{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,10]],"date-time":"2026-04-10T01:19:47Z","timestamp":1775783987546,"version":"3.50.1"},"reference-count":63,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2022,9,14]],"date-time":"2022-09-14T00:00:00Z","timestamp":1663113600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Portuguese Institute for Sport and Youth\u2014I.P.","award":["CP\/217\/DDT\/2022"],"award-info":[{"award-number":["CP\/217\/DDT\/2022"]}]},{"name":"Portuguese Institute for Sport and Youth\u2014I.P.","award":["MS-03"],"award-info":[{"award-number":["MS-03"]}]},{"name":"Universities Ministry of Spain and the European Union (NextGenerationUE)","award":["CP\/217\/DDT\/2022"],"award-info":[{"award-number":["CP\/217\/DDT\/2022"]}]},{"name":"Universities Ministry of Spain and the European Union (NextGenerationUE)","award":["MS-03"],"award-info":[{"award-number":["MS-03"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Diagnostics"],"abstract":"<jats:p>Previous studies showed that people with Fibromyalgia (FM) suffer from dysautonomia. Dysautonomia consists of persistent autonomic nervous system hyperactivity at rest and hyporeactivity during stressful situations. There is evidence that parameters reflecting the complex interplay between the autonomic nervous system and the cardiovascular system during exercise can provide significant prognostic information. Therefore, this study aimed to investigate the differences between people with FM and healthy controls on heart rate variability (HRV) and salivary parameters (such as flow, protein concentration, enzymatic activities of amylase, catalase and glutathione peroxidase) in two moments: (1) at baseline, and (2) after an exercise fatigue protocol. A total of 37 participants, twenty-one were people with fibromyalgia and sixteen were healthy controls, participated in this cross-sectional study. HRV and salivary samples were collected before and after an exercise fatigue protocol. The fatigue protocol consisted of 20 repetitions of knee extensions and flexions of the dominant leg at 180 \u00b0\u00b7s\u22121 (degrees per second). Significant differences were found in the HRV (stress index, LF and HF variables) and salivary biomarkers (with a higher concentration of salivary amylase in people with FM compared to healthy controls). Exercise acute effects on HRV showed that people with FM did not significantly react to exercise. However, significant differences between baseline and post-exercise on HRV significantly induce alteration on the HRV of healthy controls. Catalase significantly increased after exercise in healthy controls whereas salivary flow significantly increased in women with FM after an exercise fatigue protocol. Our study suggests that a higher \u03b1-amylase activity and an impaired HRV can be used as possible biomarkers of fibromyalgia, associated with a reduction in salivary flow without changes in HRV and catalase activity after a fatigue exercise protocol. More studies should be carried out in the future to evaluate this hypothesis, in order to find diagnostic biomarkers in fibromyalgia.<\/jats:p>","DOI":"10.3390\/diagnostics12092220","type":"journal-article","created":{"date-parts":[[2022,9,14]],"date-time":"2022-09-14T20:50:45Z","timestamp":1663188645000},"page":"2220","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":10,"title":["Heart Rate Variability and Salivary Biomarkers Differences between Fibromyalgia and Healthy Participants after an Exercise Fatigue Protocol: An Experimental Study"],"prefix":"10.3390","volume":"12","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-3854-9130","authenticated-orcid":false,"given":"Ana Rodrigues","family":"Costa","sequence":"first","affiliation":[{"name":"Departamento de Ci\u00eancias M\u00e9dicas e da Sa\u00fade, Escola de Sa\u00fade e Desenvolvimento Humano, Universidade de \u00c9vora, 7004-516 \u00c9vora, Portugal"}]},{"given":"Ana","family":"Freire","sequence":"additional","affiliation":[{"name":"Departamento de