Vasopressin has three main effects: 1  Increasing the water permeability of distal convoluted tubule and collecting duct cells in the kidney, thus allowing water reabsorption and excretion of more concentrated urine, i.e., antidiuresis.
It can be caused by damage to the vagus nerve, which regulates the digestive system. A damaged vagus nerve prevents the muscles in the stomach and intestine from functioning, preventing food from moving through the digestive system properly. Often, the cause of gastroparesis is unknown.
What are you experiencing is a common thing for many CPAP users : aerophagia. The main cause of aerophagia or stomach bloating is swallowing the air when you sleep. This happens in the early days of CPAP therapy, but it should go away in time. However, there are some other problems that will cause aerophagia, and you have to deal with these problems to find a relief from gas problems: