Hypothalamic-Pituitary-Adrenal Axis Suppression and Metabolic Effects of Repeated Epidural and Sacroiliac Joint Corticosteroid Injections

• Time to Normalization of Hypothalamic-Pituitary-Adrenal Axis (HPAA) Function Following Epidural or Sacroiliac Joint Corticosteroid Injection [ Time Frame: From date of enrollment (Baseline) until the date of HPAA normalization assessed every 3 weeks up to 6 months ] [ Designated as safety issue: No ]
  The high-dose rapid adrenocorticotropic hormone (ACTH) stimulation test will be performed to determine if HPAA suppression is present. Serum cortisol will be measured by electrochemiluminescence immunoassay immediately prior to and at 30 and 60 min following injection of 250 mcg cosyntropin IV. A serum cortisol level <550 nmol/L (<20 mcg/dL) at either time point following cosyntropin administration will designate HPAA suppression.
  
  

• Incidence of Hypothalamic-Pituitary-Adrenal Axis (HPAA) Suppression in Patients Presenting for Corticosteroid Injection [ Time Frame: Baseline ] [ Designated as safety issue: No ]
  The high-dose rapid ACTH stimulation test will be performed at Baseline to determine if HPAA suppression is present in patients presenting for corticosteroid injection.
  
  
• Incidence of Prolonged (≥ 3 weeks) Hypothalamic-Pituitary-Adrenal Axis (HPAA) Suppression Following Corticosteroid Injection [ Time Frame: From date of injection until the date of HPAA normalization assessed every 3 weeks up to 6 months ] [ Designated as safety issue: No ]
  The high-dose rapid ACTH stimulation test will be performed to determine if HPAA suppression is present.
  
  
• Change in Glycosylated HbA1c (%) from Baseline to 3 months [ Time Frame: Baseline and 3 months ] [ Designated as safety issue: No ]
  Percent glycosylated hemoglobin (HbA1c [%]) will be measured by turbidimetric inhibition immunoassay.
  
  
• Change in Glycosylated HbA1c (%) from Baseline to 6 months [ Time Frame: Baseline and 6 months ] [ Designated as safety issue: No ]
  Percent glycosylated hemoglobin (HbA1c [%]) will be measured by turbidimetric inhibition immunoassay.
  
  
• Change in Systolic Blood Pressure from Baseline to 3 weeks [ Time Frame: Baseline and 3 weeks ] [ Designated as safety issue: No ]
  
• Change in Systolic Blood Pressure from Baseline to 6 weeks [ Time Frame: Baseline and 6 weeks ] [ Designated as safety issue: No ]
  
• Change in Systolic Blood Pressure from Baseline to 3 months [ Time Frame: Baseline and 3 months ] [ Designated as safety issue: No ]
  
• Change in Systolic Blood Pressure from Baseline to 6 months [ Time Frame: Baseline and 6 months ] [ Designated as safety issue: No ]
  
• Change in Diastolic Blood Pressure from Baseline to 3 weeks [ Time Frame: Baseline and 3 weeks ] [ Designated as safety issue: No ]
  
• Change in Diastolic Blood Pressure from Baseline to 6 weeks [ Time Frame: Baseline and 6 weeks ] [ Designated as safety issue: No ]
  
• Change in Diastolic Blood Pressure from Baseline to 3 months [ Time Frame: Baseline and 3 months ] [ Designated as safety issue: No ]
  
• Change in Diastolic Blood Pressure from Baseline to 6 months [ Time Frame: Baseline and 6 months ] [ Designated as safety issue: No ]
  
• Change in Body Weight from Baseline to 3 weeks [ Time Frame: Baseline and 3 weeks ] [ Designated as safety issue: No ]
  Percent Change in Body Weight
  
  
• Change in Body Weight from Baseline to 6 weeks [ Time Frame: Baseline and 6 weeks ] [ Designated as safety issue: No ]
  Percent Change in Body Weight
  
  
• Change in Body Weight from Baseline to 3 months [ Time Frame: Baseline and 3 months ] [ Designated as safety issue: No ]
  Percent Change in Body Weight
  
  
• Change in Body Weight from Baseline to 6 months [ Time Frame: Baseline and 6 months ] [ Designated as safety issue: No ]
  Percent Change in Body Weight
  
  

• Pain Visual Analogue Scale (PVAS) [ Time Frame: Baseline and 3, 6, 12, and 24 weeks ] [ Designated as safety issue: No ]
  11-point scale for average pain intensity over the preceding week. Completed at Baseline, at 3 weeks following any corticosteroid injection, and at weeks 6, 12, and 24.
  
  
• Functional Capacity Visual Analogue Scale (FVAS) [ Time Frame: Baseline and 3, 6, 12, and 24 weeks ] [ Designated as safety issue: No ]
  11-point scale for average functional impairment over the preceding week. Completed at Baseline, at 3 weeks following any corticosteroid injection, and at weeks 6, 12, and 24.
  
  
• Brief Pain Inventory Short Form (BPI-SF) Pain Severity and Interference Scores [ Time Frame: Baseline and 3, 6, 12, and 24 weeks ] [ Designated as safety issue: No ]
  Completed at Baseline, at 3 weeks following any corticosteroid injection, and at weeks 6, 12, and 24.
  
  
• Medical Outcome Study Short Form 36 (SF-36) Health Survey Scores [ Time Frame: Baseline and 3, 6, 12, and 24 weeks ] [ Designated as safety issue: No ]
  Completed at Baseline, at 3 weeks following any corticosteroid injection, and at weeks 6, 12, and 24.
  
  
• Oswestry Disability Index (ODI) v2.0 Scores [ Time Frame: Baseline and 3, 6, 12, and 24 weeks ] [ Designated as safety issue: No ]
  Completed at Baseline, at 3 weeks following any corticosteroid injection, and at weeks 6, 12, and 24.
  
  
• North American Spine Society Patient Satisfaction Index (PSI) [ Time Frame: Baseline and 3, 6, 12, and 24 weeks ] [ Designated as safety issue: No ]
  Completed at Baseline (for patients with previous corticosteroid injections), at 3 weeks following any corticosteroid injection, and at weeks 6, 12, and 24.
  
  

Interventional pain procedures using corticosteroid injections (CIs), such as epidural steroid injections (ESIs) and sacroiliac joint injections (SIJIs), may have adverse metabolic and endocrine effects, including suppression of the hypothalamic-pituitary-adrenal axis (HPAA), hypertension, weight gain, and hyperglycemia. Based on sparse data on these adverse effects following repeated, long-term CIs, current guidelines suggest a maximum frequency of four to six injections annually, even though patients may benefit from more frequent treatments.

This prospective cohort study will follow first-time or repeat ESI or SIJI patients receiving injections with 0.5 mL bupivacaine 0.25% and 15 mg dexamethasone sodium phosphate at a maximum frequency of once every six weeks in order to:

• determine the frequency and duration of HPAA suppression;
• determine the incidence and predictors of prolonged (≥ 3 weeks) HPAA suppression;
• determine the baseline incidence and predictors of HPAA suppression in chronic pain patients presenting for their first CI; and
• determine the effect of CIs on body weight, resting blood pressure, and glycemic control over a six-month period.