| 41. |
- Bäcklund, Nils, 1987-
(författare)
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Diagnosing hyper- and hypocortisolism using saliva samples : pitfalls and how to avoid them
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Cushing's syndrome (CS) is caused by high cortisol secretion whereas insufficient cortisol secretion is called adrenal insufficiency (AI). Both are rare diseases with substantial diagnostic delay, and high morbidity and mortality even though effective treatment is available. This thesis aims to improve diagnostic tests for CS and AI using analyses of cortisol and its inactive metabolite cortisone in saliva samples.Methods: Papers 1 and 2 are based on a reference cohort including 155 individuals and 22 patients with CS. Salivary samples were collected at late-night (23:00 hours ± 15 minutes) and after a 1-mg overnight dexamethasone suppression test (DST). In Paper 1, reference intervals for salivary cortisol and cortisone analyzed with liquid chromatography-tandem mass spectrometry (LC-MS/MS) were established for late-night and post-DST samples. Diagnostic accuracy for CS was calculated using the established reference intervals. Potential effects of age, comorbidities, season, and sampling time point were also studied. In Paper 2, different analytical methods for measurement of salivary cortisol (3 LC-MS/MS and 3 immunoassays) and salivary cortisone (3 LC-MS/MS assays) were compared regarding reference intervals and diagnostic accuracies for CS. Paper 3 elucidated the potential effect of liquorice consumption, blood contamination, and topical hydrocortisone handling prior to sampling on salivary cortisol and cortisone. Paper 4 investigated whether salivary cortisol and cortisone are less affected than plasma cortisol by estrogen-containing oral contraceptive (OCs) in women undergoing a short Synacthen test (SST) by comparing the response in women with (n=41) and without OCs (n=46).Results: Paper 1 established reference intervals for salivary cortisol and cortisone at 23:00 hours and after DST. Using the upper reference limits as cut-offs, the diagnostic tests rendered high diagnostic accuracy for CS using salivary cortisol (sensitivity 90–95 %, specificity 96 %). There was no seasonal variation and no significant difference between samples collected at 22:00 vs 23:00 hours. Salivary cortisone showed a higher diagnostic accuracy for CS (sensitivity 100 % and specificity 94–95 %) and was less affected by other comorbidities compared to salivary cortisol. Paper 2 showed very high agreement between the three LC-MS/MS methods and that measuring salivary cortisol with immunoassays resulted in higher cortisol concentrations than with LC-MS/MS. However, using the newly established reference limits for each method, all had high diagnostic accuracy for CS. Late-night salivary cortisone analyzed with the LC-MS/MS methods and salivary cortisol analyzed with the Roche immunoassay showed the highest diagnostic accuracies. Paper 3 showed that liquorice consumption increased late-night salivary cortisol, which was sustained for up to 6 days, whereas no effect was seen on salivary cortisone. Salivary cortisol, but not cortisone, was increased by contamination of saliva with ≥0.5 % blood, which could be revealed by a clearly visible red discoloration of the saliva. Handling of topical hydrocortisone before saliva sampling affected salivary cortisol to a much higher degree than salivary cortisone. Paper 4 showed that women using OCs have considerably higher plasma cortisol levels during an SST, whereas salivary cortisol and salivary cortisone were lower compared to controls. However, the lower reference limits were not significantly different for salivary measurands, with salivary cortisone slightly more robust, opting for a common cut-off to exclude AI regardless of OCs.Conclusion: Using the reference intervals calculated for several clinically used analytical methods showed high diagnostic accuracy for CS, with cortisone showing the highest accuracy. Analyzing salivary cortisone was not affected by liquorice consumption or blood contamination. Salivary cortisone was least affected by OCs during an SST. In summary, salivary cortisone is very useful in the diagnostic work-up for CS and AI.
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| 42. |
- Bäcklund, Nils, et al.