Ci\u00eancias M\u00e9dicas e da Sa\u00fade, Escola de Sa\u00fade e Desenvolvimento Humano, Universidade de \u00c9vora, 7004-516 \u00c9vora, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5254-7409","authenticated-orcid":false,"given":"Jose A.","family":"Parraca","sequence":"additional","affiliation":[{"name":"Departamento de Desporto e Sa\u00fade, Escola de Sa\u00fade e Desenvolvimento Humano, Universidade de \u00c9vora, 7004-516 \u00c9vora, Portugal"},{"name":"Comprehensive Health Research Centre (CHRC), University of \u00c9vora, 7004-516 \u00c9vora, Portugal"}]},{"given":"Vanda","family":"Silva","sequence":"additional","affiliation":[{"name":"Family Health Unit\u2014Lusitania, Rua do Ferragial do Po\u00e7o Novo, S\/N, 7000-727 \u00c9vora, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7780-3942","authenticated-orcid":false,"given":"Pablo","family":"Tomas-Carus","sequence":"additional","affiliation":[{"name":"Departamento de Desporto e Sa\u00fade, Escola de Sa\u00fade e Desenvolvimento Humano, Universidade de \u00c9vora, 7004-516 \u00c9vora, Portugal"},{"name":"Comprehensive Health Research Centre (CHRC), University of \u00c9vora, 7004-516 \u00c9vora, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0784-1753","authenticated-orcid":false,"given":"Santos","family":"Villafaina","sequence":"additional","affiliation":[{"name":"Departamento de Desporto e Sa\u00fade, Escola de Sa\u00fade e Desenvolvimento Humano, Universidade de \u00c9vora, 7004-516 \u00c9vora, Portugal"},{"name":"Universidad de Extremadura, Facultad de Ciencias del Deporte, 10003 C\u00e1ceres, Spain"}]}],"member":"1968","published-online":{"date-parts":[[2022,9,14]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"600","DOI":"10.1002\/acr.20140","article-title":"The American College of Rheumatology Preliminary Diagnostic Criteria for Fibromyalgia and Measurement of Symptom Severity","volume":"62","author":"Wolfe","year":"2010","journal-title":"Arthrit. Care Res."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"N\u00fa\u00f1ez-Fuentes, D., Obrero-Gait\u00e1n, E., Zagalaz-Anula, N., Ib\u00e1\u00f1ez-Vera, A.J., Achalandabaso-Ochoa, A., L\u00f3pez-Ruiz, M.D.C., Rodr\u00edguez-Almagro, D., and Lomas-Vega, R. (2021). Alteration of Postural Balance in Patients with Fibromyalgia Syndrome-A Systematic Review and Meta-Analysis. Diagnostics, 11.","DOI":"10.3390\/diagnostics11010127"},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Hendrix, J., Nijs, J., Ickmans, K., Godderis, L., Ghosh, M., and Polli, A. (2020). The interplay between oxidative stress, exercise, and pain in health and disease: Potential role of autonomic regulation and epigenetic mechanisms. Antioxidants, 9.","DOI":"10.3390\/antiox9111166"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"422","DOI":"10.55563\/clinexprheumatol\/0c7d6v","article-title":"Fibromyalgia in women: Somatisation or stress-evoked, sex-dimorphic neuropathic pain?","volume":"39","year":"2021","journal-title":"Clin. Exp. Rheumatol."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Siracusa, R., Paola, R.D., Cuzzocrea, S., and Impellizzeri, D. (2021). Fibromyalgia: Pathogenesis, Mechanisms, Diagnosis and Treatment Options Update. Int. J. Mol. Sci., 22.","DOI":"10.3390\/ijms22083891"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1990","DOI":"10.1111\/imj.15430","article-title":"Central sensitivity and fibromyalgia","volume":"51","author":"Mezhov","year":"2021","journal-title":"Intern. Med. J."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Illescas-Montes, R., Costela-Ruiz, V.J., Melguizo-Rodr\u00edguez, L., De Luna-Bertos, E., Ruiz, C., and Ramos-Torrecillas, J. (2021). Application of Salivary Biomarkers in the Diagnosis of Fibromyalgia. Diagnostics, 11.","DOI":"10.3390\/diagnostics11010063"},{"key":"ref_8","first-page":"2660","article-title":"Dysautonomia among patients with fibromyalgia: A noninvasive assessment","volume":"27","author":"Raj","year":"2000","journal-title":"J. Rheumatol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"172","DOI":"10.1097\/RHU.0b013e3181a1083d","article-title":"Autonomic dysfunction in fibromyalgia assessed by the Composite Autonomic Symptoms Scale (COMPASS)","volume":"15","author":"Solano","year":"2009","journal-title":"JCR J. Clin. Rheumatol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"383","DOI":"10.1007\/s00296-005-0007-1","article-title":"Dysautonomia in fibromyalgia syndrome: Sympathetic skin responses and RR interval analysis","volume":"26","author":"Ulas","year":"2006","journal-title":"Rheumatol. Int."