Strategies for Prevention of Type 2 Diabetes By Abdullatif Husseini
Main topics: • Definitions. • Magnitude of Type 2 diabetes. • Factors associated with Type 2 diabetes. • Levels of prevention. • Types of interventions. • Barriers and obstacles. • Components of prevention programs. • Central issues in Type 2 diabetes prevention.
Type 2 Diabetes definition • It is the most common form of diabetes, characterized by disorders of insulin resistance and insulin secretion, either of which may be the predominant feature. Both are usually present at the time that the diabetes is clinically manifest. • 2hr post glucose load venous plasma glucose concentration (> 11.1 mmol/l).
Impaired glucose tolerance (IGT) definition • An intermediate category between normal glucose tolerance and unequivocal diabetes. It describes an abnormality of glucose regulation. • 2hr post glucose load venous plasma glucose concentration (7.8 - < 11.1 mmol/l).
Prevention Strategies • Strategy: A set of essential preventive measures believed sufficient to control a health problem. • The word prevention embodies the goals of medicine: to promote health, to preserve health, to restore health when it is impaired, and to minimize suffering and distress. source: Last M, 1995: Dictionary of epidemiology.
Preventive strategies: approaches in the design • A population-based strategy, involving altering the lifestyle and environmental determinants of Type 2 diabetes. • A high-risk strategy applying preventive measures on individuals identified as high-risk for Type 2 diabetes.
Magnitude of the Problem • The number of people with diabetes will nearly double within the first quarter of this millennium. World Health Report, 1997; Geneva: WHO.
Developed Vs Developing King et al, Diabetes Care 1998; 21: 1414-31
Why is the prevalence of Type 2 diabetes increasing? • Aging of the population. • Increased incidence due to urbanization especially in the developing countries. • More sedentary lifestyle. • Food consumption patterns, more foods with high fat content and more refined carbohydrates.
Non Modifiable 1- Genetic factors. 2- Demographic determinants: such as age and ethnicity. Modifiable 1- Behavioral and lifestyle-related: such as obesity and physical inactivity. 2- Metabolic and intermediate risk categories: such as IGT, IFG and GDM. Factors associated with Type 2 diabetes
Why should we prevent diabetes? • To reduce human suffering. • To alleviate the economic burden. • To prevent morbidity and mortality from diabetes-related CVD.
Levels of prevention in Type 2 diabetes • Primary: Includes activities aimed at preventing diabetes from occurring in susceptible populations or individuals. • Secondary: Early diagnosis and effective control of diabetes in order to avoid or at least delay the progress of the disease. • Tertiary: Includes measures taken to prevent complications and disabilities due to diabetes.
Why the primary prevention? • “There is an urgent need to take the prevention of cardiovascular disease more seriously. The only sensible strategy is the population approach to primary prevention.” Beaglehole, the Lancet 2001; 358: 661-3
Metabolic syndrome prevention • The main components of the metabolic syndrome are: glucose intolerance (diabetes or IGT), obesity, hypertension and dyslipidemia. • All of those components are risk factors for CVD and can be targeted in life style interventions to prevent Type 2 diabetes.
Primary prevention • Most of the results on prevention come from studies on high risk groups rather than populations. • Studies have shown that people with IGT has a 2-7 fold higher risk of progression to Type 2 diabetes than persons with normal glucose tolerance. • Among the factors that predicted progression were obesity, elevated fasting and 2-h blood glucose and fasting insulin concentrations.
Types of interventions • Behavioral interventions: including changing diet and increasing physical activity. And/or • Pharmacological interventions: utilizing pharmaceutical agents to improve glucose tolerance and insulin sensitivity.
