ORIGINAL ARTICLE Association between stress and waist-to-height ratio among medical students in a private university of Lima-Perú in 2018 Carolina Mendez-Guerra1,4, a, Andrés Quevedo-Ramirez1,4, a, Guillermo De la Borda-Prazak1,4,a, Claudia Silva-Pérez1,a, Mauricio Oscco-Tenorio1, a , Isabel Pinedo-Torres2,3, b 1. School of Medicine, Peruvian University of Applied Sciences, Lima, Peru. 2. Endocrinology Service, Department of Medicine and Office of Support for Teaching and Research (OADI), Hospital Daniel Alcides Carrión, Callao, Peru. 3. Red de Eficacia Clínica y Sanitaria (REDECS), Lima, Peru. 4. Scientific Society of Medical Students UPC (SOCIEMUPC), Lima, Peru. a. Human Medicine Student b. Endocrinologist CIMEL 2020; 26(1): 15-21 ABSTRACT Objective: To determine the association between stress and waist-to-height ratio (WTHR) in medical students in a private university of Lima in 2018. Materials and Methods: An analytical cross-sectional study. The population in this study was comprised between 2nd and 5th year medical students in a private university in Lima. The main variables were stress and waist-to-height ratio. The data was submitted to STATA 14.0 where the frequency of categoric variables and measures of central tendency and dispersion of quantitative variables were calculated. Afterwards, a bivariate analysis was done, and finally a multivariate analysis was conducted, using a Poisson regression with robust variance. Results: A total of 234 persons were analyzed. No statistically significant association was found between stress and WTHR, in the crude analysis (p=0.93) nor when adjusted according to age, sex, academic year and physical activity. (p=0.43). Statistically association was found between sex and WTHR (p<0.00). Conclusions: No association was found between the WTHR and stress. Nevertheless, 46.58% of the population had an elevated WTHR and 29.06% had stress. Keywords: Self Stress, Psychological; Waist-Height Ratio; Students medical Please cite this article as: Mendez-Guerra C et al. Association between stress and waist-to-height ratio among medical students in a private university of Lima- Perú in 2018 . CIMEL 2020; 26(1): 15-21. DOI: https://doi.org/10.23961/cimel.v26i1.1360 INTRODUCTION distribution of body fat. Compared to the BMI and abdo- Obesity represents an important global public health pro- minal circumference, it is the best measure in the assessment blem. In recent years, there has been a significant increa- of metabolic syndrome (7,8). Due to this, WHtR has been sing trend of overweight and obesity in young adults (1). gaining relevance in the prediction of chronic diseases such Worldwide, in 2016, 40% of people over 18 years of age were as diabetes mellitus and arterial hypertension (9). The most overweight, from which 13% were obese (2). Similarly, the used cut-off point is 0.5, having been evaluated in popula- prevalence of overweight and obesity in university students tions from Cuba and Colombia (10,11). from 22 countries of low and middle socioeconomic class was 22% (3). There are various risk factors associated with excess weight, among them are: poor eating habits, sedentary lifestyles, According to studies in India, 28% of medical students were among others. Similarly, several studies mention stress as overweight, while 13% were obese (4). At the national level, an important risk factor in the development of overweight in 2016, 39.7% of young adults were overweight and 8.7% and obesity, since it influences diet, physical activity and use were obese (5). Evaluation of overweight and obesity can be of addictive substances (12). The prevalence of stress is high calculated through various anthropometric measures. The in university students, mostly in demanding careers such as body mass index (BMI) is widely used to assess nutritional Human Medicine. In India, 53% of medical students suffer a status and classify it within the parameters of: underweight, type of stress level (13). At the national level, in 2012, the estima- normal weight, overweight and obesity; however, this mea- ted prevalence of stress in medical students was 77.4% (14). surement does not allow for the estimation of visceral fat, a parameter that can be measured through the waist-to-height Studies revealed that stress increases serum cortisol levels, ge- ratio (6). nerating an increase in appetite and redistribution of fat pre- This is a simple and inexpensive anthropometric measure dominantly in the abdomen, which results in a high WHtR that allows the assessment of the nutritional status and the (15). Thus, in a cohort from Whitehall II, it was found that CIMEL 2020, Volume 26, Number 1 ORIGINAL ARTICLE high levels of stress are associated with a high WHtR in both INSTRUMENTS AND DEFINITION OF VARIABLES genders (16), which is observed in the high levels of BMI re- gistered in medical students who undergo stress (17). Due Self-perception of stress: The