This work is licensed under Creative Commons Attribution 4.0 International.
Received: 25 June 2018
Accepted: 05 November 2018
DOI: https://doi.org/10.17058/reci.v9i1.12275
Abstract: Background and Objectives: Systemic Arterial Hypertension (SAH) is a health condition that represents a global public health problem and its relation with the hormone cortisol is not yet widely understood. Thus, the present study aimed to identify in the literature the association among the SAH, the hormone cortisol and the clinical methods used to evaluate this relationship. Methods: An integrative literature review was carried out, based on 17 scientific articles published between 2013 and 2017 identified in the databases EMBASE and PubMed, with the descriptors hypertension and hydrocortisone in English language. Results: There was an association of SAH with increased cortisol at the age of 62 years, increased sodium in the diet, not eating breakfast, increased caffeine consumption, metabolic syndrome, obesity, excess catecholamine’s, some types of hormones, and biomarkers. The most commonly used clinical methods for this relationship were association tests, performed with renal and / or cardiac function, metabolic syndrome, stress, chronic diseases associated with the evaluation of laboratory tests. Conclusion: The results indicated an association between cortisol and SAH with advancing age and lifestyle. Moreover, the association tests were the most used methods.
Keywords: Hypertension, Cortisol, Hydrocortisone, Clinical analysis, Health care.
Resumen: Justificación y objetivos: La Hipertensión Arterial Sistémica (HAS) es una afección de salud que representa un problema de salud pública mundial y su relación con la hormona cortisol aún no se conoce ampliamente. Por lo tanto, el presente estudio tuvo como objetivo identificar en la literatura la asociación entre la HAS, la hormona cortisol y los métodos clínicos utilizados para evaluar esta relación. Métodos: Se realizó una revisión integradora de la literatura, basada en 17 artículos científicos publicados entre 2013 y 2017 identificados en las bases de datos EMBASE y PubMed, con los descriptores hipertensión e hidrocortisona en idioma inglés. Resultados: Hubo una asociación de HAS con aumento de cortisol a la edad de 62 años, aumento de sodio en la dieta, falta de desayuno, aumento del consumo de cafeína, síndrome metabólico, obesidad, exceso de catecolaminas, algunos tipos de hormonas y biomarcadores. Los métodos clínicos más comúnmente utilizados para esta relación fueron las pruebas de asociación, realizadas con función renal y / o cardíaca, síndrome metabólico, estrés, enfermedades crónicas asociadas con la evaluación de pruebas de laboratorio. Conclusión: Los resultados indicaron una asociación entre el cortisol y la HAS con el avance de la edad y el estilo de vida. Además, las pruebas de asociación fueron los métodos más utilizados.
Palabras clave: Hipertensão, Cortisol, Hidrocortisona, Analisis clinico, Cuidados de la salud.
Resumo: Justificativa e Objetivos: A Hipertensão Arterial Sistêmica (HAS) é uma condição de saúde que representa um problema de saúde pública mundial e sua relação com o hormônio cortisol ainda não está amplamente esclarecida. Dessa forma, esse estudo teve como objetivo identificar na literatura, as circunstâncias de existência de associação entre a HAS com o hormônio cortisol e os métodos clínicos utilizados para esta relação. Métodos: Realizou-se revisão Integrativa da Literatura, a partir de 17 artigos científicos publicados entre 2013 e 2017 identificados nas bases de dados EMBASE e PubMed, com os descritores hypertension e hydrocortisone, no idioma inglês. Resultados: Verificou-se associação da HAS com o aumento do cortisol na idade a partir de 62 anos, aumento de sódio na dieta, o hábito não ingerir o desjejum, aumento do consumo de cafeína, síndrome metabólica, obesidade, excesso de catecolaminas e alguns tipos de hormônios e biomarcadores. Os métodos clínicos mais utilizados para esta relação foram os testes de associação, feitos com a função renal e/ou cardíaca, síndrome metabólica, estresse, doenças crônicas associados com a avaliação de exames laboratoriais. Conclusão: Os resultados indicaram associação entre o cortisol e a Hipertensão no avançar da idade e estilo de vida, sendo os testes de associação os métodos mais utilizados.
Palavras-chave: Hipertensão, Cortisol, Hidrocortisona, Análises Clínicas, Cuidados de saúde.
INTRODUCTION
Systemic Arterial Hypertension (SAH) is the major concern for the health public policies worldwide.1. SAH is highly prevalent, affecting approximately 10% to 25% of the general population. However, it remains underdiagnosed and poorly controlled, with high rates of morbidity and mortality being an important risk factor for heart and / or kidney diseases and stroke.2,3,4
The Renin-Angiotensin-Aldosterone System (RAAS) and the Hypothalamic-Hypophysis - Adrenal (HPA) axis, responsible for the regulation of blood pressure (BP), were reported to play an important role in the pathophysiology of SAH, and the glucocorticoid (cortisol) and mineralocorticoid (aldosterone) hormones are the respective effectors of these pathways.5,6
In fact, increased circulating or intracellular glucocorticoids levels are common and frequently associated with SAH.7. Cortisol is the main endogenous human glucocorticoid, secreted mainly in response to adrenocorticotropic hormone (ACTH), through the HPA axis.8,9,10. Additionally, cortisol is also known as the stress hormone, being influenced by a variety of biological or environmental factors.11
Acute or chronic increase in serum cortisol levels has been associated with increased BP, hyperglycemia, and endothelial dysfunction, which may be associated with cardiovascular risk.12. Cortisol is involved in the physiological regulation of BP by modulating the vasoconstrictor response via α 1 - adrenergic receptors through the action of catecholamine.13
Among the factors related to the prevalence of SAH in Brazilian adults, there are socio-demographic, behavioral, morbidities, biochemical and anthropometric alterations.14. One of the behavioral factors that is involved in the increase of the BP is the consumption of alcohol, which directly influences the heart, in the smooth muscles of the vessels, through the stimulation of the Sympathetic Nervous System (SNS) or RAAS, which can increase plasma levels of cortisol.2
Different methods have been used in clinical and scientific evaluations in different populations, and the most common is the anthropometric and hemodynamic tests.14,16. In view of the above and due to the particularities and limitations of each research methods, it is necessary to investigate the clinical methods used to evaluate the associations between cortisol and SAH, the relationship of which appears to be potentially harmful to health.
In addition, it is expected that this study may contribute to increase the knowledge and orientation of new studies in this subject. Therefore, the objective of this study was to identify in the literature, through scientific evidence, the circumstances of existence of association between SAH and the hormone cortisol, and the clinical methods used for such evaluation.
METHODS
This Integrative literature review, which is considered as an instrument of the Evidence Based Practice (EBP), focus on clinical practice. Based on guiding question, data collection enables the elaboration of a summary of the results of all studies included in the analysis.17,18
The steps used in this integrative review were: 1) identification of the subject and selection of the hypothesis or question of the research; 2) determination of criteria for the databases search; 3) determination of inclusion and exclusion criteria of the studies; 3) definition of the information to be extracted from the studies; 4) data evaluation; 5) interpretation of results and 6) synthesis of knowledge.17
To address the study and the scope of the proposed goal, based on the PICO strategy, the following clinical question was formulated: Which clinical methods are being used to verify the association between Blood Pressure and the Hormone cortisol? P: population from clinical studies; I: cortisol assessment; C: no comparison factor, O: association between cortisol and BP levels.19
The included texts met the following criteria: complete articles, available free of charge in journals indexed in the EMBASE and PubMed databases, peer reviewed, with a description of clinical studies in humans, with mandatory evaluation of BP and biochemistry assessment of cortisol, published in the last five years (2013 to 2017). Selected articles were written in English. Articles that did not evaluate the direct association between cortisol and BP levels or those studies that were performed in patients with adrenal tumors or under corticoid treatment were excluded.
In the EMBASE database, the following descriptors were used: hypertension / AND 'hydrocortisone' AND 'human' AND (2013: py OR 2014: py OR 2015: py OR 2016: py OR 2017: py) AND 'article' / it AND ('clinical article' / of OR 'clinical protocol' / of OR 'controlled study' / of OR 'major clinical study' AND ([english] / lim OR), resulting in a previous selection of 212 articles. In the Pub Med database the following Medical Subject Heading (MeSH) terms were used for the searches: "Hypertension" [Mesh] AND "Hydrocortisone / analysis" [Mesh] AND ("2012/11/03" [PDA]: "2017/11/01 "[PDat] AND" humans "[MeSH Terms]), with a pre-selection of 49 articles.
The next step consisted of reading the title and the abstracts, and then the retained articles were submitted to full reading and detailed analysis. In the search and selection of articles, the strategy recommended by the PRISMA group20 was adopted as shown in the PRISMA Flowchart (Figure 1).
For the step of full text analysis, a specific instrument was developed to extract and analyze data from the included studies. The tool comprised the following items: (1) publication, authors, journal and country; (2) objective of the study; (3) methods (study design, population, cortisol and BP assessment, other variables measured); and (4) Results. This stage was performed by four collaborators divided into two independent groups and reviewed by two reviewers, who reviewed and validated the data that were compiled. The results were compared and discussed, if necessary, until consensus.
RESULTS
The reviewed articles were published in scientific journals related to SAH and cardiovascular diseases (35.0%) and endocrinology (35.0%), as well as some multidisciplinary ones (30.0%). The number of publications was distributed over the years, 2013 (6.0%), 2014 (23.0%), 2015 (35.0%), 2016 (18.0%) and 2017 (18.0%). North America was the region with the largest number of articles (29.0%), followed by Europe (23.0%); Asia (24.0%); South America (12.0%) and Africa (12.0%).
The articles that were excluded (n = 244) from the study did not correspond to the proposed theme, since they were: referring to children, adolescents, obesity, stem cells, different types of diseases (Cushing's Syndrome, Ophthalmology, hearing aid, diabetes mellitus, tumors and occupational diseases), as well as different types of therapies, diets, drugs and surgeries.
After the full text reading, more four articles were excluded; three because they were related to patients with adrenal tumor and one that did not evaluate the association between cortisol and BP.
Figure 2
Synthesis of the analyzed studies. 2018
* pg: picogram; mg milligram
Figure 2
Synthesis of the analyzed studies. 2018 (Continuação)
* pg: picogram; mg milligram
Figure 2
Synthesis of the analyzed studies. 2018 (Continuação)
* pg: picogram; mg milligram
Main types of study, methods of clinical analysis and factors those were associated
The main methods of study were cross-sectional and the most frequent clinical analyzes were cortisol obtained through blood (10 studies), most of which were evaluated by immunoassay followed by saliva (4), urine (2) and capillary analysis (1).
Among the associated factors between SAH and cortisol, we observed a population with chronic disease already established, whose related variables are gender, age, family history, ethnicity, anthropometric measures, socio-demographic characteristics, stress questionnaires, mood, health perception, physical activity, sodium and caffeine consumption, electrocardiogram, lipid profile, MetS, insulin, glycemia and others (proteins, hormones, leptin, interleukin, nitrite, nitrate, adrenaline and serum creatinine).
DISCUSSION
The results of this study demonstrated the variety of methods of research and associations between SAH and cortisol. It is known that SAH is a chronic condition that can lead to the development of heart or kidney disease. Thus, based on the scientific evidence, one study pointed out that renal function disorders were associated with the HPA axis with RASS, showing that they are significantly associated with SAH6. Renal function parameters such as creatinine and cystatin C (eGFRcr-cys) are related to the high level of cortisol in subjects with SAH.24
Recent studies have shown that deregulation of the HPA axis together with chronic stress increases the likelihood of SAH, leading to heart disease such as ischemia, a deficit in blood perfusion and stroke-related diseases.22,23
In another investigation, it was suggested that healthy individuals with a genetic history of SAH have a marked increase in catecholamines and cortisol for stressors in relation to elevated plasma levels when compared to those with no parental history. The study compared catecholamines by urine (epinephrine and norepinephrine), excretion of cortisol and ambulatory BP in three daily microenvironments between women, with and without parental history of SAH.
The results suggest that there may be genetically linked mechanisms that raise levels of adrenaline and nocturnal levels of cortisol that contribute to elevated circadian BP.33. However, elderly people with SAH with low levels of cortisol on awakening were related to worse cognitive function.25
Another factor was the hormone testosterone (T); study indicates that low levels of T, high level of cortisol and chronic stress are associated with SAH. Thus, the authors concluded that acute and chronic stress may contribute to increase cortisol and BP in subjects with low T, contributing to an increased risk of coronary heart disease.34
Regarding the women, research examined the interaction between endocrine inflammatory mediators and aerobic exercise training in postmenopausal individuals and individuals with SAH. Thus, it was concluded that aerobic physical exercises produce a significant reduction of BP, however, without altering cortisol and leptin levels.35
Another intriguing factor is the effects of caffeine and stress on biomarkers of cardiovascular disease. A total of 52 healthy normotensive adults (26 men and 26 women), but with a family history of SAH, participated in the study to examine the reactivity to stress after caffeine consumption. Subjects after caffeine received increased systolic BP and cortisol. The study suggested that the combination of stress and caffeine may be particularly harmful for women with a family history of SAH.36
Another study correlated serum cortisol with cortisone (F/E) and BP with severe obesity before and after weight loss and the alteration of the F/E serum ratio was associated with BP alteration after weight loss.26
Patients with Human Immunodeficiency Virus (HIV) are at increased risk for metabolic complications (MetS) including SAH and excess cortisol. In this sense, a study was conducted in the Netherlands where they identified that the risk of MetS was higher in HIV-infected patients in the lower-level capillary cortisol group compared to patients with higher levels. These results contradict those of studies in uninfected individuals, where a high level of capillary cortisol is being associated with MetS.27
However, a study with adults relating MetS to the measurements of salivary cortisol levels aimed to verify whether it is affected by the variables age, gender and hormone therapy, estrogen and progestin; the results showed that the older age was related to MetS and cortisol excretion.28
In addition, high sodium (HS) diet was associated with increased cortisol in urine and its metabolites, with SAH, insulin resistance (RI), dyslipidemia, hypoadiponectinemia, higher cortisol, leading to metabolic disorders related to obesity.32
The results of a study in premenopausal women suggest that not eating breakfast is harmful because it can interrupt the cortisol rhythm and result in altered BP and, consequently, leading to cardio metabolic diseases.29
In the hospital area, a study on loco-regional anesthesia was identified, an effective method to evaluate brain function during carotid endarterectomy (CEA). Regional framework-guided anesthesia (RA) is currently used for CEA and may cause substantial perioperative SAH. Ultrasound-guided RA (US-RA) is a new method for performing RA in CEA. The study evaluated early sympathetic activity during CEA in US-RA compared to general anesthesia (GA). Regional ultrasound-guided anesthesia for carotid endarterectomy (CEA) induces early changes in hemodynamic hormone and stress. Thus, systolic BP increased in patients with RA-AR compared to AR, even before the surgery was started, remained elevated during the complete surgery and returned to baseline 1 hour after admission to the anesthesia care unit postoperative period, as well as HR and cortisol levels were also higher in the US-RA group after induction of anesthesia. The authors concluded that the US-RA technique for CEA induces temporary intraoperative SAH and an increase in levels of stress hormone.31
Regarding the types of treatments for the control of SAH, one study presented the physiological effects such as the reduction of BP in "walking in the forest" therapy, as a promising treatment strategy.30It is known that SAH requires preventive actions, such as guidelines on life habits, decreased salt intake, physical activities, and the correct use of medications and antihypertensive.37
The findings of this study reinforce the idea of how cortisol influences SAH, so we can delve into the cause of HPA axis activation and excess cortisol excretion.
This study presents as limitations the different research methods, such as cortisol collections, demographic partner factors, ethnicities and different hormones linked to it, which may influence the association of cortisol with BP elevation.
CONCLUSIONS
The results indicate that the most commonly used clinical methods for linking SAH to cortisol are association tests, performed with renal and / or cardiac function, metabolic syndrome, stress, chronic diseases together with the evaluation of laboratory tests and / or markers and measures anthropometric and physiological.
Previous studies indicate that BP is altered by HPA axis dysregulation, where stress is released into the bloodstream and its effects are possibly malefic. Thus, to help maintain BP levels within the normal range, it is recommended to adopt a healthy lifestyle.
Currently, the major challenge for science is to investigate the pathophysiological processes involved and in which situations the HPA axis secretes the hormone cortisol in excess.
Most of the articles showed a positive association between cortisol and BP, indicating the correlation between them, for several variables: increased cortisol was higher in the elderly (62 years), increased sodium in the diet, not eating breakfast, excessive caffeine during the day, Metabolic Syndrome, obesity, excess catecholamine’s, some types of hormones and biomarkers.
Due to the above, there is a need for more clinical research with other methodological approaches, highlighting the role of cortisol in the regulation of BP, in order to investigate the possible causes of the secretion of this hormone in excess and its pathophysiological effects on SAH.
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