Dr Arun Kochar discusses a very important topic of how prolonged sitting for long hours may be as harmful as smoking and may actually affect multiple body systems and cause diverse diseases.

Sitting: What are the risk factors?

It has been observed that sitting has become an important risk factor not only for cardiovascular disorders but for other illnesses as well.

We know of many traditional risk factors for heart disease. However, newer perils leading to heart ailments are increasingly being recognised also that could be as or more dangerous to our hearts. Many such risk factors have been recognised and a few of them are related to:

• Lifestyle and behaviour
• Environmental pollution
• Psychosocial stress
• Low fruit and vegetable intake
• Low birth weight and prolonged sitting

Chair is the killer

1. Conventionally, our body is equipped to be in motion with intermittent rests. It is like a perpetually moving mechanical apparatus. Our body has about 360 joints and 650 muscles to help us get going. Our skin is stretchable as well, moving over joints for easy mobility. Constant motion lets our joints stay lubricated, muscles strong and our body in holistic harmony with a healthy self. When we are physically active, our stamina improves and muscles joint power strength is maintained accordingly.
2. Evolutionarily, our bodies were always supposed to be upright. Physiologically speaking also, we are meant to stand and walk against gravity in an upright posture. Our heart and blood circulation works optimally when we move around. It has been proved that being mobile and active improves psychological functions as well. Our bone health improves, endurance builds up and bowel function is best on constant mobility.
3. Essentially, our body's torso is developed on account of the strength and power of anti-gravity muscles. These muscles help us in standing upright and moving around. Sedentary behaviour and sitting cause their wastage and atrophy.
4. Those who are bedridden, face difficulties and are prone to diseases such as deep venous thrombosis, osteoporosis, constipation and depression.

Evidence against sitting

Following are a few studies that have tried to look at the menace of sitting. There is, however, a dearth of large randomised controlled trials in this regard. Such randomised trials should be planned to find the correlation.

1. In a landmark study by The American Cancer Society, it was seen that women who sit long enough have a 10% higher risk of developing cancer than those who remain active and mobile. The study enrolled about 1,25,000 subjects and followed them for 16 good years. Sedentary women were more likely to develop certain types of cancer such as multiple myeloma, ovarian cancer, and invasive breast cancer.
2. In a recently published cohort study of 8002 adults, a more than normal amount of sedentary time was associated with a higher risk of death from cancer. Substituting sedentary time with light or moderate to vigorous-intensity physical activity was associated with a reduction in this mortality risk. 
3. However, there are certain studies that have questioned the enhanced association between sitting and adverse impacts. Whitehall 2 cohort study, for example, found a limited association of sitting with diabetes over 13 years in 4811 occupational cohort of Australian civil servants.
4. Another study of 8,00,000 people also analysed the sitting habits of the subjects. More sitters had a 112% increased risk of diabetes, 147% increased risk of cardiovascular events like heart attack and stroke, 90% increased risk of death from cardiovascular events and 49% increased risk of death from any cause compared to subjects who sit less.

The trouble arises when we refuse to move.

1. The new-age corporate executive is focused on his laptop through a myriad of virtual and physical meetings for almost the entire part of his being awake. Even during the travel time to and from the office, is utilised for doing corporate communications in the back seat of his car.
2. Most of the time today’s human is either in front of the screen, behind the wheel or at the office desk. Many of us believe and are taught that an hour of exercise would suffice for the entire day of sitting.

However, we know by Virchow’s triad, that our blood is prone to form clots in blood vessels if the circulation time is increased. Increased body weight and consequent diabetes along with hypertension are other concerns that may develop.

1. Our joints and bones could become weak.
2. Our breathing stamina gets less compliant.
3. Our gut movements become sluggish as well.

This all may translate into:

• Heart attacks
• Strokes
• Pulmonary insufficiency
• Cancers

Much like the ill effects of smoking, the phrase is apt and justified:

" Sitting is the new smoking"

1. Marathon sitting sessions slow down our body's metabolism.  The enzymes such as Lipoprotein Lipase that helps to remove circulating triglycerides from the blood, slow down. There is deconditioning of the antigravity muscles and insulin resistance is also increased. Thus sitting is a highly metabolic process leading to a plethora of clinical manifestations.
2. It is now quite an accepted fact that marathon sitting sessions can never be offset by one hour of exercise every day. For that to happen, it needs to be neutralised by periodic intermittent breaks of physical activity.
3. Sitting is a side effect of the corporate modern tech-savvy computer world. This has become a necessary evil for our existence. It is quite established that nomad hunter-gatherer humans had almost negligible bad cholesterol and no evidence of heart attacks. The current pandemic is a lifestyle disease as collateral damage to our prosperity.

The solution to the problem

Disclaimer- The views and opinions expressed in this article are those of the authors and do not necessarily reflect the official policy or position of M3 India.

The author, Dr Arun Kochar is a Senior Interventional Cardiologist practising in Mohali.