Impact of lifestyle on health-related quality of life among young university students: a cross-sectional study

ABSTRACT BACKGROUND: Lifestyle is strongly involved in the pathogenesis and progression of non-communicable diseases, and has a great impact on quality of life. The goal of the present study was to analyze the lifestyle and body composition (BC) of young university students during the pandemic, and their relationship with health-related quality of life (HrQoL). DESIGN AND SETTING: Observational cross-sectional study conducted in the Universidad Europea de Madrid, Spain. METHODS: A total sample of 56 healthy university students was recruited. Activity, sitting time, adherence to Mediterranean diet and BC were measured. RESULTS: Regarding BC, only 5% and 10.7% of the subjects had health risk values for waist circumference and waist-to-height ratio, respectively. The mean daily sitting-time was 8.26 hours, while 19.64% of the subjects spent . 10 hours per day sitting. 92.86% of the subjects complied with the World Health Organization 2020 physical activity recommendations. The mean PREDIMED score was 7.41, while 51.8% of the subjects had low adherence to the Mediterranean diet. Regarding HrQoL, 22 subjects (39.2%) and 26 subjects (46.4%) were in the lowest quintile of physical component summary and mental component summary, respectively, according to the reference values for their age range. There was a negative correlation between physical function and sitting time (r = -0.38). CONCLUSIONS: There were high levels of sedentary behavior and low HrQoL values, with a negative moderate correlation between these variables. The findings from the present study especially highlight the importance of implementing public health programs targeting reduction of sitting time among university students.


INTRODUCTION
Lifestyle, through epigenetic mechanisms, is strongly involved in the pathogenesis and progression of noncommunicable diseases (NCDs), 1 and has a great impact on quality of life. 2 In this order, physical inactivity and obesity are, respectively, the two lifestyle risk factors most associated with the development of NCDs. 3 Physical inactivity is the fourth largest risk factor for mortality worldwide, 3 and it is associated with the comorbidities of overweight and obesity. People with these two conditions account for 27% of type 2 diabetes mellitus (T2DM) cases worldwide and 30% of ischemic heart disease cases. 4 Consequently, the World Health Organization (WHO) has instituted the target of reducing the prevalence of physical inactivity by 15% worldwide by 2030. 5 Every extra hour of daily sedentary behavior has a negative impact on health. 6 Compared with subjects who sit for 6 hours a day, those who sit for 8 hours have a 14% higher cardiovascular risk and those who sit for 10 hours a day, 29%. 7 There is strong evidence that individuals who maintain sedentary behavior over time have greater all-cause mortality, as well as several negative health-related outcomes. This is more pronounced among physically inactive people, given that physical activity attenuates mortality risk. Higher physical activity levels among highly sedentary individuals are thus required. 8 The possible pathways to negative health-related outcomes facilitated by a sedentary lifestyle include promotion of increased oxidative stress. This is a strong precursor of endothelial dysfunction and gives rise to greater release of free fatty acids in the bloodstream, thus favoring I PT. Physiotherapist and Professor, Department of Physiotherapy, Faculty of Sport Sciences, Universidad Europea de Madrid, Villaviciosa de Odón, Madrid, Spain.
https://orcid.org/0000-0002-2689-1767 development of cardiovascular diseases (CVDs). 9 In addition, a sedentary lifestyle causes insulin resistance 10 and promotes accumulation of visceral fat. 11,12 Previous studies have reported that each additional hour of sedentary time is associated with greater gain in body mass index (BMI) and waist circumference (WC). 8 A sedentary lifestyle can lead to development of obesity, which is the second highest risk factor for lifestyle-related premature death, after physical inactivity. 13 Moreover, overweight and obesity cause insulin resistance 14,15,16 and promoting deposition of ectopic lipids or visceral fat in different organs. 17 This interferes with the normal function of organs, which thus increases the risk of many NCDs, especially CVD and T2DM. 18 Physical activity is essential for achieving energy balance and weight control, thereby enabling maintenance of healthier body composition (BC) with an acceptable ratio of fat and muscle. 19 It also protects against numerous NCDs, 20,21 because it has a systemic dose-dependent anti-inflammatory effect. 6,22,23 Regarding nutritional habits, adherence to the Mediterranean diet has been shown to have significant inverse associations with all-cause mortality 24 and with the prevalence of CVD and T2DM, which are related to the anti-inflammatory properties of this diet. 25,26 Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was discovered in Wuhan, Hubei province, China, in a pneumonia epidemic in January 2020. 27 On January 30, 2020, it was declared by WHO to be a global health emergency 28 and, since then, the virus has spread throughout the world, causing more than a million deaths. There is great variability in the dietary patterns of university students, in part because there are many different questionnaires assessing the adherence to the Mediterranean diet. 33 Generally, university students have a low adherence to the Mediterranean diet. 34,35 Regarding physical activity levels, university students normally are highly active, but also report high amounts of sedentary behavior. 36,37 Students with higher levels of physical activity usually report greater levels of health-related quality of life (HrQoL), especially regarding the mental component summary (MCS). [38][39][40] Further research on young adulthood is needed in order to ascertain the impact of lifestyle on HrQoL in young populations.