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"385","DOI":"10.1007\/s11916-996-0012-4","article-title":"Fibromyalgia as a sympathetically maintained pain syndrome","volume":"8","year":"2004","journal-title":"Curr. Pain Headache Rep."},{"key":"ref_12","first-page":"1787","article-title":"Abnormalities of cardiovascular neural control and reduced orthostatic tolerance in patients with primary fibromyalgia","volume":"32","author":"Furlan","year":"2005","journal-title":"J. Rheumatol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"197","DOI":"10.1016\/S0049-0172(00)80008-6","article-title":"Autonomic nervous system dysfunction may explain the multisystem features of fibromyalgia","volume":"29","author":"Hermosillo","year":"2000","journal-title":"Semin. Arthritis Rheum."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"342","DOI":"10.1016\/j.pcad.2005.11.003","article-title":"Autonomic nervous system interaction with the cardiovascular system during exercise","volume":"48","author":"Freeman","year":"2006","journal-title":"Prog. Cardiovasc. Dis."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"258","DOI":"10.3389\/fpubh.2017.00258","article-title":"An overview of heart rate variability metrics and norms","volume":"5","author":"Shaffer","year":"2017","journal-title":"Front. Public Health"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1239","DOI":"10.1161\/01.CIR.102.11.1239","article-title":"Low heart rate variability in a 2-minute rhythm strip predicts risk of coronary heart disease and mortality from several causes: The ARIC Study","volume":"102","author":"Dekker","year":"2000","journal-title":"Circulation"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"188","DOI":"10.1007\/s00296-003-0427-8","article-title":"Free radicals and antioxidants in primary fibromyalgia: An oxidative stress disorder?","volume":"25","author":"Bagis","year":"2005","journal-title":"Rheumatol. Int."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1296","DOI":"10.1002\/prca.200900076","article-title":"Detection of potential markers of primary fibromyalgia syndrome in human saliva","volume":"3","author":"Bazzichi","year":"2009","journal-title":"Proteom.\u2013Clin. Appl."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"99","DOI":"10.1159\/000358864","article-title":"The use of saliva markers in psychobiology: Mechanisms and methods","volume":"24","author":"Bosch","year":"2014","journal-title":"Saliva Secret. Funct."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"C1233","DOI":"10.1152\/ajpcell.1991.260.6.C1233","article-title":"Rat sublingual gland as a model to study glandular mucous cell secretion","volume":"260","author":"Culp","year":"1991","journal-title":"Am. J. Physiol.-Cell Physiol."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"162","DOI":"10.1067\/mpr.2001.113778","article-title":"A review of saliva: Normal composition, flow, and function","volume":"85","author":"Humphrey","year":"2001","journal-title":"J. Prosthet. Dent."},{"key":"ref_22","first-page":"S278","article-title":"Impaired Cardiac Autonomic Control in Women With Fibromyalgia Is Independent of Their Physical Fitness","volume":"27","author":"Schamne","year":"2021","journal-title":"J. Clin. Rheumatol. Pract. Rep. Rheum. Musculoskelet. Dis."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1628","DOI":"10.1016\/j.apmr.2009.02.023","article-title":"Cardiovascular autonomic modulation after acute resistance exercise in women with fibromyalgia","volume":"90","author":"Kingsley","year":"2009","journal-title":"Arch. Phys. Med. Rehabil."