Osteoporosis Treatment in CKD Explained: Bisphosphonates, Denosumab, Anabolic Therapy and Bone Turnover

Osteoporosis Treatment in CKD

Opening — Use This Content

Treating osteoporosis in chronic kidney disease becomes progressively more complicated as kidney function declines.

In early CKD, a patient with osteoporosis may often be treated similarly to a patient without CKD.

But in advanced CKD, the same low bone-mineral density may coexist with:

• secondary hyperparathyroidism;
• high-turnover renal bone disease;
• adynamic low-turnover bone disease;
• defective mineralization;
• calcium and phosphate abnormalities;
• vitamin-D disturbances.

At the same time, the safety and evidence base of osteoporosis medications also changes.

Therefore the central question is not simply:

The better sequence is:

This distinction becomes increasingly important in CKD G4, CKD G5 and dialysis.

Central Memory Box

Then:

First Question — Does The Patient Need Treatment?

This article assumes that fracture risk has already been assessed.

Relevant information may include:

• previous fragility fracture;
• DXA;
• age;
• clinical osteoporosis risk factors;
• falls;
• other established fracture-risk assessment.

Instead use:

DXA and clinical fracture-risk assessment help determine whether fracture-prevention treatment may be appropriate. They do not, by themselves, determine which osteoporosis medication is most appropriate in advanced CKD.

Why CKD Stage Changes Treatment

KDIGO separates osteoporosis treatment decisions according to CKD stage and CKD-MBD context. (KDIGO)

CKD G1–G2

For patients with:

and:

KDIGO recommends:

This is a strong recommendation in the KDIGO CKD-MBD guideline. (KDIGO)

Teaching point

Mild CKD alone does not mean that standard osteoporosis treatment principles must be abandoned.

However, normal medication-specific contraindications and precautions still apply.

CKD G3a–G3b

For:

with:

and:

KDIGO suggests:

(KDIGO)

Memory

Advanced CKD and CKD-MBD

The Difficult Group

CKD G3a–G5D with biochemical CKD-MBD

If the patient has:

• CKD G3a–G5D;
• biochemical abnormalities of CKD-MBD;
• low BMD and/or fragility fracture;

the treatment problem changes.

KDIGO recommends considering:

• the magnitude of the biochemical abnormalities;
• whether those abnormalities are reversible;
• progression of CKD;
• and, where useful, bone biopsy.

(KDIGO)

Therefore:

Why CKD-MBD Changes The Decision

The same low BMD can occur in patients with very different skeletal biology.

Examples include:

or:

or:

A drug that suppresses remodeling may have a different biological context in a patient whose bone turnover is already extremely low than in a patient with conventional postmenopausal osteoporosis.

Therefore:

but it does not automatically tell you:

Minimum Pre-Treatment CKD-MBD Assessment

Before selecting pharmacological osteoporosis treatment in a patient with significant CKD, consider the clinical context and relevant biochemical information, including:

• serum calcium;
• phosphate;
• PTH;
• alkaline phosphatase;
• bone-specific alkaline phosphatase where useful and available;
• 25-hydroxyvitamin D where appropriate;
• renal function.

The purpose is:

Does Bone Turnover Matter?

Does turnover matter?

Markedly high PTH and/or BSAP

May make:

Markedly low PTH and/or BSAP

May make:

But:

If the turnover phenotype is uncertain and knowing it would materially alter treatment:

Then immediately link:

See renal osteodystrophy and bone-turnover assessment.

Treat the CKD-MBD Driver

Treat The CKD-MBD Driver

Before asking which osteoporosis drug to use, ask:

Examples include:

• severe secondary hyperparathyroidism;
• significant calcium disturbance;
• phosphate disturbance;
• vitamin-D deficiency;
• suspected defective mineralization;
• excessive suppression of PTH.

The goal is not to normalize every laboratory value before fracture prevention can ever begin.

The principle is:

High-Turnover Disease

If the patient has evidence strongly suggesting excessive PTH-driven turnover:

The treatment plan may involve management of secondary hyperparathyroidism according to CKD stage and clinical context.

