Describe Physical Inactivity in lifestyle risk factors?
Prospective epidemiological studies have shown that a sedentary lifestyle is associated with an adverse effect on the risk of death from all causes and CAD. Relative risk .of Cardio-vascular diseases conferred by physical inactivity appears to parallel in magnitude that conferred by Hypertension, dyslipidaemia or use of tobacco products. Physical inactivity and sedentary habits are associated with at least two-fold increase in the risk of CAD. Lack of physical exercise has several harmful effects to promote atherosclerosis. There is a tendency for increase in body weight, decrease in cardiac reserve: and decrease in insulin sensitivity with impaired glucose tolerance, increase in blood lipids and a rise in blood pressure.
On the other hand regular exercise has salutary bio-chemical and metabolic effect. It decreases LDL cholesterol and triglyceiides, increases HDL cholesterol, improves insulin sensitivity and helps in maintaining ideal body weight. It also stimulates collateral circulation in the heart and improves blood supply to the heart muscle. The Framingham Offspring study found that patients who participated in at least one hour of physical activities per week had an improved cardiac risk profile and decreased presence of associated risk factors would be predicted to reduce CAD mortality. The US Railroad Study, with mortality follow-up for 17-20 years, showed that the age-adjusted risk estimate for CAD death was increased to 1.39 for sedentary men who expended less than 40 kcal /week. The relationship for physical activity was independent and statistically significant when looked into in multivariate analysis.