Bone mineral density in patients with small intestinal bacterial overgrowth.

OBJECTIVE

Malabsorption has long been recognized as a cause of osteopenia, and mild forms of osteopenia are present in many gastrointestinal disorders. The aim of this study was to determine if osteopenia is common in patients with small intestinal bacterial overgrowth.

METHODS

Bone mineral density was measured in fourteen patients with small intestinal bacterial overgrowth. Patients with obvious structural predisposing conditions such as previous gastric operations, small bowel strictures and small bowel diverticula, were excluded. Measurements were made in the distal right radius and ulna, in the hip and in the spine. The results were compared to those of a reference population. Radiographs of the spine were assessed for evidence of vertebral fractures. Blood samples were analyzed for serum concentrations of 25-hydroxyvitamin-D3 and 1,25-dihydroxyvitamin-D3, alkaline phosphatase activity, ionized calcium, intact parathyroid hormone and osteocalcin. All patients completed a questionnaire concerning, inter alia, previous fractures, past and current diseases, tobacco smoking and medication.

RESULTS

Patients with small intestinal bacterial overgrowth had significantly low bone density in the femoral neck (p < 0.01) and in the lumbar spine (p < 0.05), compared to a reference population. Six of 14 (43%) patients had had fractures.

CONCLUSIONS

Patients with small intestinal bacterial overgrowth have low bone mineral density. In patients with osteopenia of unknown origin, small intestinal bacterial overgrowth should be considered.