|Year : 2014 | Volume
| Issue : 2 | Page : 99-102
Evaluation of plasma nitric oxide in academic stress in first year medical students
Ajay Kumar1, Bharti K Uppal1, Maria Thomas1, Randhir S Deswal2, Shaveta Sagar1
1 Department of Biochemistry, Christian Medical College, Ludhiana, Punjab, India
2 Department of Psychiatry, Christian Medical College, Ludhiana, Punjab, India
|Date of Web Publication||11-Jun-2014|
Department of Biochemistry, Christian Medical College, Ludhiana 141 008, Punjab
Source of Support: None, Conflict of Interest: None
Context: Medical students undergo tremendous stress during various stages of the Bachelor of Medicine, Bachelor of Surgery (MBBS) course. Academic examinations have been considered as one of the most acute stresses experienced by the students. Nitric oxide (NO) is an important physiological messenger and effector molecule in many biological systems. There is evidence that a sustained overproduction of NO via inducible NO synthase (iNOS) is responsible, at least in part, for some of the neurodegenerative changes caused by stress . Aims: To investigate the relationship if any between plasma NO and psychological stress caused by academic pressure in first year MBBS students. Settings and Design: A 2-year prospective longitudinal study. Materials and Methods: A total of 94 first year medical students after informed consent were enrolled in the study. They were evaluated twice during their first year academic program. First evaluation was done 2 months after their joining the MBBS course and second on the day of their first professional university practical exam. On each evaluation, a history was taken, general physical examination done, and a blood sample was drawn for plasma NO, which was measured using Griess reaction. Statistical Analysis Used: For comparison of means of plasma NO values between the two evaluations, the paired Student's 't'- test was used. A 'P' < 0.05 was considered as statistically significant. Results: The mean NO values increased from 14.76 ± 10.30 during first evaluation to 22.07 ± 13.02 during second evaluation. This increase was statistically significant (P = 0.000). Conclusions: Plasma NO showed a statistically significant increase in levels during the time of examination stress. As plasma NO had a positive correlation with stress, this can be considered as a suitable biomarker for academic stress assessment.
Keywords: Academic stress, medical students, nitric oxide
|How to cite this article:|
Kumar A, Uppal BK, Thomas M, Deswal RS, Sagar S. Evaluation of plasma nitric oxide in academic stress in first year medical students. CHRISMED J Health Res 2014;1:99-102
|How to cite this URL:|
Kumar A, Uppal BK, Thomas M, Deswal RS, Sagar S. Evaluation of plasma nitric oxide in academic stress in first year medical students. CHRISMED J Health Res [serial online] 2014 [cited 2020 Aug 8];1:99-102. Available from: http://www.cjhr.org/text.asp?2014/1/2/99/134271
| Introduction|| |
It is usually observed that medical students undergo tremendous stress during various stages of the Bachelor of Medicine, Bachelor of Surgery (MBBS) course. Academic examinations have been considered as one of the most acute stresses experienced by the students.  This, when combined with the effects of a change of environment (home-based to hostel-based), change of peer group, and vastly different study methodologies, poses to be one of the stressors to which an aspiring doctor is exposed. Academic stress is a good model of psychological stress in humans and is thus useful for studying psychoneurohormonal changes. 
Nitric oxide (NO) is an important physiological messenger and effector molecule in many biological systems, including immunological, neuronal, and cardiovascular tissues.  NO is synthesized from l-arginine by the enzymes called NO synthases (NOSs), namely, endothelial NOS, neuronal NOS, and an isoform expressed during inflammatory reactions, inducible NOS (iNOS). This third isoform is a high-output inducible isoform of NOS, which mediates cytotoxicity in many cell systems, including central nervous system.  Olivenza et al., (2000) in their study investigated the role of endogenously released NO and the possible induction of iNOS in adult male rats subjected to stress (immobilization for 6 h during 21 days). They concluded that a sustained overproduction of NO via iNOS is responsible, at least in part, for some of the neurodegenerative changes caused by stress. 
Given the evidence of the involvement of NO in the development of neurodegenerative changes caused by stress, and the fact that medical students are exposed to a great degree of stress during their studies, this study was aimed to investigate the relationship between levels of plasma NO and psychological stress caused by academic pressure in the first year MBBS students.
| Materials and Methods|| |
This study was conducted in Departments of Biochemistry and Psychiatry of our institution from September 2007 till May 2009.