KDIGO recommends evaluating persistently/progressively elevated PTH in non-dialysis CKD for modifiable factors such as hyperphosphatemia, hypocalcemia, high phosphate intake and vitamin-D deficiency. In dialysis patients requiring PTH-lowering therapy, available strategies include calcimimetics, calcitriol/vitamin-D analogues or combinations; severe refractory hyperparathyroidism may lead to consideration of parathyroidectomy. (KDIGO)

See secondary hyperparathyroidism.

Low-Turnover Disease

If the patient has:

• markedly suppressed PTH;
• low BSAP;
• or other evidence suggesting very low turnover;

additional potent suppression of bone remodeling deserves particular consideration.

The correct statement is:

The following statement is too absolute:

“All antiresorptives are contraindicated.”

That is too absolute.

See adynamic low-turnover bone disease.

Osteomalacia

If a mineralization defect is suspected:

A low DXA result does not convert osteomalacia into conventional osteoporosis.

Potential causes require specific evaluation.

See osteomalacia.

Treatment Classes: Overview

Create a clean overview table.

Bisphosphonates in CKD

Bisphosphonates — Mechanism

Bisphosphonates are:

They bind to bone mineral and suppress osteoclast-mediated bone resorption.

The result is:

Their established evidence base is strongest in conventional osteoporosis populations.

Bisphosphonates In Earlier CKD

When CKD is mild or moderate and the patient does not have important biochemical CKD-MBD, treatment may often follow general osteoporosis principles, consistent with the KDIGO framework for G1–G2 and G3a–G3b with normal PTH. (KDIGO)

However:

Individual bisphosphonates differ in:

• renal labeling;
• approved indications;
• route of administration;
• precautions;
• contraindications.

Therefore:

Bisphosphonates In Advanced CKD

As CKD progresses, several problems become more important:

• evidence from large osteoporosis trials becomes less directly applicable;
• CKD-MBD becomes more common;
• renal drug considerations increase;
• very-low-turnover bone becomes more relevant.

A contemporary review emphasizes that medical fracture prevention in advanced CKD remains an area with substantial evidence gaps and requires individualized clinical judgment. (PubMed Central (PMC))

Therefore:

Bisphosphonates And Low Turnover

Bisphosphonates suppress bone resorption and remodeling.

If bone turnover is already very low:

This does not establish a universal prohibition.

Instead ask:

1. How strong is the fracture-prevention indication?
2. How advanced is CKD?
3. Is significant CKD-MBD present?
4. Is low turnover strongly suspected?
5. Would more definitive turnover information change treatment?

Memory:

Bisphosphonate Safety Principle

Denosumab in CKD

Denosumab — Mechanism

Denosumab is a monoclonal antibody targeting:

This suppresses:

Denosumab is a potent antiresorptive treatment.

But its CKD safety problem is fundamentally different from simply asking whether a drug is renally cleared.

The Most Important Denosumab Memory

Display prominently:

This should be one of the major teaching messages of the article.

Denosumab And Advanced CKD

In January 2024, the FDA added a Boxed Warning to Prolia (denosumab) because of an increased risk of severe hypocalcemia in patients with advanced CKD.

Risk is particularly important in:

and:

The FDA reported serious consequences including:

• hospitalization;
• life-threatening events;
• death.

(U.S. Food and Drug Administration)

This safety warning must be visually prominent.

Why Denosumab Can Produce Hypocalcemia

Conceptual pathway:

Combined with:

The risk is particularly important when mineral metabolism is already abnormal.

Before Denosumab In Advanced CKD

The FDA advises clinicians to assess:

• kidney function;
• calcium;
• evidence of CKD-MBD;

before Prolia treatment in advanced CKD, with involvement of clinicians experienced in CKD-MBD particularly for dialysis patients. (U.S. Food and Drug Administration)

The treatment context should include:

and:

before proceeding when denosumab is considered.

