Plasma dehydroepiandrosterone sulphate in hypothyroid premenopausal women

Plasma Metabolomics Reveals Systemic Metabolic Alterations of Subclinical and Clinical Hypothyroidism

CONTEXT

Clinical hypothyroidism (CH) and subclinical hypothyroidism (SCH) have been linked to various metabolic comorbidities but the underlying metabolic alterations remain unclear. Metabolomics may provide metabolic insights into the pathophysiology of hypothyroidism.

OBJECTIVE

We explored metabolic alterations in SCH and CH and identify potential metabolite biomarkers for the discrimination of SCH and CH from euthyroid individuals.

METHODS

Plasma samples from a cohort of 126 human subjects, including 45 patients with CH, 41 patients with SCH, and 40 euthyroid controls, were analyzed by high-resolution mass spectrometry-based metabolomics. Data were processed by multivariate principal components analysis and orthogonal partial least squares discriminant analysis. Correlation analysis was performed by a Multivariate Linear Regression analysis. Unbiased Variable selection in R algorithm and 3 machine learning models were utilized to develop prediction models based on potential metabolite biomarkers.

RESULTS

The plasma metabolomic patterns in SCH and CH groups were significantly different from those of control groups, while metabolite alterations between SCH and CH groups were dramatically similar. Pathway enrichment analysis found that SCH and CH had a significant impact on primary bile acid biosynthesis, steroid hormone biosynthesis, lysine degradation, tryptophan metabolism, and purine metabolism. Significant associations for 65 metabolites were found with levels of thyrotropin, free thyroxine, thyroid peroxidase antibody, or thyroglobulin antibody. We successfully selected and validated 17 metabolic biomarkers to differentiate 3 groups.

CONCLUSION

SCH and CH have significantly altered metabolic patterns associated with hypothyroidism, and metabolomics coupled with machine learning algorithms can be used to develop diagnostic models based on selected metabolites.

DHEAS as a new diagnostic tool

Dehydroepiandrosterone sulfate (DHEAS) is a 19-carbon steroid, situated along the steroid metabolic pathway. It is the most abundant circulating steroid hormone in the body and can be converted to either androgens or estrogens. Their physiological and pathological functions have not yet been fully identified. Serum DHEAS concentrations peak at around age 25 years and then decline steadily over the following decades. Due to its long half-life and high concentration in the blood, the levels of DHEAS remain the same 24 h a day. This makes DHEAS a very interesting new diagnostic tool for both scientific research and clinical diagnostics. Moreover, circulating concentrations of DHEAS can be changed by many factors, such as endogenous production, hormone supplementation, many kinds of drugs, and many types of disease states. As research moves forward to better understand the relationships of DHEAS with health and disease, it is essential that studies should be designed to control for the influence of many factors on serum DHEAS concentrations.

Dehydroepiandrosterone-sulfate serum levels and common age-related diseases: results from a cross-sectional Italian study of a general elderly population

The association of low serum dehydroepiandrosterone sulfate (DHEAS) levels with age, lifestyle, general health status indicators, and specific diseases was investigated in 436 men and 544 women of 65-97 yr old. In both sexes low serum DHEAS levels were associated with age, alcohol intake, number of current medications, and decreased thyroid function. Low DHEAS was also associated with low serum albumin in men and low systolic blood pressure in women. Compared to healthy men (n=106) age-adjusted serum DHEAS levels were significantly lower in men with atrial fibrillation, chronic obstructive lung disease, dementia, parkinsonism, cancer, diabetes, hypothyroidism, and in institutionalized men. Compared to healthy women (n=100) age-adjusted serum DHEAS levels were significantly lower in women with occlusive arterial disease, chronic obstructive lung disease, and osteoporosis. After controlling for differences in lifestyle and general health status parameters, low DHEAS levels remained statistically associated only with atrial fibrillation in men and osteoporosis in women, and it cannot be excluded that these association were spurious, due to multiple comparisons. These data suggest that in elderly people low serum DHEAS levels are more a non-specific indicator of aging and health status than a risk indicator of specific diseases.

Dehydroepiandrosterone sulphate is increased and dehydroepiandrosterone-response to corticotrophin-releasing hormone is decreased in the hyperthyroid state compared with the euthyroid state

OBJECTIVE

Dehydroepiandrosterone (DHEA) and DHEA-sulphate (S) have been suggested to play protective roles in many pathological states, some of which are observed in hyperthyroidism. If DHEA and DHEA-S levels change in hyperthyroidism, they might participate as a possible causative link with such pathophysiological changes in hyperthyroidism. However, the CRH-ACTH-DHEA system in hyperthyroidism has not been clearly defined. We examined plasma levels of DHEA and DHEA-S together with ACTH and cortisol in both hyperthyroid (Hyper) and euthyroid states (Eu).

METHODS

Eighteen patients (5 men and 13 women, aged 46.9 +/- 2.8 years) with Graves' disease were studied before treatment and again in the euthyroid state following treatment with methimazole. A 100 microg hCRH stimulation test and a low-dose (0.5 microg) 1-24 ACTH stimulation test were performed on separate days. Basal levels and A area under the response curve (AUC) were compared between Hyper and Eu.

