Loading

Saliva 501

DHEA and DHEAS: An Introduction to Their Function and Measurement

Background

Dehydroepiandrosterone (DHEA) and its sulfated analog (DHEA-S) are steroid hormones made principally in the adrenal cortex; smaller amounts of DHEA are also secreted from the testis and ovary. DHEA-S is the most abundant steroid in humans with serum concentrations 250-500 times higher than DHEA, 100-500 times higher than testosterone, and 1000-10000 times higher than estradiol. (1,2,3) DHEA-S is produced by sulfation of DHEA by the enzyme DHEA sulfotransferase (SULT2A1), which is most active in the adrenal glands, liver, and intestine. (3,4,5) DHEA and DHEA-S have been thought to serve primarily as precursor molecules that are circulated to peripheral tissues throughout the body. In those locations DHEA-S is desulfated by the enzyme steroid sulfatase (STS) to produce DHEA, which is in turn converted into various estrogenic and androgenic compounds, without significant leakage of these products into the circulation. (6,7,8) STS is found in many tissues throughout the body, but the major tissues where desulfation and conversion of DHEA-S to androgens and estrogens occur include the reproductive tract (endometrium, ovary, prostate, testis, placenta), breast, skin, brain, bone, and blood cells. (9) Because the sulfated and unsulfated forms of DHEA are often interconverted, it is hard to discuss one without the other, and it is common to refer to them together as DHEA(S). Due to the high circulating levels of DHEA-S and the presence of the STS activity in many tissues, it has generally been believed that circulating DHEA-S serves as a reservoir for conversion to DHEA. (5,10) The details of the conversion of DHEA-S in the blood stream appear to require further examination, however, as one recent study was unable to find evidence of significant hepatic conversion of DHEA-S to DHEA in in vivo and in vitro studies. (5) Humans and some primates are unique in that much of the conversion of DHEA(S) to active sex steroids is carried out locally in specific tissues, thereby avoiding undesirable effects of high circulating levels of these hormones. (6,11)

Circulating levels of DHEA(S) decline after birth until about the age of five, and then begin to rise a few years before sexual maturation begins. The prepubertal onset of adrenal production of DHEA-S, known as the adrenarche, is associated with the development of the zona reticularis layer within the adrenal gland, which shunts steroid biosynthesis away from cortisol and toward DHEA-S. (12) DHEA and DHEA-S have been studied for relationships to child development and behavioral disorders. (13,14,15,16,17,18) DHEA-S levels peak around the age of 20 to 30, and then decline to only 20-30% of peak levels by the age of 70 to 80. (2,3)

In addition to serving as precursors for other steroid hormones, DHEA and DHEA-S are believed to have some physiological properties of their own. DHEA is known to have anti-glucocorticoid effects, and both DHEA and DHEA-S have anti-oxidant, anti-inflammatory, and immunomodulatory effects. (3) Lowered levels of DHEA(S) have been associated with critical illness and a variety of medical conditions, including rheumatic disease, (26) cardiovascular disease, (27) immune system disorders, (28) and osteoporosis.(29) Elevated levels have been observed in connection with obesity, type II diabetes, and female hirsutism. (30,31) DHEA and DHEA-S are being investigated for relationships to mental and physical stress and psychological and behavioral disorders. (32,33,34,35,36)

DHEA and DHEA-S are also synthesized directly in the nervous system, where they appear to serve a protective function, helping to promote nerve growth and survival. (3,37,38) Brain concentrations of both molecules are higher than in plasma, and there is evidence that suggests that DHEA-S found in the brain is most likely due to local synthesis. (3) Alzheimer’s patients have been reported to have lower DHEA-S levels, while schizophrenia and psychiatric conditions have been associated with altered levels. (3,12) Studies are currently exploring relationships between DHEA(S) levels and various areas of neurological function, (39,40,41) and at least one paper has suggested that the primary effect of DHEA(S) is in fact neurological, with secondary effects on immune function and growth. (13)

