What is type 2 diabetes?

Type 2 diabetes, previously known as non-insulin dependent or adult-onset diabetes, is the most common form of diabetes mellitus and accounts for 90% to 95% of people with diabetes [1,2,3,4].

This metabolic disorder is characterised by a decrease in the effects of insulin on body cells, called insulin resistance, and/or insufficient insulin production by the pancreas. 

Since insulin regulates blood glucose levels, it leads to hyperglycaemia (high blood glucose). These abnormalities are most often triggered in people with a family history of type 2 diabetes and an unhealthy lifestyle (lack of exercise and poor eating habits), often resulting in weight gain or central obesity (fat around the stomach area) [1,3,5,6,7,8].

Symptoms

Before its onset, type 2 diabetes can develop silently for many years without noticeable symptoms [4]. For this reason, it is not uncommon for patients to discover that they have diabetes during a medical consultation initially made for other health concerns [3,4,6].

Therefore, even a person who does not experience any symptoms of type 2 diabetes may be affected by this condition.

Diabetes can also manifest itself through typical symptoms of hyperglycaemia, such as:

• fatigue;
• excessive thirst;
• weight loss;
• frequent urge to urinate;
• slow healing;
• hyperglycaemia detected during a blood test [2,3,8].

Causes

Often observed in cases of excess weight (especially around the stomach area) and obesity, type 2 diabetes is defined as having excess glucose in the blood, which occurs after cells have become resistant to insulin. This is called insulin resistance [1,2,5,6,8].

Excess blood glucose pushes the insulin-producing beta cells in the pancreas to overproduce insulin to stabilise/reduce blood glucose [1,2,5,6,8].

Type 2 diabetes is diagnosed when the pancreas can no longer produce enough insulin to compensate for insulin resistance [1,2,5,8].

Risk factors

Several genetic and environmental factors increase the risk of developing type 2 diabetes [1,3,4,6,7].

• Genetic predisposition, a recognised risk factor for developing type 2 diabetes, with a risk level of at least 40% for a person with parents who are living with diabetes [3,6].
• lack of physical activity and a high-sugar, high-fat, low-fibre diet contribute to abnormal insulin production and action [1,3,4,6,7]. 
• overweight and obesity, especially around the stomach area [3,7].   

Other factors linked to lifestyle have also been identified: 

• smoking
• insufficient and low-quality sleep
• depression and stress,
• excessive or regular alcohol consumption [3,6,7].

Treatments

Making lifestyle changes is the primary measure in treating type 2 diabetes and the best way to delay or even prevent its onset. A balanced diet, regular physical activity and weight loss help to regulate blood glucose levels [3,4,5,6].

Sometimes adopting a healthy lifestyle is not enough. Although lifestyle measures will always remain a key foundation in diabetes management, several oral medication options are available to assist in keeping blood glucose levels in target. If necessary, insulin will be offered as a treatment for type 2 diabetes if blood glucose targets are not met on oral medication [3,5,7].

In cases of obesity, bariatric surgery procedures may be beneficial in reducing excess weight and treating type 2 diabetes [9].