Monitoring After Denosumab

For advanced CKD, the FDA specifically recommends frequent calcium monitoring after Prolia administration, particularly during the period of greatest observed risk. Severe events in the FDA analysis typically occurred 2–10 weeks after injection, with greatest risk during weeks 2–5. (U.S. Food and Drug Administration)

This numerical interval may be included because it comes directly from the FDA safety communication.

However:

Denosumab And Dialysis

Dialysis represents a particularly high-risk context.

Therefore:

not:

The FDA explicitly recommends that treatment in advanced CKD, including dialysis, particularly when CKD-MBD is present, involve expertise in CKD-MBD diagnosis and management. (U.S. Food and Drug Administration)

Denosumab Discontinuation

Denosumab treatment also requires an exit strategy.

Stopping, skipping or substantially delaying treatment can be followed by:

and:

The FDA specifically warns patients not to stop Prolia without discussing fracture-prevention planning with their clinician. (U.S. Food and Drug Administration)

Therefore:

Anabolic Therapy in CKD

Anabolic Therapy — Concept

Antiresorptive treatment mainly suppresses bone breakdown.

Anabolic treatment aims to:

This distinction becomes conceptually important in CKD because some patients may already have:

However:

Teriparatide And Abaloparatide

Teriparatide and abaloparatide are PTH-receptor pathway anabolic therapies used in appropriate osteoporosis populations.

In CKD, treatment decisions become more complicated because the patient may have:

• secondary hyperparathyroidism;
• altered endogenous PTH physiology;
• low-turnover bone;
• CKD-MBD;
• limited advanced-CKD trial evidence.

Contemporary reviews describe anabolic therapy as potentially useful in selected CKD patients but emphasize the limited evidence base in advanced CKD and dialysis. (PubMed Central (PMC))

Therefore:

High PTH And Anabolic Therapy

If a patient already has severe PTH-driven high-turnover disease:

Therefore the first question should be whether uncontrolled CKD-MBD requires treatment.

Avoid this incorrect conclusion:

“Fracture + CKD = teriparatide.”

Low-Turnover Bone And Anabolic Therapy

A treatment that stimulates formation may be biologically attractive in a true low-turnover state.

However:

• biochemical markers are imperfect;
• low PTH does not prove histology;
• advanced CKD evidence is limited.

Therefore:

This distinction is essential.

Romosozumab in CKD

Romosozumab

Romosozumab targets:

Its skeletal effect includes:

and:

It is an important osteoporosis therapy in selected general-population patients.

However, advanced CKD and dialysis data remain limited compared with conventional osteoporosis populations. (PubMed Central (PMC))

Treatment decisions also need to account for the drug's established cardiovascular safety considerations.

Therefore:

Should One Drug Be Called “Best” For CKD?

There is no single osteoporosis drug that can be called:

Selection depends on:

• CKD stage;
• fracture risk;
• CKD-MBD;
• likely turnover;
• calcium status;
• renal drug restrictions;
• previous therapy;
• drug-specific adverse effects;
• ability to monitor;
• future treatment strategy.

Non-Drug Fracture Prevention

Non-Drug Fracture Prevention

Medication is only one part of fracture prevention.

Assess:

• falls;
• muscle weakness;
• gait;
• frailty;
• vision;
• sedating medications;
• postural hypotension;
• nutrition;
• smoking;
• excessive alcohol;
• physical inactivity.

Therefore:

Exercise

Appropriate exercise can support:

• muscle strength;
• balance;
• mobility;
• skeletal loading;
• fall reduction.

But the program should account for:

• frailty;
• dialysis;
• cardiovascular disease;
• neuropathy;
• previous fracture;
• mobility limitations.

Calcium

Adequate calcium availability matters for skeletal health and becomes particularly relevant with treatments capable of causing hypocalcemia.

However CKD also creates concern about:

• positive calcium balance;
• hypercalcemia;
• vascular calcification;
• excessive PTH suppression in susceptible patients.

Therefore:

Vitamin D

Vitamin-D deficiency should be recognized and appropriately managed.

But distinguish:

from:

These are not interchangeable concepts.

See vitamin D deficiency.

See vitamin D metabolism.