Because of the coincidence between the natural decline of DHEA(S) levels with age and the onset of diseases associated with the aging process, a great deal of research has been directed into an examination of the roles that both hormones play in the body, and to the possibility of supplementing levels to slow or reverse the aging process. Although these studies have reported widespread effects for the hormones, the findings have been inconsistent, and the molecular mechanisms of action for both DHEA and DHEA-S require further study. (3,42,43,44,45,46,47) Recent reviews point out that the lack of understanding about the mode of action of the two hormones, along with differences in design, methodology, and analysis among studies, have led to discrepancies among the findings. (1,3,43)

Entry of DHEA and DHEAS into saliva

DHEA is a neutral steroid, and it passes rapidly from blood into saliva by passive diffusion through the neutral lipid membranes of the salivary cells. Salivary concentrations are about 5% of plasma concentrations. (2) DHEA-S, on the other hand, is a charged molecule due to the presence of the sulfate group, and it cannot diffuse through the lipid membranes. The exact mode of entry for DHEA-S into saliva is not clear. Vining and colleagues suggested that it entered only by squeezing through the tight junctions between cells. They noted that the molecule is too large to do this readily, which would explain the relatively small amounts found in saliva–less than 0.1 % of plasma levels in parotid saliva. (48) However, more recent work has identified a large family of organic anion transport polypeptides (OATP) that actively transport molecules such as DHEA-S across membranes. It is likely that a transport polypeptide such as OATP2B1, which is known to transport steroid hormone conjugates in the placenta, brain and skin, may be responsible for the entry of DHEA-S into the saliva glands. (49,50) Because the levels of DHEA-S in blood are so much higher than in saliva, even the presence of minute quantities of blood or gingival fluid in the saliva can cause false elevation of DHEA-S levels. For this reason, there has been some concern that salivary measurement of DHEA-S is unreliable. (48) We advise that, if saliva testing for DHEA-S is to be valid, subjects must be properly screened for periodontal disease and advised about proper collection procedures that will minimize the risk of blood or gingival contamination. Saliva may also be screened for blood contamination using the Salimetrics Blood Contamination EIA Kit (Cat. No. 1-1302).

Effect of Flow Rate

Because the mode of entry appears to limit the rate at which DHEA-S molecules can move through the cell membranes of the salivary glands, it is not surprising that the DHEA-S molecules are not able to keep up with the increased flow as saliva production is stimulated. Concentrations in saliva therefore decrease as flow rates increase. Even though this behavior was clearly documented in a seminal paper on saliva testing, (48) some researchers seem unconcerned by it. Our position at Salimetrics is that measurement of DHEA-S in saliva requires a correction for saliva flow rate. We advise measuring the length of time needed to collect the desired volume of sample, so as to determine the flow rate. The measured concentration can then be combined with the flow rate to express the results as a function of time, i.e. pg/minute.

Which is preferable: DHEAS or DHEA?

Because of the concern about blood contamination and the need to adjust for flow rate when measuring DHEA-S, and a higher serum/saliva correlation for DHEA, Salimetrics originally chose to develop a kit to measure DHEA in saliva. This kit has functioned well, and it has been successfully used by investigators in published research. (18,34,51,52,53,54) Some researchers prefer to measure DHEA-S rather than DHEA, however, and their work has begun to show some interesting findings. (19,35,55,56,57,58) In response to customer requests, therefore, we have added a kit to measure salivary DHEA-S. We will continue to manufacture the kit for DHEA, as well, and researchers will be able to choose either kit, depending on their requirements.