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1243","DOI":"10.1152\/physrev.00031.2007","article-title":"Exercise-induced oxidative stress: Cellular mechanisms and impact on muscle force production","volume":"88","author":"Powers","year":"2008","journal-title":"Physiol. Rev."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"e8688","DOI":"10.1590\/1414-431x20198688","article-title":"Does whole body vibration exercise improve oxidative stress markers in women with fibromyalgia?","volume":"52","author":"Santos","year":"2019","journal-title":"Braz. J. Med. Biol. Res."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"49","DOI":"10.1111\/j.1475-097X.2007.00776.x","article-title":"Resistance exercise training improves heart rate variability in women with fibromyalgia","volume":"28","author":"Figueroa","year":"2008","journal-title":"Clin. Physiol. Funct. Imaging"},{"key":"ref_27","first-page":"572","article-title":"A randomized controlled trial on the effects of combined aerobic-resistance exercise on muscle strength and fatigue, glycemic control and health-related quality of life of type 2 diabetes patients","volume":"56","author":"Pietilainen","year":"2016","journal-title":"J. Sports Med. Phys. Fit."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1","DOI":"10.25242\/8868114020212466","article-title":"Differences in peripheral vascular response of a fibromyalgia patient in a physical fatigue situation. A case control report","volume":"11","author":"Parraca","year":"2021","journal-title":"Perspecticas Online Biol\u00f3gicas Sa\u00fade"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"210","DOI":"10.1016\/j.cmpb.2013.07.024","article-title":"Kubios HRV\u2013heart rate variability analysis software","volume":"113","author":"Tarvainen","year":"2014","journal-title":"Comput. Methods Programs Biomed."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"691","DOI":"10.1007\/s13105-015-0434-8","article-title":"Changes in the salivary protein profile of morbidly obese women either previously subjected to bariatric surgery or not","volume":"71","author":"Lamy","year":"2015","journal-title":"J. Physiol. Biochem."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"248","DOI":"10.1016\/0003-2697(76)90527-3","article-title":"A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding","volume":"72","author":"Bradford","year":"1976","journal-title":"Anal. Biochem."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"854","DOI":"10.1016\/j.archoralbio.2015.02.015","article-title":"Effects of high-fat diet on salivary \u03b1-amylase, serum parameters and food consumption in rats","volume":"60","author":"Rodrigues","year":"2015","journal-title":"Arch. Oral Biol."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"121","DOI":"10.1016\/S0076-6879(84)05016-3","article-title":"Catalase in vitro","volume":"Volume 105","author":"Aebi","year":"1984","journal-title":"Methods in Enzymology"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"15","DOI":"10.1016\/0014-4835(83)90085-4","article-title":"Superoxide dismutase, catalase and glutathione peroxidase in the human cataractous lens","volume":"36","author":"Fecondo","year":"1983","journal-title":"Exp. Eye Res."},{"key":"ref_35","unstructured":"Borg, G. (1998). Borg\u2019s Perceived Exertion and Pain Scales, Human kinetics."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"2","DOI":"10.1037\/a0024338","article-title":"Effect Size Estimates: Current Use, Calculations, and Interpretation","volume":"141","author":"Fritz","year":"2012","journal-title":"J. Exp. Psychol.-Gen."