Type 2 diabetes is a metabolic disease that causes abnormal buildup of sugar in the blood stream. A combination between genetic factors and unhealthy life style that lead to obesity are blamed to underlie it. Most people with diabetes have this type of the disease.

The cornerstone of treatment and prevention of type 2 diabetes is expressed by a healthy diet, regular physical activity and a normal body weight. Many medicines are available to help control blood glucose levels. If not responding, people with type 2 diabetes may be prescribed insulin.

Over time, untreated hyperglycemia can lead to serious, life-threatening complications, such as stroke, heart attack, blindness and kidney failure. Continuous observation and adherence to treatment plan can save patient’s health and life.

Previously called adult-onset or noninsulin-dependent diabetes, type 2 diabetes is a life-long metabolic disease in which there is a high level of glucose in the blood as a result of a lack of insulin hormone or the body's inability to use it efficiently. It is the most common form of diabetes and develops most often in middle-aged and older adults. However, increasing number of cases have been appearing in children and adolescents.

The exact causes for type 2 diabetes are still not known, but there are several important contributing factors. The most important are excess body weight and unhealthy lifestyle that lead the body to be unresponsive to insulin or producing insufficient amounts of it.

• Non-Modifiable risk factors: Some of the conditions that increase the risk of having type 2 diabetes are out of person’s control. These include:
  • Medical & Family history: Having a close relative with type 2 diabetes or medical history of gestational diabetes increases vulnerability to this disease.
  • Ethnicity: Many races have more likelihood to develop diabetes. These include: African, Asian, Latino/Hispanic, Native American and Pacific Islander descent.
  • Age: The risk of having type 2 diabetes increases with age. The incidence of the disease most frequently occurs after age 45.
• Modifiable risk factors: By some healthy changes, people can reduce their risks or delay the development of diabetes and improve their overall quality of life.
  • Excessive weight: Overweight and obesity are much related to diabetes. Nearly 90% of people with type 2 diabetes have an excess weight. The risk of having the disease will drop by losing this excess.
  • Physical inactivity: Changes in eating habits and activity related to urbanization are blamed for the sharp increase in the numbers of people who have diabetes.
  • High blood pressure: Uncontrolled hypertension has been linked to the development of diabetes. In addition, it can cause damage to the cardiovascular system.
  • Abnormal cholesterol levels: Low HDL and/or high triglycerides can increase the risk for Type 2 diabetes and cardiovascular disease.  These abnormalities can be improved by healthy diet, sufficient aerobic exercising and healthy weight. Sometimes medications are necessary.
  • Impaired glucose tolerance (IGT): In this condition, the amount of glucose in the blood is above normal, but not high enough to be classified as diabetes.

Insulin is a hormone secreted from beta cells in pancreas into the blood stream. It works to assist glucose that came from diet or liver to inter the cells in order to be used as an energy source, which lead to a decrease in blood glucose levels. This process is disrupted in diabetes.

Type 2 diabetes usually begins with insulin resistance; a condition that occurs when fat, muscle, and liver cells do not respond to insulin secretion. As a result, the body needs more of this hormone to help glucose enter cells, which could be met at first by further production and secretion. With time, the pancreas become exhausted and not able to respond with enough insulin when blood sugar levels increase, such as after meals, thus a lot of glucose remain in the blood stream.

Many people with type 2 diabetes remain unaware of their condition for a long time because the symptoms are usually less noticed than in type 1 diabetes and may take years to be recognized. Even though symptoms of type 2 diabetes may include:

• Excessive thirst (polydipsia): Fluid may be pulled from the tissue under the effect of glucose build up in bloodstream that may lead to feeling thirsty.
• Excessive urination (polyuria): The need to urinate more than usual. Affected people could notice that they wake up to void during night.
• Excessive hunger (polyphagia): Muscles and organs don’t get their need of energy source due to disrupted insulin work. This nourishes the desire of eating.
• Weight loss: The body uses alternative energy source stored in muscle and fat, which burns more calories. In addition, excess glucose is lost in the urine.
• Feeling of tiredness: If cells are deprived of sugar, the person may become exhausted and lacked of energy for daily living.
• Blurred vision: Hyperglycemia may cause Fluid to be pulled from the lenses of the eyes. This may affect sharpness of eyesight.
• Frequent infections: High glucose levels provide a suitable medium for bacteria to grow and proliferate.
• Slow wound healing: Decreased blood flow from diabetes complication can delay healing process and aggravate the situation.
• Acanthosis nigricans: A skin condition marked by dark, fluffy patches on skinfolds areas -usually in the armpits and neck. This may point to insulin resistance.

