality of care, and outcomes in adults with stroke in urban Northwestern Tanzania.

METHODS

We analyzed de-identified data from a prospective stroke registry from Bugando Medical Centre in Mwanza, the second largest city in Tanzania, between March 2020 and October 2022. This registry included all adults ⩾18 years admitted to our hospital who met the World Health Organization clinical definition of stroke. Information collected included demographics, risk factors, stroke severity using the National Institutes of Health Stroke Scale, brain imaging, indicators for quality of care, discharge modified Rankin Scale, and in-hospital mortality. We examined independent factors associated with mortality using logistic regression.

RESULTS

The cohort included 566 adults, of which 52% (294) were female with a mean age of 65 ± 15 years. The majority had a first-ever stroke 88% (498). Premorbid hypertension was present in 86% (488) but only 41% (200) were taking antihypertensive medications before hospital admission; 6% (32) had HIV infection. Ischemic strokes accounted for 66% (371) but only 6% (22) arriving within 4.5 h of symptom onset. In-hospital mortality was 29% (127). Independent factors associated with mortality were severe stroke (adjusted odds ratio (aOR) = 1.81, 95% confidence interval (CI) = 1.47-2.24, p < 0.001), moderate to severe stroke (aOR = 1.49, 95% CI = 1.22-1.84, p < 0.001), moderate stroke (aOR = 1.80, 95% CI = 1.52-2.14, p < 0.001), leukocytosis (aOR = 1.19, 95% CI = 1.03-1.38, p = 0.022), lack of health insurance coverage (aOR = 1.15, 95% CI = 1.02-1.29, p = 0.025), and not receiving any form of venous thromboembolism prophylaxis (aOR = 1.18, 95% CI = 1.02-1.37, p = 0.027).

CONCLUSION

We report a stroke cohort with poor in-hospital outcomes in urban Northwestern Tanzania. Early diagnosis and treatment of hypertension could prevent stroke in this region. More work is needed to raise awareness about stroke symptoms and to ensure that people with stroke receive guidelines-directed therapy.

A systematic review of the epidemiology and the public health implications of stroke in Sub-Saharan Africa

BACKGROUND

With approximately 11 million strokes occurring annually worldwide, and over 6.5 million deaths annually, stroke has made its place as one of the major killers in the world. Although developing countries make up more than 4/5 of the global stroke burden, well-grounded information on stroke epidemiology remains lacking there.

AIMS

This systematic review study aimed to provide a synthesis of studies on the incidence and prevalence of stroke among adults in sub-Saharan Africa (SSA), subsequently deduce the associated risk factors and public health implications (mortality rates and economic costs) of the disease on the population of this region.

METHODS

A systematic review of studies carried out in the region and published on PUBMED. Eligibility criteria were established using the PEO (Population/Patient, Exposure, Outcome) format. Research articles investigating either (or all) of the following: ischemic or haemorrhagic stroke, incidence, prevalence, and risk factors of stroke in adults (≥ 18 years old), in at least one region of SSA were included. Exclusion criteria comprised studies involving populations younger than 18 years old, research conducted outside the designated research region, and articles inaccessible in full text. The PRISMA guidelines were used for the search strategy.

RESULTS

Fifty-two studies were included review. Among them, over 11 studies investigated the prevalence of the disease. Some older studies within the continent (Nigeria, 2011) showed a prevalence of 1.3 per 100 while more recent studies (Zambia, 2021) showed a prevalence of 4.3 per 1000. The highest prevalence noted in this region was in Madagascar (2017) with 48.17 per 100, while the lowest was recorded in (Zimbabwe, 2017) with 0.61 per 100. The study in Tanzania showed a crude incidence of 94·5 per 100 000 (76·0-115·0) while the study in Ghana in 2018 showed an incidence of 14.19 events per 1000 person-years [10.77-18.38]. The identified risk factors included hypertension, diabetes, smoking, alcohol consumption, physical inactivity, poor diets (more salt, less vegetables), dyslipidaemia, HIV/AIDS co-infection, heart disease (cardiomyopathies, cardiac arrhythmias), obesity, previous stroke and/or family history of stroke. Over 21 studies investigated the mortality rates due to stroke in SSA, with most of the studies being in West Africa. These studies revealed mortality rates as high as 43.3% in Ghana, and as low as 10.9% in Cameroon. Few studies reported on the economic costs of stroke in the region; two in Benin, two in Nigeria and one in Tanzania.

