Until recently I filled my tires with a mixture of gases, 78% nitrogen, 21% oxygen and about 1% of assorted gases. I called this mixture .... air.

The main reason we use nitrogen alone is because we eliminate two destructive elements, water and oxygen. Both of these are destructive to rubber and metals, by attacking the rims, tire rubber the valve stem and its seal. Water in the air is high on a humid summer day or practically non-existent on a frigid winter day, living in Canada I see both

Air and nitrogen expand about the same so air pressures in tires will fluctuate minimally differently with either of these gases inside. A large decrease in the temperature can lower the pressure enough to trigger the TPMS light, especially if the pressure was a little low to start with. Similarly a large increase in temperature can increase the pressure and if the tires are then ran at high speed the pressures could exceed safe levels, a not likely but possible scenario.

Low profile tires naturally have a lesser volume inside them than regular tires so the loss of a small amount of gas has a larger effect on the pressure. The TPMS light coming on frequently may mean that it is not calibrated correctly or faulty. Correct pressures would indicate this to be the case.

Keep the tires checked regularly, just because the light is not on does not mean they are inflated to the correct pressure. and never run them without the valve stem caps. If you use nitrogen keep using it if you can, but a top up with air adds 79% nitrogen anyway.