Congratulations with your -25 pounds!
The occurrence of PVC's can be influenced by exercise, but also by many other things.
A list I found on how to minimize PVC's said:
1. Get Stress Under Control
2. Eliminate the Stimulants and Other Vices
3. Get Enough Sleep
4. Eat a High Potassium and Magnesium Diet
5. Right amount of Exercise
6. Keep Your Blood Pressure Under Control
further info : http://drjohnday.com/stop-pvcs/
So, I guess the answer must be YES! Your exercising has a positive effect on your PVC.