- By Bone & Body
Bariatric surgery is an effective treatment for obesity and can significantly improve obesity-
related conditions such as type 2 diabetes, hypertension and obstructive sleep apnoea.
However, it is also associated with adverse effects on bone health, potentially reducing bone mineral density (BMD) and increasing the risk of fracture and osteoporosis.
The type of procedure performed influences the risk factor, with malabsorptive procedures
having the most effect. The Roux-en-Y gastric bypass and biliopancreatic diversion procedures both reduce calcium absorption by bypassing sections of the small bowel where calcium is primarily absorbed.
Vitamin D deficiency is also common after surgery, further impairing calcium absorption and contributing to secondary hyperparathyroidism, a condition that accelerates bone resorption.
In addition, rapid weight loss reduces mechanical loading on the skeleton, leading to decreased bone formation, while hormonal changes following surgery may further disrupt normal bone remodelling. The gastric sleeve procedure is considered less malabsorptive, but decreased bone density can still occur.
The greatest decline in BMD occurs during the first two years after surgery, although it can
continue for years afterwards. Individuals at highest risk include post-menopausal women, older adults and those with vitamin D deficiency and low bone mass.
Regular monitoring of bone health is essential after bariatric surgery. A DXA bone density
scan is the gold standard for assessing BMD and provides early identification of low bone
density before fractures occur. Tracking calcium, vitamin D and parathyroid hormone levels can help identify nutritional deficiencies and metabolic changes that contribute to bone loss.
In addition, adequate protein intake, regular weight-bearing and resistance exercise will help maintain muscle mass, preventing sarcopenia (low muscle mass). A DXA body composition scan can assess lean muscle mass, helping identify those at risk of sarcopenia post-surgery.
If you are planning a bariatric procedure a baseline DXA bone density scan should be
considered, particularly if you have other risk factors such as rheumatoid arthritis, overactive thyroid or have been through menopause.
Ensure follow-up with your healthcare provider and reduce the long-term risk of osteoporosis and sarcopenia.
Next time: Optimising bone health in children
