Steroid-Induced Osteoporosis: Causes, Prevention, and Treatment

What Is Steroid-Induced Osteoporosis?

Steroid-induced osteoporosis, formally called glucocorticoid-induced osteoporosis (GIOP), is bone loss caused by prolonged use of corticosteroid medications such as prednisone, prednisolone, methylprednisolone, and dexamethasone. It is the most common form of secondary osteoporosis and the leading iatrogenic cause of the disease [1].

An estimated 30% to 50% of patients on long-term glucocorticoid therapy develop osteoporosis or osteopenia [2]. The problem is widespread because glucocorticoids remain a mainstay treatment for rheumatoid arthritis, asthma, COPD, inflammatory bowel disease, lupus, and organ transplant rejection. A large UK database study by Van Staa et al. (N=244,235) found that the relative risk of vertebral fracture increased 2.60-fold and hip fracture risk increased 1.61-fold in patients taking oral glucocorticoids compared to non-users [3]. These numbers climb with higher doses. Patients on prednisone equivalents above 7.5 mg per day faced a 5.18-fold increase in vertebral fracture risk [3].

The 2022 American College of Rheumatology (ACR) guideline for the prevention and treatment of GIOP represents the most current clinical standard. It conditionally recommends fracture risk assessment for all adults aged 40 and older who are starting or already receiving glucocorticoid therapy expected to last 3 months or longer [4]. For adults under 40, assessment is recommended when additional risk factors are present.

How Glucocorticoids Destroy Bone

Glucocorticoids attack bone through multiple pathways simultaneously, making steroid-induced bone loss faster and more damaging than age-related osteoporosis alone. Bone loss is most aggressive in the first 6 to 12 months of therapy, with trabecular bone (spine, ribs, pelvis) affected earliest and most severely [5].

At the cellular level, glucocorticoids suppress osteoblast differentiation and accelerate osteoblast apoptosis, reducing new bone formation. They also extend the lifespan of osteoclasts, the cells that break down bone [5]. The net effect is a sharp imbalance: bone resorption outpaces bone formation.

Steroids impair calcium absorption in the gut and increase calcium excretion through the kidneys [6]. They suppress gonadal hormone production, reducing estrogen and testosterone levels, which compounds bone loss in both women and men. Glucocorticoids also inhibit growth hormone and insulin-like growth factor-1 (IGF-1), further weakening the bone formation pathway [5].

One aspect that makes GIOP particularly dangerous is that fractures occur at higher bone mineral density (BMD) thresholds than in postmenopausal osteoporosis. A patient on glucocorticoids with a T-score of -1.5 (technically osteopenia) may carry the same fracture risk as a patient with a T-score of -2.5 (osteoporosis) who is not taking steroids [7]. This means DEXA alone underestimates true fracture risk in glucocorticoid users.

Who Is Most at Risk?

Any patient taking systemic glucocorticoids for 3 months or longer faces increased fracture risk, but several factors raise that risk further. The combination of glucocorticoid use with postmenopausal status or male hypogonadism creates compounding bone loss from two directions [4].

Dose matters. Risk increases in a roughly dose-dependent fashion, though no truly "safe" dose exists. The Van Staa data showed elevated vertebral fracture risk even at daily prednisone equivalents of 2.5 to 7.5 mg [3]. Higher cumulative lifetime exposure also worsens outcomes.

Age amplifies risk significantly. Postmenopausal women already lose 1% to 2% of bone mass annually due to estrogen decline [8]. Adding glucocorticoids accelerates that trajectory. Men over 50 on long-term steroids represent an underdiagnosed population. Male osteoporosis accounts for roughly 30% of all hip fractures worldwide, and glucocorticoid use is among its top three causes alongside aging and hypogonadism [9].

Other risk-multiplying factors include:

• Prior fragility fracture (the single strongest predictor of future fracture)
• Low body weight (BMI <20)
• Parental history of hip fracture
• Smoking and excess alcohol intake (3 or more units daily)
• Concurrent use of other bone-toxic medications such as aromatase inhibitors or proton pump inhibitors

The 2022 ACR guideline uses FRAX (Fracture Risk Assessment Tool) with glucocorticoid dose adjustment to categorize patients into low, moderate, high, and very high fracture risk groups, each with different treatment recommendations [4].

