While the most direct and immediate ill effects of smoking are associated with the lungs — that it could lead to pulmonary conditions, lung cancer, tuberculosis, etc. — there are still many dangers that need to be spoken about to increase awareness. One such ill effect of smoking is how it impacts musculoskeletal health. It is known to deteriorate muscles and bones without showing any apparent signs or symptoms until it becomes irreversible.
Effect of smoking on musculoskeletal health
People who smoke or are exposed to cigarette smoke are at high risk of developing musculoskeletal dysfunctions, even before other symptoms of smoking become evident. Experts list several ways by which smoking can affect muscles and bones, thereby impairing their functioning:
1. Affects bone formation
“Smoking has a direct impact on the bone mineral content or the bone mineral density,” says Dr Raghu Nagaraj, an orthopedic and joint replacement surgeon from Fortis Hospital, Bengaluru.
It has an inhibitory effect on osteoblasts, which are the cells responsible for building and strengthening the bone.
“Smoking decreases estrogen and testosterone levels, thereby decreasing bone mineral density in both males and females,” he adds. A decrease in bone mineral density leads to osteoporosis, which is more common in women after menopause.
Dr Nagaraj further explains, “It has an indirect effect on the enzymes that produce vitamin D, thereby reducing vitamin D levels in the body.”
This leads to reduced calcium absorption from the diet, thereby affecting bone density.
2. Increases fracture risk
Smoking reduces bone density in many ways. This leads to an increased risk of fracture in smokers, especially in the hip and spine.
3. Increases healing time
Nicotine present in cigarettes prevents neoangiogenesis (development of new blood vessels).
“If a chronic smoker suffers a fracture or undergoes surgery, the fracture or the surgical wound will take a very long time to heal, as there is reduced blood flow to the region,” says Dr Ananya Puttaraju, a senior consultant and robotic joint replacement and foot ankle surgeon from HOSMAT Hospital, Bengaluru.
“This can result in a higher risk of infection in smokers, because even if antibiotics are administered, their ability to reach the bones will be limited since the blood flow to the region is reduced. Hence, an individual undergoing surgery is advised to stop smoking about three to four weeks prior to the procedure,” adds Dr Puttaraju.
4. Causes avascular necrosis
Avascular necrosis is a condition where the bone tissue dies due to insufficient blood supply to the bones.
“Though it can be seen in any bone of the body, smoking generally leads to avascular necrosis of the hip bone,” adds Dr Puttaraju.
5. Increases the risk of arthritis
Smoking increases the chances of developing rheumatoid arthritis, which is a type of inflammatory arthritis. It can also increase the risk of developing osteoarthritis.
“If an individual is already suffering from arthritis, it increases the severity of the condition,” adds Dr Nagaraj.
6. Inhibits muscle synthesis
Smoking causes inflammation of the muscles, thereby reducing blood circulation in them. This affects muscle protein and muscle collagen synthesis as well.
“Individuals who are at risk of muscular injuries have a higher risk for tendon ruptures or ligament tears because of poor collagen synthesis,” adds Dr Nagaraj.
7. Stimulates muscle protein breakdown
Cigarette smoke has several constituents that have the potential to stimulate the breakdown of muscle proteins. For example, exposure to the acetaldehyde present in cigarette smoke was found to reduce protein synthesis in human muscle cells that were cultured. Another constituent called acrolein can induce atrophy and the breakdown of muscle fibres.
When the muscle proteins break down, it leads to muscle atrophy, thereby reducing muscle strength.