Perceived Stress Scale 14 (PSS- to the aforementioned, the general objective of the present 14) was used. This one contains 7 positive items and 7 negati- study was to determine the association between stress and ve items, about the perceived feelings during the last month. WHtR in Human Medical students from a private university It displays questions such as: “In the last month, how often of Lima. have you felt like you couldn’t cope with all the things you had to do?” or “In the past month, how often have to suc- MATERIALS AND METHODS cessfully handled life’s irritating little problems?” Each item is measured on a scare from 0-4, with “0” equivalent to ne- Study design: An analytical cross-sectional study was carried ver and “4” to very often. The maximum score is 56 points out. (17). A score greater than 28 indicates a presence of stress, taking as a reference a study carried out in Chilean medical Location of study: Universidad Peruana de Ciencias Aplica- students, in which the cut-off point was used (18). das (UPC), an educational institution that has a Human Me- dicine degree. Waist-to-height ratio (WHtr): The WHtR is defined as the ratio between the abdominal circumference and the height. Study population: Made from medical students from 2nd The presence of WHtR at risk was defined as WHtR greater to 5th year in their career enrolled in the academic cycle than or equal to 0.5. 2018-02, of the UPC, based in Lima, Peru. Being a private university, a large part of its students come from families Physical activity: Physical activity was categorized as inactive, with a medium-high socioeconomic level. Likewise, those minimally active, or active. Said classification was based on students older than 18 years and with a BMI lower than 35 the IPAQ criteria, these being the number of times per week kg/m2 were considered as the unit of analysis. Those partici- that exercise was performed, the intensity and how many pants who suffered from an affective or eating disorder, prior MET-minutes were achieved per week. to the start of the race, or were UPC qualified athletes were excluded. The evaluation of the listed exclusion criteria was An inactive should not get a necessary score for the other 2 carried out through the questionnaire and was self-reported categories. In addition, the classification, minimally active, by the study subjects. must have 3 or more days of vigorous activity with a mini- mum of 20 minutes duration per day, 5 or more days of mo- The calculation of the sample size was carried out in the derate activity lasting minimum 30 minutes per day, or 5 or OpenEpi 3.01 program, based on a pilot study of 29 students more days of any type of activity mentioned in the question- where an increased WHtR was found in 56% of students not naire (vigorous, moderate or walking) with a total physical exposed to stress and in 77% of students exposed to stress. In activity of at least 600 MET- minutes/week. To calculate the addition, the ratio of exposed to not exposed was 1.23. Con- corresponding MET, formulas proposed in the scoring pro- sidering these values, a significance of 95% and a power of tocol of the questionnaire will be used. Similarly, the active 80%, a calculated same size of 160 study subjects is obtained, classification was considered as a vigorous activity of 3 days, according to the Fleiss method. On this value, a loss of 10% reaching a total physical activity of 1500 MET- minutes per of the collection records was considered due to incomplete week or 7 days of any activity mentioned in the questionnaire or inconsistent data. Therefore, 160 / (1-0.10)= 1160 / 0.9= with a minimum total physical activity of 3000 MET-minute 178 study subjects will need to be reviewed. per week. It should be noted that the variable was dichotomi- zed as inappropriate (inactive) or adequate (minimally active Legal aspects: The study was started after the approval from or active). the Ethics Committee at UPC and an informed consent was used, where there was a description of the procedures, the PROCEDURES benefits, and the risks; also, it was indicated that the parti- cipation was completely voluntarily. To ensure data confi- Information collection: Once the approval from the Ethics dentiality, these were recorded anonymously. Lastly, as it was Committee at UPC was obtained and the participation of an observational study, the subjects were not exposed to any the subjects was confirmed through the informed consent, risk. a recollection of data was carried out using a questionnaire, CIMEL 2020, Volume 26, Number 1 ORIGINAL ARTICLE which included the evaluation of the exclusion criteria, ge- Data analysis: The analysis was carried out using the STA- neral epidemiological data, the independent variable (stress, TA 14.0 statistical program, a 95% confidence interval and measured with the PSS-14) and the physical activity variable a significance level of 0.05 were considered.