17-KETOSTEROIDS URINE

Overview

17-Ketosteroids (17-KSs) are urinary metabolites of steroids secreted by the adrenal glands, testes, and to some extent the ovaries. They serve as an important marker of adrenocortical and testicular function, and their measurement aids in the diagnosis and monitoring of endocrine disorders. In men, about two-thirds of urinary 17-KSs are derived from adrenal steroids, while one-third comes from testosterone secreted by the testes. In women and children, nearly all 17-KSs originate from the adrenal cortex. The primary components include androsterone, epiandrosterone, dehydroepiandrosterone (DHEA), and etiocholanolone. Measurement is typically performed on 24-hour urine collections due to diurnal variation in steroid secretion. Estimation methods include colorimetry, chromatography, and spectrophotometry, with normal ranges of 10–25 mg/day in males and 6–14 mg/day in females.

Symptoms

(Clinical features prompting 17-KS urine testing)

1. Signs of adrenal dysfunction: fatigue, weakness, low blood pressure, and hyperpigmentation in adrenal insufficiency.
2. Virilization in women: hirsutism, deepening of voice, and menstrual irregularities.
3. Hypogonadism in men: reduced libido, infertility, gynecomastia, and muscle weakness.
4. Cushing’s syndrome manifestations: weight gain, moon face, central obesity, purple striae, and hypertension.
5. Tumor-related symptoms: rapid onset of hormonal changes suggesting adrenal, testicular, or ovarian tumors.

Causes

(Conditions leading to abnormal 17-KS levels)

1. Decreased levels:
   1. Primary hypogonadism (e.g., Klinefelter’s syndrome, castration).
   1. Secondary hypogonadism (panhypopituitarism).
   1. Pituitary hypoadrenalism (Addison’s disease).
2. Increased levels:
   1. Adrenal tumors.
   1. Cushing’s syndrome.
   1. Testicular tumors (interstitial cell tumors, chorioepithelioma).
   1. Ovarian tumors and dysfunction (e.g., polycystic ovarian disease).
   1. Congenital adrenal hyperplasia (CAH).
3. Drug interference:
   1. Decreased levels caused by digoxin, carbamazepine, glucose, and pregestational agents.
   1. Increased levels caused by chlorpromazine, penicillin, dexamethasone, and spironolactone.

Risk factors

(Populations most likely to benefit from 17-KS testing)

1. Men with infertility or suspected hypogonadism.
2. Women with hirsutism, virilization, or menstrual disturbances.
3. Patients with suspected adrenal or testicular tumors, especially when presenting with endocrine symptoms.
4. Individuals with Cushing’s syndrome features such as obesity, hypertension, and glucose intolerance.
5. Children with suspected congenital adrenal hyperplasia (CAH), where adrenal androgen excess leads to abnormal development.
6. Patients undergoing hormone replacement therapy, where monitoring of 17-KS excretion supports treatment adjustment.

Prevention

(Strategies to optimize testing and reduce errors)

1. Accurate sample collection:
   1. Collect 24-hour urine samples to account for diurnal variation.
   1. Use a clean plastic container with 10 mL concentrated HCl preservative.
   1. Refrigerate the sample during collection.
   1. Discard the first urine sample, then collect all urine for the next 24 hours, including the final sample at the same time next day.
2. Avoid interfering factors: withhold medications known to affect 17-KS levels (when clinically safe) before testing.
3. Laboratory methods: use validated techniques such as colorimetry, chromatography, or spectrophotometry for precise quantification.
4. Clinical correlation: interpret results alongside patient history, symptoms, and other endocrine investigations such as serum DHEA-S, which is a more specific marker for adrenal androgen production.
5. Prevent misdiagnosis: acknowledge that not all 17-KSs are androgens and not all androgens are 17-KSs; hence testing should always be integrated with broader endocrine evaluation.
6. Quality control: ensure proper calibration and standardization of laboratory assays to avoid variability in results.