Nutritional status , cardiovascular health , VO 2 max and habits in university students : a comparison between two health promotion careers

1 Universidad Católica de Temuco Technical Faculty Temuco Chile. 2 Departamento de Salud Municipal Gorbea Chile. 3 Universidad de La Frontera Faculty of Education, Social Sciences and Humanities Department of Physical Education, Sports and Recreation Temuco Chile. 4 Universidad de La Frontera Faculty of Medicine Department of Public Health -Temuco Chile. 5 Universidad Santo Tomás School of Education Physical Education Undergraduate Program Temuco Chile.


Introduction
Overweight and obesity affect a large percentage of adults worldwide, reducing life expectancy and posing a great economic burden for society.Between 2009 and 2010, the National Health Survey (ENS in Spanish) reported a high prevalence of overweight (64.5%), sedentary lifestyle (88.6%) and metabolic syndrome (35%) in the adult Chilean population (1).These high figures have also been obtained in young university students (2,3).
There is a clear relationship between lifestyles and risk factors (4), which are also associated with cardiovascular diseases (CVD).Currently, obesity is the leading cause of death in adults (5,6), thus generating a serious public health problem around the world (7).In Chile, the situation is similar due to the demographic and epidemiological transition of the last decades (8,9).
Physical inactivity is a risk factor (10) that can be observed in the alteration of muscles when metabolizing fats and glucose, resulting in modern chronic, metabolic and cardiovascular pathologies (11).In this sense, VO 2 max measuring is recommended as an indicator of aerobic capacity, as it shows the real health status and allows to detect risk groups prone to suffer morbidity conditions, since a healthy person should have an acceptable aerobic capacity (12).
University students are at a point in their lives that is key for adopting different lifestyles, which they will share with their relatives, and in social and work environments (13).For this reason, in order to achieve successful prevention programs, several studies have suggested the importance of identifying risk factors in young adults (14)(15)(16).
The purpose of this study was to determine VO 2 max, fat mass percentage, biochemical profile, and alcohol and tobacco consumption in first year university students enrolled in the Nutrition and Dietetics and Physical Education Pedagogy programs at a Chilean university.

Materials and methods
53 students voluntarily participated in this research during their first year in two health promotion careers at Universidad de La Frontera in 2014.30 were enrolled in the Physical Education Pedagogy program (62.5%), and 23 in the Nutrition and Dietetics program (52.3%).
This study followed the agreements of the Declaration of Helsinki 2013 (17) and was approved by the Ethics Committee of Universidad de La Frontera.Each student signed an informed consent to participate in the research.

Data collection
The students were summoned to a lecture where the objectives of the research were exposed.Personal history (age, date of birth, contact data), and smoking and alcohol consumption were determined after interviewing each participant.Smoking one or more cigarettes per day, as well as drinking alcohol one or more times per week were considered relevant for the study, since these two factors generate alterations at the endothelium level.
Blood pressure (BP) measurement complied with the procedure established by the Clinical Guide for Primary or Essential Hypertension in persons aged 15 years and over (18).An arm digital blood pressure monitor CITIZEN CH-452 was used.Prior to the evaluation, the subjects were asked to have a 10-minute rest period sitting down.Values of ≥130/85 mmHg were considered as prehypertension and values of ≥140/90 mmHg as hypertension, according to the classification of the European Society of Hypertension (19).
Weight and fat mass percentage (FM%) were determined through bioimpedanciometry using Tanita TBF-300A.During this stage, participants were barefoot and in underwear.Ranges from 8% to 15% (men), and from 13% to 20% (women) were considered as normal for fat mass percentage (20).In order to calculate height, a portable ADE set in millimeters was used.Size was classified as normal from 18.5 kg/m 2 to 24.9 kg/m 2 , overweight from 25 kg/m 2 to 29.9 kg/m 2 , and obesity ≥30 kg/m 2 .The waist circumference (WC) was established with a Lufkin W606PM anthropometric tape set in centimeters, yielding normal values of <90 for men and <80 for women (21).
The assessment of the biochemical parameters was done taking blood samples after fasting for eight hours or more.Samples were centrifuged at 2500 rpm for 10 minutes.Basal glycemia was determined through the GOD-PAP method, with normal values of <100mg/dl.Basal insulin was measured by chemiluminescence, with normal values of <12mg/dl.The lipid profile was obtained using CHOD-PAP for total cholesterol, with normal total cholesterol values of <200, LDL <100 and HDL >45.Finally, triglycerides were measured through immunological GPO-PAP-HDL, with normal triglycerides values of <150 (22).In addition, insulin resistance was observed through HOMA based on the formula fasting insulin values x fasting glycemia/405, obtaining <2.5 as a normal value (23).
In turn, aerobic capacity was assessed using a cycle ergometer (Corival-Lode, Groningen) and a gas analyzer (Ultima™ CPX Medgraphics, Minesotta), previously calibrated for volume and reference gases.VO 2 max was evaluated through continuous heart rate monitoring (Polar FT4, Finland) using the modified Astrand Test (24).The parameters considered for men were: poor <24.8 ml/kg/min; fair from 25 ml/kg/min to 33.9 ml/kg/min; average from 34 ml/kg/min to 42 ml/kg/min; good from 43 ml/kg/min to 52.9 ml/kg/min, and excellent >53 ml/kg/min.On the other hand, the parameters considered for women were: poor <23.9 ml/kg/min; fair from 24 ml/kg/min to 30.9 ml/kg/min; average from 31 ml/kg/ min to 38.9 ml/kg/min; good from 39 ml/kg/min to 49 ml/kg/min, and excellent >49 ml/kg/min (24).