References

  1. Tchernof, A., Labrie, F.  (2004).  Dehydroepiandrosterone, obesity and cardiovascular disease risk: A review of human studies.  Eur J Endocrinol, 151(1), 1-14.
  2. Krobath, P.D., Salek, F.S., Pittenger, A.L. et al. (1999).  DHEA and DHEA-S: A review.  J Clin Pharmacol 39(4), 327-48.
  3. Maninger, N., Wolkowitz, O.M., Reus, V.I., et al. (2009).  Neurobiological and neuropsychiatric effects of dehydroepiandrosterone (DHEA) and DHEA sulfate (DHEAS).  Front Neuroendocrinol, 30(1), 65-91.
  4. Pall, M., Nguyen, M., Magoffin, D., et al. (2009).  Effect of sex steroids and insulin on dehydroepiandrosterone sulfate (DHEAS) production by HEPG2 cells.  Fertil Steril, 91(6), 2551-56.
  5. Hammer, F., Subtil, S., Lux, P., et al. (2005).  No evidence for hepatic conversion of dehydroepiandrosterone (DHEA) sulfate to DHEA: In vivo and in vitro studies.  J Clin Endocrinol Metab, 90(6), 3600-05.
  6. Labrie, F., Bélanger, A., Cusan, L., Candas, B. (1997).  Physiological changes in dehydroepiandrosterone are not reflected by serum levels of active androgens and estrogens but of their metabolites: Intracrinology.  J Clin Endocrinol Metab, 82(8), 2403-09.
  7. Labrie, F., Bélanger, A., Bélanger, P., et al. (2006).  Androgen glucuronides, instead of testosterone, as the new markers of androgenic activity in women.  J Steroid Biochem Mol Biol, 99(4-5), 182-88.
  8. Labrie, F., Bélanger, A., Bélanger, P., et al. (2007).  Metabolism of DHEA in postmenopausal women following percutaneous administration.  J Steroid Biochem Mol Biol, 103(2), 178-88.
  9. Reed, M.J., Purohit, A., Woo, W.L., et al. (2005).  Steroid sulfatase: Molecular biology, regulation, and inhibition.  Endocrine Rev, 26(2), 171-202.
  10. Williams, M.R., Ling, S., Dawood, T., et al. (2002).  Dehydroepiandrosterone inhibits human vascular smooth muscle cell proliferation independent of ARs and ERs.  J Clin Endocrinol Metab, 87(1), 176-81.
  11. Labrie, F., Bélanger, A., Luu-The, V., et al. (1998).  DHEA and the intracrine formation of androgens and estrogens in peripheral target tissues: Its role during aging.  Steroids, 63(5-6), 322-28.
  12. Campbell, B. (2006).  Adrenarche and the evolution of human life history.  Am J Hum Biol, 18(5), 569-89.
  13. Shirtcliff, E.A., Dahl, R.E., Pollak, S.D. (2009).  Pubertal development: Correspondence between hormonal and physical development.  Child Dev, 80(2), 327-37.
  14. Shirtcliff, E.A., Zahn-Waxler, C., Klimes-Dougan, B., Slattery, M. (2007).  Salivary dehydroepiandrosterone responsiveness to social challenge in adolescents with internalizing problems.  J Child Psychol Psychiatry, 48(6), 580-91.
  15. van Goozen, S.H., van den Ban, E., Matthys, W., et al. (2000).  Increased adrenal androgen functioning in children with oppositional defiant disorder: A comparison with psychiatric and normal controls.  J Amer Acad Child Adolesc Psychiatry, 39(11), 1446-51.
  16. Goodyer, I.M., Park, R.J., Netherton, C.M., Herbert, J. (2001).  Possible role of cortisol and dehydroepiandrosterone in human development and psychopathology.  Brit J Psychiatry, 179, 243-49.
  17. Brown, G., McGarvey, E., Shirtcliff, E., et al. (2008).  Salivary cortisol, dehydroepiandrosterone, and testosterone interrelationships in healthy young males: A pilot study with implications for studies of aggressive behavior.  Psychiatry Res, 159(1-2), 67-76.
  18. Dorn, L.D., Kolko, D.J., Susman, E.J., et al. (2009).  Salivary gonadal and adrenal hormone differences in boys and girls with and without disruptive behavior disorders: Contextual variants.  Biol Psychol, 81(1), 31-39.
  19. Summarized in: Whetzel, C.A., Klein, L.C. (2010).  Measuring DHEA-S in saliva: Time of day differences and positive correlations between two different types of collection methods.  BMC Res Notes, 3:204.
