Why Worry About Those Bones?

In our practice, we have preoperative bone densities done on all bariatric surgery patients with follow-up studies done on a yearly basis. A number of years ago at the International conference on obesity in Greece a few of the surgeons questioned why we would do this. Although the answer to this question comes in the results of our baseline studies my first response was “Did you read the memorandum sent by Dr. Mason to all of us in July 2000 as well as his article on calcium in the November 2000 issue of Beyond Change?”

We have had a number of patients in their early 30’s whose bone density studies have indicated the diagnosis of osteopenia. [Osteopenia is known as a thinning of the bones.] We are seeing approximately 78% of our patients who have a vitamin D deficiency prior to surgery. [Vitamin D is an important supplement that helps with the absorption of calcium.] One of our 21 year old male patients was diagnosed with osteoporosis at the time of his preoperative bone density. [Osteoporosis, or porous bone, is a disease characterized by low bone mass and structural deterioration of bone tissue, leading to fragility of and an increased susceptibility to fractures of the hip, spine and wrist.] This young man admitted to drinking milk but did confess that he drank more colas then milk products. His vitamin D level was on the very low end of normal and he had been sedentary most all of his life. At a weight of 458 lbs. and BMI of 64 who would think of this young man as being malnourished and having bad bones?

In the memorandum sent to us that year by Dr. Edward Mason, founding father of the American Society for Bariatric Surgery, there was a clear warning for those of us who do bariatric surgery to watch the potential of bone loss in our bypass patients. Dr. Mason had been searching the medical literature about osteoporosis and stomach surgery. The search was initiated because of a patient who just had her Roux-en-Y gastric bypass reversed after 14 years because of severe osteoporosis and severe iron deficiency anemia. Although our focus with past blood work had been on serum (blood) calcium levels, Dr. Mason warns that the parathyroids (small glands of the endocrine system located behind the thyroid gland) are quite efficient in maintaining serum calcium but at the expense of the bones. In other words the calcium levels in the blood could be normal while at the same time the calcium in the bones is being depleted. His recommendation was to check the parathyroid hormone levels as well as the alkaline phosphatase levels in the labs we do. If they are elevated we must look at what could be happening to the bones. It is known that patients with a high level of parathyroid hormone can have complaints of bone pain and in severe form; bones can give up so much of their calcium that the bones become brittle and break (osteoporosis and osteopenia). Dr. Mason asks, “How many of the patients with duodenal bypass have secondary hyperparathyroidism?” [This includes patients who have had gastric bypasses and duodenal switch procedures.]

This information from Dr. Mason encouraged us to now focus on the bone health of our patients. We are now routinely doing PTH, vitamin D 25-hydroxy and alkaline phosphatase levels, 24 hour urine for calcium and bone density studies. This does help us monitor our patient’s bone health more accurately.

So much of what we do in medicine happens to be based on good old common sense. The answer to why we do baseline bone densities as well as the other studies is that if we are aware that a patient has a problem prior to surgery we can act on behalf of the patient very quickly. The patient can be sent to the endocrinologist for treatment and just as important is that we will know that a malabsorption procedure did not cause the disease. Also important, is that we will hopefully be able to prevent the exacerbation of the disease in the future. Dr. Mason, at that time also suggested to us that we not do the bypass surgery if we have negative results from these studies. Our practice is to leave this choice up to the patient with a warning that should they choose to have bariatric surgery they will have to be monitored by an endocrinologist as well as the bariatric surgeon for years to come.

The main concern for all of us who do bariatric surgery is that our patients will be compliant in order that they will have the best possible healthy weight loss. A study out of the University of California a number of years ago indicated that approximately 75% of the American population is not compliant with medication intake. How do we get our patients who have had malabsorption procedures to understand the seriousness of vitamin and mineral intake? Perhaps the best way is to make sure they understand why we are asking them to take them in the first place. It is hard to believe there is a gastric bypass patient out there who would want their surgery reversed because of bone loss or any other reason for that matter. If our patients understand what their responsibility is in the prevention of bone loss as well as a myriad of other potential deficiencies perhaps they would not forget their supplements, not forget their follow-up appointments, not forget to have regular lab work and not forget to have bone density studies.

To all of the surgeons who question the necessity of preoperative bone densities, as well as all other studies related to bone health, it is best to remember that if we are not paying attention, the problem of bone loss is a silent one that can come back to haunt us in years to come. We may appreciate the weight loss our patients experience as they do also but as Dr. Mason states, “Weight loss is pleasing and obvious. Bone reduction is not obvious until it becomes painful and difficult to treat.”

Jacquelyn K. Smiertka, RN