Introduction
Type 2 diabetes is a very common long-term health issue that affects a lot of people worldwide, no matter where they live. It makes up most cases of diabetes in certain ethnic groups and about 85% in Caucasians. (Understanding Type 2 Diabetes)
In 2010, around 285 million people had diabetes globally, and most of them lived in less wealthy countries. About 6.6% of adults between 20 to 79 years old had diabetes.
By 2030, it’s expected that around 438 million people will have diabetes. This increase will be highest in countries like India and China because more people are eating high-energy food, being less active, and living in cities. This means more people are getting diabetes at a younger age.
People with diabetes for a long time are more likely to have health problems related to their blood sugar levels. This could cost a lot for healthcare and affect the growth of economies in these places.
The way we diagnose diabetes has changed over time, which affects how we understand how many people have it. In the past, the level of blood sugar considered normal was higher than it is now. This means more people are now considered to have ‘pre-diabetes’ or a higher risk of getting diabetes.
Having problems with how our body handles sugar in the blood is often linked with being overweight, having high blood pressure, and having issues with fats in the blood. These things together are called metabolic syndrome and increase the chances of getting diabetes and heart problems.
But there’s good news! Making changes like exercising more and eating healthier can lower the chances of getting diabetes and heart issues by a good amount, like 40-60%.
Risk factors for type 2 diabetes
A few things can make someone more likely to get Type 2 diabetes. These include getting older, being overweight, eating too much, especially foods high in animal fats and sugary drinks, not being active, having family members with diabetes, and certain health conditions like high blood pressure or high cholesterol.
When some of these problems like high blood pressure, high blood sugar, high triglycerides, low ‘good’ cholesterol, and belly fat come together, it’s called metabolic syndrome. This happens more with a lifestyle that’s like the Western way of living, especially in cities.
Being overweight plays a big role in getting Type 2 diabetes. The risk goes up as someone’s weight increases, especially around the belly. This is a bigger problem for some ethnic groups like Native Americans, African Americans, South Asians, and certain Asian populations. Being overweight can make the body resistant to insulin and cause issues with how the body handles fats and sugar.
Having metabolic syndrome makes the risk of getting diabetes two to five times higher in most people.
Some studies suggest that certain things that happen early in life, like being underweight when born or not getting enough food before birth, might also make someone more likely to get diabetes or heart problems later in life.
Recent emerging risk factors
Not getting enough sleep, like many of us do nowadays, could also be a big part of why more people are getting Type 2 diabetes. Studies show that not getting proper sleep messes with how our bodies handle sugar and insulin, increasing the risk of diabetes and obesity. For instance, research with lots of women found that those who slept less had a much higher chance of getting diabetes over time.
We’re also learning that certain medicines might affect our bodies, making diabetes more likely. Some high doses of medications for things like high blood pressure or certain mental health conditions might make insulin work less effectively or affect how the body handles sugar.
Certain chemicals in our environment might also play a role in causing diabetes. Some pollutants found in the environment seem to be connected to diabetes and problems with how our body handles sugar and fats. These chemicals can build up in our body fat and mess up our hormones, affecting how we process sugar and fat.
There’s also a link between how babies grow in their moms’ bellies and their chances of getting diabetes later in life. Babies who didn’t get enough nutrition before birth or were small at birth might have a higher chance of getting diabetes when they grow up. This seems especially important in places that are changing fast, like areas where the economy is growing quickly.
Even with all these new findings, the main things that increase the risk of diabetes are still the usual ones: getting older, being overweight, not being active, eating unhealthy foods, having family members with diabetes, and having other health issues like high blood pressure or cholesterol.
Methodologic issues in the epidemiology of type 2 diabetes
When we study Type 2 diabetes, how we do the research is really important. We need good methods to compare different studies. It’s best to study a big group of people randomly picked from a community. But sometimes, where we get people from, like workplaces or if they already have another disease, can change the results.
Age matters a lot when studying diabetes because it’s more common as people get older. So, we need to look at different age groups and compare them properly. Also, how we check if someone has diabetes, like with a blood sugar test, affects what we find.
In different parts of the world, we’re seeing more people with diabetes. There are a few reasons for this: more people being diagnosed with diabetes, populations getting older, diabetes starting at a younger age, people with diabetes living longer, and more new cases of diabetes happening.
Over time, the way we define diabetes has changed. In the past, there wasn’t a clear definition for diabetes until the 1980s. But even after that, the levels of blood sugar used to define diabetes have changed. This affects how many people are considered to have diabetes in a population. Sometimes, using different tests to diagnose diabetes also gives different results.
Some reports say that more older people and even younger ones are getting diabetes now. This might mean diabetes is starting earlier in life, especially in countries that aren’t very wealthy. It’s also interesting that in some places where more people have problems handling sugar but don’t have diabetes yet (called IGT), the number of these cases is going down as the number of diabetes cases goes up. This might show that areas with more IGT cases are just starting to have a diabetes problem, and we might be able to prevent more cases there. Looking at the ratio of IGT to diabetes could help us see how big the diabetes problem is in a certain place.
Regional and ethnic patterns of type 2 diabetes worldwide
This section looks at where diabetes is most common and how it’s changing over time in different parts of the world. The main sources of data used are the Diabetes Atlas by the International Diabetes Federation and a review by Wild et al.
Africa
In Africa, diabetes affects people differently depending on whether they live in urban or rural areas. Places like North Africa show increasing rates of diabetes due to urbanization, while sub-Saharan Africa, where poverty and malnutrition are more common, has lower rates. The overall adult population affected by diabetes in Africa was around 3.8% in 2010 and is expected to reach 4.7% by 2030. There are unique forms of diabetes in Africa, such as “ketosis-prone” diabetes and malnutrition-related diabetes.
North Africa: Countries like Sudan, Tunisia, and Egypt have relatively high diabetes rates. In Egypt, for example, some urban areas have a prevalence of 14-20% while rural areas have lower rates around 5%. Similar differences are seen in other North African countries.
Sub-Saharan Africa: There’s not much data on diabetes in this region, but studies from countries like Ghana, Nigeria, Cameroon, Tanzania, and South Africa show varying rates. For instance, diabetes was rare in urban Ghana and Nigeria in the past but has been increasing in recent years. Undiagnosed cases are common, showing that diabetes is still at an early stage in this region.
South Africa: Diabetes is more common in both urban and rural areas here. Studies in Cape Town showed rates of 8% for diabetes and 7% for a pre-diabetic condition called IGT. In a rural community, diabetes affected about 4% of the population.
Factors influencing diabetes risk in African populations include family history, ethnic background, body fat distribution, and lack of physical activity. Access to healthcare is limited in many parts of Africa, leading to poor control of diabetes and frequent complications.
The Americas
In North America (USA and Canada), diabetes is a significant health issue. Studies in the USA showed a rise in diabetes prevalence, especially among certain ethnic groups like African-Americans and Mexican-Americans. The prevalence among elderly individuals from these groups was notably high, exceeding 30%.
Different groups in the USA and the Americas have varying rates of diabetes. In the US, Latino people and African-Americans have higher rates compared to White people. For example, in the early 1990s, diabetes rates were 6% in White people, 10% in African-Americans, and around 13% in Mexican-Americans and Puerto Ricans. These differences have continued over time.
Native American Indian communities, especially the Pima Indians, have very high diabetes rates. About half of the Pima Indians have diabetes, and it’s also affecting younger people more now compared to 20 years ago.
Similar trends are seen in Canada among aboriginal communities, where diabetes rates have more than doubled compared to non-aboriginal populations.
Other groups like native Hawaiians, second-generation Japanese-Americans, and Chinese-Americans in the USA also have higher rates of diabetes. These increases in diabetes are linked to factors like body fat distribution and lifestyle changes.
The number of Americans with diagnosed diabetes is expected to rise significantly by 2050, with African-Americans being most affected. The costs associated with diabetes in the USA are quite high, reaching millions of dollars in medical expenses.
In Central and South America, data on diabetes are limited, but urban areas generally have higher rates compared to rural areas. For instance, in Mexico City, diabetes rates were higher compared to the national average.
In the Caribbean, countries like Jamaica have seen a rise in diabetes rates over the years, especially among women.
Europe
Europe has a mix of countries with different wealth levels, and not all countries have recent data on diabetes rates. In countries where data is available, diabetes rates vary from 2.1% in Iceland to 12% in Germany.
United Kingdom (UK): In the UK, diabetes affects inner-city areas with diverse populations. People from the Indian subcontinent have higher rates of diabetes compared to Caucasians. Poverty and social deprivation play a role in increasing diabetes rates, especially in inner-city areas like Manchester. Unhealthy diets and lack of physical activity are also linked to higher diabetes rates.
Scandinavia: In countries like Sweden and Finland, diabetes rates among the white population are around 8-10%. There’s a history of high rates of a pre-diabetic condition called IGT. Lifestyle changes, like better diet and more exercise, have been found to reduce diabetes risk.
Continental Europe: In Italy, the prevalence of diabetes is around 2.5% overall but increases with age. In France, it’s about 7-19% in older age groups. The Netherlands sees around 8% of elderly Caucasians affected by diabetes. Greece has seen an increase in diabetes rates linked to aging and obesity. Turkey reports rates of 6-9% for diabetes and pre-diabetes.
Eastern Europe: Data from Eastern Europe are limited, but countries like Russia and Uzbekistan report rates of 6-10% for diabetes and pre-diabetes. There’s a lack of diagnosis and treatment in some areas, contributing to the burden of diabetes.
Asia
India has the highest number of people with diabetes. Studies show a steady increase in diabetes rates since the 1970s. Urban areas have higher diabetes rates compared to rural ones. The trend is shifting towards younger people getting diabetes.