CONCLUSION

The increasing incidence/prevalence, lifestyle factors and interactions with other diseases, including major communicable diseases, stroke is becoming a pressing public health problem for SSA. Reducing the incidence of stroke in Africa will surely lower mortality, morbidity, disability, and the neurological as well as cognitive aftereffects of stroke, as is clear from the experience of higher-income nations. We recommend a collective intervention involving the governments of nations, international organizations, civil society, and the private sector for greater impact and sustainable outcomes reducing the epidemiology and implications of stroke in SSA.

Examining the influence of global smoking prevalence on stroke mortality: insights from 27 countries across income strata

BACKGROUND

This study investigates the influence of Global Smoking Prevalence (GSP) on Stroke Death Rates (SDR) across 27 countries categorized into High-Income Countries (HIC), Upper Middle-Income Countries (UMIC), Lower Middle-Income Countries (LMIC), and Low-Income Countries (LIC).

METHODS

Analysing data from two distinct periods (1990-1999 and 2010-2019), countries exhibiting an increased SDR were selected. The study uses a polynomial regression model, treating income groups as cross-sectional and years as time series data.

RESULTS

Results from the regression model reveal that 17 countries observed a significant impact of GSP on SDR, with only Turkey, Solomon Islands, and Timor-Leste resulting in negative values. However, the study emphasises that out of all 27 countries, the highest occurrence of the impact of GSP on SDR has been reported in the LMIC stratum for the period under review.

CONCLUSION

It is evident that GSP affects the risk of incidence of stroke death, specifically in the LMIC stratum. Furthermore, it has been identified that GSP is a major preventable risk factor affecting global mortality. To mitigate the risk of stroke death attributable to smoking prevalence, necessary preventive steps should be adopted to encourage smoking cessation, and essential policies should be implemented to reduce the burden of SDR.

Stroke as the index presentation of traditional cardiovascular risk factors and Human Immunodeficiency Virus in a South African population

OBJECTIVES

We sought to identify what proportion of each cardiovascular risk factor and Human Immunodeficiency Virus (HIV) was first diagnosed at the time of stroke, compared to those that were diagnosed prior to the event, and to explore if this had any impact on the severity of stroke.

METHODS

Adult patients presenting with a new stroke to a quaternary hospital in Johannesburg between 2014 and 2017 were prospectively recruited. Patients were investigated for undiagnosed traditional cardiovascular risk factors (hypertension, diabetes mellitus, dyslipidaemia, atrial fibrillation, obesity and smoking), as well as HIV infection. Stroke severity was assessed using the National Institutes of Health Stroke Scale (NIHSS).

RESULTS

346 patients were included. Stroke was the index presentation for at least one risk factor in 199 (57.5 %) patients. Dyslipidaemia was newly diagnosed in 76.0 % of all dyslipidaemics (95 out of 125). Newly-diagnosed dyslipidaemia was associated with a more severe neurological deficit (Median NIHSS of 12 (8-16) vs 7 (4-12), p=0.0007) and younger age on presentation (53 (44-63) years vs 62 (51-71) years, p=0.02) as compared to previously-diagnosed dyslipidaemia.

CONCLUSIONS

More than half of patients had previously undiagnosed modifiable risk factors at the time of their stroke. Dyslipidaemia was undiagnosed in a very high proportion, and this was associated with a higher stroke severity and younger age of presentation.

Effectiveness of health management among individuals at high risk of stroke: An intervention study based on the health ecology model and self-determination theory (HEM-SDT)

Background

Stroke is the second leading cause of death in adults worldwide. However, up to 80% of strokes can be prevented by modifying risk factors.

Objective

The study aims to assess the effectiveness of the Health Ecology Model and Self-Determination Theory (HEM-SDT) based health management intervention among individuals at high risk of stroke.

Methods

A randomized controlled trial was conducted in Zhengzhou from May 1st, 2020, to December 31st, 2020. A total of 229 participants were recruited for the study, with 116 individuals at high risk of stroke being randomly assigned to the HEM-SDT health management group, while 113 participants were enrolled in the control group, following their current routine practices. The Generalized Estimating Equation model (GEE) was used to analyze the differences in health knowledge, belief and, behavior between the two groups at the beginning of the intervention, and at 6-month intervals after the intervention. The chi-square test was utilized to assess the control rate of risk factors.