Behavioral interventions • Several studies has shown that diet and physical activity reduced the incidence of Type 2 diabetes. • Example: The Swedish Malmo study showed that diet and exercise for 5 years in men with IGT reduced the incidence of Type 2 diabetes by 50%. Eriksson et al, Diabetologia 1991; 34: 891-8
Examples • The DaQing Chinese study showed that over 6 years there were significant and similar reductions in the incidence of diabetes in subjects with IGT who were randomized to diet, exercise, or combined diet-exercise treatment groups. Pan et al, Diabetes Care, 1997; 20: 537-44
Cumulative incidence of diabetes at 6 years Data from: Pan et al, Diabetes Care, 1997; 20: 537-44
Examples- Cont • The Finnish Diabetes Prevention Study showed that Type 2 diabetes can be prevented by changes in the lifestyles of high-risk subjects (middle-aged, overweight subjects with IGT). The risk of diabetes was reduced by 58% in the intervention group. The cumulative incidence was 11% in the intervention group compared to 23% in the control group. Tuomilehto et al. NEJM, 2001; 344: 1343-50
Pharmacological interventions • Several studies examined the effects of various therapeutics in the prevention of diabetes. • The evidence for the ability of pharmacological interventions to prevent Type 2 diabetes awaits confirmation.
Examples • The Diabetes Prevention Program (DPP) funded by the NIH-USA to perform a major IGT intervention to examine the potential for prevention of Type 2 diabetes. It includes both lifestyle and pharmacological interventions. Diabetes Prevention Program, Diabetes Care 1999; 22: 623-4
Population-based prevention • Solid data on the ability of community –wide programs encouraging healthy diet and exercise to reduce the incidence of Type 2 diabetes are not yet available. • However, some studies has shown the ability of such programs in reducing the risk factors for diabetes among other non-communicable diseases.
Secondary prevention • The purpose of secondary prevention activities such as screening is to identify asymptomatic people with diabetes. • Is there an effective intervention that may retard the progression of disease or the severity of its complications?
Screening approaches • Population screening • Selective screening • Opportunistic screening
Tertiary prevention • Includes actions taken to prevent and delay the development of acute or chronic complications. • Acute complications: such as hypoglycemia, severe hyperglycemia and infections. • Chronic complications: such as atherosclerosis, retinopathy, nephropathy, neuropathy and foot problems.
Effective interventions • Strict metabolic control, education and effective treatment. • Screening for complications in their early stages when intervention is more effective.
Obstacles and barriers for prevention • Economic problems: unavailability of needed resources. • Socio-cultural problems. • Lack of data, knowledge and skills.
Examples of socio-cultural barriers: • Obesity is not considered negatively. • No value given to physical exercise. • Changing diet is very difficult. • No time is granted to do physical exercise at work. • Fatalism.
Major components of effective prevention programs • Standardized data collection on disease magnitude, risk factors and mortality statistics. • Clear action plan with specific targets, and well defined evaluation. • Initiating community-based interventions for primary prevention. • Advocacy for influencing policies.
Major components of effective prevention programs- Cont • Advocacy for the rights of people with diabetes for quality care at all levels. • Establishing acceptable standards for health care for people with diabetes. • Establishing an effective referral system and defining the role of each level of health care.
Major components of effective prevention programs- Cont • Educating the population about this important global epidemic. • Provision of appropriate training for health care providers. • Coordination of prevention efforts.
Central issues in Type 2 diabetes prevention • Type 2 diabetes prevention must be integrated in a major program addressing the prevention of other lifestyle related disorders like CVD and some cancers. • Primary prevention is of the essence especially in resource-constrained countries. • Diabetes prevention is an inter-sectoral effort requiring cooperation and coordination.
Central issues in Type 2 diabetes prevention- Cont • Diabetes prevention should be addressed within the context of health system reform ensuring the availability of acceptable health care standards. • Culturally appropriate and economically feasible interventions should be adopted. Imposing unacceptable or unaffordable interventions will have a negative impact.
What do we know about Type 2 diabetes prevention? • Type 2 diabetes is a major challenge to human health. • Type 2 diabetes can be prevented. • Primary prevention is a suitable and affordable choice. • There is strong evidence that lifestyle interventions are effective in diabetes prevention. • Barriers for prevention should be addressed.