GPAC guideline: Special Endocrine Testing
A new BC Guideline has been developed to provide recommendations to primary care practitioners for the appropriate use of selected endocrine hormone tests in patients who are 19 years and older, as well as to help constrain inappropriate test utilization—particularly as it pertains to practices that are marketed as providing wellness and antiaging services. The guideline is available at www.BCGuidelines.ca.
Key recommendations
• Testosterone testing in women for the investigation of low libido is not useful.
• Estradiol testing in men is not useful unless there are signs of spontaneous feminization.
• 1,25(OH)2 vitamin D testing, with rare exception, is indicated for the investigation of hypercalcemia with concomitantly low parathyroid hormone (PTH) only and is not indicated for monitoring patients receiving calcitriol.
• Insulin testing is primarily useful for investigation of spontaneous hy-poglycemia or to help distinguish type 1 diabetes from type 2 diabetes, but not for establishment of insulin resistance.
• The utility of salivary hormone testing in any clinical context is limited to Cushing syndrome screening using late-night salivary cortisol levels.
• Screening for growth hormone–related disorders with insulin-like growth factor 1 (IGF1) is indicated only in patients who demonstrate symptoms of growth hormone excess (acromegaly) or deficiency.