(författare)
-
Reference intervals of salivary cortisol and cortisone and their diagnostic accuracy in Cushing's syndrome
- 2020
-
Ingår i: European Journal of Endocrinology. - : Bioscientifica. - 0804-4643 .- 1479-683X. ; 182:6, s. 569-582
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: The challenge of diagnosing Cushing's syndrome (CS) calls for high precision biochemical screening. This study aimed to establish robust reference intervals for, and compare the diagnostic accuracy of, salivary cortisol and cortisone in late-night samples and after a low-dose (1 mg) dexamethasone suppression test (DST). Design and methods: Saliva samples were collected at 08:00 and 23:00 h, and at 08:00 h, after a DST, from 22 patients with CS and from 155 adult reference subjects. We also collected samples at 20:00 and 22:00 h from 78 of the reference subjects. Salivary cortisol and cortisone were analysed with liquid chromatography-tandem mass spectrometry. The reference intervals were calculated as the 2.5th and 97.5th percentiles of the reference population measurements. Diagnostic accuracies of different tests were compared, based on areas under the receiver-operating characteristic curves. Results: The upper reference limits of salivary cortisol and cortisone at 23:00 h were 3.6 nmol/L and 13.5 nmol/L, respectively. Using these reference limits, CS was detected with a sensitivity (95% CI) of 90% (70-99%) and specificity of 96% (91-98%) for cortisol, and a 100% (84-100%) sensitivity and 95% (90-98%) specificity for cortisone. After DST, cortisol and cortisone upper reference limits were 0.79 nmol/L and 3.5 nmol/L, respectively. CS was detected with 95% (75-100%) sensitivity and 96% (92-99%) specificity with cortisol, and 100% (83-100%) sensitivity and 94% (89-97%) specificity with cortisone. No differences in salivary cortisol or cortisone levels were found between samples collected at 22:00 and 23:00 h. Conclusion: Salivary cortisol and cortisone in late-night samples and after DST showed high accuracy for diagnosing CS, salivary cortisone being slightly, but significantly better. © 2020 European Society of Endocrinology Printed in Great Britain.
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| 43. |
- Bäcklund, Nils, et al.
(författare)
-
Reference intervals of salivary cortisol and cortisone and their diagnostic accuracy in Cushing’s syndrome
- 2020
-
Ingår i: European Journal of Endocrinology. - : Bioscientifica. - 0804-4643 .- 1479-683X. ; 182:6, s. 569-582
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: The challenge of diagnosing Cushing's syndrome (CS) calls for high precision biochemical screening. This study aimed to establish robust reference intervals for, and compare the diagnostic accuracy of, salivary cortisol and cortisone in late-night samples and after a low-dose (1 mg) dexamethasone suppression test (DST).Design and methods: Saliva samples were collected at 08:00 and 23:00 h, and at 08:00 h, after a DST, from 22 patients with CS and from 155 adult reference subjects. We also collected samples at 20:00 and 22:00 h from 78 of the reference subjects. Salivary cortisol and cortisone were analysed with liquid chromatography-tandem mass spectrometry. The reference intervals were calculated as the 2.5th and 97.5th percentiles of the reference population measurements. Diagnostic accuracies of different tests were compared, based on areas under the receiver-operating characteristic curves.Results: The upper reference limits of salivary cortisol and cortisone at 23:00 h were 3.6 nmol/L and 13.5 nmol/L, respectively. Using these reference limits, CS was detected with a sensitivity (95% CI) of 90% (70-99%) and specificity of 96% (91-98%) for cortisol, and a 100% (84-100%) sensitivity and 95% (90-98%) specificity for cortisone. After DST, cortisol and cortisone upper reference limits were 0.79 nmol/L and 3.5 nmol/L, respectively. CS was detected with 95% (75-100%) sensitivity and 96% (92-99%) specificity with cortisol, and 100% (83-100%) sensitivity and 94% (89-97%) specificity with cortisone. No differences in salivary cortisol or cortisone levels were found between samples collected at 22:00 and 23:00 h.Conclusion: Salivary cortisol and cortisone in late-night samples and after DST showed high accuracy for diagnosing CS, salivary cortisone being slightly, but significantly better.
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| 44. |
- Bäcklund, Nils, 1987-, et al.