Many Blood tests are used to diagnose diabetes and prediabetes and because there may not be obvious symptoms in the early stages of type 2 of the disease, blood glucose tests can detect the problem before it gets worse. These tests include:

• Glycated hemoglobin (A1C) Test: A blood test that reflects the average of blood glucose levels along the past 2-3 months without showing daily fluctuations. The test does not require fasting before and can be performed at any time of the day.
• Fasting Plasma Glucose Test (FPG): Considered the most common test used for diagnosing diabetes by measuring blood glucose after fasting for at least 8 hours. It is most reliable when administered in the morning.
• Oral Glucose Tolerance Test (OGTT): A more sensitive test than the FPG test, but less convenient to have. It Measures blood glucose after at least 8 hours of fasting and 2 hours after drinking a liquid containing 75 grams of glucose dissolved in water.
• Random Blood Glucose test (RPG): A blood sample will be taken at any time to be analyzed which used sometimes to diagnose diabetes during a regular health checkup when the result is 200 mg/dl or above and the individual also have symptoms of diabetes.

It is recommended to check type 2 diabetes every 3 years starting at age 45, or younger if the person has risk factors. Prediabetes condition needs consultation regarding frequency of testing. Overweight children who have other risk factors for diabetes have to start checking at age 10, then repeated every 2 years.

Noticing signs and symptoms of the disease should force the person to undergo diagnostic tests. It is worth mentioning that finger-stick devices are not accurate enough for diagnosis of the diabetes, but may be used as a quick indicator of hyperglycemia.

The goal of treatment aims for two important things: lowering high blood glucose level and preventing complications at the Long-term.

