Obesity is one of the important risk factors triggering diabetes (mainly type 2 diabetes), and due to the modernization of lifestyle and lagging health awareness, people’s physical activity gradually decreases, coupled with the unreasonable dietary intake of high calorie, high fat and high protein, low fiber, bringing overweight and obesity, resulting in an increasing prevalence of diabetes.
According to statistics, the prevalence of diabetes in people with long-term obesity is as much as four times higher than that of the general population. On the other hand, 80% of the type 2 diabetic patients are obese. Moreover, the longer the occurrence of obesity, the greater the chance of developing diabetes.
Trends in the prevalence of diabetes worldwide and in China
According to the latest statistics of IDF, there are about 194 million people with diabetes worldwide. According to current epidemiological trends, this number will increase to 330 million by 2025, mainly due to population growth, aging societies, global urbanization, and physical inactivity lifestyles.
The increase in diabetes over the longer term will occur primarily in developing countries, with the number of people with diabetes in Africa, the Eastern Mediterranean, the Middle East and Southeast Asia predicted to double by 2025 from the current level. At least 50% of these patients are unaware that they have the disease, and in some countries this percentage can be as high as 80%.
In the vast majority of developed countries, diabetes has become the fourth leading cause of death, and recent WHO data show that 3.2 million people die from diabetes worldwide each year, equivalent to six deaths per minute. In these countries, diabetes is the number one cause of death from cardiac emergencies and stroke, as well as the number one cause of blindness and kidney failure. The cost of diabetes and its related complications currently accounts for 5-10% of all health spending worldwide. If current epidemiological trends continue, this proportion will increase to 40% by 2025.
China is one of the countries with the largest number of diabetic patients in the world today, and the prevalence of diabetes and abnormal glucose tolerance is increasing year by year, with an accelerated growth rate in recent years and a huge absolute number of patients. The WHO predicts that the number of people with diabetes in China will reach 43 million by 2025, making China the second largest country in the world with diabetes after India.
The prevalence of diabetes in China was only 0.67% in 1979 when the reform and opening up started, and the prevalence rate has been in a slow growth stage in the following decade, reaching 1.2% in 1990, i.e. one diabetic per 100 people, and the total number of diabetics in China has reached 14.4 million. Since the 1990s, China’s economic development has entered a period of rapid growth, and the prevalence of diabetes among the population is also in a stage of dramatic increase, reaching 1.5% in 1995, and the total prevalence has reached 2.4% in 2000.
The prevalence of diabetes among residents aged 20 to 74 has reached 3.21%, which is more than double that of 1990, with an annual growth rate of more than 10% and an average net increase of more than 1.5 million people per year. In addition, the prevalence of type 2 diabetes in children and adolescents has increased significantly in China due to urbanized lifestyles and an increase in obese patients.
Similar to other countries in the world, the diagnosis and treatment rate of diabetic patients in China is also low. a survey in Guangdong in 1999 showed that 70% of diabetes was first detected during a special survey. In other words, only 30% of diabetic patients in China were diagnosed, less than 6 million of the 20 million diabetic cases were diagnosed, while another 14 million were unaware or undetected, and experts estimate that only about 40% of the diagnosed diabetic patients, i.e. 2.4 million people, are taking medication consistently.
The cost of diabetes treatment in China has also increased at an alarming rate in recent years, and a study has conducted a statistical analysis with the relevant data in 1993. health care expenditures, and indirect socioeconomic losses.
Diabetes and Obesity
In modern society, people’s living standards are gradually improving, physical work is often replaced by machines, physical activity is decreasing, and obesity is increasing due to overnutrition, which in turn makes people prone to type 2 diabetes. Obesity is an independent high-risk factor for type 2 diabetes, and 80% of type 2 diabetes patients are overweight or obese at the time of diagnosis. Increased body weight is highly correlated with the risk of developing type 2 diabetes.
If the risk of developing diabetes with a body mass index (BMI) <23 kg/m2 is set at 1.0, the risk for BMI ≥25 kg/m2 is 5.5, which means the risk of developing diabetes is increased by 5.5 times; the risk for BMI ≥30 kg/m2 is 25, while the risk for BMI ≥35 kg/m2 is 72, and the degree of obesity is positively correlated with the prevalence of type 2 diabetes. A survey in 14 provinces and cities in China showed that the relative risk of diabetes in obese people was 2.91 times higher than that in non-obese people.
The occurrence of diabetes is not only related to the degree of obesity, but also related to the duration of obesity. Some studies have found that the annual incidence of diabetes is 2.48 for those who have been obese for less than 5 years, 3.52 for those who have been obese for 5 to 10 years, and up to 5.98 for those who have been obese for more than 10 years.
The cause of obesity leading to type 2 diabetes is related to factors such as the decrease in the number of insulin receptors on adipocyte membranes and the decrease in the affinity of insulin receptors for insulin. The density of insulin receptors on the membrane of normal human adipocytes is about 10 receptors per square micron, and there are about 10,000 receptors on each adipocyte. In obese people, the density of insulin receptors on the membrane of fat cells is reduced, the number is decreased and the affinity with insulin is reduced.
Since the body is insensitive to insulin and therefore has an increased demand for insulin, pancreatic B cells must secrete more insulin to meet the body’s needs in order to control blood glucose in the normal range. After the occurrence of type 2 diabetes, the body’s glucose and lipid metabolism will be further disrupted, resulting in higher blood glucose, higher blood lipids and redistribution of fat, which will also increase the degree of obesity to a certain extent. Thus obesity and type 2 diabetes form a vicious circle of mutual cause and effect.
A recent study shows that although obesity is closely related to type 2 diabetes, older adults of normal weight who have the wrong body fat distribution may also be at increased risk of developing diabetes. The study found that men and women over the age of 70 who are of normal weight may be associated with a risk of diabetes if they have a large amount of fat in their abdominal or thigh muscle tissue.
Dr. Goodpaster, who led the study at Pittsburgh Medical Center, said that if seniors are not overweight or obese, it does not mean they are not at risk for diabetes. Older adults of normal weight may still have excess body fat, and the distribution of fat in the body is an important factor in the risk of developing diabetes. Of the nearly 3,000 men and women who participated in the study, those with type 2 diabetes or abnormal glucose tolerance had more fat in their abdomen or spread across their thigh muscles than those with normal glucose tolerance.
Visceral obesity is one of the most important causes of type 2 diabetes, and generally speaking adults with a body mass index (BMI) greater than 25 are susceptible to visceral obesity. However, a study by Professor Xiang Kun-san, a member of the Chinese Academy of Engineering, showed that 14% of Chinese adults with a BMI less than 25 also suffer from visceral obesity. This means that compared to Caucasians, Chinese people are more likely to have fat accumulate around their internal organs and are therefore more likely to develop type 2 diabetes.
Overcoming obesity to prevent diabetes
It is now believed that type 2 diabetes is a polygenic, multifactorial disease, and that in addition to genetic factors, the involvement of acquired environmental factors is more important. Aging, obesity, reduced physical activity, long-term high calorie intake and unreasonable dietary structure, history of delivery of huge fetuses and psychological stress are closely related to the occurrence of diabetes, among which overweight and obesity are the main risk factors that can be intervened in type 2 diabetes. The sensitivity to insulin in obese people can be changed, the key is to control the diet, excessive food intake is often one of the reasons for obesity.
The IDF believes that lifestyle interventions such as a healthy diet and moderate intensity physical activity can reduce the risk of diabetes by 60%. The risk of diabetes is reduced by 60%.
In addition, a sensible lifestyle not only delays or prevents the onset of type 2 diabetes, but also reduces the risk of chronic complications in people with diabetes.
The American Diabetes Prevention Program conducted a comparative study of 3,234 people with abnormal glucose tolerance. Researchers divided these people into three groups, with the first group changing their lifestyle habits, such as losing weight and exercising regularly, the second group taking oral diabetes medication, and the third group taking only a placebo. The results of the three-year follow-up study showed that only 14 percent of the people in that group who lost weight transformed into type 2 diabetes, 11 percent of the people in the oral diabetes medication group developed diabetes, and 29 percent of the people in the group taking the placebo transformed into diabetes.
A leading American diabetes expert has said that genes can determine who develops diabetes, but there are many variables in the process of developing diabetes, and that variable is exercise and diet structure. Some relevant scientific findings also show that better exercise, proper diet and weight control can delay the onset of type 2 diabetes, thus also avoiding complications caused by diabetes, such as diabetic nephropathy or diabetic retinopathy.
A 6-year prospective study conducted in Daqing, China, also showed that the incidence of progression of abnormal glucose tolerance to diabetes was reduced by 46% over 6 years through health education, implementation of interventions to increase physical activity, and attention to dietary balance.
However, individual behaviors alone are not sufficient to stop the current epidemic of diabetes, as stated in WHO Resolution WHA55.23 of the 57th World Health Assembly on the Global Strategy on Diet, Physical Activity and Health: Governments, in collaboration with other stakeholders, have a central role in creating environments that promote and encourage behavior change among individuals, families and communities to make life-enhancing decisions about healthy eating and physical activity patterns. Governments, in partnership with other stakeholders, have a central role in creating environments that promote and encourage behavior change among individuals, families and communities to make positive life-enhancing decisions about healthy eating and physical activity patterns.
On this World Diabetes Day we want to raise awareness among the public, health care professionals, government policy makers and the media about the close link between overweight, obesity and diabetes. The goal is to prevent diabetes through healthy lifestyles.