Phosphate

Phosphate management is part of CKD-MBD management where clinically indicated.

But osteoporosis medication should not be selected simply according to phosphate alone.

See phosphate homeostasis.

See hyperphosphatemia.

Dialysis Patients

A dialysis patient may simultaneously have:

• very high fracture risk;
• severe CKD-MBD;
• high turnover;
• low turnover;
• previous parathyroidectomy;
• calcium/phosphate abnormalities;
• multiple comorbidities;
• high fall risk.

Therefore:

It is a distinct metabolic context.

Treatment decisions should integrate:

Denosumab-associated hypocalcemia is particularly important in this population. (U.S. Food and Drug Administration)

Kidney Transplantation

Kidney transplantation creates another special context.

Bone disease may reflect:

• pre-existing renal osteodystrophy;
• persistent hyperparathyroidism;
• glucocorticoid exposure;
• osteoporosis;
• changing mineral metabolism.

KDIGO suggests BMD testing in transplant recipients with osteoporosis risk factors when results will alter therapy and gives specific guidance for the first post-transplant year. (KDIGO)

Monitoring Treatment

Monitoring — General Principle

Monitoring should match:

• CKD stage;
• selected drug;
• baseline CKD-MBD;
• calcium/phosphate status;
• turnover concerns;
• adverse-effect profile.

Potential domains include:

• calcium;
• phosphate;
• renal function;
• PTH;
• ALP/BSAP where clinically useful;
• vitamin-D status where relevant;
• interval BMD assessment where appropriate;
• incident fractures;
• falls;
• adverse effects;
• adherence.

Treatment Success

Do not define success only as:

The clinically important goal is:

while maintaining:

• acceptable treatment safety;
• appropriate CKD-MBD control;
• functional independence;
• fall prevention.

Therefore:

Treatment Algorithm

Implement this as the major article algorithm.

CKD G1–G2

CKD G3a–G3b + NORMAL PTH

CKD G3a–G5D + BIOCHEMICAL CKD-MBD

High turnover likely

Low turnover likely

Mineralization defect suspected

Phenotype uncertain and treatment depends on it

Then:

Bisphosphonate?

Denosumab?

Anabolic therapy?

Romosozumab?

Final:

Drug Comparison

Implement responsively.

Worked Clinical Cases

Case 1 — CKD G2

Patient has osteoporosis and CKD G2 without important CKD-MBD.

Principle

KDIGO recommends this approach. (KDIGO)

Case 2 — CKD G3b with normal PTH

Patient has CKD G3b, normal PTH and high fracture risk.

Principle

according to KDIGO's CKD-MBD framework. (KDIGO)

Case 3 — CKD G4 with severe SHPT

Patient has:

• fragility fracture;
• low BMD;
• markedly elevated PTH;
• elevated BSAP.

Wrong approach

“Choose an osteoporosis drug from the T-score.”

Better approach

Address the metabolic bone process as part of the treatment plan.

Case 4 — CKD G4 with suspected low turnover

Patient has:

• low BMD;
• markedly suppressed PTH;
• low BSAP;
• diabetes.

Question

Should a potent antiresorptive automatically be started?

Answer

The possibility of already-low turnover should influence the decision.

Case 5 — Bisphosphonate in early CKD

Patient has conventional osteoporosis with mild CKD.

Lesson

Use the specific drug's renal prescribing information and the patient's clinical context.

Case 6 — Bisphosphonate in advanced CKD

Patient has CKD G5, low BMD and uncertain turnover.

Lesson

Do not prescribe solely because the T-score is low.

Case 7 — Denosumab and dialysis

Dialysis patient is being considered for denosumab.

Major concern

Lesson

The FDA specifically identifies dialysis as a particularly high-risk setting. (U.S. Food and Drug Administration)

Case 8 — Denosumab with CKD-MBD

Advanced CKD patient has biochemical CKD-MBD and pre-existing hypocalcemia.

Wrong approach

“Denosumab is not renally cleared, so kidney disease is not relevant.”

