From the Guidelines
Saliva testing is a more reliable method for assessing estrogen levels than blood work due to its ability to measure free, bioavailable hormones. When evaluating estrogen levels, it's essential to consider the differences between saliva and blood testing. Saliva contains only the unbound, biologically active hormones that have diffused from blood into tissues, providing a better representation of the hormone levels actually affecting the body 1. In contrast, blood tests measure both bound and unbound hormones, potentially overestimating the amount of hormone available to cells. Some key points to consider when evaluating estrogen levels include:
- The binding of estrogen to proteins like sex hormone-binding globulin (SHBG) and albumin, which makes it inactive
- The ability of saliva testing to capture fluctuations in hormone levels throughout the day
- The less invasive nature of saliva collection, allowing for multiple samples to be taken easily
- The importance of following collection instructions carefully to ensure accurate results It's also worth noting that the American Society of Clinical Oncology/College of American Pathologists guideline recommendations for immunohistochemical testing of estrogen and progesterone receptors in breast cancer provide valuable insights into the predictive validity of hormone receptor levels 1. However, these guidelines are more relevant to breast cancer treatment and may not directly apply to general estrogen level assessment. In the context of real-life clinical medicine, saliva testing is preferred for assessing estrogen levels due to its ability to measure biologically active hormones and capture daily fluctuations. This approach can provide a more accurate representation of hormone levels and their impact on the body, ultimately informing treatment decisions and improving patient outcomes.
From the Research
Estrogen Levels in Saliva vs Blood
- Saliva testing is considered an accurate method for determining estrogen levels, including estradiol, estrone, and estriol 2.
- Saliva is a natural ultrafiltrate of blood, and steroids not bound by carrier proteins in the blood freely diffuse into saliva, making it an excellent medium for measuring biologically active fractions of steroid hormones 3.
- The advantages of saliva testing over serum testing include simplicity, non-invasiveness, stress-free and painless collection, and cost-effectiveness 3.
Comparison with Blood Work
- Saliva testing offers multiple advantages over serum testing, including cost and convenience 2.
- The collection time for saliva testing is more controllable than that for serum testing, and the transport of saliva samples can be done inexpensively via mail 3.
- Saliva testing can detect the fertile window of a menstrual cycle, with estrogen levels turning positive 24 hours before luteinizing hormone (LH) 4.
Clinical Applications
- Saliva testing can be used to identify or monitor clinical conditions such as climacteric changes in perimenopausal or postmenopausal women, adrenal disorders, and androgen deficiency in men and women 3.
- Saliva testing can also be used to detect ovulation and the fertile period, making it a useful tool for women trying to conceive or using natural family planning methods 4.