Diabetes is a disease caused by the dysfunction of the insulin signaling pathway within the cells. Our body requires insulin for glucose transport from the bloodstream across the cell membrane into cells, especially the brain, liver, and muscles, to be the substrate for energy production. Insulin functions by binding to the insulin receptor in the cell membrane, which stimulates glucose transporters called GLUT4 to move to the cell membrane to facilitate the entry of glucose into the cells. In the event of insulin signaling dysfunction, known as insulin resistance, a higher level of insulin is required for the same metabolic effect, which puts stress on the insulin-producing beta cells in the pancreas. When the beta cells fail to keep up with the high insulin demand, their production eventually falls, fasting blood sugar persistently rises above a clinical threshold of 126 mg/dL, and frank diabetes ensues.
The kidney can usually reabsorb all glucose from the glomerular ultrafiltration of nephrons. However, high blood glucose can result in glycosuria (glucose presence in urine) if the filtered glucose load exceeds the glucose reabsorption capacity of the proximal tubule of a nephron. If this problem persists without proper treatment, severe complications to the kidney can follow.
Types of Diabetes
- Type I diabetes– is an autoimmune disease with the immune cells damaging the insulin-producing cells in the pancreas, resulting in an insulin deficiency.
- Type II diabetes– is due to insulin resistance and eventual fall in insulin production.
- Special type diabetes– occurs from damage to the pancreas or congenital diseases relating to insulin production.
- Gestational diabetes– occurs during pregnancy and resolves after giving birth, but with increased risk of future type 2 diabetes.
Type II diabetes is the most common. It has genetic components but is mainly caused by our lifestyle, for example, too much sugar and starch, ultra-processed food, being overweight, central obesity, less physical activity, physical inactivity, etc.
This type of diabetes usually occurs in people over 30 years old. However, it is becoming more prevalent in younger people, 20-30 years old, relating to high ultra-processed food consumption, less physical activity, and obesity. Young patients with type II diabetes may find it hard to manage their diseases with more risk of complications and tend to have severe complications at younger ages.
Therefore, it is crucial to keep diabetes under control. Screening for diabetes in young people for timely prevention and treatment of diabetes can decrease diabetes complications in the long run.
When blood sugar levels are too high for an extended time, it exerts a direct, detrimental effect on both large and small blood vessels, resulting in heightened inflammation and atherosclerosis. Chronically high blood sugar also affects the immune system disrupting white blood cell function, making them less effective in fighting against germs and increasing the chance of infection.
Diabetic retinopathy is one of the eye complications of diabetes. Chronic high blood sugar can damage the blood vessels of the retina. If untreated, capillary rupture with micro bleeds, swelling, retinal detachmentม, and vision loss can occur. Patients with diabetes also have an elevated risk of cataracts and glaucoma.
Diabetic nephropathy denotes renal complication of diabetes. In an early stage, the kidney works harder because of high glomerular arterial pressure secondary to the vasodilator effect of high blood sugar levels. Kidney function at this stage would show no signs of dysfunction or albumin leak in the urine. The kidney’s function declines when albumin is detectable in the urine. If not treated, the kidney function will gradually deteriorate which may lead to chronic kidney failure and eventual hemodialysis.
Neuropathy is a common diabetic complication. Patients typically have numbness in their hands or feet with a sensation of wearing gloves or socks. Some might experience pins and needles or a burning sensation in their hands and feet. Less common neuropathy includes lack of or excessive sweating, heart arrhythmia, food aspiration, bloating, and epigastric discomfort. These are symptoms of dysfunction of the parasympathetic nervous system that controls gastrointestinal motility.
Symptomatic arterial occlusions commonly occur in the legs. Common symptoms include cold feet, leg hair loss, shiny foot skin, and severe leg cramps when walking or running, which improve after resting or dangling your feet. If left untreated, the narrowed arteries can progress to complete occlusion with critical inadequate blood supply to the foot, infection, and eventual toe or leg amputation.
Narrowing of Coronary Arteries
Narrowed coronary arteries are a severe and common complication in diabetic patients, causing myocardial ischemia or myocardial infarction if there is sudden complete occlusion from ruptured arterial plaque, and luminal clot formation leading to inadequate heart muscle contraction, low blood pressure, heart arrhythmia, cardiac arrest, and sudden death.
Ischemic stroke is another dire complication of diabetes. Occlusion of a cerebral artery causes disruption or cessation of the brain and nerve function in the ischemic zone. Paralysis, facial palsy, slurred speech, or numbness on one side of the body can follow.
How do you know you have diabetes?
Although diabetes complications can be severe and cause disability or death, if we know the underlying causes and receive early detection and treatment, we can significantly curtail diabetic complications.
Diabetic symptoms may range from none to hyperglycemic shock. Symptoms of diabetes are tired easily, frequent thirst and urination, especially at night (more than three times), unexplained rapid weight loss, extremity numbness or burning, pin and needle sensation, chronic or slow-healing wounds, sexual dysfunction, blurred vision, or sharper vision in a nearsighted person.
People at risk of diabetes are overweight, have a BMI ≥ 23 kg/m2, have central obesity, waist circumference ≥ 90 cm for men and ≥ 80 for women, have a family history of diabetes, women who had gestational diabetes or gave birth to newborn weighing over 4 kilograms. In addition to the aforementioned, Asians over 35 without risk factors should also receive diabetic screening.
- Currently, there are 4 diabetic diagnostic tests. The following 3 tests are accurate and popular in Thailand:
- Fasting blood sugar – measures blood sugar after 8-12 hours of fasting. A level above 126 mg/dl of blood sugars on 2 or more occasions indicates diabetes.
- Oral glucose tolerance test - measures blood sugar 2 hours after 75 grams of oral glucose. Over 200 mg/dl of blood sugar indicates diabetes.
- Random blood sugar without fasting – over 200 mg/dl of blood sugar with diabetic symptoms, such as frequent urination and thirst, indicates diabetes.
Diabetes management requires collaboration among doctors, nurses, nutritionists, and patients who must acknowledge the importance of treatment by understanding first-hand that diabetes is a chronic condition that is manageable and controllable to as near normal as possible. Diabetic patients can continue their lives, carry on activities, and work as usual. However, they must keep their blood sugar in check by controlling their diet, exercising, and taking medications to lower blood sugar. Moreover, regular follow-up visits can considerably reduce the risk of complications.
Diet is a vital component of measures to reduce blood sugar. It is the central pillar of treatment every diabetic patient should understand and adhere to properly. Food diabetes can have in unrestricted amounts includes leafy greens, lean meats, and egg whites. Eat fruits in limited amounts emphasizing low-sugar fruits such as guava, rose apple, and dragon fruit. Avoid ultra-processed food and refined carbohydrates such as white bread, sugar-sweetened beverages, and fruit juices.
For diabetic patients, exercise is another essential treatment because it helps lower blood sugar levels. Doctors recommend aerobic exercises like jogging, swimming, and cycling at least 150 minutes per week and resistance exercises like weightlifting at least 45 minutes, two days a week. Patients should avoid being sedentary or lying down idly for more than 90 minutes; they should take a short walk if it is over the limit.
The doctor will prescribe medication based on the types of diabetes you have. For instance, treatment of type I diabetes is with insulin injection. As for type II diabetes, the doctor will consider the severity of symptoms and complications, risk of hypoglycemia, and socioeconomic status of the patients in choosing the right prescription for a patient.
Is diabetes preventable?
Although type I diabetes is not preventable, type II diabetes eminently is. Many studies show that diabetes incidence is lower significantly when people at risk of diabetes regularly exercise in tandem with strict diets until they lose 7-10% of body weight.
Is diabetes curable?
In the past, diabetes treatments were limited to blood sugar control and reduction of complications only; curability was out of reach. Today, ongoing research yielded a treatment modality that can cure diabetes permanently, especially in newly diagnosed patients. The method is bariatric surgery for obese diabetic patients. Bariatric surgery not only helps with weight loss but can also permanently cures diabetes for many patients. However, not everyone is suitable for the procedure due to postoperative side effects. Therefore, it is selectively performed on certain patients when the benefits outweigh the risks.
Diabetes is a chronic condition; its incidence is ever-increasing. Although besieged by many complications, it is a manageable condition. If patients understand the disease and cooperate in their care, they can have nearly the same quality of life as healthy people.
Dr Sasipas Chontong
Endocrine and metabolic diseases