Diabetes Mellitus is a chronic metabolic disease characterized by elevated blood glucose (hyperglycemia). It is associated with an absolute or relative deficiency in the secretion and/or action of insulin.
There are three main forms of diabetes: type 1, type 2, and gestational diabetes. Type 2 diabetes is the most common, accounting for approximately 85% to 90% of all cases. It is related to modifiable risk factors such as obesity or overweight, physical inactivity, and high-calorie diets of low nutritional value.
Metabolic syndrome is characterized by the presence of prediabetes in conjunction with one other cardiovascular disease (CVD) risk factor (hypertension, upper body obesity or dyslipidaemia).
Diabetes and TB
Diabetes and tuberculosis are two chronic diseases with high impact in populations of developing countries. The risk for tuberculosis is augmented by impaired host defence in individuals, such as those with HIV and diabetes.
Who is affected?
The burden of diabetes to an individual and to society is chiefly associated with increased disability and premature mortality due to complications. Diabetes complications and premature mortality are believed to be exacerbated by poor quality of care. In addition, the risk of dying from cardiovascular disease (CVD) is between two and three times higher among people with diabetes versus those without.
In clinical studies, it was found that after 20 years of living with diabetes, the frequency of chronic complications was: 48% for retinopathy, 6.7% for blindness, 42% for neuropathy, 1.5% for kidney damage, 6.7% for myocardial infraction (heart attack), 3.3% for stroke and 7.3% for lower limb amputations.
Prevalence of Diabetes Mellitus, Overweight (BMI ≥25) and obesity (BMI≥30) by gender in selected countries
Some population groups are at greater risk for complications than others. For example, studies in Barbados demonstrated a high incidence of lower limb amputations (936 per 100,000) and a higher prevalence of retinopathy among blacks (28.5% of black diabetics).
While diabetes and its complications are largely preventable, lack of access to quality health care services and lack of knowledge of preventive measures are widespread.
Obesity as a Precursor to Diabetes
The obesity epidemic, which is linked to the rise in diabetes, is largely driven by the twin trends of changing dietary patterns and decreasing physical activity. Most countries in Africa are experiencing a shift in dietary patterns toward increased consumption of energy-dense foods, rich in saturated fat, sugars, and salt. This pattern, coupled with the fact that 30 to 60% of the population does not meet minimum recommended levels of physical activity (e.g., 30 minutes walking per day) contribute in large part to the high rates of overweight persons and obesity in the Region.
Adults are considered overweight if they have a body mass index (BMI) between 25 kg/m2 and 29.9 Kg/m2 and considered obese if their BMI is above 30 Kg/m2. Research has demonstrated a strong and consistent link between obesity and diabetes; increases in BMI are associated with increased risk for diabetes and abdominal obesity has emerged as a strong predictor of diabetes.
Environmental changes are the major contributors to the aforementioned changes in diet and physical activity patterns. A combination of government policies, regional and global market forces, inadequate response to changing demographic patterns, technological advances that precipitate behaviour and lifestyle changes, and lack of awareness and action by civil society are key factors leading to the rising epidemics of obesity and diabetes. However, the strong social and environmental determinants of obesity and ill health provide an important area for intervention with strong evidence-based data to guide action
Women and Diabetes
In many countries, obesity and diabetes affect women disproportionately. Gestational diabetes in particular has detrimental consequences for both mother and child, increasing the frequency of perinatal morbidity and mortality. In addition, maternal obesity and diabetes have been linked to increased susceptibility for the child to develop diabetes during their youth, creating a vicious circle.
Diabetes also affects other health conditions; because it impairs immunity; for example, diabetes has been associated with tuberculosis. The relationship among diabetes, maternal and newborn morbidity and tuberculosis may have a negative impact. Furthermore, low birth weight is associated with an increased risk for type 2 diabetes during adulthood. This may exacerbate the diabetes epidemic in low and middle income countries that are still struggling with a high frequency of low birth weight.
