THU436 Small Intestinal Bacterial Overgrowth Causing Osteoporosis In An Adult Male

Disclosure: S. Aziz: None. S.A. Patrick: None. V. Mupparaju: None. S. Kode: None. Background: Small intestinal bacterial overgrowth (SIBO) is a disease caused by intestinal dysbacteriosis which can lead to nutrients malabsorption and chronic metabolic acidosis which affect bones health and cause osteoporosis. Clinical Case: A 45-year-old man with medical issues of GERD presents to the endocrinology clinic in 02/2022 for evaluation of incidental finding of T5 vertebral fracture noted in the chest x-ray done for evaluation of chest tightness. During the clinic visit the patient reported chronic bloating and gassiness. Denied symptoms suggestive of eating disorders, chronic fatigue, decreased libido, recurrent fractures, elastic skin, hypermobile joints or joint dislocation, and steroid use. Patient is married and has two biological children. He drinks alcohol socially and denied tobacco use. Patient was taking cholecalciferol 1000 IU daily at home. His weight is 64 kg with a BMI of 21 kg/m2. Physical examination did not reveal any abnormality. Bone mineral density showed the worst Z-score of -2.3 in his spine. Workup for osteoporosis included 24-hour urine calcium, CBC, CMP (including serum calcium, phosphorus, electrolytes, ALP, and creatinine), PTH, TSH, free plasma cortisol, ACTH, morning total testosterone, 25-hydroxyvitamin D level, SPEP, UPEP, celiac disease screening tests (tissue transglutaminase IgA and tTG IgG), IGF-1 and HbA1c were all within normal limits. The patient was started on alendronate 70 mg once weekly and was referred to a local gastroenterologist for further evaluation of his GI symptoms; he subsequently was diagnosed with SIBO which is the most likely cause for his osteoporosis. Conclusion: SIBO is a disease caused by intestinal dysbacteriosis, which is caused by replacement of physiologic bacteria by pathogenic bacteria from the large intestine leading to maldigestion and malabsorption of nutrients including fat, carbohydrates and protein leading to vitamins deficiencies and metabolic acidosis. Due to impaired absorption of nutrients it can cause systemic complications including osteoporosis. Fat malabsorption can lead to deficiencies of fat-soluble vitamins A, D, K and E. SIBO can also result in protein-losing enteropathy. The state of chronic metabolic acidosis caused by SIBO increases alkali mobilization from the bone and induces dissolution of the bone thus promotes the development of osteoporosis. Gastrointestinal diseases including SIBO should be considered in cases of osteoporosis of unknown origin. Presentation: Thursday, June 15, 2023