In countries like Pakistan, Bangladesh, and Sri Lanka, diabetes rates are also increasing. Central obesity and insulin resistance are major factors. Asian babies, especially in India, are born smaller but have more body fat, which increases their risk of diabetes later in life.
In Mauritius, diabetes is common across different ethnic groups, especially in urban areas. Rates are high among people aged 45-74.
The Middle East: Countries in this region, due to changes in lifestyle and urbanization, are seeing a sharp rise in diabetes rates. Affluent countries like the UAE, Saudi Arabia, and Kuwait have high diabetes rates.
Western Pacific region
Australia: In Australia, the number of people with diabetes has been rising steadily. A study in 2000 found that about 7.5% of adults aged 25 or older had diabetes, with higher rates in older age groups. More than half of these cases were not diagnosed previously. Type 2 diabetes (T2DM) is more common and is increasing over time.
Indigenous Populations: In both Australia and New Zealand, native populations like Aboriginal Australians and Torres Strait Islanders have higher rates of diabetes. In New Zealand, Polynesians have a higher risk than Caucasians and often develop diabetes at a younger age.
Pacific Islands: Different Pacific Island populations have varying rates of diabetes, influenced by lifestyle and economic factors. Places like Nauru and Papua New Guinea have some of the highest rates worldwide. Fiji’s Indian migrants had higher rates than Melanesians. Urbanization in places like Papua New Guinea has led to a surge in diabetes rates.
Japan: In Japan, diabetes has become more common since the 1960s, especially among children. This rise is linked to changes in diet and lifestyle. Diabetes-related complications like coronary artery disease are increasing, possibly due to dietary shifts.
China: China’s diabetes rates have dramatically increased in recent years, mainly due to rising obesity levels, especially among children. The country has experienced a significant shift from low diabetes rates to an alarming increase, especially in urban areas. This trend might continue unless effective measures are taken.
Southeast Asia: Countries in this region, like Cambodia, Vietnam, Indonesia, and the Philippines, have seen an increase in diabetes rates despite their traditional lifestyles. Thailand, Malaysia, and Singapore also have rising diabetes rates, linked to obesity and adopting more Westernized diets.
Korea: In Korea, the prevalence of diabetes is also increasing, with alarming rates of impaired fasting glucose (IFG), which could predict a future diabetes epidemic.
In Singapore, for example, the number of people with diabetes has been going up since the 1970s, especially among certain groups like Malays and Indians. They also tend to have higher rates of obesity. About 8.2% of adults there have diabetes.
Impact of diabetes
Diabetes causes big problems for people and communities. Treating its complications, like stroke, blindness, heart disease, kidney failure, amputation, and infections, costs a lot. In 2007, around 3.8 million people died because of diabetes and its related issues. Most of them passed away due to heart disease or kidney failure.
Different places have different problems related to diabetes. In places with more white people, heart disease and amputation are common issues. But in Chinese and Asian groups, kidney failure and strokes happen more. People from the Pacific Islands face nerve problems, and South Asians have a higher risk of heart disease.
Having high sugar levels for a long time causes these problems. But simple and low-cost measures can help prevent diabetes and its complications. Instead of just focusing on sugar levels, it’s better to pay attention to heart disease risks. The challenge is to provide good care that everyone can afford.
Diabetes makes people more likely to die early, mostly because of heart problems. It’s a bigger problem in poorer countries. In 2010, about 4 million younger adults died because of diabetes.
Different parts of the world have different diabetes issues. Some places have more heart problems, others have more kidney issues or strokes. For example, Hong Kong has fewer heart problems but more strokes compared to Europe. Native American centers in the US have more heart attacks.
Diabetes also increases the risk of cancer, like pancreatic, liver, or breast cancer. Having high sugar levels makes this risk higher.
Prevention of type 2 diabetes
Preventing Type 2 diabetes is really important because it’s super expensive to treat. People have tried different things to stop it from happening or delay it. They found that changing the way you live, like learning about healthy habits, exercising, eating better, and losing some weight, can help a lot. These changes are not just good for your wallet; they also keep working for a long time.
Some medicines used for diabetes and obesity have also been tested to prevent Type 2 diabetes. Some worked well, like metformin or certain types of pills. Even some medicines for high blood pressure could help. Scientists are trying out more medicines, but for now, changing your lifestyle is the best and cheapest way to prevent diabetes.
Conclusions
Mixing genes that make us prone to diabetes with a lifestyle filled with fast food and not moving much is making more people have trouble with sugar in their bodies. Places in Asia with economies growing quickly will see a big rise in diabetes cases. The problems that come from diabetes, like issues with blood vessels and other body parts, make it tough for hospitals and clinics to handle.
Recent studies found that managing lots of things together, like food and exercise, can help stop bad things happening because of diabetes. If we eat better and move more, we can stop sugar problems from turning into diabetes. So, even though diabetes is common, we can stop it or handle it well with ways that aren’t super expensive.