},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Coolican, H. (2017). Research Methods and Statistics in Psychology, Psychology Press.","DOI":"10.4324\/9780203769836"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"2100","DOI":"10.1161\/CIRCULATIONAHA.113.005361","article-title":"Physical activity and heart rate variability in older adults: The Cardiovascular Health Study","volume":"129","author":"Sattelmair","year":"2014","journal-title":"Circulation"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"486","DOI":"10.1016\/j.psyneuen.2009.01.014","article-title":"Salivary alpha-amylase as a non-invasive biomarker for the sympathetic nervous system: Current state of research","volume":"34","author":"Nater","year":"2009","journal-title":"Psychoneuroendocrinology"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"449","DOI":"10.1016\/j.psyneuen.2010.12.019","article-title":"\u03b1-Amylase as a reliable and convenient measure of sympathetic activity: Don\u2019t start salivating just yet!","volume":"36","author":"Bosch","year":"2011","journal-title":"Psychoneuroendocrinology"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"747","DOI":"10.1016\/0003-9969(74)90161-7","article-title":"The influence of sympathetic activity and isoprenaline on the secretion of amylase from the human parotid gland","volume":"19","author":"Speirs","year":"1974","journal-title":"Arch. Oral Biol."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"137","DOI":"10.1016\/j.psyneuen.2005.05.012","article-title":"Salivary alpha amylase as marker for adrenergic activity during stress: Effect of betablockade","volume":"31","author":"Rohleder","year":"2006","journal-title":"Psychoneuroendocrinology"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"199","DOI":"10.1097\/AJP.0b013e3182928da0","article-title":"Has catechol-O-methyltransferase genotype (Val158Met) an influence on endocrine, sympathetic nervous and humoral immune systems in women with fibromyalgia syndrome?","volume":"30","year":"2014","journal-title":"Clin. J. Pain"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"68","DOI":"10.1016\/j.psyneuen.2015.09.018","article-title":"Stress exacerbates pain in the everyday lives of women with fibromyalgia syndrome\u2014The role of cortisol and alpha-amylase","volume":"63","author":"Fischer","year":"2016","journal-title":"Psychoneuroendocrinology"},{"key":"ref_45","unstructured":"Pintor, F.M., Escolano, A.F., Rodr\u00edguez, J.R., Ardid, J.M.C., and Gourlot, A.R. (2014). Niveles de-Amilasa seriada salival en mujeres con fibromialgia. Cuad. Med. Psicosom\u00e1tica Y Psiquiatr. Enlace, 18\u201324. Available online: https:\/\/dialnet.unirioja.es\/servlet\/articulo?codigo=4802222."},{"key":"ref_46","first-page":"55","article-title":"Psicobioquimica (estr\u00e9s, ansiedad y depresi\u00f3n) en fibromialgia","volume":"3","year":"2014","journal-title":"Cuad. Monogr\u00e1ficos Psicobioqu\u00edmica"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"1361","DOI":"10.1007\/s00296-014-2978-2","article-title":"Effects of 12-week combined exercise therapy on oxidative stress in female fibromyalgia patients","volume":"34","year":"2014","journal-title":"Rheumatol. Int."},{"key":"ref_48","first-page":"165","article-title":"Nitric oxide, lipid peroxidation products, and antioxidants in primary fibromyalgia and correlation with disease severity","volume":"39","author":"Shukla","year":"2020","journal-title":"J. Med. Biochem."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"117","DOI":"10.4103\/1110-161X.189642","article-title":"Impact of an intensive dynamic exercise program on oxidative stress and on the outcome in patients with fibromyalgia","volume":"43","author":"Soliman","year":"2016","journal-title":"Egypt. Rheumatol. Rehabil."},{"key":"ref_50","first-page":"1","article-title":"Cardiac autonomic impairment and chronotropic incompetence in fibromyalgia","volume":"13","author":"Roschel","year":"2011","journal-title":"Arthritis Res. Ther."},{"key":"ref_51","doi-asserted-by":"crossref","unstructured":"Villafaina, S., Biehl-Printes, C., Parraca, J.A., de Oliveira Brauner, F., and Tomas-Carus, P. (2022). What Mathematical Models Are Accurate for Prescribing Aerobic Exercise in Women with Fibromyalgia?. Biology, 11.","DOI":"10.3390\/biology11050704"},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"R190","DOI":"10.1016\/j.autneu.2006.10.006","article-title":"Regulation of salivary gland function by autonomic nerves","volume":"133","author":"Proctor","year":"2007","journal-title":"Auton. Neurosci."