Monitoring Tests for Congenital Adrenal Hyperplasia in Adults
Adults with both classical and non-classical CAH require regular monitoring with morning 17-hydroxyprogesterone (17-OHP) and androstenedione levels, along with serum electrolytes, renin, and ACTH to assess treatment adequacy and prevent both under- and over-treatment complications. 1
Core Laboratory Monitoring
Hormonal Assessment
- Measure morning (8 AM) 17-hydroxyprogesterone (17-OHP) as the primary marker of disease control, with target levels of 400-1200 ng/dL (12-36 nmol/L) to balance adequate suppression without overtreatment 1, 2
- Check androstenedione levels to assess androgen excess, particularly important in females with symptoms of hyperandrogenism (hirsutism, acne, menstrual irregularities) 2, 3
- Monitor morning cortisol and ACTH levels to evaluate for both adrenal insufficiency from undertreatment and suppression from glucocorticoid overtreatment 1
- Measure plasma renin activity or direct renin concentration to guide mineralocorticoid replacement dosing in salt-wasting forms 3
Electrolyte and Metabolic Monitoring
- Check serum electrolytes (sodium, potassium) regularly to detect mineralocorticoid deficiency or excess, particularly in classical CAH 1, 3
- Monitor fasting glucose or HbA1c to screen for diabetes, as glucocorticoid therapy increases cardiometabolic risk 2
- Assess lipid profile periodically given increased cardiovascular risk from chronic glucocorticoid exposure 2
Additional Monitoring Parameters
Cardiovascular Assessment
- Measure blood pressure at each visit to detect hypertension, which can result from either the disease (11-beta-hydroxylase deficiency) or glucocorticoid overtreatment 4, 2
- Perform ECG if hypertension is present or cardiovascular symptoms develop 4
Bone Health Monitoring
- Assess bone mineral density with DEXA scanning periodically in adults, as both the disease and glucocorticoid treatment compromise bone health 2
- Monitor vitamin D and calcium levels to optimize bone health 2
Reproductive Health (Females)
- Document menstrual cycle regularity as a clinical marker of adequate androgen suppression 2
- Measure testosterone levels if symptoms of hyperandrogenism persist despite treatment 2, 5
- Assess fertility parameters (FSH, LH, estradiol) when pregnancy is desired 6
Monitoring Frequency
Classical CAH
- Laboratory testing every 3-6 months during stable periods, with more frequent monitoring (monthly to every 2 months) during dose adjustments or periods of stress 3
- Annual comprehensive metabolic assessment including glucose, lipids, blood pressure, and bone density evaluation 2
Non-Classical CAH
- Monitor every 6-12 months if on treatment, focusing on androgen levels and symptoms of hyperandrogenism 5
- Annual screening for cardiometabolic complications even in untreated patients, as they remain at risk 2
Special Considerations
Distinguishing Classical from Non-Classical Forms
- Classical CAH patients require both glucocorticoid and mineralocorticoid monitoring, with particular attention to renin and electrolytes 3
- Non-classical CAH patients may not require mineralocorticoid replacement, so monitoring focuses primarily on androgen suppression and glucocorticoid-related complications 5
Pitfalls to Avoid
- Do not rely solely on 17-OHP levels, as they can be misleadingly elevated in the afternoon or with inadequate suppression, while morning levels better reflect overnight control 3
- Avoid over-suppression of androgens, as this indicates glucocorticoid excess and increases risk of obesity, diabetes, and osteoporosis 2, 3
- Monitor for adrenal crisis risk factors including intercurrent illness, surgery, or trauma, which require stress-dose glucocorticoid coverage 3