Related Experiment Video
Updated: Jul 18, 2026
06:18
An In Vivo Estrogen Deficiency Mouse Model for Screening Exogenous Estrogen Treatments of Cardiovascular Dysfunction After Menopause
Published on: August 13, 2019
Wide variability in laboratory reference values for serum testosterone.
Stephen Lazarou1, Luis Reyes-Vallejo1, Abraham Morgentaler1
1Harvard Medical School, Division of Urology, Beth Israel Deaconess Medical Center, Boston, MA, USA.
The Journal of Sexual Medicine
|November 15, 2006
Summary
Laboratory testosterone testing for hypogonadism faces challenges due to numerous assays and diverse reference ranges. Current testosterone reference values lack clinical relevance, prompting a call for improvement.
Area of Science:
- Endocrinology
- Clinical Chemistry
- Laboratory Medicine
Background:
- Accurate laboratory determination of testosterone is crucial for diagnosing hypogonadism.
- Multiple testosterone assays and inconsistent reference ranges complicate diagnosis.
Purpose of the Study:
- To evaluate current laboratory practices for testosterone assays and reference value utilization.
- To identify variations in testosterone testing methodologies and reference standards across different laboratory types.
Main Methods:
- A telephone survey was conducted among academic, community, and national medical laboratories.
- The survey focused on the types of androgen assays offered and the methods for determining reference values.
Main Results:
- Significant variability exists in testosterone assays and reference ranges among surveyed laboratories.
- Eight different assays for total testosterone and four for free testosterone were identified.
- Reference values for total testosterone showed a 350% difference in low values and 325% in upper values.
Conclusions:
- Laboratory reference values for testosterone are highly variable and not based on clinical considerations.
- Lab directors expressed a preference for clinically relevant testosterone reference ranges.
Related Concept Videos
01:26Testosterone: Functions and Regulation
The intricate hormonal interplay essential for male reproductive health begins with the release of gonadotropin-releasing hormone (GnRH) by the hypothalamus. This hormone prompts the pituitary gland to secrete follicle-stimulating hormone (FSH) and luteinizing hormone (LH). LH targets the Leydig cells in the testes, stimulating them to produce and release testosterone. In concert with testosterone, FSH acts on the Sertoli cells within the seminiferous tubules to facilitate the release of...
01:11Variability: Analysis
Measures of variability are statistical metrics that reveal the dispersion pattern within a dataset. They are pivotal in biostatistics, providing insights into the heterogeneity within health and biological data. Variability signifies the degree to which data points diverge from one another, helping researchers understand the potential range of values and associated uncertainty within the data.
The range is a simple measure of variability, indicating the difference between the highest and...
The range is a simple measure of variability, indicating the difference between the highest and...
01:24Dosage Regimen: Individualization
Individualization in dosing regimens is the customization of medication doses for individual patients. Its necessity arises from the goal of maximizing therapeutic benefits while minimizing risks. This approach is pivotal because human responses to drugs can vary widely; what is effective for one person may be inadequate or excessive for another. Interpatient (intersubject) variability refers to differences in drug responses between individuals, while intrapatient (intrasubject) variability...
01:24Serum Studies: Renal Function Tests
Renal function tests are crucial for assessing kidney health, monitoring disease progression, and evaluating the kidneys' efficiency in waste elimination, fluid balance, and electrolyte regulation. These tests offer critical insights into kidney function, even though routine measurements may appear normal until there is a significant decline in the glomerular filtration rate or GFR. Typically, signs of kidney impairment only become evident when the GFR falls to about 50% of its normal level.
01:20Disorders of the Male Reproductive System
Men's health issues are increasingly recognized as significant, with several conditions posing common threats. Among these, testicular cancer is especially prevalent in younger men, particularly those aged 20 to 35 years. The disease often manifests as a painless mass in the testicles, sometimes accompanied by a sensation of heaviness or a dull ache.
Prostate disorders are another major concern. These conditions can impair urinary flow due to the prostate's location around the urethra. Symptoms...
Prostate disorders are another major concern. These conditions can impair urinary flow due to the prostate's location around the urethra. Symptoms...
01:16Drug toxicity: Idiosyncratic Reactions
Idiosyncratic drug reactions represent abnormal chemical responses that vary significantly among individuals, ranging from extreme sensitivity to low doses to insensitivity to high doses. These reactions often occur due to the drug's covalent binding with serum proteins, forming a foreign hapten that triggers an immunotoxicological response. The variability in drug reactions has a strong pharmacogenetic foundation, with genetic differences crucial in how individuals metabolize drugs. For...