(författare)
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Salivary cortisol and cortisone can circumvent confounding effects of oral contraceptives in the short synacthen test
- 2024
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Ingår i: Journal of Clinical Endocrinology and Metabolism. - : Oxford University Press. - 0021-972X .- 1945-7197. ; 109:7, s. 1899-1906
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Tidskriftsartikel (refereegranskat)abstract
- Context: Adrenal insufficiency (AI) is usually diagnosed by low plasma cortisol levels following a short Synacthen test (SST). Most plasma cortisol is bound to corticosteroid-binding globulin, which is increased by estrogen in combined estrogen-progestin oral contraceptives (COCs). Women with AI using COCs are therefore at risk of having an apparently normal plasma cortisol level during SST, which would not adequately reflect AI.Objective: To test whether salivary cortisol or cortisone during SST is more robust against the COC effect and to calculate the lower reference limits (LRLs) for these to be used as tentative diagnostic cutoffs to exclude AI.Methods: Forty-one healthy women on COCs and 46 healthy women without exogenous estrogens performed an SST with collection of plasma and salivary samples at 0, 30, and 60 min after Synacthen injection. The groups were compared using regression analysis with age as covariate and the LRLs were calculated parametrically.Results: SST-stimulated plasma cortisol levels were significantly higher in the COC group versus controls, while mean salivary cortisol and cortisone levels were slightly lower in the COC group. Importantly, COC use did not significantly alter LRLs for salivary cortisol or cortisone. The smallest LRL difference between groups was seen for salivary cortisone.Conclusion: Salivary cortisol and especially salivary cortisone are considerably less affected by COC use than plasma cortisol during SST. Due to similar LRLs, a common cutoff for salivary cortisol and cortisone during SST can be used to exclude AI in premenopausal women irrespective of COC use.
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| 45. |
- Bäcklund, Nils, et al.
(författare)
-
Salivary cortisol and cortisone in diagnosis of Cushing's syndrome - a comparison of six different analytical methods
- 2023
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Ingår i: Clinical Chemistry and Laboratory Medicine. - : Walter de Gruyter. - 1434-6621 .- 1437-4331. ; 61:10, s. 1780-1791
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Salivary cortisol and cortisone at late night and after dexamethasone suppression test (DST) are increasingly used for screening of Cushing's syndrome (CS). We aimed to establish reference intervals for salivary cortisol and cortisone with three liquid chromatography-tandem mass spectrometry (LC-MS/MS) techniques and for salivary cortisol with three immunoassays (IAs), and evaluate their diagnostic accuracy for CS.Methods: Salivary samples at 08:00 h, 23:00 h and 08:00 h after a 1-mg DST were collected from a reference population (n=155) and patients with CS (n=22). Sample aliquots were analyzed by three LC-MS/MS and three IA methods. After establishing reference intervals, the upper reference limit (URL) for each method was used to calculate sensitivity and specificity for CS. Diagnostic accuracy was evaluated by comparing ROC curves.Results: URLs for salivary cortisol at 23:00 h were similar for the LC-MS/MS methods (3.4-3.9 nmol/L), but varied between IAs: Roche (5.8 nmol/L), Salimetrics (4.3 nmol/L), Cisbio (21.6 nmol/L). Corresponding URLs after DST were 0.7-1.0, and 2.4, 4.0 and 5.4 nmol/L, respectively. Salivary cortisone URLs were 13.5-16.6 nmol/L at 23:00 h and 3.0-3.5 nmol/L at 08:00 h after DST. All methods had ROC AUCs =0.96.Conclusions: We present robust reference intervals for salivary cortisol and cortisone at 08:00 h, 23:00 h and 08:00 h after DST for several clinically used methods. The similarities between LC-MS/MS methods allows for direct comparison of absolute values. Diagnostic accuracy for CS was high for all salivary cortisol and cortisone LC-MS/MS methods and salivary cortisol IAs evaluated.
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| 46. |
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| 47. |
- Consiglio, Camila, et al.
