Pearsonn Correlation Coefficient of Averages

#1
I have a question regarding using PCC in a specific scenario.

Suppose I have 10 subjects of different ages. I want to know if there is a correlation between age and a specific parameter. That parameter for example is the area of pituitary cells. So in essence I want to know if there is a correlation between age and the area of pituitary cells.

If I take a sample of 10 cells from each subject and average it, it gives me the average size of a pituitary cell for that subject.

Can I then use PCC to calculate the correlation between age and the average size of the pituitary cells?

Thanks.
 
#4
One person will only have one age, right?

So, take the average of the area of pituitary cells and pair that with the persons age, plot them, estimate the correlation, and do the liner regression average area on age, ie age as explanatory variable.