|Sample Test Volume||100 µl|
|Recommended Collection Volume||175 µl|
Posture affects levels - we recommend sampling after 30 minutes in position.
Licorice (real) mimics aldosterone and should be avoided 2 weeks before collection.
|Collection Protocol||Download PDF|
Recent studies have shown that primary aldosteronism (PA) is the most common cause of secondary hypertension with a prevalence of approximately 5-10% among all hypertensive patients and an even higher prevalence among selected patients with advanced stages of hypertension and resistant hypertension. (1) Screening for PA among hypertensive patients is important due to its association with risk for cardiovascular disease and renal damage, (1) and non-invasive salivary aldosterone measurements have recently been explored as a means to facilitate this screening. Morning salivary aldosterone measurements alone were found to have some ability to discriminate between patients with PA and essential hypertension, and the presence or absence of a diurnal decline showed promise for distinguishing between the two forms of the disease (adenomas vs. bilateral hyperplasia). (2)
Dysregulation of circulating aldosterone levels has also been associated with psychiatric disorders, and a recent study has similarly reported a significant negative association between morning salivary aldosterone levels and trait anxiety scores. Those with the high anxiety trait may be associated with an inability to respond with adequate cortisol levels during stress. (3)
Produced largely in the adrenal glands, aldosterone is classified as a mineralocorticoid steroid since its classical effect is to regulate the transport of sodium and water across cells of the kidney in exchange for potassium and hydrogen ions, thereby regulating blood volume and pressure. (4,5)
Additionally, rapid non-genomic actions and local production of aldosterone have been identified in other tissues, including the heart, vascular system, adrenal gland, and kidney. These non-genomic mechanisms are being studied in connection with a range of diseases including cardiovascular disease, cirrhosis, kidney disease, insulin resistance, and diabetes. (6,7,8)
No specific binding protein for aldosterone has been identified in blood. (4) Circulating aldosterone not bound to serum proteins enters saliva by passive diffusion. (9) Salivary aldosterone levels correspond approximately to 30% of those found in plasma, with good correlation found between plasma and non-extracted salivary aldosterone. (10) Salivary aldosterone levels are unaffected by salivary flow rate or hormone-binding proteins. (11) Both salivary and plasma aldosterone increase significantly while standing, compared to being seated; this effect is significantly higher in females than in males. A diurnal rhythm for salivary aldosterone exists for healthy individuals, with highest levels in the morning. (10)
The effects of freeze thaw on most biological measures, regardless of biospecimen type, can be dramatic. Analytes in oral fluid are not distinct or different in this way. As a general rule, multiple freeze-thaws should be avoided. The most practical way to address this concern is by aliqouting samples after collection. Some analytes are more resistant to freeze thaw than others. We recommend that investigators consult the literature for the analytes of interest. If there is freeze thaw data for a specific biological measure in traditional biospecimens, it is reasonable to assume this would also be true for saliva.
No, but the literature is rather extensive on this subject for several salivary analytes; especially for salivary alpha-amylase and cortisol. We do not track that information internally.
With modern search tools online, we no longer maintain records of this type. We suggest that you use Pubmed or Psychlit to search the literature or you can Ask An Expert and we will be happy to assist you in your search.
If the analyte you are interested in is not noted in our website, please contact Dr. Granger at [email protected] to find out what developments are in the pipeline.
Salimetrics does not release products for sale if the quality control (QC) testing shows any issues. Here are some probable causes:
1) Can timing of adding reagents be off? For instance with a multichannel you can pipette the conjugate and TMB so many times before you refill, but you can pipette the stop twice as fast because it is a smaller volume. If you do this, it shortens the time the bottom rows have with TMB.
2) Can your washer be uneven and sheering off antibody in the bottom corner? Aspirate and check the amount of fluid left. It should be even in all wells and no wells should be completely dry.
3) Are you mixing faster than recommended? Or slower?
4) Are all reagents completely at room temperature? A bottle of assay diluent takes 2 hours to come to RT. You can pour some off into a smaller tube to warm up quicker for the zero and nsb.
5) Are you leaving the plate come to room temperature BEFORE opening the bag? (Otherwise moisture due to humidity may form in the wells and this is particularly a problem in this high humidity weather)
6) Are your multichannel pipettes dispensing the same amount each time reliably? We discard the first and last dispenses as they are not as reliable.
7) Are you incubating with TMB in the dark? (We no longer recommend aluminum foil.)
8) Are you testing one plate at a time? For example, do not put the standards on 5 plates then go back and fill in with samples. This delays the addition of conjugate to the plates.
9) Clean your plate reader filter. Dust from the lab can collect on the filter.
10) Are you adding assay diluent to the zero in sequence after the standards and not the last thing?
11) Never put the multichannel pipette tips into the wells as you can drag down standard from the wells above it causing lower readings in other wells.
12) Thoroughly blot all wells just before adding TMB but do not let the plate dry out.