Health Hazards
25 Jan 2019

Negative Health Consequences of Sedentary Lifestyle

Negative Health Consequences of Sedentary Lifestyle

 A sedentary lifestyle can be defined as any activity characterised by low energy expenditure in a sitting or reclining position on a regular basis which includes behaviours such as sitting, watching television or using computer/devices for professional/entertainment purpose. Spending maximum time of the day in a sitting position is pretty much harmful for every aspect of our health since it may not only weaken our muscles, impair blood circulation, and increase our risk of chronic diseases like heart disease, cancer, and obesity but it may also be damaging to our mental health. According to the World Health Organization (WHO), 60 to 85% of the population worldwide does not engage in enough activity. Making physical inactivity a severe worldwide problem and the fourth leading risk factor for global mortality surpassed only by hypertension, tobacco use and high blood glucose levels (Diabetes).

We the humans are not programmed to be physically inactive and Physical inactivity is also associated with increased risk of morbidity or worsening of many chronic diseases and health conditions. Let’s understand some of these:

INCREASED BLOOD CHOLESTEROL LEVELS&FORMATION OF ATHEROSCLEROTIC LESIONS WITHIN BLOOD VESSELS:

Prolonged physical inactivity as a consequence of sedentary lifestyle results in a reduction in insulin sensitivity within our body. Insulin resistance develops which can induce an imbalance in glucose metabolism and manifest as chronic high blood glucose levels. This, in turn, develops an inflammatory response due to the generation of oxidative stress leading to cell damage. Insulin resistance can also alter body fat metabolism which then leads to the development of abnormal blood cholesterol levels (Dyslipidaemia) and manifests As

  • High levels of plasma triglycerides.
  • Low levels of HDL (Good Cholesterol)
  • Increased levels of LDL (Bad Cholesterol).

This triad, along with the damage to the endothelium (Inner layer of Blood vessels) contributes to the formation of plaques (Atherosclerotic lesions) within these blood vessels.

CARDIOVASCULAR DISEASE& STROKE (PARALYSIS):

More the people sit, the higher is the likelihood that they will show signs of injury to their heart. Chronic physical inactivity results in a decline in insulin sensitivity and abnormal body fat metabolism. This manifests in the increase in the levels of blood cholesterol and that too of bad cholesterol (LDL cholesterol). Excess of cholesterol builds up inside the walls of the arteries supplying blood to the heart in the form of plaques. Over the time, calcium accumulates in these plaques. This further narrows down the lumen of blood vessels supplying blood and oxygen to the heart muscles. Insufficient blood and oxygen supply to the heart can manifest as chest pain (Angina), and if this continues for a longer time may results in Heart attack (myocardial infarction) due to death of cardiac muscles as a consequence of lack of sufficient blood and oxygen supply.

When a similar mechanism happens within the blood vessels supplying our brain tissue, it may manifest as paralysis (Ischemic stroke).

HIGH BLOOD PRESSURE (HYPERTENSION):

 Chronic physical inactivity due to a sedentary lifestyle can increase our risk of suffering from high blood pressure. How? Let’s see,

  • Physical inactivity is invariably associated with excess body fat accumulation. This fat accumulation tends to occur around our waistline and surrounding internal organs (Central Obesity). Obesity being itself a risk factor for hypertension, chances of high blood pressures are increased in a person living a sedentary lifestyle.
  • Obesity and sedentary lifestyle hamper the capacity of the body to neutralise the Reactive oxygen radicals (Free radicals) which are formed in the body as a consequence of routine metabolism. This increases the oxidative stress damages the inner walls of blood vessels and makes them harder and less flexible. This increases the resistance to the flow of blood through them and consequently increase the blood pressure.

OVERWEIGHT/OBESITY:

Physical inactivity due to a sedentary lifestyle is associated with less muscular activity and reduced energy expenditure when this is aided by increased energy intake (excess food consumption) it leads to a positive energy balance. It decreases the sensitivity of peripheral tissues to the action of the hormone insulin. If this continues for an extended period, it leads to the development of an insulin resistance state. It manifests in impaired metabolism of blood sugar and the accumulation of excess fat within the body, especially in and around abdominal region and also around & within the internal organs such as the Liver. This excess fat accumulation contributes to the development of obesity and a further worsening of insulin resistance; thus the vicious cycle continues. Once an individual develops obesity, it has further negative impact on his overall health, as it brings other health issues like Diabetes, hypertension, etc together.

