Is memory leaking?

Hi
Wondering if my server is leaking memory..pls see my 2 vmstat captures (before and after) below

BEFORE
procs memory swap io system cpu

r b swpd free buff cache si so bi bo in cs us sy id wa st
1 0 0 76065624 1355196 29078672 0 0 0 34 6459 11450 1 0 98 0 0
1 0 0 76064656 1355196 29079180 0 0 0 90 6276 10389 1 0 98 0 0

AFTER:

1> vmstat 2
procs -----------memory---------- ---swap-- -----io---- --system-- -----cpu-----
r b swpd free buff cache si so bi bo in cs us sy id wa st
1 0 0 48951484 1430436 53445256 0 0 0 13 1 0 1 1 98 0 0
1 0 0 48952188 1430436 53445336 0 0 0 106 5915 11745 1 0 98 0 0
7 0 0 48951956 1430436 53445464 0 0 0 46 5716 10091 1 0 98 0 0
2 0 0 48952560 1430436 53445592 0 0 0 84 6829 11867 2 0 98 0 0
2 1 0 48951940 1430436 53445680 0 0 0 50 5774 10536 1 0 99 0 0
^C

Is my memory leaking, I am not sure as the cache also getting bigger.

Thanks for advise.