• Weight control: Maintaining a normal body weight can adjust type 2 diabetes. Some people with this disease can stop taking medications after losing weight even they still have diabetes. Very obese patients whose diabetes is not well managed with diet and medication may consider undergoing weight loss (bariatric) surgery, such as Gastric bypass.
• Healthy Diet: Learning what to eat, how much to eat and when to eat can give the patient a good health and help managing his condition. Coordination between the physician, patient and registered dietitian can help to put together a meal plan that fits health goals, food preferences and lifestyle. In general, people with diabetes are advised to
  • Increase their intake of foods rich in fibers, like vegetables and fruits.
  • Consume whole grains instead of refined forms.
  • Limit consumption of meat, sugar and processed foods.
• Physical activity: Exercises can improve insulin sensitivity, which allow glucose to enter the cells and thus decrease blood glucose level. Physical activity burns excess calories and fat that help losing weight. Regular exercising can also improve blood flow and blood pressure. All these benefits participate in controlling type 2 diabetes and drive away its complications. It is recommended to consult the doctor before starting exercise regimen to know if there is a need to take special steps before, during, and after workout. The target is 150 minutes moderate-intensity aerobic physical activity per week or 75 minutes a week of vigorous-intensity aerobic physical activity or a combination of the two with muscle-strengthening for at least 2 days per week. Patient may need to check blood sugar before and after exercise. He also recommended to warm up before and cool down at the end. Drinking enough amount of water is integral for healthy functioning. There may be a need to have snack before starting to prevent dropping glucose levels below normal (hypoglycemia).
• Oral hypoglycemic Medication: If diet and exercise do not help keep blood glucose at normal or near-normal levels, the doctor may prescribe medication. One drug or more may be given depending on the condition. The main types include:
  • Biguanides (Metformin or Glucophage): The first pharmacological line of treatment for type 2 diabetes that also can be given in some cases of prediabetes. It makes cells in the body more sensitive to hormone insulin and decreases glucose production in the liver. This drug doesn’t cause hypoglycemia. However, users can complain of GI side effects like diarrhea, which could be tolerated as body used to the drug.
  • Sulfonylureas: If metformin didn’t work alone, another drug may be prescribed. These medications enhance insulin secretion from the pancreas. The main Side effects of them is hypoglycemia. Examples are: glyburide, glipizide and glimepiride.
  • Meglitinides: Compared with the previous group, Meglintides stimulate faster secretion of insulin for a shorter period of time. They also carry the risk of decreasing blood glucose levels below normal. They include:  Repaglinide and nateglinide.
  • Thiazolidinediones: they can lower glucose levels by increasing insulin sensitivity and reducing rates of glucose new formation in the liver. However, they can lead to weight gain and some serious side effects like increased risk of heart failure and fractures. Examples are: Rosiglitazone and pioglitazone.
  • Dipeptidyl Peptidase-IV (DPP-4) Inhibitors: suppress the degradation of bioactive peptides that lead to trigger insulin release and lowering blood sugar. Sitagliptin, saxagliptin, and linagliptin are major examples.
  • Glucagon-like peptide-1 (GLP-1) receptor agonists: They effectively lower A1C and weight while having a low risk of hypoglycemia. Examples are: Exenatide and liraglutide
  • Sodium-glucose co-transporter 2 (SGLT2) inhibitors: A new class of diabetes medications that blocks the reabsorption of glucose in the kidney, increases glucose excretion into urine and thus lowers blood glucose level. Examples: Canagliflozin and dapagliflozin. Yeast urinary tract infection is the most common side effect of these medications.
• Insulin therapy: If neither lifestyle changes nor oral hypoglycemic drugs helped controlling type 2 diabetes, insulin become a necessary therapeutic option. Type, dose and frequency of insulin injection will be determined by the doctor based on the current situation and the degree of disease control.
• Monitoring blood glucose levels: If the person has been diagnosed with type 2 diabetes, he/she needs to work closely with the doctor. Regular checkups and follow-ups are important. Most people with type 2 diabetes only need to check their blood sugar once or twice per day or even a few times a week if blood sugar level is under control. Self-testing can be done when waking up, before or after meals, and at bedtime. However, some patients need to test more often like when they are sick, or cases of poor controlled and fluctuated blood sugar. Keeping a record of blood glucose levels can help in setting and adjusting care plan. Based on the numbers, people may need to make changes to their meals, activities, or medications to keep blood sugar levels in the right range. A1C test need to be checked 2-4 times a year. The targeted level for most people with diabetes is recommended to be less than 7%. This test is a better indicator of diabetes management than daily blood sugar tests, while these can help in day to day controlling of the disease and keep eyes on any emergent conditions like severe hyper or hypoglycemia.

