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Diabetes and complications of the heart in Sub-Saharan Africa: An urgent need for improved awareness, diagnostics and management
Nadezhda Glezeva1, Master Chisale 2, Kenneth McDonald1, Mark Ledwidge1, Joe Gallagher1, Chris J Watson3*
1 gHealth Research Group, UCD Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Ireland2 Mzuzu Central Hospital, Mzuzu, Malawi, Africa3Centre for Experimental Medicine, Queen’s University Belfast, Northern Ireland
* Corresponding author:Dr. Chris Watson, Wellcome-Wolfson Building, Centre for Experimental MedicineQueen’s University BelfastBelfastBT9 7BLE-mail [email protected]. +442890976478
Abstract
Type 2 diabetes mellitus is no longer a disease of high income countries but a global health pandemic. With the continued and rapid increase in its prevalence worldwide it is forecasted that diabetes will be a leading cause of morbidity and mortality. A major concern stems from its role in development and progression of cardiovascular disease, including cardiac dysfunction and heart failure. Within low- and middle-income areas such as Sub-Saharan Africa the burden of diabetes is already significant driven by many factors, including, socioeconomic (urbanisation), nutritional (high-calorie “western-diet”, obesity) and lifestyle (physical inactivity) changes. Insufficient economic and community resources, poor health care system development and chronic disease management, poor education, and a lack of preventative and diagnostic measures further aggravate the severity of the diabetes problem. This review outlines the burden of type 2 diabetes mellitus in Sub-Saharan Africa and highlights the need for improved community health care and regulations to reduce its epidemiological spread and devastating impact on health.
Keywords
Type 2 Diabetes Mellitus; Sub-Saharan Africa; low-income countries; cardiovascular disease; diabetic cardiomyopathy; diabetes clinical trials
2
1. Introduction
Diabetes is a major component and cause for cardiovascular disease (CVD) on a global scale. There is a steady increase in the prevalence of diabetes particularly in low-income areas such as Sub-Saharan Africa (SSA). The 2015 update of the International Diabetes Federation (IDF) diabetes atlas reported an estimated 14.2 (9.5-29.4) million people aged 20-79 living with diabetes in the Africa region, with numbers predicted to increase by approximately 2.4-fold, reaching 34.2 (23.7-67.7) million in 2040 1. This will be the largest relative increase globally. Type 2 Diabetes mellitus (T2DM) is the most common form of diabetes in SSA accounting for 90-95% of all cases 2. The remainder of fewer than 10% constitute type 1A (autoimmune) and 1B (ketosis-prone, idiopathic) diabetes, and gestational diabetes.
2. Epidemiology and prevalence of T2DM
The overall prevalence T2DM in Africa among 20-79 year-olds is 3.2% (2.1-6.7%) with the majority of people in the 40-79 age bracket 1. Furthermore, there were more than 321 000 deaths attributed to diabetes in 2015 alone with the highest proportion – 79%, of those in people under the age of 60. Population prevalence of diabetes among SSA countries is between 2.7% and 17.9% and varies widely based on the socioeconomic status of the country, the living location, and the gender of the participants (Table 1) 4-34. The major risk factors for T2DM in Africa identified in these epidemiological and population studies are: 1) modifiable factors, i.e. excess body weight (obesity), bad nutrition (high-fat western-style diet, non-diverse diet), physical inactivity, urbanization, higher income, and poor education; 2) non-modifiable factors, i.e. age, gender, ethnicity, family history of diabetes, and genetic predisposition; and 3) other factors, including gestational diabetes, tuberculosis, and anti-retroviral therapy. The most recent data on the prevalence, diagnosis and care of diabetes in SSA revealed pooled analysis of individual data from 12 countries including Benin, Comoros, Guinea, Kenya, Liberia, Mozambique, Namibia, Seychelles, South Africa, Tanzania, Togo, and Uganda 3. In a sample size of 38 311 individuals with a biomarker measurement for diabetes (fasting glucose and HbA1c) the median prevalence of diabetes was 5% (range 2–14%) and the median prevalence of overweight or obesity, two major risk factors for diabetes, was 27% (range 16–68%). The report highlighted the unmet need for diabetes diagnosis and care which significantly increased with the level of educational attainment (highest in the group with <1 year of education) and in reverse proportion to age (highest in the age group 15–39 years, followed by the group 40-54 years). The study also emphasized the urgent need for novel health policies and programmes to increase awareness of diabetes and expand coverage of preventive counselling, diagnosis, and linkage to diabetes care in SSA countries.