Statistical analysis
Data were presented as mean ±SD, frequencies and percentage (%).The normality of the variables was measured through the Kolmogorov-Smirnov test.The Student's T test was used for comparing quantitative parametric variables between two groups, and the Mann-Whitney U-Test for the non-parametric variables.All analyzes were done using the SPSS program, version 22.0.The confidence level was 95% (p<0.05).

Results
When comparing by academic programs, significant differences were found in the variables VO 2 max and body fat mass (p<0.05).The other study variables did not report any statistical differences (Table 1).32% of the students had excess weight, of which 18.8% were overweight and 13.2% were obese.50.9% had pressure alteration; 28.3% prehypertension, and 22.6% hypertension.Regarding fat mass percentage, 50.9% of students reported a level above normal, being higher in Nutrition and Dietetics students with 69.5% versus 36.6% in Physical Education Pedagogy (Table 2).Data presented as number of students by category and percentages according to the study sample.FM%: fat mass percentage.Source: Own elaboration based on the data obtained in the study.
Moreover, Table 3 shows that 18.8% of the students had a smoking habit, and 41.5% reported frequent alcohol use.Regarding VO 2 max, the students, in general, were in the range between poor and fair (48.8%).Similarly, 27.6% were included in the parameters good and excellent; most of them were students of the Physical Education Pedagogy program (36%), and 18.1% of the Nutrition and Dietetics program (Table 4).Data presented as number of students by category and percentage according to the study sample.Source: Own elaboration based on the data obtained in the study.

Discussion
The results of this study show low levels of physical fitness, since 48.8% of the evaluated students presented a VO 2 max between fair and poor, which are negative values compared to the results of a study conducted at other Chilean universities (27).The mean BMI was 24.38 kg/m 2 , which is lower than that reported in a sample of Mexican students (27).32% of the students evaluated had excess weight, of which 18.8% were overweight and 13.2% were obese.These values are similar to those of university students in the same city -in which 35.6% were overweight or obese (28)-and to the findings obtained in students from Saudi Arabia, which reached 31.2% (29).However, differences can be found with other research works that assessed Chilean students as well, obtaining a figure of 78.6% students with normal ranges and only 12% overweight (26).
Regarding fat mass percentage, 50.9% of the evaluated students had excess body fat, which is lower than the results in São Paulo, where the same measurement characteristics were used, finding that 60% of the students reached these levels (30).Furthermore, Cossio et al. (31) found 55%, and Zea et al. (32), 56.3% of body fat excess in university students.
It should be noted that excess body fat and sedentary lifestyle determine the true risk for health-related obesity.Therefore, including their assessment in health and lifestyle studies is highly relevant (33).
The students had a mean blood pressure of 126.10 mmHg, similar to that reported in university students from northern Turkey (34), but higher than that reported in university students from southern Chile (35.36) and from Somaliland (37).It is alarming that 34.7% of Nutrition and Dietetics students were prehypertensive, and that 30% of students of Physical Education Pedagogy had high blood pressure, which are results similar to those in students from the same country, where 35.1% were prehypertensive (38), although the classification criteria were different.The latter condition is associated with alcohol and nicotine consumption, as well as with poor diet schedules and quality, and physical inactivity.
This work showed alcohol consumption in 41.5% of the students, which coincides with the results of a research conducted in Colombian medical students (39).Regarding tobacco consumption, 18.9% claimed they were smokers, which is lower than numbers of sedentary university students from Temuco, who reached 45.1% (40).These results are alarming, since, in most cases, these habits have been proven to increase as university studies advance (41).For this reason, reducing tobacco use would reduce plasma disorders caused by smoking (42).In relation to this, total cholesterol, HDL-C, LDL-C and triglycerides showed lower values in these students than in other investigations, in which smoking was higher (36,40), as in basal glucose (35).
The university population is considered essential for the promotion and prevention of health for future generations (43).Studies have shown that risk factors in students tend to increase, even during the first semester in the university (44).In consequence, identifying their nutritional status and the frequency of physical activity is crucial to actually understand the resources necessary to promote a healthy lifestyle (45).

Conclusions
The results obtained in this research show a poor physical condition in students, who have high fat mass percentages and high levels of overweight or obesity and blood pressure.This proves that they are in a critical period, during which they are prone to develop noncommunicable diseases.This is a highly concerning situation, since they will turn into professional role models of healthy lifestyles.Thus, it is necessary to create greater and better instances of education in order to generate an impact, that is to say, to improve the quality of life and to create concrete habits in relation to food consumption and physical activity.

Table 1 .
Comparison of variables per academic program.
Data presented as mean ±SD; p values <0.05 are significant; BMI: body mass index; WC: waist circumference.cHDL: HDL cholesterol; Total Col: total cholesterol; cLDL: LDL cholesterol; IR index: insulin resistance index.Source: Own elaboration based on the data obtained in the study.

Table 2 .
Frequency of students.

Table 3 .
Frequency of students who smoke and consume alcohol.Data presented as number of students by category and percentage according to the study sample.Source: Own elaboration based on the data obtained in the study.

Table 4 .
VO 2 max per academic program.