There is a very important lesson to be learnt from the bone pain saga of the last eight months or so.
Nocturnal dialysis is a very different ball game compared to conventional thrice a week in center dialysis. PTH levels are a very important factor for people on dialysis. A lot of dialyzors have something called secondary hyperparathyroidism which is basically an abnormally high parathyroid hormone level in the blood. The body regulates the Calcium level in the blood by secreting this hormone from the parathyroid glands. In people on dialysis, this mechanism of Calcium contol is disturbed and the body starts secreting excess parathyroid hormone.
In nocturnal dialysis, this system is affected by an extra factor. The dialysate. The blood is in contact with the dialysate for about seven to eight hours every day. This is almost a third of the day. This can have a great effect. What happens is that the contents of the dialysate affect the composition of the blood. Excess calcium, for example, in the dialysate can move into the blood. Less calcium in the dialysate can cause calcium to be pulled off from the blood. The body also keeps calcium balanced between the blood and other parts of the body, notably the bones.
The cause for the bone pain was the extremely low calcium in my acid cans which forms my dialysate.
Now coming to the solution. The key to getting all the lost calcium into my bones was increasing the absorption of calcium from the food into the blood and subsequently into the bones. This is achieved by Vitamin D. So, I would need to take Vitamin D supplements. The supplement of choice in most dialyzors is calcitriol which is the active form of Vitamin D, the form that is used directly by the body. The problem with calcitriol is that it suppresses PTH. And a low PTH causes another set of problems - Adynamic Bone Disease being the most common.
That however was not the case with me. I was on a relatively high dose of calcitriol with no suppression of PTH. The reason behind this was the long exposure to the Calcium in the dialysate. The PTH is inversely proportional to the amount of Calcium in the blood. So, the dialysate Calcium was affecting the blood Calcium which in turn was affecting the PTH. This effect was much greater than any suppression caused by the Vitamin D.
This would not usually be the case with conventional dialysis where the exposure to Calcium in the dialysate is much, much less due to the short duration and lesser frequency of dialysis.
The thing with nocturnal dialysis is that it is relatively new and there are very few people on this modality. As a result, a lot of the decisions have to be made by the doctors more out of common sense than by relying on any systematic and published studies.