How can individuals with diabetes minimize the risk of hip avascular necrosis (AVN)?

Minimizing Hip Avascular Necrosis Risk in Diabetes

Individuals with diabetes should prioritize strict glycemic control (A1C <7%), avoid hypoglycemic episodes, and discontinue thiazolidinediones if currently prescribed, as these are the primary modifiable factors that reduce hip fracture and bone complications. 1

Primary Prevention Strategies

Glycemic Control

• Target A1C <7% to reduce fracture risk, as each 1% rise in A1C increases fracture risk by 8% (RR 1.08,95% CI 1.03-1.14). 1
• Poor glycemic control (A1C >9%) over 2 years correlates with a 29% heightened fracture risk. 1
• Maintain consistent glucose levels without wide fluctuations to protect bone microarchitecture. 2

Hypoglycemia Prevention

• Avoid hypoglycemic episodes aggressively, as hypoglycemia escalates hip fracture risk by 52% (RR 1.52,95% CI 1.23-1.88). 1
• Severe hypoglycemia increases fracture risk more than 2-fold (HR 2.24,95% CI 1.56-3.21). 1
• Implement a structured hypoglycemia management protocol and monitor closely during insulin adjustments. 3

Medication Optimization

• Discontinue thiazolidinediones (TZDs) in women, as 1-2 years of TZD use doubles fracture risk (HR 2.23,95% CI 1.65-3.01). 1
• Fracture risk decreases after TZD discontinuation: 43% reduction after 1-2 years (HR 0.57) and 58% reduction after >2 years (HR 0.42). 1
• Consider alternative glucose-lowering medications with safer bone profiles, particularly metformin, GLP-1 agonists, or SGLT2 inhibitors. 3

Risk Assessment and Monitoring

Screening Protocols

• Perform DXA scan at least 5 years after diabetes diagnosis in type 2 diabetes patients without other comorbidities. 1
• Reassess BMD every 2-3 years depending on additional risk factors. 1
• For type 1 diabetes, consider BMD assessment after age 50, when hip fracture risk begins increasing. 1

High-Risk Identification

Patients with diabetes duration >10 years face significantly elevated fracture risk due to microvascular and macrovascular skeletal damage. 1 Additional high-risk features include:

• Cardiovascular disease, nephropathy, retinopathy, or neuropathy. 1
• Frequent falls related to peripheral neuropathy or impaired gait. 1
• T-score ≤-2.0 on DXA scanning. 1

Important caveat: In type 2 diabetes, hip fracture risk is increased even with normal or higher BMD, so standard T-score thresholds underestimate true fracture risk. 1

Lifestyle Interventions

Physical Activity

• Engage in moderate aerobic and weight-bearing exercise to enhance muscle health, gait coordination, and balance. 1
• Weight-bearing activities counteract bone loss and reduce fall risk through improved sarcopenia and coordination. 1

Nutritional Support

• Ensure adequate daily intake of calcium and vitamin D to meet recommended daily allowances through diet or supplementation. 1
• Maintain adequate protein intake as part of comprehensive bone health strategy. 1
• Smoking cessation is essential, as tobacco use compounds fracture risk. 1

Vascular Complication Management

Vascular complications in diabetes create distinct bone fragility phenotypes. 2 Patients with diabetic vascular disease show:

• Significantly impaired trabecular microarchitecture (lower BV/TV, higher Tb.Sp). 2
• More severe bone deterioration compared to diabetics without vascular complications. 2

Therefore, aggressive management of microvascular and macrovascular complications is critical, including:

• Blood pressure control to target <130/80 mmHg. 1
• Comprehensive cardiovascular risk reduction with statins and ACE inhibitors/ARBs. 1
• Nephropathy and retinopathy surveillance and treatment. 1

Treatment for Established Risk

Pharmacologic Bone Protection

• Consider antiresorptive medications or osteoanabolic agents for patients with T-score ≤-2.0 or prior fragility fractures. 1
• Refer patients with multiple comorbidities or particularly high risk to a bone metabolic specialist. 1

Post-Fracture Management

If fragility fracture occurs, diagnose osteoporosis regardless of DXA data and initiate therapy immediately, as subsequent fracture risk is highest in the first 1-2 years. 1

Critical distinction: While the evidence primarily addresses hip fractures rather than avascular necrosis specifically, one meta-analysis suggests diabetes may increase AVN risk (OR 2.46,95% CI 1.14-5.32), though evidence is limited. 4 The bone protection strategies outlined above remain the best available approach to minimize all hip complications in diabetes, including potential AVN risk through improved vascular health and bone quality.