Conditions that change the bone conversation

Type 2 (and type 1) diabetes

People with type 2 diabetes fracture more often than people without it — even though their bone density on DXA is usually normal or higher. In a large analysis of older adults, the fracture risk at a given T-score was about what a person without diabetes would face with a T-score roughly half a point lower (about 0.6 in women, 0.4 in men), and FRAX understated it. FRAX does not include type 2 diabetes as a risk factor at all (type 1 diabetes can be entered under 'secondary osteoporosis'; type 2 cannot), so a normal-looking score can be falsely reassuring.

The Trabecular Bone Score (TBS), a texture read from the same spine DXA image, tends to be lower in diabetes, and a TBS-adjusted FRAX captures some of the extra risk. Whether that adjustment should change treatment decisions is still being worked out.

Why: High blood sugar stiffens the collagen scaffold inside bone and opens tiny pores in the outer shell. Neither shows up as density — which is why this is the clearest real-world case for 'quality, not just quantity'.

The question to bring

"I have diabetes. Could my DXA and FRAX be understating my risk — and is a Trabecular Bone Score or a diabetes adjustment available?"

Sources: Schwartz et al., JAMA (2011) — BMD, FRAX and fracture in older adults with type 2 diabetes · Leslie, Rubin, Schwartz & Kanis, J Bone Miner Res (2012) — Type 2 diabetes and bone · Ferrari, Abrahamsen, Napoli et al., Osteoporos Int (2018) — Diagnosis and management of bone fragility in diabetes (review, incl. FRAX and type 1 vs type 2)

Chronic kidney disease (CKD-MBD)

Fracture risk rises as kidney function falls — in advanced chronic kidney disease and on dialysis it is up to about four times that of the general population. The kidneys activate vitamin D and clear phosphorus, so as function falls, calcium, phosphorus, vitamin D and parathyroid hormone drift together — the 'mineral and bone disorder' of kidney disease. Several osteoporosis medicines are dosed or chosen differently when the kidneys are impaired, which is why nephrology belongs in the conversation. Since 2017, KDIGO guidance has supported a DXA scan in kidney disease when the result would change treatment.

Why: Bone in kidney disease can be turning over too fast, too slowly, or be poorly mineralised — and a density number alone cannot tell which. That is why the blood tests and the specialist matter as much as the scan.

The question to bring

"I have kidney disease. Should my bone evaluation and any treatment choice be made together with my nephrologist — and which osteoporosis medicines are dosed or chosen differently for me?"

Sources: Fracture risk in chronic kidney disease: addressing an overlooked complication (review, 2025) · KDIGO 2017 CKD-MBD guideline update — executive summary, Kidney International · National Kidney Foundation — Mineral and bone disorder (CKD-MBD), patient overview

Celiac disease and other malabsorption

Low bone density is a frequent finding in adults newly diagnosed with celiac disease, along with a higher fracture risk, because a damaged intestine absorbs calcium and vitamin D poorly. In a 2015 systematic review, a strict gluten-free diet brought partial recovery of density by one year in every study reviewed and, in the studies that followed people long enough, full recovery by about the fifth year. Recovery is less certain in older adults. Society guidance differs on when to scan; ask whether a baseline DXA is appropriate at diagnosis or after a year on the diet. Other causes of malabsorption — inflammatory bowel disease, bariatric surgery, chronic pancreatitis — raise the same questions.

Why: Bone cannot be built from calcium and vitamin D that never cross the gut wall. Healing the gut is the first bone treatment; supplements only help once they can be absorbed.

The question to bring

"Given my celiac diagnosis, is a baseline DXA appropriate now or after a year on the gluten-free diet — and should my vitamin D, calcium and parathyroid hormone be checked?"

Sources: Grace-Farfaglia, Nutrients (2015) — Bone mineral density recovery in celiac disease: a systematic review · Bone mineral density at diagnosis of celiac disease and after one year of gluten-free diet (2014)

Thyroid and parathyroid

Too much thyroid hormone — from an overactive gland, or a levothyroxine dose that is now too high — speeds up bone turnover and raises fracture risk. In an Ontario cohort of 213,511 adults over 70 taking levothyroxine, fracture risk rose with higher current doses; a Danish register study found the excess risk tracked the time spent over-replaced. The fix is a dose check, not stopping. An overactive parathyroid gland (primary hyperparathyroidism) is a classic, treatable secondary cause of bone loss: it shows on a simple calcium and PTH blood test, and the 2022 international guideline counts low bone density or a vertebral fracture among the reasons to consider surgery.

Why: Thyroid hormone sets the pace of remodeling; parathyroid hormone pulls calcium out of bone to hold blood levels steady. Too much of either means more bone leaving than arriving — and both are found with ordinary blood tests.

The question to bring

"When were my thyroid dose and TSH last rechecked — and have my calcium and parathyroid hormone ever been measured as part of a bone work-up?"

Sources: Turner et al., BMJ (2011) — Levothyroxine dose and fractures in older adults · Abrahamsen et al., J Bone Miner Res (2015) — Excess fracture risk in hypothyroidism is driven by cumulative hyperthyroid time · Bilezikian et al., J Bone Miner Res (2022) — Evaluation and management of primary hyperparathyroidism, Fifth International Workshop · American Thyroid Association — Too much thyroid hormone increases fractures in the elderly