OBJECTIVE
We aimed to analyze the lifestyle and BC of young university students during the pandemic, and their relationship with HrQoL. We hypothesized that physical activity levels, sedentary behavior, unhealthy BC and poor adherence to the Mediterranean diet would have moderate negative associations with HrQoL.

Design
An observational cross-sectional study was developed, following the STROBE (strengthening the reporting of observational studies in epidemiology) guidelines, between October and November 2020 at Universidad Europea de Madrid, in Spain.

Settings and participants
A total sample of 56 healthy young students was recruited at were recruited via e-mail between October and November 2020.
The potential participants were reassured that nonparticipation would not have any consequences. A code was assigned to participants, prior to statistical analysis, thus guaranteeing the confidentiality of their data.
The inclusion criteria were that the participant needed to be a student at the Universidad Europea de Madrid 34 and be between 18 and 34 years of age. 41 The exclusion criteria were situations of: 1) having a chronic disease; 42 2) undergoing pharmacological therapy; 42 or 3) having any condition that led to development of pain or any disturbances during physical exercise. 42

Ethical considerations
The current study was approved by the Research Ethics The Spearman correlation test with 95% coefficient intervals was carried out to analyze the relationships between continuous variables. The magnitudes of correlations between continuous variables were qualitatively interpreted using the following criteria: , very large (r = 0.7-0.9) and almost perfect (r ≥ 0.9). 51 Otherwise, correlation was interpreted as the observed magnitude. The statistical significance was set at an alpha level of < 0.05.
All analyses were conducted using IBM SPSS for Windows, version 23 (IBM Corporation, Armonk, New York, United States).

Sociodemographic data of the sample
A total of 56 subjects aged 23.5 ± 3.4 years were analyzed. and CV% for all the continuous variables is presented in Table 1.

Correlations between body composition, lifestyle and HrQoL
The Spearman correlation test with 95% coefficient intervals was used to analyze possible correlations between continuous variables (Table 2) Table 2). Nonsignificant differences in BC, physical activity and HrQoL were found between medium-high and low adherence to the Mediterranean diet ( Table 3). The comparisons of BC, physical activity and HrQoL between risk and non-risk sitting times are displayed in Table 4.

DISCUSSION
The  53 This was similar to the results reported in other studies with a student population. 36,37 Physical activity attenuates mortality risk, and higher physical activity levels are required among highly sedentary individuals. 8 Table 3. Differences in body composition, physical activity and health-related quality of life between medium-high and low adherence to the Mediterranean diet Comparisons are between high (n = 27) and low (n = 29) adherence to the Mediterranean diet. * Mean ± standard deviation (SD) (minimum-maximum) or † Median ± interquartile range (IR) (minimum-maximum). Statistical significance was set at an alpha level of < 0.05 ( * ). ‡ Mann-Whitney U test was used.  Table 4. Differences in body composition, physical activity and health-related quality of life between risk and non-risk sitting time Comparisons are between risk (n = 25) and non-risk (n = 31) sitting time. * Mean ± standard deviation (SD) (minimum-maximum) or † median ± interquartile range (IQR) (minimum-maximum). Statistical significance was set at an alpha level of < 0.05 ( * ). ‡ Mann-Whitney U test was used. In fact, in other populations, WC is a better indicator of poor physical HrQoL than BMI. 59 The aim of this study was to characterize the lifestyle of young students in a pandemic period. We mainly found that these subjects were complying with the 2020 WHO physical exercise recommendations 53

Study limitations and future lines
Our sample was obtained from just one particular university in one particular city. It would be very useful to obtain information from more universities in different locations. In addition, studying the implementation of a strengthening program or physical activity in relation to the Mediterranean diet, both among healthy individuals and among individuals presenting any pathological condition (e.g. COVID-19, musculoskeletal disorders or metabolic diseases) would be very interesting. Lastly, no comparative data from before the pandemic were obtained and, thus, the PCS and MCS cannot be attributed to the COVID-19 pandemic.

CONCLUSION
In this young student population, the results showed that the subjects generally had healthy BC, high physical activity levels,