Results

After 6 months of intervention, there were significant improvements in health knowledge, behavior, and belief among the participants. The study found significant differences in the interaction effects between time and group for health knowledge (Mean, SD = 25.62 ± 3.88, 95%CI: 7.944-9.604, P＜0.001), health belief (Mean, SD = 87.18 ± 14.21, 95%CI: 23.999-29.887, P＜0.001), and health behavior (Mean, SD = 173.28 ± 24.22, 95%CI: 22.332-36.904, P＜0.001). Additionally, the rates of hypertension, hyperglycemia, dyslipidemia, high or medium risk condition of stroke, obesity, hyperhomocysteinemia, smoking, alcohol consumption, and lack of exercise also showed statistical significance (P＜0.05) after the intervention.

Conclusion

The HEM-SDT health management model improves the health knowledge, behavior, and beliefs in people at high risk of stroke and remarkably it shows improvement in modifiable risk factors. It can be recommended for systematic health management in people at high-risk of stroke.

Hypertension among persons living with HIV-Zambia, 2021; A cross-sectional study of a national electronic health record system

Hypertension is a major risk factor for cardiovascular disease, which is a common cause of death in Zambia. Data on hypertension prevalence in Zambia are scarce and limited to specific geographic areas and/or populations. We measured hypertension prevalence among persons living with HIV (PLHIV) in Zambia using a national electronic health record (EHR) system. We did a cross-sectional study of hypertension prevalence among PLHIV aged ≥18 years during 2021. Data were extracted from the SmartCare EHR, which covers ~90% of PLHIV on treatment in Zambia. PLHIV with ≥2 clinical visits in 2021 were included. Hypertension was defined as ≥2 elevated blood pressure readings (systolic ≥140 mmHg/diastolic ≥90 mmHg) during 2021 and/or on anti-hypertensive medication recorded in their EHR ≤5 years. Logistic regression was used to assess for associations between hypertension and demographic characteristics. Among 750,098 PLHIV aged ≥18 years with ≥2 visits during 2021, 101,363 (13.5%) had ≥2 recorded blood pressure readings. Among these PLHIV, 14.7% (95% confidence interval [CI]: 14.5-14.9) had hypertension. Only 8.9% of PLHIV with hypertension had an anti-hypertensive medication recorded in their EHR. The odds of hypertension were greater in older age groups compared to PLHIV aged 18-29 years (adjusted odds ratio [aOR] for 30-44 years: 2.6 [95% CI: 2.4-2.9]; aOR for 45-49 years: 6.4 [95% CI: 5.8-7.0]; aOR for ≥60 years: 14.5 [95% CI: 13.1-16.1]), urban areas (aOR: 1.9 [95% CI: 1.8-2.1]), and on ART for ≥6-month at a time (aOR: 1.1 [95% CI: 1.0-1.2]). Hypertension was common among PLHIV in Zambia, with few having documentation of treatment. Most PLHIV were excluded from the analysis because of missing BP measurements. Strengthening integrated management of non-communicable diseases in HIV clinics might help to diagnose and treat hypertension in Zambia. Addressing missing data of routine clinical data (like blood pressure) could improve non-communicable diseases surveillance in Zambia.

The Burden and In-Hospital Mortality of Stroke Admissions at a Tertiary Level Hospital in Namibia: A Retrospective Cohort Study

Background

Despite stroke being a leading cause of morbidity and mortality globally, there is a dearth of information on the burden and outcomes of stroke in sub-Saharan Africa and Namibia in particular.

Methods

A hospital-based, retrospective cohort study was conducted to analyse non-electronic medical records of all consecutive stroke patients who were admitted to one of the highest tertiary-level hospitals in Namibia for 12 months (2019-2020). The primary outcome of the study was to establish the in-hospital mortality, stroke subtypes, and associated complications.

