Multiplying the insulin sensitivity function SX by a decreasing function dependent on the initial age and progression time, we obtain the function SX,AGE:S(X,AGE)=1−gX11+exp−gX2X−gX3*1−gA11+exp−AGE0/gA0+t/gA2−gA3,where AGE0 represents the age of participants at their first visit; the variable t denotes the time since the first visit; gA3 stands for a horizontal shift; gA0 and gA2 are scale factors; the parameter gA1 controls the magnitude of age-related insulin resistance and gA2 governs the rate at which insulin sensitivity decreases with age. Here, INS is linked to Insulin resistance.