Just to be a pedant, the increase in NMW and National Insurance for employers has cost companies money, not people. So I think what the PP's meant above is that their companies have had to pay more, not themselves personally.
This, of course, means that profits are less, and hence their own wages / dividends, which is related.
I speak from experience here as I was about to employ staff (sorry, I think they're all called 'colleagues' these days) for my business, however the increase in employers NI made it unsustainable, so I didn't. And subsequently I am unable to grow my business until the business can afford it. To enable the business to afford it, I need staff so that I can take on more work, but I can't afford to employ them etc etc.
So my own returns from the business are smaller as there is only so much I can do by myself. Oh, and of course that means less corporation tax as the business can't grow.