Results

In total, 220 patients were included in the study, their mean age was 53 (SD13.8) years, and 55.5% were males. 61.0% had an ischaemic stroke (IS), and 39.0% had a haemorrhagic stroke (HS). The mean age was significantly lower in patients with HS vs. IS (48.2 ± 12.2 vs. 56.1 ± 13.3, p < 0.001). Of the IS patients, the majority (29.0%) had total anterior circulation infarct (TACI), while in the HS group, 34.0% had basal ganglia haemorrhage with or without intraventricular extension. Hypertension (p = 0.015), dyslipidaemia (p = 0.001), alcohol consumption (p = 0.022), and other cardiovascular diseases (p = 0.007) were more prevalent in patients with IS compared to those with HS. The prevalence rate of intravenous thrombolysis was 2.2% in IS and use of intravenous antihypertensives in 25.9% of patients with HS than IS. The in-hospital mortality was 26.4% with complications such as raised ICP, aspiration pneumonia, hydrocephalus, and sepsis significantly high in those that died. Aspiration pneumonia (OR 2.79, 95% CI 1.63-4.76, p < 0.001) and increased ICP (OR 0.30, 95% CI 0.16-057, p < 0.001) were independent predictors of in-hospital mortality on the multivariate analysis.

Conclusion

Our findings showed a younger mean age for stroke and mortality rate comparable to other low- to middle-income countries (LMICs). Hypertension and alcohol consumption were the main risk factors for both stroke subtypes, while aspiration pneumonia and raised intracranial pressure predicted in-hospital mortality.

Prevalence and Characteristics of HIV-Associated Stroke in a Tertiary Hospital Setting in South Africa

BACKGROUND AND OBJECTIVES

Antiretroviral treatment (ART) era HIV-associated stroke data from sub-Saharan Africa are limited. We determined the prevalence of HIV in patients presenting with acute symptomatic stroke and compared risk factors, clinical characteristics, and brain imaging with age-matched stroke patients without HIV.

METHODS

We conducted a retrospective study of adults presenting with any type of stroke to Tygerberg Hospital in a 12-month period. Patients living with HIV (PLWH) and HIV-uninfected (HIV-) patients were matched based on age group (1:2 ratio). Patients were identified by keyword search, while HIV status was ascertained from laboratory data. Clinical and imaging data were extracted from medical records.

RESULTS

Among 884 patients presenting with acute strokes, the minimum prevalence of HIV infection was 9.3% (95% CI: 7.4%-11.2%), with 496 patients (56.1%) with negative HIV status and 306 patients with unknown HIV status (34.6%). The mean age at presentation in PLWH was 46 (±11) years compared with 55 (±14) years in HIV- patients (p < 0.001). Smoking was less prevalent in PLWH with an adjusted relative risk ratio of RR = 0.58 (95% CI: 0.39-0.86). Concurrent infection was more prevalent in PLWH (25.6% vs 4.9%, p ≤ 0.001) with an adjusted relative risk ratio of RR = 2.07 (95% CI: 1.49-2.84), largely in patients with a CD4 count <200 cells/μL. PLWH with higher CD4 counts (≥200 cells/μL, 51.3%) had more traditional risk factors and less concurrent infection. Among PLWH, 68.3% were on ART, and 39.3% of them had been started or restarted on ART within the past 6 months. Basal ganglia infarcts (35.6% vs 18.3%, p = 0.014) and multiple vascular territory involvement (25.4% vs 7.7%, p = 0.002) were more common in PLWH. Clinical presentation, ischemic stroke type, and in-hospital outcomes did not differ between the groups.

DISCUSSION

Stroke patients with HIV were younger, had less traditional cardiovascular risk factors, and more concurrent infections than patients without HIV, especially those with a lower CD4 count. Recent ART initiation or reinitiation rates were high. Significant differences in CT brain imaging findings were seen. Understanding the multifactorial mechanisms underlying increased stroke risk, including associated infections and potential ART-associated immune reconstitution, is crucial and needs further study.

