How Unhealthy Lifestyle Can Cause Prediabetes and Diabetes, Animation

How Unhealthy Lifestyle Can Cause Prediabetes and Diabetes, Animation

November 6, 2019 6 By Bertrand Dibbert


Diabetes refers to a group of conditions characterized
by high levels of blood glucose, commonly known as blood sugar. Glucose comes from digestion of carbohydrates
in food, and is carried by the bloodstream to various body tissues. But glucose cannot cross the cell membrane
to enter the cells on its own; to do so, it requires assistance from a hormone produced
by the pancreas called insulin. Binding of insulin to its receptor on a target
cell triggers a signaling cascade that brings glucose transporters to the cell membrane,
creating passageways for glucose to enter the cells. In most tissues, muscles for example, glucose
is used as an energy source, while in the liver and adipose tissue, it is also stored
for later use, in the form of glycogen and fats. When the body is in the fasted state, the
liver produces and secretes glucose into the blood, while adipose tissues release free
fatty acids to the liver where they are converted into additional metabolic fuel. Diabetes happens when insulin is either deficient
or its action is compromised. Without insulin, glucose cannot enter the
cells; it stays in the blood, causing high blood sugar levels. There are 2 major types of diabetes. Type 1 is when the pancreas does not produce
enough insulin; and type 2 is when the body’s cells do not respond well to insulin – they
are insulin-resistant. Both types are caused by a combination of
genetic and environmental factors but genetics plays a major role in type 1, while lifestyle
is a predominant risk factor for type 2. For this reason, type 1 diabetes usually starts
suddenly in childhood, while type 2 progresses gradually during adulthood, going through
a so called pre-diabetic stage, which is defined as borderline blood sugar levels: higher than
normal, but lower than diabetic. Pre-diabetes is very common, and while not
always developing into full-blown diabetes, over time, it can cause much the same damage
to the body. Unhealthy lifestyle is the trigger of pre-diabetes
and the main driving force behind its progression to diabetes type 2. The key factors are obesity and physical inactivity. There are at least 2 ways by which obesity
can cause insulin resistance and high blood glucose. First, in obesity, fat cells have to process
more nutrients than they can manage and become stressed. As a result, they release inflammatory mediators,
known as cytokines. Cytokines interfere with the signaling cascade
by insulin receptor, blocking the action of insulin, thereby causing the cells to become
less responsive to insulin. Second, excess adipose tissue releases abnormally
large amount of free fatty acids to the liver – an event that normally happens only when
the body is fasting. This tricks the liver into producing and releasing
more glucose into the blood. High blood glucose stimulates further insulin
secretion. Constant high insulin levels de-sensitize
body tissues, causing insulin insensitivity. Intra-abdominal fat appears to produce more
fatty acids and cytokines, and therefore has more severe effect on blood glucose, than
subcutaneous, or peripheral fat. For this reason, large waist size is a greater
risk factor than high body mass index. Sedentary lifestyle, apart from having indirect
effect by causing weight gain, has its own direct impact on insulin resistance. This is because physical activity is required
to maintain healthy blood sugar levels. Physical activity increases energy demand
by the muscles, which consume glucose from the blood, and subsequently from glucose storage
in the liver and adipose tissue. High energy expenditure helps to clear up
faster the spikes of blood glucose that follow every meal. High energy demand also promotes better cellular
response to insulin, increasing insulin sensitivity. Studies have shown that physical inactivity,
even for a short period of time, results in consistently higher spikes of blood sugar
after meals, which can trigger pre-diabetic changes in healthy individuals, or speed up
transition from pre-diabetes to diabetes. More importantly, this happens not only to
over-weight patients, but also to people with seemingly healthy weight. This is probably because inactivity reduces
muscle mass and replaces it with adipose tissue, thus having serious effects on blood sugar
levels while still maintaining an overall normal weight. The bottom line is, in order to prevent diabetes,
weight management must be combined with physical activity or exercise.