90% of all diabetes cases are type 2 diabetes which is now one of the most common metabolic disorders worldwide and is characterised by three main factors:
● defective insulin production and secretion by pancreatic islet β-cells
● inability of otherwise insulin-sensitive cells to respond to insulin
● an inadequate compensatory insulin secretory response
These mechanisms should be tightly regulated – any defects will lead to the metabolic imbalance of this disease.
The disease itself is characterised by elevated blood levels of glucose (hyperglycaemia) which over a period of time will result in irreparable damage to:
● the heart
● the cardiovascular system
● the kidneys
● the eyes
● the nervous system
What are the risk factors for type 2 diabetes?
Sufferers of type 2 diabetes are typically obese with their higher body fat percentage being predominantly distributed in the abdominal region. The global rise in obesity, sedentary lifestyles and poor nutrition are seen as the main drivers of this escalating epidemic.
The major risk factors for type 2 diabetes are:
● obesity
● lifestyle factors
● genetic predisposition
● gut dysbiosis
Current scientific data suggest a role for adipokine dysregulation, inflammation, abnormalities in gut microbiota (see probiotics) and immune dysregulation as important pathophysiological factors.
The alarming epidemiological facts of type 2 diabetes
The epidemiology of type 2 diabetes is affected by:
● genetics
● environment
It is important to note that genetic predisposition only becomes a factor when the abuse of an environment characterised by sedentary behaviour and a high calorie unhealthy diet exerts its effects.
Although individual predisposition to type 2 diabetes due to the non-modifiable risk factors of genetic predisposition is a factor, strong evidence from epidemiological studies suggests that many cases of this disease can be prevented by improving the primary modifiable risk factors of obesity, inadequate physical activity and an unhealthy diet.
Data according to the International Diabetes Federation shows that in 2019 type 2 diabetes caused 4.2 million deaths with 463 million adults aged between 20 and 79 years living with the disease – a figure that is projected to rise to in excess of 700 million by 2045. This may well be conservative as it is believed that many more cases are misdiagnosed. To put the scale of the problem in perspective this disease was responsible for at least $720 billion in health expenditure in just one year (2019).
For further reading on the science underlying type 2 diabetes, I thoroughly recommend the 2020 paper Pathophysiology of Type 2 Diabetes Mellitus.