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Table 1: Population-based prevalence studies on type 2 diabetes mellitus and associated risk factors in Sub-Saharan Africa as per recent statistics from the countries
Country Sample Setting Age Prevalence (%) Risk factors for diabetes
Ref.
Overall Male FemaleAngola 421 rural ≥30 2.8 3.2 2.7 Age, overweight,
diabetes family history4
Angola 615 urban 20-72 5.7 5.5 5.9 Upper socioeconomic class
5
Angola 781 urban 18-65 2.69 Age >40 years, overweight, obesity
6
Cameroon 2465 urban and rural
≥15 6.2(urban)
4.7(rural)
4.7(urban)
2.9(rural)
Urban location, physical inactivity, obesity, high blood
pressure
7
Cameroon 10824 urban ≥15 6.06 6.4 5.7 8
Cameroon 1623 urban 3.3 4.2 2.7 Age, hypertension, obesity, abdominal
obesity
9
Democratic Republic of Congo
699 urban and rural
≥20 3.5(urban
4.0,rural 1.7)
Age and urban location,
abdominal obesity (for urban location)
10
Democratic Republic of Congo
3962 rural >15 2.8 (obese
3.5, metaboli
c syndrom
e 7.2)
Age, waist circumference,
abdominal obesity, blood pressure
11
Ethiopia 354,524
urban and rural
≥14 (53.4±12)
2.2(82% of urban
residents and 28% of rural
residentshave
T2DM)
Urban location, overweight (increase in
BMI)
12
Ghana 4733 urban ≥25 6.3 7.7 5.5 Age, male sex 13
Guinea 1537 urban and rural
≥35 6.1(urban
7.7,rural 4.0)
Urban location, age, waist to hip ratio,
excess waist circumference,
hypertension, high systolic and diastolic
blood pressures
14
Kenya 4396 urban and rural
≥50 6.6(urban
10,rural 5)
Urban location, hypertension, obesity
15
Malawi 3056 rural and urban
25-64 5.6 6.5 4.7 Urban location, male gender
16
Nigeria 502 urban ≥40 7.9 9.1 6.3 Overweight or obesity, family history of
17
4
diabetes, physical inactivity, heavy
alcohol consumption, age, high social status
Nigeria 858 rural ≥40 4.4 7.3 3.3 Age, overweight and obesity, hypertension
18
Senegal 600 urban ≥20 17.9 14.0 21.8 Age, female gender, overweight or obesity
19
South Africa 1025 rural >15 3.9 3.5 3.9 Age, diabetes family history, heavy alcohol
consumption, waist circumference, systolic blood pressure, serum
triglycerides, total cholesterol
20
South Africa 642 urban ≥31 8.1 Age, ethnicity 21
South Africa 1311 urban 40±16
3.4 2.9 3.7 Female gender, overweight or obesity, hypertension, elevated
blood glucose
22
South Africa 1099 urban 12.1(age-
standardized – 13.1)
10.2 (age-
standardized – 11.3)
13.8 (age-
standardized – 14.7)
In women – older age, diabetes family history,
overweight, better quality housing, lower
sense of coherence score (SOC); in men –older age, overweight
23
South Africa 1099 urban 25-74 13.8 Age, body mass index, urban location
24
Tanzania 1698 urban and rural
>15 5.9(urban)
1.7(rural)
5.7(urban)
1.1(rural)
Overweight, obesity, large waist:hip ratio
25
Tanzania 640 urban 44±11
11.9 Age, positive first degree relative with
diabetes, alcohol intake, smoking,
hypertension
26
Tanzania (T) and Uganda (U)
229 (T), 497 (U)
peri-urban and rural
≥18 10.1 (16.1
rural U, 7.6 peri-urban U, 8.3 urban
T)
9.7 10.3 Family history, hypertension
27
Togo 2000 urban ≥18 7.3 6.9 7.3 28
Uganda 2283 urban ≥18 3.5 Age, education, region of residence
29
Uganda 1497 rural and peri-urban
35-60 7.4 (rural 6.8, peri-
urban 10.4)
6.5 8.1 Overweight, obesity, physical inactivity, low
dietary diversity
30
Uganda 3689 rural and urban
≥18 1.4(2.7
urban, 1.0 rural)
1.6 1.1 Age, sex, household floor finish, abdominal
obesity
31
Zambia 1928 urban ≥25 2.7 2.1 3.0 Age, mild hypertension 32
Zambia (Z) 45,767 urban ≥18 2.9 % 2.7 (Z), 3.0 (Z), Age, obesity, 33
5
and South Africa (West Cape, (WC))
(Z), 12,496 (WC)
and rural
(Z), 9.4% (WC).Age-
standardized -
3.5% (Z) 7.2% (WC)
6.0 (WC)
11.1 (WC)
education, household socio-economic
position
Zimbabwe 3081 urban and rural
≥25 10 34
In addition to T2DM, metabolic syndrome is becoming a huge clinical concern in SSA. Metabolic syndrome is the clustering of risk factors for the development of T2DM and cardiovascular disease (abdominal obesity, hyperglycaemia, dyslipidemia, and hypertension,) and it has an increasing prevalence in SSA35. The relationship between metabolic syndrome, diabetes and hypertension is complex, as high glucose intolerance and blood pressure are criteria for metabolic syndrome diagnosis, while diabetes and hypertension are discretely health conditions. Obesity is a major contributor to increased glucose intolerance, high blood pressure and lipid disorders that result in metabolic dysfunction and is also increasing in Africa36. Abdominal obesity is a consistent marker of metabolic syndrome diagnosis.