Diagnosing Steroid-Induced Bone Loss

Baseline DEXA scanning should be performed within 6 months of starting glucocorticoid therapy expected to last 3 months or more. The ACR guideline conditionally recommends DEXA at the lumbar spine and hip, with follow-up scans every 1 to 3 years depending on risk category [4].

DEXA results in glucocorticoid users require careful interpretation. As the American Association of Clinical Endocrinology (AACE) 2020 guidelines note, "In glucocorticoid-treated patients, fractures occur at higher BMD values than in patients with postmenopausal osteoporosis, and therapeutic intervention may need to be considered at T-score values above the conventional osteoporosis threshold of -2.5" [10].

FRAX calculates 10-year probability of major osteoporotic fracture and hip fracture. For glucocorticoid users, FRAX includes a binary yes/no adjustment, but this underestimates risk for patients on higher doses. The 2022 ACR guideline provides a dose-based FRAX adjustment: multiply the FRAX major osteoporotic fracture probability by 1.15 for low-dose (prednisone <2.5 mg/day), leave unadjusted for medium-dose (2.5 to 7.5 mg/day), and multiply by 1.20 for high-dose (>7.5 mg/day) [4].

Vertebral fracture assessment (VFA) or lateral spine imaging should be considered for patients with height loss of 1.5 inches or more, as vertebral compression fractures are common in GIOP and are frequently asymptomatic. Laboratory evaluation should include serum 25-hydroxyvitamin D, calcium, and basic metabolic panel. Checking testosterone in men on long-term steroids is warranted given the high rate of glucocorticoid-induced hypogonadism [9].

Prevention: The First-Line Approach

Prevention begins with glucocorticoid stewardship. Use the lowest effective dose for the shortest duration. This is simple in principle. It is hard in practice when diseases like lupus nephritis or giant cell arteritis require months of high-dose therapy [11].

For all patients on glucocorticoids expected to last 3 months or longer, the ACR conditionally recommends [4]:

• Calcium: 1,000 to 1 to 200 mg daily (diet plus supplements)
• Vitamin D: 600 to 800 IU daily (higher doses if serum 25(OH)D is below 20 ng/mL)
• Lifestyle measures: weight-bearing exercise, fall prevention, smoking cessation, alcohol moderation

These measures alone are insufficient for patients at moderate, high, or very high fracture risk. Pharmacologic therapy is needed.

For moderate-risk patients (10-year major osteoporotic fracture probability 10% to 19%), the ACR conditionally recommends oral bisphosphonates as first-line treatment [4]. Alendronate 70 mg weekly or risedronate 35 mg weekly are the most commonly prescribed options. A randomized controlled trial by Saag et al. (N=428) demonstrated that alendronate 5 to 10 mg daily increased lumbar spine BMD by 2.9% over 48 weeks in glucocorticoid-treated patients versus 0.7% with placebo [12].

For patients who cannot tolerate oral bisphosphonates, intravenous zoledronic acid 5 mg annually is an alternative. The Reid et al. trial (N=833) showed zoledronic acid was non-inferior to risedronate for GIOP prevention, with a 4.1% lumbar spine BMD increase versus 2.7% for risedronate at 12 months [13].

Treatment for High-Risk and Very High-Risk Patients

Patients at high fracture risk (10-year probability 20% or greater, or T-score at or below -2.5, or prior fragility fracture) require more aggressive treatment. The 2022 ACR guideline conditionally recommends teriparatide or denosumab over oral bisphosphonates for these patients [4].

Teriparatide (Forteo), a parathyroid hormone analog given as a 20 mcg daily subcutaneous injection, directly stimulates osteoblast activity. This is a targeted advantage in GIOP, where osteoblast suppression is the primary pathologic mechanism. The landmark Saag et al. head-to-head trial (N=428) compared teriparatide to alendronate in glucocorticoid-induced osteoporosis over 36 months. Teriparatide increased lumbar spine BMD by 7.2% versus 3.4% for alendronate, and vertebral fracture incidence was 1.7% with teriparatide versus 7.7% with alendronate [14].

As Dr. Kenneth Saag of the University of Alabama at Birmingham stated regarding the trial results, "Teriparatide was associated with greater increases in bone mineral density at the lumbar spine and total hip and fewer new vertebral fractures than alendronate in patients with glucocorticoid-induced osteoporosis" [14].

Denosumab (Prolia), a RANKL inhibitor given as a 60 mg subcutaneous injection every 6 months, is another option for high-risk patients. It suppresses osteoclast activity and has shown BMD gains in glucocorticoid-treated patients [15]. One consideration: discontinuing denosumab triggers rapid rebound bone loss and increased vertebral fracture risk, so patients must transition to a bisphosphonate after stopping it [16].