  20. Rosenfeld, R.S., Rosenberg, B.J., Fukushima, D.K., Hellman, L. (1975).  24-Hour secretory pattern of dehydroisoandrosterone and dehydroisoandrosterone sulfate.  J Clin Endocrinol Metab, 40(5), 850-5.
  21. Carlström, K., Karlsson, R., Von Schoultz, B. (2002).  Diurnal rhythm and effects of oral contraceptives on serum dehydroepiandrosterone sulfate (DHEAS) are related to alteration in serum albumin rather than to changes in adrenocortical steroid secretion.  Scand J Clin Lab Invest, 62(5), 361-68.
  22. Goodyer, I.M., Herbert, J., Altham, P.M. (1998). Adrenal steroid secretion and major depression in 8- to 16-year-olds, III. Influence of cortisol/DHEA ratio at presentation on subsequent rates of disappointing life events and persistent major depression.  Psychol Med, 28(2), 165-73.
  23. Young, A.H., Gallagher, P., Porter, R.J. (2002).  Elevation of the cortisol-dehydroepiandrosterone ratio in drug-free depressed patients.  Am J Psychiatry, 159(7), 1237-39.
  24. Harris, D.S., Wolkowitz, O.M., Reus, V.I. (2001).  Movement disorder, memory, psychiatric symptoms and serum DHEA levels in schizophrenic and schizoaffective patients.  World J Biol Psychiatry, 2(2), 99-102.
  25. Christeff, N., Gherbi, N., Mammes, O., et al. (1997).  Serum cortisol and DHEA concentration during HIV infection.  Psychoneuroendocrinology, 22(suppl 1), S11-18.
  26. Imrich, R. (2002).  The role of neuroendocrine system in the pathogenesis of rheumatic diseases.  Endocr Regul, 36(2), 95-106.
  27. Thijs, L., Fagard, R., Forette, F., et al. (2003).  Are low dehydroepiandrosterone sulphate levels predictive for cardiovascular diseases? A review of prospective and retrospective studies.  Acta Cardiol 58(5), 403-10.
  28. Chen, C.C., Parker, C.R. Jr. (2004).  Adrenal androgens and the immune system.  Semin Reprod Med 22(4), 369-77.
  29. Dharia, S., Parker, C.R. Jr. (2004).  Adrenal androgens and aging.  Semin Reprod Med 22(4), 361-8.
  30. Rosmond, R. (2006).  Androgen excess in women--a health hazard?  Med Hypotheses 67(2), 229-34.
  31. Bergfeld, W.F. (2000).  Hirsutism in women: Effective therapy that is safe for long-term use.  Postgrad Med 107(7), 93-4.
  32. Kellner, M., Muhtz, C., Peter, F., et al. (2010).  Increased DHEA and DHEA-S plasma levels in patients with post-traumatic stress disorder and a history of childhood abuse.  J Psychiatr Res, 44(4), 215-19.
  33. Golubchik, P., Mozes, T., Maayan, R., Weizman, A. (2009).  Neurosteroid blood levels in delinquent adolescent boys with conduct disorder.  Eur Neuropsychopharmacol, 19(1), 49-52.
  34. Azurmendi, A., Braza, F., Garcia, A., et al.  (2006).  Aggression dominance and affiliation:  Their relationships with androgen levels and intelligence in 5-year-old children.  Horm Behav, 50(1), 132-40.
  35. MacLaughlin, B.W., Wang, D., Noone, A.-M., et al. (2010).  Stress biomarkers in medical students participating in a mind body medicine skills program.  eCAM [doi:10.1093/ecam/neq039]
  36. Wang, H.T., Chen, S.M., Lee, S.D., et al. (2009).  The role of DHEA-S in the mood adjustment against negative competition outcome in golfers.  J Sports Sci, 37(3), 291-97.
  37. Majewska, M.D., Demirgören, S., Spivak, C.E., et al. The neurosteroid dehydroepiandrosterone sulfate is an allosteric antagonist of the GABAA receptor.  Brain Res, 526(1), 143-46.
  38. Charalampopoulos, I., Alexaki, V.-I., Tsatsanis, C., et al. (2006).  Neurosteroids as endogenous inhibitors of neuronal cell apoptosis in aging.  Ann NY Acad Science, 1088, 138-52.
  39. Yadid, G., Sudai, E., Maayan, R., et al. (2010).  The role of dehydroepiandrosterone (DHEA) in drug-seeking behavior.  Neurosci Biobehav Rev, [epub ahead of print]