Metabolic syndrome is highly prevalent among the HIV-infected population as a result of their long-term dependence on antiretroviral therapy (ART) regimen, which has been shown to be a contributing factor to developing metabolic complications, such as lipodystrophy, dyslipidemia and insulin resistance. Hypertension is a common AIDS-unrelated condition among HIV-positive persons, with an estimated prevalence of between 4.7% and 54.4% in high-income countries and 8.7%–45.9% in LMICs. The causative and predisposing factors of developing these conditions are similar among all populations, regardless of HIV status, and include sociodemographic change, an aged population, globalisation, overweight, obesity and sedentary lifestyles. A summary of recent studies on metabolic syndrome in Africa is shown in Table 2.
Table 2: Recent studies on metabolic syndrome in Africa
Year of publication
Population Metabolic syndrome prevalence
201737 364 adults age 20-30 years in Ghana
12.4% (Females 18.4%, males 5.7%)
2017 38 528 adults in Kenya 25.6%2017 39 183 postmenopausal
women in Algeria57.9%
201740 748 adults with HIV in 24.1%-28.2% depending on
6
South Africa criteria used2017 41 371 adolescents in
South Africa3.1% of female participants, 6% of male participants
2017 42 188 farm workers in South Africa
Overall 42.6% (46.3 female, 29.3% male)
201743 Systematic review of studies of metabolic syndrome in people living with HIV
30.5% in Africa in people living with HIV
3. Medical care challenges and proposed solutions for T2DM in Africa
T2DM is becoming more prevalent due to socioeconomic (urbanisation), nutritional (high-calorie “western-diet”, obesity) and lifestyle (physical inactivity) changes in African communities 44. A retrospective record review of 354,524 patients who visited the outpatient department of the Gondar referral hospital in Ethiopia between 2000 and 2009 showed a 125% increase in the proportion of type 2 diabetics over the 10 years of the study 12. Two recent cross-sectional studies from Zambia (198 randomly selected T2DM patients) 45 and Ethiopia (325 adults with T2DM) 46 showing poor glycaemic control status in 61.3% and 70.9% of all patients respectively. A report from a cross-sectional study of 1267 T2DM patients in Cameroon and Guinea has shown that limited access to an HbA1c test is one of the key factors for the poor glycaemic control 47. Such reports raise public awareness for the urgent need of cost-effective and accessible comprehensive diabetes prevention, treatment, and care programs in SSA. There are several primary issues to address in order to tackle diabetes in SSA: 1) the under resourced health care system and limited patient electronic data collection and organization; 2) limited availability, accessibility and affordability of medicines and health care; 3) poor medical staff education/training and poor patient education, awareness and adherence to guidelines and medication; 4) inexistent/insufficient preventative measures, diagnostic and screening programs; and 5) insufficient community involvement and diabetes associations 48-50. Due to the constantly increasing prevalence of T2DM and its risk factors, the substantial cost of treatment of diabetes and its associated co-morbidities, and the challenges that resource-poor SSA health-care systems face, it is crucial and urgent to implement cost-effective solutions. The key points to be addressed for improving diabetes care in SSA proposed by the International Insulin Foundation are: 1) re-organisation of the health-care system, improvement of documentation, and expansion of data collection, 2) improving accessibility and affordability of medicines and care, implementation of healthcare system policy changes to regulate diabetes medications and early screening tests under the medical insurance, 3) improving training and availability of health-care workers, improving patient education, awareness, and adherence, 4) prioritization of diabetes prevention, establishment/improvement of government and public awareness to the economic
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benefits of prevention and early diagnosis of diabetes, and 5) support for and from community and diabetes associations 49.
