Introduction

Diabetes has become a significant health, economic and social problem, even in the countries with the high socio-economic status. Currently, 537 million people aged 20-79 suffer from diabetes, including 61 million people in Europe (International Diabetes Federation, 2022). According to the report of the National Institute of Health, there is also a high incidence of diabetes in Poland, with 8% of the population suffering from this disease. It is estimated that in 2040 the incidence of diabetes will increase to 11% (Kalbarczyk, 2018).

Type 2 diabetes mellitus (T2DM) is currently the most common type of diabetes. It affects a significant percentage of people and constitutes 90% of all diabetic cases (Ahmad, Lim, Lamptey, Webb, Davies, 2022). The disease occurs mainly in the middle-aged and elderly population. However, scientific reports of the recent years indicate an increasing incidence of T2DM among young people (Wild, Roglic, Green, Sicree, 2004, Lascar et al., 2018). Type 2 diabetes accounts for 8-45% of the cases of diabetes diagnosed in this age group (Surma, Szyndler, Narkiewicz, 2017). The incidence of this lifestyle disease is increasing among people under 30 years of age (U.S. Department of Health and Human Services. Centres for Disease Control and Prevention, 2020). According to Magliano et al. (2020), in the early stage of type 2 diabetes diagnosed in people up to 40 years of age, the risk of complications is higher than in patients with type 1 diabetes, and these findings are disturbing. It certainly affects life expectancy of people with T2DM. The research conducted among societies from 19 countries with the high socio-economic status showed that people with type 2 diabetes diagnosed in their 30s, 40s and 50s died much earlier (by 14, 10 and 6 years, respectively) than their peers who were not diagnosed with this metabolic disease (Emerging Risk Factors Collaboration, 2023).

According to recent reports, diabetes may accompany other diseases. It is directly related to insulin resistance and causes diseases, such as: hypertension, ischemic heart disease, peripheral arterial disease, retinopathy, chronic kidney disease and preeclampsia in pregnancy (Chudek, Wikarek, Więcek, 2013, Mazzone, Chait, Plutzky, 2008, Zegarska, Brzozowska, Bendykowska, Mędrek, 2022). A significant percentage of women (40) affected by insulin resistance is predisposed to the development of T2DM (Jabeen et al., 2022). According to Deswal, Narwal, Dang and Pundir (2020), the risk of type 2 diabetes is much higher (5-10 times) in women with polycystic ovary syndrome (PCOS) than in women not affected by this endocrine disorder. The incidence of PCOS in women of reproductive age ranges from 4 to 20% (Ovalle, Azziz, 2002). Kudiyirickal and Pappachan (2015) highlight another aspect related to T2DM i.e. the relationship between the level of blood glucose and the development of periodontitis. At the same time, the studies of the cited authors did not show any relationship between dental caries and the incidence of diabetes.

According to literature, some diseases may occur regardless of the type of diabetes. Diabetic complications include: diabetes insipidus, nephropathy, osteoporosis, diabetic foot disease (Evans, Capell, 2001, Waliłko, Sawicka-Gałązka, 2012, Christ-Crain et al., 2019). Depression is another dangerous consequence of diabetes. According to Sartorius (2018), thismental disorder occurs twice as often in patients with diabetes than in people who have not been diagnosed with this disease. According to Leong, Yip, Kuo and Tsai (2022), there is a relationship between the incidence of diabetes and autoimmune diseases, including chronic fatigue syndrome (CFS), which increasingly affects children and adolescents.

In order to change the disturbing epidemiological situation and reduce the threats posed by T2DM, preventive actions are taken to change the lifestyle of certain groups of society.

There are many improper health behaviours among young people that predispose them to the development of type 2 diabetes, regardless of the place where they study (Huk-Wieliczuk, 2021, Huk-Wieliczuk, 2023).

The aim of this study was to assess the knowledge of physically active university students about the selected issues regarding type 2 diabetes. These issues are important for health educators - students of the University of Physical Education.

In order to achieve the aim of the study, the following research questions were formulated:

Material and methods

195 students (120 men and 75 women) of the Józef Piłsudski University of Physical Education in Warsaw, Branch in Biała Podlaska, participated in the research. The respondents studied in the following fields and specialties:

study curriculum, students’ physical activity amounted to 8 units of sports activities (45 minutes).