Interventions for the Prevention and Management of Diabetes and Obesity
Prevention and management strategies are crucial to turn back the tide regarding obesity and diabetes. Evidence demonstrates that risks of chronic disease begin in the uterus and continue into old age. Therefore, strategies to address the problem at all stages of the life cycle are important, including paying particular attention to obesity and diabetes in women of reproductive age.
The frequency of medical care and health expenditures among those with diabetes increases as early as eight years before clinical onset of the disease. This means that persons at the highest risk for type 2 diabetes are often already in contact with the health system and can be easily identified. People with prediabetes have been shown to have increased risk for diabetes and cardiovascular diseases. Diabetes screening facilities are the opportune identification point for such at-risk individuals, or for those in the early stages of obesity and diabetes, when non-pharmacological treatment may still be a preferred option. Studies have demonstrated that approximately one-third of people with type 2 diabetes are undiagnosed, and already present complications at the time of diagnosis.
Two approaches need to be used to implement prevention strategies: the population-based approach and the individual, high-risk approach. The individual approach focuses on high-risk or affected individuals through direct interventions.
The population and individual approaches are complementary and function best when combined in an integrated manner.
AHO Programme of action
Primary Prevention of Obesity and Diabetes
Primary prevention at the population level through activities such as health promotion, creation of healthy public policies focused on food, diet and physical activity, and creation of healthy environments. Key actions include fiscal/policy incentives for production and consumption of healthy foods, guidelines to regulate the marketing and sale of foods to children and adolescents, wide promotion of fruit and vegetable consumption, the elimination of trans fats in processed foods, workplace wellness initiatives, physical education curricula and healthy feeding programs in schools, urban planning that encourages walking and biking, improved access to recreation and sports through partnerships, and massive education campaigns.
Creation and implementation of guidelines for the prevention of obesity and diabetes in primary health care, including meal and exercise plans, or medication if required.
Screening for Diabetes and Pre-Diabetes
Identification of people at risk for diabetes (with two or more risk factors for type 2 diabetes (such as a family history of diabetes, high blood pressure, a history of hyperglycemia or gestational diabetes, or overweight) when preventive services are available and enroll those at risk in weight reduction programs or in courses of care for the management of obesity and diabetes.
Secondary Prevention of Complications
Strategies include patient and provider education, efforts aimed at smoking cessation, increased physical activity, and healthy eating.
A number of clinically proven strategies are available for the secondary prevention of complications.
Cardiovascular disease: blood sugar control, blood pressure control, smoking cessation, aspirin treatment, lipid reduction treatment, rennin-angiotensin system (RAS) inhibitors;
Nephropathy (Kidney damage): blood sugar control, blood pressure control, and medications including RAS inhibitors angiotensin receptor blocker (ARB, and angiotensin converting enzyme (ACE);
Retinopathy: blood sugar control, blood pressure control, lipid reduction treatment;
Blindness: annual eye examinations, and prompt treatment of problems in order to minimize visual loss; this includes panretinal laser surgery for eyes with advanced proliferative retinopathy, and focal laser photocoagulation for eyes with clinically significant vision-threatening macular oedema;
Amputations: foot exam and foot care education.
Improving Management of Obesity and Diabetes
Standards for care and management of obesity and diabetes should be developed and implemented at the primary care level. The chronic care model is a framework to identify gaps in care with the aim of designing strategies for quality improvement. Adoption of this model at the national level can facilitate improved management. Additionally, the list of essential medicines should include those that are necessary for the management of diabetes, including insulin, metformin and glibenclamide. In settings with more resources available for health, access to medications for lipid and blood pressure reduction and certain diagnostic and treatment procedures are strongly encouraged.
The creation of community services within the civil society can provide additional support to people with obesity and diabetes.
Surveillance and Monitoring
Various sources of information can be used for the surveillance of diabetes and obesity in populations, including periodical population-based surveys, health service statistics, school-based surveys and routinely collected vital statistics. Countries can use monitoring risk factors for chronic disease such as STEPS methodology, which is a simple, standardized method for collecting, analysing, and disseminating risk factor data.