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1155\/2019\/5425021","article-title":"Salivary and plasmatic antioxidant profile following continuous, resistance, and high-intensity interval exercise: Preliminary study","volume":"2019","author":"Souza","year":"2019","journal-title":"Oxidative Med. Cell. Longev."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"1036","DOI":"10.1097\/00005768-199708000-00008","article-title":"The effect of exercise intensity on lipid peroxidation","volume":"29","author":"Leaf","year":"1997","journal-title":"Med. Sci. Sports Exerc."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"202","DOI":"10.1265\/ehpm.12.202","article-title":"Effects of anaerobic exercise and aerobic exercise on biomarkers of oxidative stress","volume":"12","author":"Shi","year":"2007","journal-title":"Environ. Health Prev. Med."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"604","DOI":"10.1080\/02701367.2009.10599599","article-title":"Total protein of whole saliva as a biomarker of anaerobic threshold","volume":"80","author":"Bortolini","year":"2009","journal-title":"Res. Q. Exerc. Sport"},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"1015","DOI":"10.1080\/02640410410001716733","article-title":"The effect of single and repeated bouts of prolonged cycling and circadian variation on saliva flow rate, immunoglobulin A and-amylase responses","volume":"22","author":"Li","year":"2004","journal-title":"J. Sports Sci."},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"1639","DOI":"10.1016\/j.archoralbio.2015.07.012","article-title":"The effect of physical exercise on salivary secretion of MUC5B, amylase and lysozyme","volume":"60","author":"Ligtenberg","year":"2015","journal-title":"Arch. Oral Biol."},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"129","DOI":"10.1080\/026404199366226","article-title":"The effects of high-intensity intermittent exercise on saliva IgA, total protein and alpha-amylase","volume":"17","author":"Walsh","year":"1999","journal-title":"J. Sports Sci."},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"475","DOI":"10.2217\/17460816.3.5.475","article-title":"Heart rate variability as a biomarker of fibromyalgia syndrome","volume":"3","author":"Staud","year":"2008","journal-title":"Future Rheumatol."},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"131","DOI":"10.1179\/135100006X116628","article-title":"Total antioxidant capacity and the severity of the pain in patients with fibromyalgia","volume":"11","author":"Altindag","year":"2006","journal-title":"Redox Rep."},{"key":"ref_62","doi-asserted-by":"crossref","first-page":"736","DOI":"10.1016\/j.clineuro.2012.08.028","article-title":"Plasma nitrite levels, total antioxidant status, total oxidant status, and oxidative stress index in patients with tension-type headache and fibromyalgia","volume":"115","author":"Neyal","year":"2013","journal-title":"Clin. Neurol. Neurosurg."},{"key":"ref_63","doi-asserted-by":"crossref","first-page":"1","DOI":"10.4172\/2471-2701.1000147","article-title":"Physiological adaptation in women presenting fibromyalgia: Comparison with healthy controls","volume":"3","author":"Lange","year":"2017","journal-title":"Clin. Exp. Psychol."}],"container-title":["Diagnostics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2075-4418\/12\/9\/2220\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T00:31:21Z","timestamp":1760142681000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2075-4418\/12\/9\/2220"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,9,14]]},"references-count":63,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2022,9]]}},"alternative-id":["diagnostics12092220"],"URL":"https:\/\/doi.org\/10.3390\/diagnostics12092220","relation":{},"ISSN":["2075-4418"],"issn-type":[{"value":"2075-4418","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,9,14]]}}}