Subjects were first year medical students who got admission to MBBS course between July 2007 and September 2008. All the students from batch of 2007 and batch of 2008 who gave their consent and were not under exclusion criteria were part of the study. They were evaluated at two times during their first year academic program. First evaluation was done 2 months after their joining the MBBS course. The 2 months time was given to allow the students to acclimatize to the surroundings of a professional college, new hostel, and MBBS course. This was considered as the nonstress period. Second evaluation was done on the day of their first professional university practical exam. This was considered as the stress period. The study was approved by Institutional Medical Ethics and Research Committees.
Students joining the MBBS course after high school studies.
Students suffering from any acute or chronic inflammatory disorders.
Students suffering from any psychiatric illness or taking any antipsychotic medicines.
An informed written consent was obtained from all participants in this study. After taking a careful history to rule out students suffering from acute or chronic inflammatory disorders, psychiatric illness, or those taking antipsychotic medicines, a general physical examination was performed on all participants to rule out acute or chronic illnesses.
During each evaluation a blood sample was taken and plasma separated from it. NO was measured in plasma using the Greiss reaction.  This detects nitrite ion (NO 2− ) in a variety of biological and experimental liquid matrices such as plasma, serum, urine, and tissue culture medium.
Expected range <27 μM/l.
| Results|| |
There were a total of 94 students and they were categorized on the basis of age, sex, permanent residence, and current residence status as shown in [Table 1].
[Table 2] shows mean plasma NO levels in students during first evaluation and second evaluation. A statistically significant increase was seen in all students during the second evaluation. All categories of students also showed an increase in NO levels during second evaluation but day scholars showed a decrease in level of NO; this was, however, not statistically significant.
|Table 2: Comparison of plasma NO during fi rst and second evaluation in various categories of students|
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[Table 3] shows the baseline plasma NO levels in various categories of students. Males and day scholars had higher value of NO, which was statistically significant. Residents of Punjab also had a higher value of NO in comparison with non-Punjab residents.
|Table 3: Comparison of plasma NO during fi rst evaluation (nonstress period) in various categories based on gender, permanent residence, and current residence status|
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[Table 4] shows the NO values during the second evaluation. Males, Punjab residents, and hostellers showed a higher NO in their respective categories, but none of this was statistically significant.
|Table 4: Comparison of plasma NO during second evaluation (stress period) in various categories based on gender, permanent residence, and current residence status|
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| Discussion|| |
Despite increased attention being paid to research about the factors that contribute to the decline in students' mental health,  there are few studies that address the influence of gender on stress among medical students. Some studies suggest that female students have higher levels of stress than their male counterparts.  Other studies do not reveal gender difference.  There are also suggestions that gender may influence the way students in health care professions perceive stress.  Stress evaluation can be carried out by administering a variety of questionnaires and by testing certain biomarkers associated to have a significant change in stressful conditions. The limitation of questionnaire is that all participants may not answer the questions with devoted concern (full concentration). Therefore, biomarkers can be used as a better tool to identify stress.
In the present study, a highly statistically significant increase in NO was seen when compared from nonstress to stress period. During nonstress period, mean NO value was 14.76 μM/l, which increased to 22.07 μM/l at the time of stress [Table 2]; P = 0.000].
In another study conducted by Eskiocak et al., in 2006,  similar results were seen where seminal plasma NO during nonstress period was 10.02 ± 0.49 μM/l, which increased to 17.28 ± 0.56 during the stress period (P ≤ 0.001).
The increased NO levels in hostellers [Table 2] at the time of stress indicates environmental changes as a contributor to the academic stress. These findings consisted with a study on medical students where environmental factors were found to be one of the top five stressors for students.  There could be many other possible stressors continuing to be potential contributing to academic stress faced by medical students, which needs to be evaluated individually by further studies. It is well known that persistent stress that is not resolved through coping or adaptation, deemed distress, may lead to anxiety or withdrawal (depression) behavior. The implications of establishing a biomarker such as NO as a tool for academic stress assessment would help us identify the students who are likely to suffer the ill effects of academic stress later in their career, and this would help us strategize methods or activities for stress relief, which would modulate the future detrimental effects on health.
| Acknowledgment|| |
The authors would like to acknowledge the participation of first year medical students in this study, without which this study would not have been possible.
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[Table 1], [Table 2], [Table 3], [Table 4]