Health Hazards

 

TYPE-2 DIABETES MELLITUS:

Lack of adequate physical activity and excess caloric intake in people living sedentary lifestyle results in the accumulation of excess fatty tissues within the body. This fat is usually deposited around the waist region and around the organs which leads to obesity. This excessive accumulation of fats develops inflammation in the body through secretion of harmful chemicals. This inflammation weakens the action of insulin (Hormone responsible for active metabolism and utilisation of blood sugar). Insulin fails in the effective metabolism of blood sugar and its usage at various body cells and tissues. E.g. skeletal muscles (This is called Insulin resistance). When our body fails to overcome this insulin resistance, blood sugar level remains high and manifests as Type-2 Diabetes mellitus.

 

CANCER:

We have already seen that physical inactivity is linked with the development of diabetes, obesity, and cardiovascular disease. The problem can even get worse as it also increases the risk of suffering from certain types of cancers.

Physical inactivity is associated with the development of insulin resistance (a condition where the hormone insulin becomes less effective at lowering blood sugar levels). Insulin resistance can increase the risk of developing inflammation in the body. According to some studies, excessive inflammation when present within the body may have a role in the development of different types of cancers, such as:

  1. 1. Prostate Cancer
  2. Breast Cancer
  3. Colorectal Cancer
  4. Lung Cancer
  5. Ovarian Cancer
  6. Endometrial Cancer

 

DECREASED MUSCLE STRENGTH AND FUNCTION:

Prolonged physical inactivity can affect the metabolism in skeletal muscles with increased break down of muscle proteins and fall in its synthesis. This manifests as decreased muscles mass and reduced muscle function. The skeletal muscles become weak regarding strength and physical performance which makes a person prone to frequent falls and injuries.

 

WEAK BONES (OSTEOPOROSIS) AND FRACTURES:

 There are two types of cells which are primarily associated with metabolism in adult bones. The first type of cell (Osteoclast) is related to the removal of damaged and aged bone tissues associated with usual wear and tear. The other kind of cell (Osteoblast) deals with the laying down of new and functionally active bone tissue. The well-balanced activity of these two cell types keeps our bones strong and healthy.

Physical inactivity is associated with increased activity of cells that reduce bone mass(osteoclasts) and reduced activity of the cells (Osteoblasts) that promote bone growth. This imbalance in the metabolism of adult bone results in a gradual reduction in functional bone tissue and bone mass. Gradually the bones become thin and weak (osteoporotic). As the age of a person goes increasing the problem gets worsened with an increased risk of fractures and injuries.

 

PHYSICAL DISABILITY:

Reduced muscle mass and muscle function, weak bones can increase the risk of frequent falls and injuries such as fractures. This can lead to physical disability in the people living a sedentary lifestyle without any necessary physical activity.

 

DEPRESSION/MEMORY LOSS/ALZHEIMER’S DISEASE:

Recent clinical studies also demonstrate that prolonged physical inactivity and sedentary lifestyle is associated with neuro and psychological issues like Depression/Memory loss or even Alzheimer’s disease, etc.

 

DYSFUNCTION OF IMMUNE SYSTEM:

We have already seen that physical inactivity due to a sedentary lifestyle is associated with generation toxic chemicals such as Free radicals, which can contribute to the immune system dysfunction. This can either make our immune system overactive causing Autoimmune inflammatory diseases or less active making it incapable of fighting against pathological agents putting us at the risk of acquiring repeated infections respectively.

 Thus living an active lifestyle is utmost important from our health perspective. Giving up on a sedentary lifestyle and increasing activity during day time is necessary to prevent the development of adverse health issues as mentioned above.

 

References:

  1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2857522/
  2. http://www.revespcardiol.org/en/sedentary-lifestyle-and-its-relation/articulo/90326038/
  3. https://www.sciencedaily.com/releases/2016/08/160815190019.htm
  4. https://www.sciencedaily.com/releases/2016/04/160427221204.htm
  5. https://www.ahajournals.org/doi/pdf/10.1161/CIR.0000000000000440
  6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5586440/
  7. http://researchonline.ljmu.ac.uk/5253/1/2016holdermphil.pdf
  8. http://diabetologia-journal.org/wp-content/uploads/2018/05/RIC-box-example.pdf
  9. https://bmjopen.bmj.com/content/3/6/e002901
  10. https://www.ahajournals.org/doi/pdf/10.1161/01.ATV.0000158311.24443.af
  11. http://www.scielo.br/scielo.php?pid=S0066-782X2010001200009&script=sci_arttext&tlng=en

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