(författare)
-
Immune system adaptation during gender-affirming testosterone treatment
- 2023
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Ingår i: Journal of Reproductive Immunology. - : Elsevier. - 0165-0378 .- 1872-7603. ; 159, s. 29-30
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Biological sex impacts human immune responses, modulating susceptibility and severity to immune-related diseases. Female generally mount more robust immune responses than males, resulting in lower infection severity and greater autoimmunity incidence. Here, we addressed the contribution of testosterone to human immune function by analyzing a cohort of subjects undergoing gender-affirming testosterone treatment. We performed systems-level immunomonitoring through mass cytometry, scRNA and scA-TAC-Sequencing, and proteome profiling of blood samples at baseline and following 3 and 12 months of treatment. Testosterone treatment was associated with a low-grade inflammatory profile, evidenced by upregulation of proinflammatory plasma proteome (e.g., EN-RAGE, OSM, TNF), and induction of an inflammatory transcriptional program associated with NFkB signaling, and TNF signaling. Following testosterone treatment, higher NFkB activity was revealed in CD4 T, CD8 T, and NK cells in scATACseq analyses. Further, testosterone increased monocytic inflammatory responses upon bacterial stimulation in vitro. Although testosterone was associated with this inflammatory profile, it also exerted negative effects on antiviral immunity. Firstly, the percentage of plasmacytoid dendritic cells (pDC) decreased over transition, with pDC also displaying phenotypic changes associated with lower IFN responses. Secondly, bulk transcriptomics analyses show an overall reduction of IFNa responses. Thirdly, testosterone treatment led to reduced IFNa production upon PBMCs stimulation with a viral agonist. Our results show that testosterone has broad effects on the human immune system, and significantly modulates important players in antiviral immunity and inflammatory response. Identifying pathways involved in immune sexual dimorphism will help define novel targets for effective prevention and treatment of immune-mediated diseases.
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| 48. |
- D, Andesson, et al.
(författare)
-
Ergonomiskt utformning av styckningsarbete
- 1985
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This research work was carried out together with the Department of Industrial Ergonomics at Linköping University, Linköping. A comment: Publishing consumer reports was the praxis during this (early) period of time at Chalmers University of Technology, as well as probably at some other universities. This means that frequent and vast academic publication by means of e.g. conference papers and refereed contributions to scientific journals was almost unheard of. At least so for some of the applied science disciplines. However, today are the situation indeed very different (i.e. earlier was the publication in many respects focused on trying to satisfy the executive administrator the research foundation in question etc.). To be more precise, this early praxis was definitively the case for the research and development work carried out at the Department of Transportation (a broadly applied science discipline), which was characterized by more practical strives to e.g. engineer research results. Rather than relying on truer scientific efforts in a narrower sense. Functional satisfaction (i.e. something engineered work as planned instead verification/falsification of a hypothesis) was judged as being a primary aim of this research and development work. Therefore are (in the context of the publications registered in Chalmers Public Library CPL) the author making distinctions between consumer reports, on one hand. And, one the other hand, reports and preprints (manuscripts), while instead the academically orientated publications are various sort of scientific contributions presented at conferences or published in scientific journals (actually it is somewhat more complex, but further explanations are omitted here). The consumer reports were aimed at a various external organization with who the authors cooperated, and these are in many cases not available in PDF format to be easily read by logging in at CPL. This particular approach has judged as being fair/relevant fair in order to mirror of work conducted by the author or authors during the passing decades. Besides, the competencies at Chalmers Library, who actually have been very helpful, have not managed to provide appropriate answers to the various questions implied being at hand just above (this despite trying to get hold of such answers, hence this very comment).
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| 49. |
- Dahlqvist, Anna, et al.
(författare)
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The Rebound Effect in Energy-Intensive Industries : A Factor Demand Model with Asymmetric Price Response
- 2021
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Ingår i: Energy Journal. - : International Association for Energy Economics. - 0195-6574 .- 1944-9089. ; 42:3, s. 177-204
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this paper is to estimate industry-specific direct rebound effects and to relate these effects to industry energy efficiency programs. The rebound effect represents economic behavior that will offset energy savings from energy efficiency improvements. The paper focuses on four energy intense sectors in Sweden; pulp and paper, iron and steel, chemical, and mining, during 2001-2012. We apply a factor demand model that allows for asymmetric energy price responses, i.e. that firms respond differently to increasing and decreasing energy prices. The results show considerable rebound effects. For electricity and non-fossil fuels, efficiency improvements could even ‘backfire’. To mitigate this effect, policies, such as voluntary energy efficiency programs, should be combined with an increase in energy taxes if the ambition is to reduce overall energy use.
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| 50. |
- Dahlqvist, Jonas, et al.
(författare)
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Business start-up reasons and firm performance
- 2000
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Ingår i: Frontiers of entrepreneurship research 2000. - Wellesley, Mass. : Babson College. - 0910897212
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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