For very high-risk patients (recent fracture within 12 months, fractures on current osteoporosis therapy, or T-score at or below -3.5), romosozumab (Evenity) may be considered off-label, though it carries a cardiovascular risk warning and is not yet specifically approved for GIOP [17].

Special Populations: Men and Premenopausal Women

Male osteoporosis is underdiagnosed across the board, and GIOP in men receives even less attention. Roughly 1 in 4 men over 50 will sustain an osteoporotic fracture in their remaining lifetime [9]. Glucocorticoids rank among the top modifiable risk factors for male osteoporosis, alongside hypogonadism and alcohol excess.

Men on long-term glucocorticoids should have testosterone levels checked. If serum total testosterone falls below 300 ng/dL consistently, testosterone replacement therapy may partially protect bone, though it is not a substitute for bisphosphonate or anabolic therapy when fracture risk is elevated [9]. The ACR 2022 guideline applies the same FRAX-based risk stratification and treatment algorithm to men as to postmenopausal women [4].

Premenopausal women present a different challenge. FRAX was developed and validated in postmenopausal populations and may underestimate risk in younger women on high-dose glucocorticoids. The ACR guideline conditionally recommends using clinical risk factors (prior fracture, dose, duration) rather than FRAX alone for premenopausal women [4]. Bisphosphonates are generally avoided in women of childbearing potential due to theoretical teratogenic risk. The bisphosphonate half-life in bone exceeds 10 years. For premenopausal women at high fracture risk, teriparatide is preferred because it does not accumulate in bone matrix [4].

Children and adolescents on chronic glucocorticoids (common in Duchenne muscular dystrophy, juvenile idiopathic arthritis, and nephrotic syndrome) represent another underserved group. Pediatric GIOP management follows separate guidelines and should involve pediatric endocrinology.

Monitoring and Duration of Therapy

Once pharmacologic treatment begins, follow-up DEXA should be performed at 1 to 3 year intervals. The ACR guideline conditionally recommends reassessing fracture risk with each DEXA and adjusting therapy accordingly [4]. If a patient's glucocorticoid dose decreases substantially or is discontinued, risk category may shift downward, and treatment can potentially be de-escalated.

Teriparatide carries a maximum treatment duration of 24 months. After completing a course, patients should transition to a bisphosphonate to maintain BMD gains [14]. Denosumab requires a mandatory transition to bisphosphonate therapy upon discontinuation to prevent rebound vertebral fractures, ideally starting a bisphosphonate within 6 months of the last denosumab injection [16].

Bisphosphonate duration in GIOP is guided by ongoing glucocorticoid use. Unlike postmenopausal osteoporosis, where bisphosphonate holidays after 3 to 5 years are common, patients who remain on glucocorticoids generally continue bisphosphonate therapy for the duration of steroid use [4].

Serum CTX (C-terminal telopeptide) and P1NP (procollagen type 1 N-terminal propeptide) are bone turnover markers that can help monitor treatment response between DEXA scans, though they are not yet recommended as standalone decision tools in the ACR guideline [4].

Reducing Glucocorticoid Exposure

The most effective strategy for preventing GIOP is minimizing glucocorticoid use. Steroid-sparing agents have expanded considerably across rheumatology, pulmonology, and gastroenterology.

In rheumatoid arthritis, biologic DMARDs (adalimumab, tocilizumab, rituximab) and JAK inhibitors (tofacitinib, baricitinib) allow many patients to taper off prednisone entirely [18]. In inflammatory bowel disease, vedolizumab and ustekinumab reduce steroid dependence. In asthma, biologic therapies such as omalizumab, mepolizumab, and dupilumab have reduced oral corticosteroid use by 50% to 75% in severe asthma populations [19].

When glucocorticoids cannot be avoided, dose optimization matters. Alternate-day dosing does not reliably protect bone. Inhaled corticosteroids at standard doses carry minimal systemic bone risk, though high-dose inhaled steroids (fluticasone >1 to 000 mcg/day equivalent) may reduce BMD modestly over years [20].

The median prednisone dose threshold at which vertebral fracture risk becomes statistically significant is 2.5 mg daily, based on the Van Staa epidemiologic data [3]. Clinicians should aim to taper below this threshold whenever disease activity permits.