Description

• Characterized by calcification and ossification of soft tissues, primarily ligaments and entheses; most commonly in the spine, especially thoracic segments
• Typically defined as flowing calcification across four or more contiguous vertebral segments with preservation of disc spaces
• Synonym(s): Forestier disease; vertebral ankylosing hyperostosis

Geriatric Considerations

• Diffuse idiopathic skeletal hyperostosis (DISH) is typically asymptomatic; it may, however, decrease spinal mobility and predispose patients to fractures after only mild trauma.
• DISH and osteoarthritis (OA) may coexist. Both affect the same population (elderly and obese).
• Bone mineral density (BMD) measurements obtained by dual energy x-ray absorptiometry (DEXA) and quantitative CT may not be accurate (falsely high) due to lumbar ossification/calcification in DISH.
• DISH should be considered in elderly patients with unexplained respiratory distress or dysphagia (1).

Epidemiology

• Most common in elderly, obese males
• Prevalence varies geographically.

Incidence
Incidence increases with age and is higher in men.

Prevalence

• Difficult to calculate due to variable classification criteria used across literature
• Japan: 19.5% (2)
• Thought to be similar in other populations

Etiology and Pathophysiology

• The etiology is unknown. Increased levels of insulin, insulin-like growth factor 1, and transforming growth factor-β1 are believed to stimulate osteoblasts and bone proliferation (1).
• Low serum levels of bone formation inhibitors (e.g., bone morphogenetic protein 2 or Dickkopf-1 [DKK-1], an inhibitor of the Wnt pathway required for new bone formation) may also play a role in DISH and are associated with more severe spinal involvement (1).

Risk Factors

• Age
• Male gender
• Increased BMI
• Hypertension
• Metabolic syndrome
• Diabetes
• Hyperuricemia
• Dyslipidemia
• Lumbar spondylosis and knee OA

General Prevention

Control modifiable risk factors and the associated metabolic diseases.

Commonly Associated Conditions

Metabolic derangements associated with DISH:

• Obesity; large waist circumference
• Diabetes; hyperinsulinemia/insulin resistance
• Metabolic syndrome
• Hypertension
• Dyslipidemia
• Hyperuricemia