• Long-term complications: Diabetes can cause damage in nerves and small, large blood vessels. These conditions develop over a period of time with poor Diabetes management that can lead to:
  • Diabetic retinopathy (eye disease): Considered the top cause of blindness and visual disability. It arises from small blood vessel damage in the retina that can be early detected through regular eye examinations.
  • Diabetic Nephropathy (kidney disease): It is the leading cause of dialysis and kidney transplant in developed countries. It happens when the functioning units of the kidney are destroyed by damaged blood vessels in that organ. Kidney function test and urine test for protein can help early detection.
  • Cardiovascular disease: Hyperglycemia works in narrowing arteries on the long-term through hastening a process called atherosclerosis. This could lead to life threatening conditions such as heart attack and stroke.
  • Diabetic Neuropathy (nerve disease): It is the most common complication of diabetes. It originates from nerve damage by hyperglycemia and decreased blood flow to the nerve cells. This can lead to loss of sensation, damage to limbs and impotence among men.
  • Diabetic foot: Disrupted neural functions and poor circulation in the feet can increase the risk of ulceration, infection of them. People with diabetes face a risk of amputation that may be 25 times greater than that in people without this disease.
  • Periodontal disease: Poor glucose control increasing the risk of inflammation of the tissue surrounding the teeth. This condition called Periodontitis and considered a major cause of teeth loss, also associated with an increased risk of cardiovascular disease.
• Short-term complications: Some complications may happen in short period (days, hours, or even minutes) with improper use of insulin and not adhering to treatment plan. From these:
  • Hyperglycemic Hyperosmolar Nonketotic Syndrome (HHNS): A serious condition most frequently seen in older patients, especially with type 2 diabetes and often preceded by an illness or infection. It is caused by sharp elevation in blood sugar that reaches 600 mg/dl and leads to excessive urination and dehydration. Mental status may be affected and consciousness may be lost if not treated rapidly.
  • Diabetic Ketoacidosis (DKA): A life-threatening condition that mainly affects type 1 diabetes, but those with type 2 are also under the risk. It develops when body starves for glucose and starts using fat for energy, which result in forming ketones that reach the blood stream and lead to chemical imbalances. It can be manifested by excessive thirst and urination, Confusion, vomiting and fruity breath odor.
  • Hypoglycemia: Despite the contradiction of terms, people who treated for diabetes have the potential of their blood glucose to drop below normal levels (less than 70 mg/dl). This may take place for skipping a regular meal, having more medication/insulin than usual or doing more physical activity than normal. It is considered a serious complication that may lead -if untreated- to comma or even death.

A healthy life style can play a huge role in deporting type 2 diabetes. Losing 5-7% of body weight can reduce chances of having prediabetes by 50%. Eating healthy food and being physically active are two fundamental approaches to ward off the disease.

Complication prevention

For those who already have type 2 diabetes, several ways are available and recommended to delay the development of its upsetting complications. That include:

• Adhering to the planned treatment and commitment to a healthy life style as much as possible.
• Undergoing scheduled tests, like yearly eye examination and (A1C) test every 3 months or as ordered by the doctor.
• Getting the recommended immunization, like flu vaccine, as high blood sugar can weaken the immune system.
• Doing Routine mouth care such as brushing twice a day and visiting the dentist every 6 months or when needed to check and treat gum and teeth problems.
• Looking after the feet by daily checkup and cleaning with lukewarm water, then drying gently before applying lotion except for between toes. Careful nail cut and suitable shoes are also recommended.
• Controlling hypertension and dyslipidemia, which can be achieved through limiting sodium and unhealthy fat consumption, physical activity and taking prescribed medications.
• Quitting smoking and limiting alcohol drinking as they participate -separately or in combination- in the progression of life-threatening diabetes complications such as heart attack.

Diabetes is a lifelong disease and there is no proven complete cure until now. Some people with type 2 diabetes no longer need medication if they lose weight and become more active. The own self insulin and the healthy diet can be enough to control type 2 diabetes when person reaches the ideal body weight. If untreated probably, the disease can progress to serious complications that affect life quality and expectancy.

Diabetes is considered by International diabetes federation as one of the largest global health emergencies of this century. It accounted for nearly 8.8% of all adult population around the world in 2015, three-quarters of them are living in low and middle-income countries. In addition to the 415 million adults who are estimated to currently have diabetes, there are 318 million at high risk of developing the disease in the future.

World Health Organization (WHO) estimates that globally, high blood glucose is the third highest risk factor for premature mortality. Five million people lost their lives in 2015 by this disease. In almost all high-income countries, diabetes is a leading cause of cardiovascular disease, blindness, kidney failure and lower-limb amputation.

There are about 15.6 million more men than women with diabetes. Currently, more people with diabetes are in urban than in rural areas, with 269.7 million, 145.1 million, respectively. Diabetes People at age 20-64 accounting for 73.6% of total Affected by this disease, while 22.6% are at age 65-79.

Type 2 diabetes is the most common type of the disease. It usually occurs in adults, but is increasingly seen in children and adolescents. In most diabetes prevalence studies conducted in adults, the prevalence of type 1 and type 2 diabetes is not reported separately. In high-income countries, a few studies have estimated that approximately 87% to 91% of all people with diabetes are guessed to have type 2 diabetes. No sufficient detail in low and middle-income countries are available.