A study published in the Journal of Bone and Mineral Research shows that there is a 30 per cent increase in the risk of fractures after a gastric bypass operation. The study also discovered that falls increase after these operations as well.
“Gastric bypass is a well-established method that has proven effective in reducing obesity, diabetes and mortality, so naturally our findings do not mean that you should stop providing these types of operations,” says Mattias Lorentzon, professor of geriatrics at Sahlgrenska Academy, University of Gothenburg, Sweden, and Chief Physician at the University Hospital.
The study was based on 38,971 patients that underwent gastric bypass operations, 7,758 of those had diabetes and 31,213 did not. The people who had the surgery were compared with individuals in the larger group that did not have the operation but had the same morbidity background.
The study found that regardless of whether the patient had diabetes or not, patients that had the operation had a 30 per cent increase in the risk of fractures. People without diabetes had a 32 per cent increased risk of fractures and diabetics had an increased risk of 26 per cent.
The risk increase applies to fractures in general, except for the lower legs. The study showed after surgery, fractures of the lower legs happened less frequently.
The strengths of the study are in the sample size. Also, the data is more equivalent since the researchers focused on the dominant method used to correct obesity surgically, in this case, gastric bypass and excluded other forms.
In a gastric bypass operation, most of the stomach and part of the small intestine are removed. Food goes directly into the small intestine instead of passing through the whole stomach; this increases the sense of being full. Gastric bypass is used in people who are extremely overweight and have tried to lose weight using other means.
There are two steps involves in a Gastric Bypass
- The first step involves making the stomach smaller, through the use of staples to divide the stomach into a small upper section and a larger bottom section. The top section of the stomach which is about the size of a walnut is where the food consumed will go. The top section only holds about 28 grams of food; this is why the surgery is effective at reducing weight.
- The second phase is the bypass; this involves connecting the small part of the small intestine to the small hole in the top of the intestine. The food consumed will then travel from the upper separated portion of the stomach into the new opening into the intestine. As a result, the will absorb fewer calories.
The prevailing explanation for the increased risk in bone fracture after having diabetes surgery reduction in weight and the skeleton becomes weaker after reduction in load. However, this study did not show a relationship between fracture rate and reduced weight.
An increase in falls was however noted, which in self could account for the increase in fractures. More studies need to be done on why individual who have gastric bypass are more prone to falls.
“The fact that the risk of fractures increases and also seems to increase over time means that it will be important to follow patients, evaluate the fracture risk and, when required, institute measures to prevent fractures,” says Kristian Axelsson, doctoral student at Sahlgrenska Academy, University of Gothenburg, and resident physician in orthopedics at Skaraborg Hospital Skövde.