A significant effort to boost diabetes prevention, care, education, and awareness has been demonstrated in Africa over the last couple of years. Several examples include the African Diabetes Care Initiative (ADCI) launched in 2010 and the ADCI- and IDF- supported Diabetes Conversations project launched in 21 SSA countries in 2012 that strengthened diabetes education by access to structured group education through standardized tools 51. In addition, applicability of the structured “directly observed treatment, short course” (DOTS) framework – the best care system for tuberculosis management in resource-poor settings, to the management of diabetes has shown significant potential in SSA countries 52.
On a country-based scale, important achievements have been made in the past several years with the implementation of different community-based programmes that follow either an educational, support, awareness, or interventional approach. A new randomized trial (PACTR201205000380384) has been set up in South Africa to evaluate the effectiveness of group T2DM education programme in 45 public sector community health centres in underserved communities 53. Another randomized controlled trial (PACTR201105000297151) has recently started in South Africa to evaluate efficacy of a community church-based lifestyle intervention programme to control high normal blood pressure and/or high normal blood glucose in 300 members from 12 churches with an outlook to prevent the development of hypertension and/or diabetes 54. In addition, the recent "Take Five School" structured group education programme for T2DM in South Africa has reported a significant improvement in adherence to a diabetic diet, physical activity, foot care, self-education, and willingness to educate others and holds particular promise for improving public sector primary care 55. Another new participant-customised nutrition education programme in 81 T2DM patients in 2 community health centres in the resource-limited Moretele district of South Africa has shown that group education and hands-on activities contributed to improvement in dietary behaviours including reduction of starchy food and median energy intake 56. In Mozambique, significant improvement in diabetes care was achieved by the implementation of the “Diabetes UK Twinning Programme” which provided development of a comprehensive non-communicable disease plan, strengthened the diabetes association by expanding membership and training of 265 health workers in diabetes care in all provinces, improved the access to patient education materials, and expanded public awareness, e.g. establishing a World Diabetes Day 57. A further community-based peer support program was initiated in Cameroon and its implementation, in addition to the usual diabetes care, was found to significantly improve metabolic control in people with uncontrolled T2DM 58. In Nigeria, T2DM patient participation and adherence to a 12-week therapeutic exercise program reduced neuromusculoskeletal disorders and decreased the burden of diabetes 59. Another Nigerian initiative, namely, a 12-week physical exercise programme, significantly improved metabolic parameters including fasting glucose, triglycerides, waist circumference, and systolic blood pressure (males) and lowered cardiovascular risk in T2DM patients 60. A new medication adherence study that included both a descriptive (retrospective) and a prospective evaluation showed an 86.8%
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improvement in adherence rates and a decline in non- adherence rates of Nigerian T2DM patients following interventions including health education and counselling 61. In Malawi, application of the DOTS framework for tuberculosis control to the management of T2DM patients has significantly improved diabetes monitoring and control in this extremely resource-limited country 62. In South Africa, use of the South African Chronic Disease Outreach Program (CDOP) to follow T2DM and hypertensive patients over 2 years, support primary health care nurses, and improve health systems for disease management was successful in improving early disease as well as advanced disease detection, ensuring early high-risk referral to a specialist centre, improving poorly-controlled patient care and had positive impact on primary health care nurses’ knowledge and confidence 63.
In diagnosis and prevention, periodic evaluation of HbA1c alongside a fasting blood glucose test in Nigerian diabetics was shown to correctly identify susceptibility for T2DM complications and guide therapy 64. The combined single use of the fasting plasma glucose and HbA1c point-of-care tests in diabetes screening in rural low-income Uganda has proven to correctly identify people at lower risk for type 2 diabetes and thus aids disease management 65. In Senegal, dobutamine stress echocardiography for early detection of silent myocardial ischaemia was shown to optimize the care of T2DM patients with high cardiovascular risk factors 66 but is not feasible for widespread use. For the purposes of diabetes diagnosis and prevention in extremely resource-limited rural areas without access to conventional screening tests other tools have shown to be particularly effective. In rural Tanzania, an algorithm using basic risk assessment tools and fasting blood sugar testing instead of HbA1c testing could allow for T2DM screening programs with improved sensitivity and specificity 67. In Ghana, an innovative technique was applied which establishes dietary patterns that are related to biochemical risk factors for type 2 diabetes 68. This reduced rank regression (RRR) technique has correctly identified a dietary pattern attributed to increased serum triglycerides to increase the odds of T2DM in urban Ghanaians and may also be applied to different populations and communities to improve risk stratification, diagnosis and prevention of diabetes. Also very recently, a predictive model for diabetes using the handgrip strength (HGS) technique in combination with other basic health measurements (age, blood pressure and BMI) has proven to be a viable screening method of early detection of diabetes 69.
4. T2DM, Cardiovascular disease and diabetic cardiomyopathy in
Africa
A major concern regarding the growing incidence and prevalence of T2DM in SSA stems from its close association with cardiovascular disease (CVD). Diabetes is a major contributor to the increasing burden of CVD in Africa and CVD is a main complication and primary cause of morbidity and mortality in type 2 diabetics 70, 71. Cardiovascular complications of diabetes include macrovascular (coronary artery disease, cerebrovascular disease, and peripheral vascular disease) and microvascular (retinopathy, nephropathy and peripheral
9
neuropathy) complications and their prevalence in selected SSA communities has been summarized elsewhere 50. Independent of concomitant macro- and microvascular disorders, T2DM also has direct effects on the heart. Chronic hyperglycemia, insulin resistance and accumulation of collagen and glycation end-products in the myocardium of T2DM patients promote pathological myocardial remodelling resulting in diabetic cardiomyopathy. Diabetic cardiomyopathy is a prevalent condition associated with left ventricular (LV) diastolic (and systolic) dysfunction, cardiomyocyte hypertrophy, myocardial interstitial fibrosis and stiffness, cardiomyocyte apoptosis, and oxidative stress 72, 73. It has important clinical consequences including increased incidence, susceptibility, and risk of hypertension, coronary artery disease; an increased mortality rate after acute myocardial infarction, and progression to symptomatic heart failure 74-76. Diabetic cardiomyopathy is the main cause of heart failure in up to 37.4% of Sub-Saharan African adults 70. Despite the important contribution of cardiomyopathy to cardiovascular injury and cardiac failure in diabetic patients, only a few studies have examined its prevalence in T2DM patients in Africa. Mbanya et al. reported a 40% and 55% prevalence of LV hypertrophy and systolic dysfunction in 40 normotensive T2DM patients in Cameroon 77. Two recent studies from Nigeria reported sub-clinical cardiomyopathy by showing 72% and 65.6% LV diastolic dysfunction and significantly increased LV mass in normotensive T2DM patients 78, 79. Similarly, a Ugandan study in 202 diabetic patients, 156 (77.2%) of who had T2DM, reported echocardiographic abnormalities including LV diastolic dysfunction, systolic dysfunction, LV hypertrophy, and wall motion abnormalities in 76% of the patients with normal blood pressure 80. And 2 studies from Tanzania identified concentric hypertrophy in 36.7%, enlarged left atrial volume in 44.3% and LV diastolic dysfunction in 20.5% of asymptomatic T2DM patients 81, 82. Ischemic heart disease has traditionally been considered rare in Africa but recent data challenges this particularly in the context of rising diabetes and hypertension83. The low rate of ischemic heart disease is likely due to the low rates of risk factors for ischemic heart disease previously such as obesity and diabetes, the low life expectancy and the high rates of causes of cardiomyopathy such as valvular disease seen in rheumatic heart disease. Genetic differences may also play a role with a recent study showing that African Americans have lower levels of natriuretic peptide84. natriuretic peptide protects against myocardial fibrosis and pressure overload of the heart.
