6.4Diabetes
SeeBackground Chapter 6.4
The impact of diabetes and of diabetes-related illnesses place an enormous burden on the health care systems of most countries throughout the world. It has been estimated that by the year 2025, 300 million people will have diabetes — a remarkable 5.4% of the world’s projected population. There are primarily two types of diabetes. Type 1 diabetes is an auto-immune disease in which the pancreas can no longer produce insulin and thus the body cannot control blood sugar. The annual rate of new cases of Type 1 diabetes varies widely around the globe (see Figure 6.4.1).
Figure 6.4.1
Source:International Diabetes Federation, Diabetes Atlas, 2nd edition. (The absence of data from African and Asian countries reflects the dearth of such survey data and not necessarily the absence of diabetes in these regions).
"Adult" Type 2 diabetes is a metabolic derangement in which the body gradually becomes insensitive to the action of insulin so that blood sugar control is also compromised. Overall, the prevalence of Type 2 diabetes dominates the total diabetes burden, although there is an alarming trend for juveniles to develop Type 2 diabetes. Chapter 5 mentioned the global demographic changes taking place with regard to aging and the differences in life span between genders. Data on the diabetes
burden (both Type 1 and Type 2) for Europe and the world, see Figure 6.4.2, reveal that the diabetes burden is higher for females than males for the world, for the EU15 and for the EU10.[i]
Figure 6.4.2: Diabetes mellitus (DALYs per 1000 by age)
Source: WHO Global Burden of Disease Database
In the EU10, the total per capita diabetes burden shifts from men to women after the age of 60, which is about a decade earlier than in the EU15. These overall trends are expected to increase as a result of the aging of the population combined with longer female life span. The newer EU10 countries have a lower overall diabetes burden per capita.
The projected increase in the prevalence of diabetes will be four times higher in the developing world than in the developed world.[1] In 2025, the countries with the largest number of diabetics will be India, the People's Republic of China and the USA. In view of the burden and associated costs of diabetes, the ongoing epidemic represents a major public health problem requiring effective control.
There is a large gap between diabetes prevalence and treatment rates. It has been estimated that 30%-50% of diabetes cases remain undiagnosed. People with Type 1 diabetes require lifelong insulin replacement and face the additional complications of diabetes-related diseases. At present, there is no real ability to provide effective, long-term, tight blood sugar control through insulin replacement therapy. Moreover, insulin requires refrigeration and this creates an access problem in many developing countries.
Type 2 diabetes is increasing due to urbanization and industrialization, which leads to a reduction in physical activity and consumption of a high fat diet. These lifestyle changes result in obesity, the most important risk factor for diabetes. Management of Type 2 diabetes has always centered on control of metabolism i.e., achieving a negative calorie balance and optimal intake of carbohydrates and lipids. Evidence suggests that controlling obesity and physical inactivity can prevent, or at least delay, the development of the disease in many genetically susceptible individuals. However, success in controlling these risk factors on a large scale has been limited.
There are many oral agents that improve glucose control in diabetes by either improving insulin secretion or improving insulin action if diet and exercise are not working. The pharmaceutical industry considers development of effective diabetes medications as a major goal. However, there is still a need for these oral agents to act in a more efficient manner within the body (i.e., faster absorption by the body, action to control blood glucose taking place over a longer time period, fewer side-effects, paediatric formulations). For patients requiring insulin, current methods of insulin administration cannot reproduce the body’s ability to precisely control blood glucose and other metabolic variables.
Diabetes is an example of a disease with an unmet global medical need and conforms to the "commonality of interest" principle of the Priority Medicines Project. The increases in diabetes projected over the next several decades require a global strategy for prevention, treatment and medicine development. The EU could contribute to this by creating an infrastructure to facilitate diabetes clinical trials, in particular comparative clinical “head-to-head” trials to compare efficacy, side-effects and cost-effectiveness using full pharmaco-economic analyses. Heat-stable insulin, available for use in developing countries lacking a regular refrigeration system would be a major public health advance.
[i]We note that graphs of DALYs by age are commonly misinterpreted as the DALY burden at each age. DALYs actually measure incident DALYs due to new cases and new deaths at each age. For a long-term condition like diabetes, disability-adjusted life shown at age x may actually be lived at older ages. For short-term conditions or conditions where death dominates, like cancer, this misinterpretation is not a problem.
[1]IDF. Diabetes atlas. 2nd ed. Brussels: International Diabetes Federation; 2003.