  40. Ritsner, M.S., Strous, R.D. (2009).  Neurocognitive deficits in schizophrenia are associated with alterations in blood levels of neurosteroids: A multiple regression analysis of findings from a double-blind, randomized, placebo-controlled, crossover trial with DHEA.  J Psychiatr Res, 44(2), 75-80.
  41. Ferrari, E., Magri, F. (2008). Role of neuroendocrine pathways in cognitive decline during aging.  Ageing Res Rev, 7(3), 225-33.
  42. Widstrom, R., Dillon, J.S. (2004).  Is there a receptor for dehydroepiandrosterone or dehydroepiandrosterone sulfate?  Semin Repro Med, 22(4), 289-98.
  43. Dillon, J.S. (2005).  Dehydroepiandrosterone, dehydroepiandrosterone sulfate and related steroids: Their role in inflammatory, allergic and immunological disorders.  Curr Drug Targets Inflamm Allergy, 4(3), 377-85.
  44. Panjari, M. (2010).  DHEA for postmenopausal women: A review of the evidence.  Maturitas, 66(2), 172-79.
  45. Buford, T.W., Willoughby, D.S. (2008).  Impact of DHEA(S) and cortisol on immune function in aging: A brief review.  Appl Physiol Nutr Metab, 33(3), 429-33.
  46. Panjari, M., Davis, S.R. (2007).  DHEA therapy for women:  Effect on sexual function and wellbeing.  Hum Reprod Update, 13(3), 239-48.
  47. Liu, D., Si, H., Reynolds, K.A., et al. (2007).  Dehydroepiandrosterone protects vascular endothelial cells against apoptosis through a Gαi protein-dependent activation of phosphatidylinositol 3-kinase/akt and regulation of antiapoptotic BCl-2 expression.  Endocrinology, 148(7), 3068-76.
  48. Vining, R.F., McGinley, R.A., Symons, R.G. (1983).  Hormones in saliva: Mode of entry and consequent implications for clinical interpretation.  Clin Chem, 29(10), 1752-56.
  49. Konttinen, Y.T., Stegaev, V., Mackiewica, Z., et al. (2010).  Salivary glands – ‘An unisex organ’?  Oral Dis, [epub ahead of print]
  50. Pomari, E., Nardi, A., Fiore, C., et al. (2009).  Transcriptional control of human organic anion transporting polypeptide 2B1 gene. J Steroid Biochem Mol Biol, 115(3-5), 146-52.
  51. Laine, M., Porola, P., Udby, L., et al. (2007).  Low salivary dehydroepiandrosterone and androgen-regulated cysteine-rich secretory protein 3 levels in Sjögren’s syndrome.  Arthritis Rheum, 56(8), 2575-84.
  52. Matchock, R.L., Dorn, L.D., Susman, E.J. (2007).  Diurnal and seasonal cortisol, testosterone, and DHEA rhythms in boys and girls during puberty.  Chronobiol Int, 24(5), 969-90.
  53. Ansai, T., Soh, I., Ishisaka, A., et al. (2009).  Determination of cortisol and dehydroepiandrosterone levels in saliva for screening of periodontitis in older Japanese adults.  Int J Dent, 2009:280737 [epub 2010]
  54. Gavrilova, N., Lindau, S.T. (2009).  Salivary sex hormone measurement in a national, population-based study of older adults. J Gerontol B Psychol Sci Soc Sci, 64(suppl 1), i94-105.
  55. Patacchioli, F.R., Monnazzi, P., Simeoni, S., et al. (2006).  Salivary cortisol, dehydroepiandrosterone-sulphate (DHEA-S) and testosterone in women with chronic migraine.  J Headache Pain, 7(2), 90-94.
  56. Huang, Y.-J., Chen, M.-T., Fang, C.-L., et al. (2006).  A possible link between exercise-training adaptation and dehydroepiandrosterone sulfate – An oldest-old female study.  Int J Med Sci, 3(4), 141-47.
  57. Assies, J., Visser, N., Nicolson, T., et al. (2004).  Elevated salivary dehydroepiandrosterone-sulfate but normal cortisol levels in medicated depressed patients: Preliminary findings.  Psychiatry Res, 128(2), 117-22.
  58. Floyd, K., Riforgiate, S. (2008).  Affectionate communication received from spouses predicts stress hormone levels in healthy adults.  Communication Monographs, 75(4), 351-68.