5. Clinical trials on CVD medications and alternative approaches to
manage T2DM in Africa
The high percentage of sub-clinical cardiomyopathy in African T2DM patients and the strong link to cardiovascular complications, echocardiographic abnormalities, and heart failure provides a rationale for the use of standard medical treatments applied for heart failure also in patients with T2DM. Such medications include glycaemic control (e.g. metformin), lipid
10
lowering agents, (e.g. statins), anti-hypertensive medications (e.g. angiotensin converting enzyme inhibitors [ACEi], angiotensin receptor blockers [ARB], and calcium antagonists), and regulators of heart rate (e.g. beta-blockers [BB]).
Due to limited economic resources just 4 therapeutic trials have been performed in T2DM patients in Africa and those investigate the benefits of glycaemic and insulin control for reduction of cardiovascular risk and heart failure in diabetes type 2. Three of these trials have been completed in South Africa 85-87 and one – in Senegal 88. The South African studies explored the benefits from the use of new insulin formulations and showed: equivalent glycaemic control with improved cost effectiveness with Bioinsulin 30/70 (BEST study 85); improved effectiveness and safely with Biphasic insulin aspart 30 monotherapy or combination therapy with oral antidiabetic drugs (PRESENT study 86); comparable glycaemic control of insulin degludec to insulin glargine without new adverse effects but with reduced dosing frequency (87). In the Senegal study, combination therapy with metformin and sulfonylurea following monotherapy was shown to significantly improve glycemic control, cholesterol level, and BMI in obese T2DM patients 88.
Besides clinical trials on regular anti-diabetic medications for treating T2DM patients in the SSA region, there have been 2 studies utilizing cardiac/cardiovascular medications to alleviate CVD burden in these populations. The first was a retrospective review of the medical records of 382 diabetic-hypertensive patients from a single diabetic centre in Ethiopia for the period between August 2014 and January 2015 89. It identified the most frequently prescribed antihypertensive drug classes in T2DM patients which were angiotensin converting enzyme inhibitor (enalapril, 84% of patients), calcium channel blocker (nifedipine, 60%), and beta blocker (atenolol, 38%). The second was a randomized controlled trial with low-dose spironolactone in Cameroon (NCT02426099) and showed particular effectiveness of the drug in reducing blood pressure to optimal levels in T2DM patients with resistant hypertension 90.
Alternative approaches that involve traditional medicines have been, and still are, widely used to tackle cardiovascular risk in T2DM patients. These include zinc and chromium supplementation (91, 92, Tunisia), extracts from Zygophyllum gaetulum (93, Morocco), Fadogia ancylantha (94, Malawi), Nauclea diderrichii (De Wild.) Merr. (ND) and Sarcocephalus pobeguinii Hua ex Pellegr. (SP) (95, Gabon), root ethanolic extract of Aristolochia ringens V. (REAR) (96, Nigeria) , and combinations plant extracts from Moringa oleifera, Cymbopogon citrullus, Hagenia abyssinica, Aloe vera, Clausena anisata, Cajanus cajan, Artimisia afra, and Persea americana (97, Tanzania). These medications have shown considerable beneficial hypoglycaemic, anti-oxidative, and anti-microbial effects in African T2DM patients.
With the difficulty of conducting clinical trials in resource-limited and remote, rural settings in SSA which at the same time are of urgent need of help to tackle the ever growing diabetes and CVD crisis, other strategies that may successfully manage CV risk in diabetes 2 patients in Africa involve: 1) use of community health workers to raise public awareness and manage diabetes, CVD, and the associated risks; and 2) use of a polypill approach where a fixed dose pill containing a combination of multiple CV medications into one tablet is used.
