The effect of heart disease differential mortality rate on cholesterol distribution

In a good deal of studies cholesterol distribution, as a risk factor, demonstrates a special treatment towards age so that it shows an upward trend up to an age group and exhibits a downward trend for older age brackets thereafter. To investigate this phenomenon, two general points of view are presented. First, this issue may occur naturally for many subjects and it may be due to natural treatment of cholesterol variable with age. Second, it could be related to differential mortality, i.e. mortality changes in different age groups. In other words, it can be said that higher levels of cholesterol are relevant to younger-age mortality rate. Constructing a parametric model based on Weibull distribution, the association of this phenomenon with differential mortality was investigated. This study revealed that the effect of differential mortality on cholesterol distribution in the age groups younger than 65 were insignificant and it could partly be justifiable just in older age groups because it involves 35% changes in the 85-95 age groups. Thus, the differential mortality justifies just a part of cholesterol changes and other parts are due to intrinsic changes of cholesterol variable with time.