Obesity and Diabetes
Diabetes is a familiar term easily understandable by the common man because its incidence has increased during the 21st century. In 2000, the incidence of diabetes worldwide was 171 million. Studies by WHO estimate that these numbers are set to rise to 366 million by the year 2030. WHO (World Health Organization) defines diabetes as a chronic metabolic disease characterized by elevated blood glucose levels (blood sugar), leading to severe damage to the heart, blood vessels, eyes, kidneys, and nerves. Diabetes is of two types, type one, and type two diabetes.
Type One diabetes is an autoimmune condition in which the pancreas’ beta cells, responsible for producing insulin (a glucose-lowering hormone), are destroyed by the body’s immune system. As a result, the glucose levels rise in the blood. Type one diabetes accounts for 10% of diagnosed cases for diabetes. Some risk factors include autoimmune, genetic, and environmental.
Type Two Diabetes is a more common type of diabetes that accounts for 90% of diagnosed cases. It is characterized by insulin resistance and an inadequate response by the beta cells. It associated with metabolic syndrome or Syndrome X defined by the International Diabetes Federation (IDF) as Central obesity (defined as waist circumference with ethnicity-specific values) and two of the following: Hypertension (BP> 130/85mmHg) Triglycerides> 150mg/dl HDL<40 in men, <50 in women, Fasting blood glucose>100 mg/dl or already diagnosed type two diabetes.
HOW IS OBESITY A RISK FACTOR FOR TYPE TWO DIABETES?
Does obesity cause diabetes? According to studies, 89% of diabetic patients are also suffering from obesity or are overweight. This suggests that not all diabetics are suffering from obesity, but obesity is a major contributing risk factor for developing type two diabetes. One mechanism by which obesity predisposes to Diabetes type two is that it decreases insulin sensitivity. This causes blood glucose levels to increase.
Insulin is an anabolic hormone (a chemical messenger that promotes protein synthesis) that plays a crucial role in regulating glucose metabolism. This hormone is released in response to food intake and causes glucose to enter cells. The glucose provides energy for cells to function. The higher the quantity of glucose in the blood, the more insulin is released. Basically, insulin causes glucose to enter cells where it provides energy to function or otherwise gets stored. When blood glucose levels decrease, the stored glucose is broken down by insulin to be released into the blood. Insulin also encourages the uptake of amino acids and fats into cells. It promotes fat storage and prevents protein breakdown.
MECHANISM OF OBESITY CAUSING DIABETES
The primary pathology of obesity causing diabetes is based on insulin resistance. Insulin is a protein hormone that requires receptors present on the cell membrane for its action. Typically, when insulin levels increase in response to high glucose levels in the blood, insulin receptors also increase. This is called an increase in the sensitivity of insulin. In obesity, the opposite happens. The number of receptors does not increase even in response to increase insulin production. Therefore, despite an adequate amount of insulin in the blood, it cannot act on the cells to produce its action. The increased amount of fatty acids released in obesity contributes to insulin resistance. There is increased glucose production in the liver when it senses that there is no glucose available for cells to function. This further increases the glucose levels. This is the primary pathology for the development of type two diabetes.
The three distinct mechanisms in obesity that predispose to insulin resistance are described as follows:
Release of Pro-inflammatory cytokines:
Pro-inflammatory cytokines are chemical messengers that are released in the blood in response to inflammation or cell injury. In obesity, pro-inflammatory hormones like tumor necrotic factor-alpha, resistin, and retinol-binding proteins are increased. At the same time, protective hormones like adiponectin are decreased.
Ectopic fat deposition:
In obesity, there is abnormal fat deposition, particularly in the liver and skeletal muscles, as observed through studies. This contributes to the development of metabolic syndrome by causing glucose metabolic dysfunction.
Mitochondria are energy-producing organelles that play an essential role in energy production, energy expenditure, and free radicals disposal. It plays its role in balancing energy production and expenditure while protecting cells from damage by free radicals. Any dysfunction in mitochondria disturbs the metabolic processes like causing lipid accumulation and insulin resistance.
TREATMENT OF OBESITY IN TYPE TWO DIABETES
There is substantial and robust evidence that the treatment of obesity delays the progression of pre-diabetes to Diabetes type two. Weight loss is shown to improve glycemic control and reduces the need for glucose-lowering medications. The treatment ways for obesity include dietary modifications and physical activity. Nutritional modifications include eating less processed carbohydrates and shifting to low fat-diet, lean proteins, fruits, and healthy vegetables like nuts, avocado, olive oil, and canola oil. One should know which food to restrict, like high fat and high carbohydrates. Lifestyle changes include getting proper guidance with managing diet and participation in intensive physical activity, hence focusing on losing weight with on-going monitoring.
Treatment of type two Diabetes is incomplete without mention of glucose-lowering medicines. Some common ones include metformin, alpha-glucosidase inhibitors, glucagon-like peptide1 agonists, which cause weight loss in addition to managing glucose levels.
Bariatric surgery is also one of the most effective and long-lasting methods for weight loss. This surgery is performed in two ways, sleeve gastrectomy involving the resection of part of the stomach and gastric bypass surgery, which consists of creating a small pouch for food passage of food. Bariatric surgery is recommended for adults with BMI> 30kg/m2 or with diabetes, especially when there is the development of difficult to control complications.
Diabetes is a significant adverse outcome of obesity. About 89% of people with diabetes are suffering from obesity. Insulin resistance is the primary pathology for type two diabetes. Treating obesity helps us to improve diabetes outcomes and prevent its complications. Bariatric surgery is an efficient and long-lasting treatment option for overcoming obesity and diabetes.