Type 2 diabetes mellitus red zone

Mapping type 2 diabetes mellitus in the whole globe is both interesting and striking when looking at the actual number of affected people with type 2 diabetes mellitus. Calculating the number of diabetic patients using the prevalence of this disease and the total number of targeted population of any given community, provides a good estimate of the number of people affected by the disease. More than 50% of the global number of diabetic patients inhabit a specific geographical area. This area is located in the northern tropical zone, involving North Africa, and the southwest, southern, southeast and eastern part of Asia. It could be labeled as a type 2 diabetes mellitus red zone, which has variable human and land geography. The diabetes red zone occupies less than 20% of the total land global surface area, but at the same time, is inhabited by more than 50% of the total human population [1].

Geographically, the type 2 diabetes red zone is variable, ranging from dry desert areas to heavily raining green land. At the same time, it has the lowest level below sea and the highest mountains above sea level. This area is also unique for its wide cultural, social and ethnic variations. This makes the diabetes red zone area a positive research field for both the geographical and cultural impact of the disease.

There is enough epidemiological data to support the fact that type 2 diabetes has a different presence in different populations that are reflected by the incidence of the disease and its prevalence. These could be attributed to different risk factors that affect any given population. Ethnicity, family history and ageing are unavoidable factors, all of which contribute to the high diabetes prevalence in certain populations [2]. Lifestyle change in both developed and developing countries, namely globalization, has had an effect on diabetes prevalence, which is associated with high calorie intake, low physical exercise and obesity. Further studies have confirmed the continuous increase in diabetes prevalence in every country, with a variable figure ranging between 1.4% in rural Vietnam [3] and 70% among Pima Indians in United States [4].

WHO studied the rising prevalence of diabetes mellitus and impaired glucose tolerance based on 75 communities in 32 countries [5] and it is time now for further studies that link the global diabetes database to the status of human health, and its burden on world economy.

A population based surveys of the type 2 diabetes red zone would give the greatest chance to study the role of different risk factors that has been linked to the raising type 2 diabetes prevalence. There is enough scientific evidence to link urbanization to an increase of type 2 diabetes mellitus, regardless of the country’s financial status. There are many poor developing countries in this red zone that are affected by globalization and have demonstrated an increase in the incidence of this disease. This has been exacerbated by the new global increase of type 2 diabetes mellitus among children, as a result of the high prevalence of obesity and the change in lifestyle in the form of high calorie dietary intake and low physical activity in that age group [6].

The International Diabetes Federation (IDF) has produced a document listing the top 10 countries in terms of number of people with diabetes aged 20–79 years. This shows 5 out of 10 countries to be from the red zone, namely India, China, Japan, Pakistan and Egypt. These five countries contributed to 94.6% of the total number of people with diabetes among the top 10. It is anticipated that by 2025, Bangladesh will join the top 10 countries, replacing Japan. But when looking at the top 10 countries in terms of prevalence of diabetes, eight countries are located in the red zone area, namely Nauru, United Arab Emirates, Saudi Arabia, Bahrain, Kuwait, Oman, Tonga and Egypt. These countries will remain the top in year 2025.

Table 1 shows the top 10 countries, according to the number of diabetic patients and the prevalence of diabetes, which compare data from the year 2007 with expected changes in the year 2025. Although India and China are inhabited by the largest number of diabetic patients (80.7millions) as a result of their large population size, neither country appeared in the top 10 countries when diabetes prevalence was looked at. When looking to the highest prevalence of diabetes mellitus in the top 10 countries, six countries are from the Arab World (i.e., Middle East), but five of them are from the gulf countries, namely the United Arab Emirates, Saudi Arabia, Bahrain, Kuwait, and Oman. Gulf States have a higher prevalence rate than other Middle East countries such as Egypt. This observation provides a strong clue that Arab Ethnicity is at a higher risk of developing type 2 diabetes mellitus and that populations from Gulf States are the highest. It is anticipated that these countries will continue to be among the top 10 countries in the year 2025.

The type 2 diabetes red zone could now be easily divided into two parts: the eastern part, which has the largest number of diabetic patients but with a prevalence rate of less than 10%; and the western part, which has the highest diabetes prevalence (more than 10%) but a smaller number of diabetic patients, due to their small population size. The western part consists of Middle Eastern countries, which are inhabited mainly by Arab Ethnicity. The Republic of Nauru, an Island in the South Pacific, has the highest global prevalence rate of type 2 diabetes, but is only inhabited by 12,000 people with different ethnicities, according to a United Nations estimation.

There are numerous global studies that link ethnicity to type 2 diabetes susceptibility, regardless of environmental factors. Studies have proved that even with equal lifestyle changes, the prevalence of type 2 diabetes mellitus differs between people with different ethnicity, regardless of their geographical location. Jenum et al. have demonstrated the high prevalence of diabetes among South Asian women in Norway after adjustment for age, adiposity, physical activity and education that could be explained by ethnicity [7]. Asian Americans and Pacific Islanders have also been found to be significantly more at risk of developing type 2 diabetes than non-Hispanic whites [8]. These scientific clues may mean that the ethnicity of people from the red zone has a special effect on type 2 diabetes etiology. Tan et al. have shown the effect of ethnicity between Chinese, Malay and Indians in Singapore for type 2 diabetes, especially among females [9], which confirms the ethnicity effect within the red zone geographical location.

Arabs who could be considered an ethnicity with high frequency for type 2 diabetes have demonstrated the high prevalence in the Middle East, and also as an immigrant to different parts of the world, as shown in different studies [10].

The red zone for type 2 diabetes relates to high prevalence or large population, and warrants more study and a better focus when fighting this disease and its complications globally. This area is also expected to have more than 50% of mortality and morbidity from this disease. Half of the global economic impact of type 2 diabetes is from this area. This geographical area thus needs more attention when considering prevention programs and drugs supply.