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With respect to the first strategy, community health worker programmes have been established to address the growing burden of non-communicable diseases in African communities. Gaziano et al. suggested that community health workers are ideally positioned and capable of providing comprehensive community-based screenings and referrals to people at risk for CVD, as efficiently and accurately as nurses and physicians do 98. A simple non-invasive CVD risk prediction indicator is used to assess the results from screenings, to classify them into non-urgent or urgent, and to advice on referral to a hospital unit. With advantages including: a) high level of mobilization and outreach to distant areas; b) an in-depth knowledge of the communities' cultural norms, barriers, and opportunities; c) the opportunity to have screenings done in community sites or at the homes of community participants; as well as d) the integration of both screening and referral into a single structure which allows for faster, cheaper, and more effective disease management, the community health worker scheme offers great potential to bridge prevention, management, and control of non-communicable diseases in SSA.
The second strategy for managing CVD risk in T2DM patients in Africa entails the adoption of the popypill approach. This approach has shown major success in improving cardiovascular factors in patients at risk for or with established CVD in different countries and communities worldwide. Examples of polypill trials in CVD include the TIPS (NCT00443794) 99, PILL (ACTRN12607000099426) 100, TIPS-2 (CTRI/2010/091/000054) 101, Wald et al. (ISRCTN36672232) 102, and UMPIRE (NCT01057537) 103 trials. Combined data from these trials shows that the polypill formulation could be conveniently and more efficiently used to reduce multiple risk factors and cardiovascular risk by reducing systemic blood pressure (systolic and diastolic) and improving lipid profiles (total cholesterol, LDL-cholesterol). These results were largely due to the significantly improved medication adherence of the patients to a single (poly)-pill with fixed drug doses as opposed to a varying combination of multiple pills/tablets at different, changing doses. A polypill approach for the management and treatment specifically of diabetes type 2 patients was presented a decade ago by Kuehn et al. in JAMA under the beguiling title "Polypill" could slash diabetes risks 104. The polypill (metformin, aspirin, statin, angiotensin-converting enzyme inhibitor) was presented as an inexpensive means to reduce the risks of diabetes complications, improve healthcare and reduce economic costs. In the following years, several other articles presented their viewpoints on the advantages and pitfalls of the polypill concept and defended approaches based on the change of lifestyle 105-107. More recently two clinical trials in T2DM showed that introduction of a polypill (aspirin, statin, blood pressure-lowering agent(s)) in high-risk patients is beneficial and might reduce prescription gaps and increase medication adherence 108, and, moreover, a triple oral fixed-dose diabetes polypill formulation (glimepiride, metformin, pioglitazone ) was shown to be superior to an insulin + metformin formulation in the efficacy demonstration study for the treatment of advanced type 2 diabetes (the TrIED study-II) 109. The latter study provides an apt example for the vast potential from the use of CVD medications in diabetes type 2 management. Given the low cost, higher effectivity, and the ease of distribution and prescription, the polypill approach could be the Way Ahead for improving the management and treatment of T2DM patients in resource-limited settings such as Sub-Saharan Africa.
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6. Summary
Diabetes is a growing global phenomenon with the highest rates of growth being seen in low and middle income countries and particularly in Africa. Studies have shown that diabetic cardiomyopathy is prevalent in Africa also. Challenges in African health systems in providing chronic disease care exist particularly in remote and rural areas. In particular access to health workers, access to diagnostics and therapeutic options are limited. Development of community health worker skills, adapting existing health programmes for diseases such as TB and HIV for diabetes management, access to HbA1c testing and the use of polypill strategies may help alleviate the burden of this condition. Further research and urgent action is required to ensure that the double burden of infectious diseases and non-communicable diseases does not further overwhelm health systems in Sub-Saharan Africa.
7. Acknowledgements
None
8. Funding
Department for Economy Northern Ireland – Global Challenges Research Fund (grant code, R3887CEM). Health Research Board of Ireland (grant code, CSA2012/36).
9. Conflict of interest
Conflict of interest: None.
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