Correct principle

Address hypocalcemia and CKD-MBD before treatment is considered. (U.S. Food and Drug Administration)

Case 9 — Denosumab discontinuation

Patient receiving long-term denosumab wants simply to stop treatment.

Lesson

Stopping or delaying treatment can increase vertebral-fracture risk. (U.S. Food and Drug Administration)

Case 10 — Low PTH and teriparatide

Advanced CKD patient has low PTH.

Wrong conclusion

“Low PTH means teriparatide is indicated.”

Correct conclusion

The whole CKD-MBD and turnover context matters.

Case 11 — Osteomalacia

Patient has low BMD but biochemical evidence suggests defective mineralization.

Lesson

Do not automatically treat the DXA result as conventional osteoporosis.

Case 12 — Falls

Older CKD patient has osteoporosis plus recurrent falls and muscle weakness.

Lesson

Common Mistakes

Mistake 1

Every CKD patient needs a special osteoporosis drug.

Wrong.

Mistake 2

Standard osteoporosis treatment can never be used in CKD.

Wrong.

Mistake 3

A low T-score automatically determines the drug.

Wrong.

Mistake 4

CKD G2 osteoporosis should always be treated differently from the general population.

Wrong.

Mistake 5

CKD G3b automatically prohibits standard osteoporosis treatment.

Wrong.

Mistake 6

PTH does not matter when choosing therapy in advanced CKD.

Wrong.

Mistake 7

Low PTH proves adynamic bone.

Wrong.

Mistake 8

High PTH proves osteitis fibrosa.

Wrong.

Mistake 9

Bone biopsy is required before every osteoporosis treatment in CKD.

Wrong.

Mistake 10

Bisphosphonates are prohibited in every patient with CKD.

Wrong.

Mistake 11

All bisphosphonates have one universal renal cutoff.

Wrong.

Mistake 12

Low BMD automatically means a bisphosphonate should be prescribed.

Wrong.

Mistake 13

Denosumab is automatically safe because it is not handled like renally cleared bisphosphonates.

Wrong.

Mistake 14

Denosumab cannot cause dangerous hypocalcemia in dialysis.

Wrong. The FDA has issued a boxed warning. (U.S. Food and Drug Administration)

Mistake 15

CKD-MBD does not affect denosumab risk.

Wrong. The FDA identifies CKD-MBD as an important risk enhancer. (U.S. Food and Drug Administration)

Mistake 16

Denosumab can simply be stopped when no longer wanted.

Wrong.

Mistake 17

Low PTH automatically means teriparatide should be given.

Wrong.

Mistake 18

Romosozumab is proven to be the preferred treatment in dialysis.

Wrong.

Mistake 19

Osteomalacia is treated exactly like conventional osteoporosis.

Wrong.

Mistake 20

Fracture prevention is only about medication.

Wrong.

Osteoporosis Treatment in CKD in One Minute

G1–G2

G3a–G3b + normal PTH

G3a–G5D + CKD-MBD

High turnover?

→ address CKD-MBD driver.

Low turnover?

→ caution with further suppression.

Mineralization defect?

→ treat the defect.

Uncertain + phenotype changes therapy?

→ consider biopsy.

Then:

Bisphosphonate

Denosumab

Anabolic therapy

Romosozumab

Final:

Frequently Asked Questions

Key Take-Home Messages

Osteoporosis treatment in CKD should become progressively more individualized as kidney disease advances.

In:

and often:

the general osteoporosis treatment framework usually remains applicable according to KDIGO. (KDIGO)

But when the patient has:

the treatment question changes.

Before selecting a drug, consider:

Bisphosphonates are not universally prohibited in CKD, but renal restrictions and turnover context matter.

Denosumab requires particular caution.

In advanced CKD, particularly dialysis and CKD-MBD, denosumab can cause severe hypocalcemia and carries an FDA boxed warning. (U.S. Food and Drug Administration)

Anabolic treatments may be useful in selected patients, but:

and evidence in advanced CKD remains limited. (PubMed Central (PMC))

Finally, medication is only one part of fracture prevention.

The final decision should follow:

Final memory: