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Exploring the Correlation Between Anxiety Levels and Biophysiological Indicators in Cancer Patients for Enhanced Care Approaches
*Corresponding author: Dr. Giriyapura Rudrappa Gireesh, Department of Nursing Foundation, Yenepoya Nursing College, Yenepoya (Deemed to be University), Deralakatte, Mangaluru 575018, Karnataka, India. gireeshsachin@gmail.com
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Received: ,
Accepted: ,
How to cite this article: Gireesh GR, Chacko LK. Exploring the Correlation Between Anxiety Levels and Biophysiological Indicators in Cancer Patients for Enhanced Care Approaches. J Health Allied Sci NU. doi: 10.25259/JHASNU_201_2025
Abstract
Objectives
The study aimed to assess the leviel of anxiety among patients with cancer and to determine its association with selected physiological parameters, including heart rate, respiratory rate, blood pressure, and salivary amylase levels.
Material and Methods
A descriptive cross-sectional study was conducted among 148 patients diagnosed with cancer, selected through purposive sampling. Anxiety levels were assessed using the DASS-21 anxiety subscale. Physiological parameters, including heart rate, respiratory rate, blood pressure, and salivary amylase levels, were measured using standardized assessment tools.
Results
The findings revealed a weak but statistically significant positive correlation between anxiety and salivary amylase (ρ = 0.291, p <0.001), diastolic blood pressure (ρ = 0.259, p = 0.002), and respiratory rate (ρ = 0.358, p <0.001). These results indicate mild sympathetic activation associated with increasing anxiety levels. However, no significant correlation was observed between anxiety and heart rate or systolic blood pressure.
Conclusion
Bio-physiological markers such as salivary amylase, diastolic blood pressure, and respiration rate can serve as useful indicators of anxiety in cancer patients. Incorporating psychological care into cancer treatment is strongly supported by these findings, highlighting the importance of holistic care approaches.
Keywords
Anxiety
Biophysiological markers
Cancer
Salivary amylase
Stress
INTRODUCTION
Cancer continues to be a significant global health challenge, attributable not only to its lethal potential but also to its extensive effects on patients’ physical, psychological, and social welfare. Improvements in diagnostic and therapeutic methods have enhanced survival rates; however, the psychological burden linked to the disease remains significant.[1] Anxiety is one of the most commonly reported psychological responses in cancer patients, frequently stemming from uncertainty regarding prognosis, treatment outcomes, and the potential for recurrence.[2] Recent literature indicates that psychological distress, especially anxiety, can hinder patients’ adherence to treatment protocols and reduce overall quality of life, underscoring the necessity of integrating mental health considerations into cancer care.[3]
Notwithstanding increased awareness, the correlation between anxiety and its physiological manifestations in cancer patients remains inadequately investigated.[4] Research indicates that anxiety triggers physiological stress responses that may impact biological processes, including inflammation, immune regulation, and neuroendocrine function, potentially influencing treatment efficacy and recovery outcomes.[5]
Research further suggests that psychological distress may lead to hormonal imbalances, heightened cortisol levels, and increased sympathetic activity, potentially exacerbating disease progression and hindering therapeutic efficacy.[6] Although interventions such as cognitive behavioural therapy and pharmacological management have demonstrated efficacy in alleviating anxiety, there is a paucity of systematic research investigating the correlation between anxiety and biophysiological parameters, including heart rate, blood pressure, respiratory rate, and non-invasive biomarkers like salivary amylase, particularly in cancer patients receiving active treatments such as radiation therapy.[7]
Cancer patients are also expected to experience varying levels of anxiety depending on disease stage, prognosis, and treatment-related side effects. Physical discomfort, fear of recurrence, and uncertainty about therapeutic outcomes can heighten psychological distress. These emotional states are often reflected in physiological responses mediated by the autonomic nervous system. Among available biomarkers, salivary alpha-amylase has emerged as a promising non-invasive marker of sympathetic nervous system activation and acute stress response. Its secretion is directly influenced by activation of the sympathetic-adrenal-medullary (SAM) axis, and unlike cortisol, it demonstrates rapid responsiveness with minimal circadian variation. This makes salivary amylase particularly suitable for assessing moment-to-moment anxiety fluctuations in cancer patients undergoing radiation therapy.
This study seeks to examine the relationship between anxiety and specific biophysiological markers like heart rate, blood pressure, respiration, and salivary amylase in cancer patients undergoing radiation therapy. By focusing on this underexplored population within the Indian context, the study aims to elucidate the intricate mind-body interactions in oncology. Moreover, employing salivary amylase as a non-invasive stress biomarker provides a pragmatic and patient-centred approach to evaluating physiological stress responses. The results are anticipated to aid in the formulation of integrated care models that encompass both psychological and biophysiological aspects of cancer, thereby enhancing patient outcomes and improving the quality of comprehensive cancer care.
MATERIAL AND METHODS
A descriptive cross-sectional research design was adopted to examine the correlation between biophysiological factors like heart rate, respiratory rate, blood pressure, salivary amylase, and anxiety levels in cancer patients undergoing radiation therapy. The study was conducted in the radiation oncology department of a tertiary care teaching hospital in southern India over a period of 14 months, from May 2023 to July 2024. Ethical approval was obtained from the Institutional Scientific Review Board and Ethics Committee (Approval No: YEC-1/2021/030). Written informed consent was obtained from all patients participating in this study after providing detailed information regarding the study’s objectives, procedures, potential risks, and benefits. Strict confidentiality and anonymity were ensured throughout the study.
The study population comprised cancer patients participating in this study receiving radiation therapy. A total of 148 patients participating in this study were recruited using a non-probability purposive sampling technique. Eligibility criteria included: age ≥18 years, diagnosed with stage II or III cancer, currently receiving radiation therapy, and able to provide informed consent. Patients with pre-existing psychiatric disorders or under psychiatric treatment, those who had undergone recent major surgery or were receiving concurrent chemotherapy, patients diagnosed with stage I or stage IV cancer, and those unwilling to consent were excluded.
Sample size calculation
The sample size for this correlation study was estimated using the formula:
Thus, the minimum required sample size was 85 participants. Allowing for a 10% attrition rate, the adjusted target sample was ∼95 participants, and finally, 148 participants were recruited to enhance precision and reliability.[8]
Data were collected using a structured questionnaire and standardised measurement techniques. Demographic and clinical data were obtained through face-to-face interviews. Biophysiological parameters were recorded as follows: heart rate in beats/minute using a digital heart rate monitor, respiratory rate by manual observation, and blood pressure in mmHg with a validated digital sphygmomanometer.
Measurement of salivary amylase
Saliva samples were collected in sterile polypropylene containers after the physiological measurements were taken. Each participant was asked to refrain from eating, drinking, or brushing teeth for at least 1 hour before sample collection to avoid contamination and diurnal variation. The samples were collected between 8 am and 10 am in a quiet room to minimise external stress influences. Salivary amylase levels were analysed using an enzymatic colorimetric kinetic method with a semi-automated biochemical analyser (AgappeMispa Nano, Kerala, India). The assay is based on the hydrolysis of 2-chloro-4-nitrophenyl maltotrioside (CNPG3) substrate, and the rate of increase in absorbance at 405 nm was measured. The results were expressed in U/mL, and values ranging from 30 to 120 U/mL were considered within the normal range.
Anxiety levels were measured using the Depression, Anxiety, and Stress Scale-21 (DASS-21), focusing on the anxiety subscale (7 items scored on a 4-point Likert scale from 0 to 3). The DASS-21 has been widely validated across diverse populations, with reported Cronbach’s alpha coefficients for the anxiety subscale ranging from 0.81 to 0.84. In the present study, the reliability of the instrument was confirmed with a Cronbach’s alpha of 0.82, indicating strong internal consistency. Content validity was established by subject experts in psychiatry, psychology, and oncology nursing.
Eligible patients participating in this study were approached during scheduled radiation therapy appointments. After a 5-minute seated rest in a quiet room, physiological parameters were measured to minimise external influences. Saliva samples were collected immediately after, followed by administration of the DASS-21 questionnaire, with clear instructions provided to ensure comprehension.
Data analysis was performed using both descriptive and inferential statistics. Descriptive statistics (frequency, percentage, mean, standard deviation) were used to summarise demographic and clinical characteristics. Anxiety levels were classified into normal, mild, moderate, severe, and extremely severe categories as per DASS-21 scoring guidelines. The Kolmogorov-Smirnov test was used to assess the normality of data distribution. Since the variables did not follow a normal distribution, Spearman’s Rank Correlation Coefficient (ρ) was applied to determine the correlation between anxiety scores and biophysiological parameters. A p <0.05 was considered statistically significant.
RESULTS
Distribution of patients participating in this study based on demographic characteristics
A total of 148 cancer patients participated in the study. The majority were aged 46-50 years (31.1%), followed by 51-55 years (22.3%), indicating that most patients participating in this study were in mid-adulthood. Females (53.4%) slightly outnumbered males (46.6%). Most participants were married (66.9%) and resided in rural areas (64.2%). Regarding religion, nearly half identified as Hindu (49.3%), followed by Muslim (31.8%) and Christian (16.9%). Nearly half of the participants were employed in the private sector (45.9%), while 31.8% were unemployed. The majority reported a monthly income between ₹10,001-20,000 (39.2%). Over half of the participants (56.1%) had been diagnosed with cancer for 1-5 years, and 52.7% reported a family history of cancer.
The biophysiological parameters were presented as median and interquartile range (IQR) due to non-normal data distribution [Table 1]. All physiological values were within normal clinical ranges, indicating overall stability among participants. However, the slightly elevated salivary amylase levels suggest sympathetic nervous system activation commonly associated with psychological stress. The anxiety scores reflected mild to moderate anxiety among the patients. These findings indicate that even subtle physiological variations may reflect underlying emotional distress in cancer patients.
| Variable (Unit) | Median | IQR (Q1-Q3) |
|---|---|---|
| Heart rate (beats/min) | 75 | 71-80 |
| Respiratory rate (breaths/min) | 16 | 14-18 |
| Systolic blood pressure (mmHg) | 120 | 114-126 |
| Diastolic blood pressure (mmHg) | 70 | 64-76 |
| Salivary amylase (U/mL) | 95 | 84-106 |
| Anxiety score (DASS-21) | 7 | 4-10 |
Values are presented as median with interquartile range (IQR; Q1-Q3); higher DASS-21 anxiety scores indicate greater anxiety. IQR: Interquartile range, DASS: Depression, Anxiety, and Stress scale.
A weak but statistically significant positive correlation was observed between anxiety and respiratory rate, diastolic blood pressure, and salivary amylase levels [Table 2]. This indicates that increases in anxiety are accompanied by mild elevations in these physiological markers, likely due to sympathetic activation. Heart rate and systolic blood pressure did not show significant associations, suggesting they may be less sensitive indicators of anxiety in this population. Overall, the findings highlight that certain parameters—especially salivary amylase—are more responsive to changes in anxiety levels. These results support the relevance of physiological monitoring in understanding psychological distress among patients with cancer.
| Biophysiological parameter | Spearman’s ρ | p value | Interpretation |
|---|---|---|---|
| Heart rate | 0.157 | 0.057 | Weak, not significant |
| Respiratory rate | 0.358 | <0.001* | Weak but statistically significant positive correlation |
| Systolic blood pressure | 0.100 | 0.228 | Not significant |
| Diastolic blood pressure | 0.259 | 0.002* | Weak but statistically significant positive correlation |
| Salivary amylase | 0.291 | <0.001* | Weak but statistically significant positive correlation |
p < 0.05 is statistically significant.
DISCUSSION
This study identified a weak but statistically significant positive correlation between anxiety and selected biophysiological parameters like respiratory rate, diastolic blood pressure, and salivary amylase, highlighting the interplay between psychological stress and autonomic nervous system activation.[9] These findings align with previous studies that recognise hyperventilation as a physiological manifestation of anxiety and support the role of salivary amylase as a non-invasive biomarker of acute stress.[10]
Anxiety triggers complex physiological responses, including increased sympathetic and endocrine activity. The elevated respiration rate, diastolic blood pressure, and salivary amylase observed in this study indicate heightened sympathetic activation.[11] The strong correlation between anxiety and respiratory rate (r = 0.358, p < 0.001) supports the established link between psychological distress and hyperventilation. Similarly, the correlation between anxiety and diastolic blood pressure (r = 0.259, p = 0.002) suggests that anxiety-induced vasoconstriction may contribute to elevated cardiovascular responses.
The findings revealed a weak but statistically significant positive correlation between anxiety and salivary amylase (ρ = 0.291, p < 0.001), diastolic blood pressure (ρ = 0.259, p = 0.002), and respiratory rate (ρ = 0.358, p < 0.001). These results indicate mild sympathetic activation associated with increasing anxiety levels. However, no significant correlation was observed between anxiety and heart rate or systolic blood pressure, between salivary amylase and anxiety (r = 0.291, p < 0.001), reaffirming its potential as a rapid, reliable, and non-invasive biomarker of psychological stress.[12-14] Compared to cortisol, salivary amylase reflects acute sympathetic activation and is less affected by circadian variation, making it particularly suitable for assessing anxiety among cancer patients undergoing treatment.[13]
Interestingly, heart rate and systolic blood pressure showed no significant correlation with anxiety. This may be attributed to the transient nature of heart rate fluctuations, the use of medications such as beta-blockers or antihypertensives, and individual physiological adaptation to chronic illness.[15] Heart rate variability (HRV) is known to be a more sensitive indicator of emotional regulation than raw heart rate, which may explain the non-significant results.[16] Furthermore, systolic blood pressure tends to exhibit delayed changes in response to psychological stress compared to diastolic measures. The study emphasises the physiological impact of anxiety in cancer patients, who often experience distress related to disease prognosis, treatment burden, and fear of recurrence.[17] The integration of salivary amylase monitoring into cancer care could enable early detection of stress and guide psychosocial interventions to improve coping and adherence.[18,19]
Despite its strengths, this study is limited by its cross-sectional design, which restricts causal inference. The use of purposive sampling may also limit generalisability. Future longitudinal studies including diverse cancer types and treatment modalities are recommended to validate these findings and explore temporal changes in stress responses.
Overall, the findings highlight the close interconnection between psychological and physiological well-being in oncology patients and support the inclusion of mental health assessment as part of comprehensive cancer care.[19-20]
CONCLUSION
This study found a weak but statistically significant positive correlation between anxiety and selected biophysiological parameters—respiratory rate, diastolic blood pressure, and salivary amylase—among cancer patients undergoing radiation therapy. The findings indicate mild sympathetic activation associated with increasing anxiety levels, with salivary amylase emerging as a sensitive non-invasive biomarker. These results emphasize the importance of integrating psychological assessment and physiological monitoring into comprehensive cancer care to promote holistic patient management.
Acknowledgement
We would like to thank the participating patients and healthcare professionals for their invaluable contributions to this study.
Ethical approval
The study approved by the Institutional Scientific Review Board and Ethics Committee at Yenepoya (Deemed to be University), number YEC-1/2021/030, dated 9th September 2021.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given consent for clinical information to be reported in the journal. The patient understands that the patient’s names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
Use of artificial intelligence (AI)-assisted technology for manuscript preparation
The authors confirm that there was no use of artificial intelligence (AI)-assisted technology for assisting in the writing or editing of the manuscript, and no images were manipulated using AI.
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