Providing Neurocritical Care in Resource-Limited Settings: Challenges and Opportunities

Acute neurologic illnesses (ANI) contribute significantly to the global burden of disease and cause disproportionate death and disability in low-income and middle-income countries (LMICs) where neurocritical care resources and expertise are limited. Shifting epidemiologic trends in recent decades have increased the worldwide burden of noncommunicable diseases, including cerebrovascular disease and traumatic brain injury, which coexist in many LMICs with a persistently high burden of central nervous system infections such as tuberculosis, neurocysticercosis, and HIV-related opportunistic infections and complications. In the face of this heavy disease burden, many resource-limited countries lack the infrastructure to provide adequate care for patients with ANI. Major gaps exist between wealthy and poor countries in access to essential resources such as intensive care unit beds, neuroimaging, clinical laboratories, neurosurgical capacity, and medications for managing complex neurologic emergencies. Moreover, many resource-limited countries face critical shortages in health care workers trained to manage neurologic emergencies, with subspecialized neurocritical care expertise largely absent outside of high-income countries. Numerous opportunities exist to overcome these challenges through capacity-building efforts that improve outcomes for patients with ANI in resource-limited countries. These include research on needs and best practices for ANI management in LMICs, developing systems for effective triage, education and training to expand the neurology workforce, and supporting increased collaboration and data sharing among LMIC health care workers and systems. The success of these efforts in curbing the disproportionate and rising impact of ANI in LMICs will depend on the coordinated engagement of the global neurocritical care community.

Diagnostic Value of Image Features of Magnetic Resonance Imaging in Intracranial Hemorrhage and Cerebral Infarction

This study aimed to investigate the differential diagnosis value of routine magnetic resonance imaging (MRI) and magnetic resonance diffusion-weighted imaging (DWI) in hyperacute intracranial hemorrhage (HICH) and hyperacute cerebral infarction (HCI). Fifty-five patients with HICH were set as group A, and 55 patients with HCI were selected as group B. All the patients underwent routine MRI and DWI examinations. The morphological distribution and signal characteristics (low, high, or mixed) of the lesions in the two groups were recorded. The diagnostic accuracy, sensitivity, and specificity of routine MRI and DWI were compared for distinguishing HICH and HCI. The results suggested that the lesions in patients with HICH were mainly manifested as mixed signals (40 cases), while those in patients with HCI showed high signals (48 cases). HICH occurred in the basal ganglia in 44 cases, in the brain stem in 6 cases, in the cerebellum in 4 cases, in the cerebral cortex in 0 cases, and in the corpus callosum in 1 case. HCI occurred in the basal ganglia area, brain stem, cerebellum, cerebral cortex, and corpus callosum in 5, 3, 35, 12, and 0 cases, respectively. The diagnostic accuracy, specificity, and sensitivity of DWI for HICH and HCI were significantly higher than those of routine MRI (P < 0.05). It was indicated that compared with routine MRI, DWI was more effective in the diagnosis of HICH and HCI, with clearer and more accurate images and better diagnostic performance.

Inpatient Management of Acute Stroke of Unknown Type in Resource-Limited Settings

Stroke is the second leading cause of death and disability worldwide, with a disproportionate burden on low- and middle-income countries. Critical elements of guideline-based stroke care developed in high-income countries are not applicable to resource-limited settings, where lack of access to neuroimaging prevents clinicians from distinguishing between ischemic stroke and intracranial hemorrhage, requiring challenging clinical decision-making, particularly in the acute setting. We discuss strategies for acute inpatient management of stroke of unknown type with a focus on blood pressure management and antiplatelet therapy when neuroimaging is unavailable, and review some of the challenges and strategies for successfully implementing stroke unit care in resource-limited health care settings.

Trends and Clinical Characteristics of HIV and Cerebrovascular Disease in Low- and Middle-Income Countries (LMICs) Between 1990 and 2021

PURPOSE OF THE REVIEW

To describe trends and clinical characteristics of HIV and cerebrovascular disease between 1990 and 2021 in LMICs and identify the gaps in our understanding.

RECENT FINDINGS

In the era of antiretroviral therapy (ART), people living with HIV (PLWH) live longer and risk excess cerebrovascular events due to ageing and HIV-driven factors. Despite the highest burden of HIV infection in low-to-middle income countries, there is underreporting in the literature of cerebrovascular events in this population. We systematically reviewed published literature for primary clinical studies in adult PLWH and cerebrovascular disease in LMICs. The clinical phenotype of cerebrovascular disease among PLWH over the last three decades in LMICs has evolved and transitioned to an older group with overlapping cerebrovascular risk factors. There is an important need to increase research in this population and standardise reporting to facilitate understanding, guide development of appropriate interventions, and evaluate their impact.