RESULTS

DHEA-S was higher in Hyper than in Eu. However, basal DHEA did not differ between Hyper and Eu. The ratio of DHEA to DHEA-S was lower in Hyper than in Eu. AAUC of DHEA during a CRH test was lower in Hyper than in Eu. However, AAUC of DHEA during an ACTH test was similar in both Hyper and Eu. Basal ACTH was higher in Hyper than in Eu. In both CRH and ACTH tests, AAUC of cortisol response was lower in Hyper than in Eu, although the basal cortisol level was not different.

CONCLUSION

The balance of the conversion between DHEA-S and DHEA in the hyperthyroid state favoured DHEA-S. Similar to cortisol, the DHEA response in the CRH test in hyperthyroidism seemed to be insufficiently compensated for by increased ACTH, although the DHEA response to low-dose ACTH was similar in the hyperthyroid and euthyroid states. Increased DHEA-S might play some role in the pathological states in many organs in hyperthyroidism.

Serum Dehydroepiandrosterone, Dehydroepiandrosterone Sulfate, and Pregnenolone Sulfate Concentrations in Patients with Hyperthyroidism and Hypothyroidism

Background: Dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEA-S) have been suggested to have protective effects against cardiovascular disease, cancer, immune-modulated diseases, and aging. We examined serum concentrations of DHEA, DHEA-S, and pregnenolone sulfate (PREG-S) in patients with thyroid dysfunction.

Methods: Steroids extracted with methanol from serum sample were separated into an unconjugated fraction (DHEA) and a monosulfate fraction (DHEA-S and PREG-S), using a solid-phase extraction and an ion-exchange column. After separation of unconjugated steroids by HPLC, the DHEA concentration was measured by enzyme immunoassay. The monosulfate fraction was treated with arylsulfatase, and the freed steroids were separated by HPLC. The DHEA and PREG fractions were determined by gas chromatography–mass spectrometry, and the concentrations were converted into those of DHEA-S and PREG-S.

Results: Serum concentrations of DHEA, DHEA-S, and PREG-S were all significantly lower in patients with hypothyroidism (n = 24) than in age- and sex-matched healthy controls (n = 43). By contrast, in patients with hyperthyroidism (n = 22), serum DHEA-S and PREG-S concentrations were significantly higher, but the serum DHEA concentration was within the reference interval. Serum concentrations of these three steroids correlated with serum concentrations of thyroid hormones in these patients. Serum albumin and sex hormone-binding globulin concentrations were not related to these changes in the concentration of steroids.

Conclusions: Serum concentrations of DHEA, DHEA-S, and PREG-S were decreased in hypothyroidism, whereas serum DHEA-S and PREG-S concentrations were increased but DHEA was normal in hyperthyroidism. Thyroid hormone may stimulate the synthesis of these steroids, and DHEA sulfotransferase might be increased in hyperthyroidism.

Dehydroepiandrosterone sulphate in critical illness: effect of dopamine

OBJECTIVE

As part of a study on the effect of dopamine therapy on pituitary dependent hormone secretion in critical illness, we documented the impact of this inotropic and vasoactive catecholamine on the serum concentrations of dehydroepiandrosterone sulphate (DHEAS). Concomitantly, serum levels of PRL and cortisol were determined.

PATIENTS AND DESIGN

In a prospective, randomized, controlled, open-labelled clinical study, 20 critically ill, adult polytrauma patients receiving dopamine treatment (5 micrograms/kg/mi i.v. for a median 109 hours (range (21-296 hours)), were studied to evaluate the effect of dopamine withdrawal on serum concentrations of DHEAS, PRL and cortisol. The median age of the studied patients was 37 years (range 18-83 years).

MEASUREMENTS

Serum DHEAS and cortisol concentrations were measured by RIA and PRL by IRMA. The assessed serum samples were obtained at 0300 h on each of two consecutive study nights.

RESULTS

Withdrawal of dopamine infusion was found to elicit a median 25% increase of serum DHEAS concentrations within 24 hours whereas no significant change in DHEAS levels was observed when dopamine infusion was continued throughout both study nights (P = 0.01 continued vs interrupted dopamine). Prolactin levels were undetectable as long as dopamine was infused, and increased to a median of 317 IU/l after 24 hours of dopamine withdrawal (P = 0.0007). Elevated serum cortisol levels remained comparable with continued and interrupted dopamine infusion.

CONCLUSIONS

Dopamine infusion appears to suppress serum DHEAS concentrations in critically ill patients without affecting their elevated serum cortisol levels, suggesting a differential regulation of DHEAS and cortisol metabolism in critical illness. The lowering effect of dopamine on DHEAS levels could be linked to the concomitant suppression of circulating PRL. The simultaneous suppression of circulating PRL and DHEAS by dopamine infusion may be an iatrogenic factor maintaining or aggravating the anergic state of prolonged severe illness.

The adrenal androgen-stimulating hormone does not exist

The existence of a separate but so-far-unidentified pituitary cortical androgen-stimulating hormone that acts in concert with adrenocorticotrophic hormone (ACTH) to stimulate adrenal androgen production (the "adrenarche") from mid-childhood onwards is still strongly argued. It is suggested here that the postulated hormone does not exist and that the adrenarche, which parallels the development of the inner zone, the zona reticularis, is best explained by a morphological and functional change in the inner cells that is induced locally by high levels of cortisol. Downstream "pollution" and slow flush-out of reticularis blood vessels after each pulse of ACTH would expose the inner-zone cells to the highest cortisol levels for the longest time.