The age of the respondents ranged from 19 to 23 years; I group (19-20 years old) and II group (21-23 years old). The research participants agreed to complete the survey. A diagnostic survey, which was the research method, was conducted in 2023. The pilot study was carried out among 20 people (9 male and 11 female students of different fields and years of studies). An original survey questionnaire, which was used as the research tool, was applied to collect data. In addition to demographics, the questionnaire included questions organized into the following three thematic categories: 1) risk factors of T2DM – improper nutrition and eating behaviours, using psychoactive substances (alcohol, cigarettes, energy drinks, coffee), sedentary lifestyle, irregular physical activity, stress and sleep disorders, 2) knowledge about diagnostic indicators of diabetes, 3) knowledge of the symptoms of hypoglycaemia (somatic and related to the central nervous system). The material was subjected to statistical analysis using the chi-square test of independence. The significance level of p<0.05 was adopted in the analysis.

Results

Table 1 presents the knowledge of University of Physical Education students about lifestyle-related risk factors of type 2 diabetes, broken down by gender. Improper nutritional habits have a significant impact on the pathogenesis of diabetes. Almost all respondents declared that bad eating habits predispose to the development of type 2 diabetes. Among many dietary mistakes, the respondents indicated irregular eating times. According to a higher percentage of female than male students, skipping breakfast is one of the causes of T2DM, 86.7 and 58.3, respectively (statistically significant differences). In the opinion of almost 93% of men and 95% of women, the consumption of products with high values of indicators, such as glycaemic index and glycaemic load, increases the incidence of diabetes. A role of vitamin Ddeficiencyinthepathogenesis ofdiabetes was mentioned by over 28% of male respondents and by almost 47% of female respondents. A high percentage of the respondents (65.8 men and 88.0 women) (statistically significant differences at the level of p<0.05) declared eating unhealthy snacks as a habit increasing the risk of diabetes. The respondents also indicated the relationship between eating disorders and the risk of T2DM. In the opinion of more than 58% of male students and 76% of female students, night eating syndrome is a factor contributing to the development of type 2 diabetes (statistically significant differences at the level of p<0.05). A similar tendency and results for women and men were reported in the case of binge eating disorder. Every third male respondent and every second female respondent declared that bulimia may be a determinant of type 2 diabetes (χ²=6.05, differences p<0.05, statistically significant differences). According to the majority of study participants (over 88% of male students and 93% of female students), the method of food preparation also causes changes in the blood glucose levels. The research showed that university students, regardless of gender, did not indicate any interaction between the consumption of energy drinks and the risk of type 2 diabetes. Every fifth respondent claimed that drinking three cups of coffee a day increased the risk of diabetes. According to the respondents, using other stimulants may to a certain extent increase the risk of T2DM. In the opinion of the vast majority of male and female students (82.4% vs. 75.0%), smoking cigarettes every day and smoking up to 10 cigarettes a day (92.0% vs. 82.5%) also cause type 2 diabetes. Smaller number of respondents (every fourth male student and every third female student) indicated the relationship between the risk of diabetes and the use of e-cigarettes. Young women (37.1%) more often than men (21.7%) declared that high consumption of alcoholic beverages increases the incidence of type 2 diabetes. Other important factors in the pathogenesis of this metabolic disease, in the opinion of the respondents, are sedentary lifestyle and the lack of regular physical activity. A higher percentage of female students compared to male students believed that stress, regardless of its duration, is a determinant of the disease manifested by chronic hyperglycaemia. Every second female respondent and every fourth male respondent believed that prolonged stress increases the incidence of T2DM. According to a significant percentage of female students (36), even short-term episodes of stress increase the risk of type 2 diabetes. As for sleep disorders, the largest percentage of university students declared that insomnia increases the risk type 2 diabetes (14.4% more female students expressed this opinion). According to almost 19% of the respondents, short duration of night rest may be a risk factor for diabetes. Similar results were obtained in the case of sleep over 8 hours. Over 14% of men and 16.0% of women indicated the relationship between napping and the risk of T2DM.

The respondents’ knowledge about lifestyle-related determinants of type 2 diabetes depending on age is presented in Table 2. Students aged 21-23 in a greater percentage than those aged 19-20 declared that skipping breakfast is a risk factor of T2DM, 98.2% and 95.3%, respectively (χ²=11.51, differences p<0.05, statistically significant differences). In the opinion of senior students, inappropriate diet i.e. the consumption of products with high glycaemic index and glycaemic load may increase the incidence of type 2 diabetes. As for the knowledge of the relationship between eating disorders and the incidence of type 2 diabetes, a higher percentage of university students belonging to group II (47.3) than group I (32.9) declared that bulimia has an impact on changes in the blood glucose levels. The results regarding improper nutrition and eating behaviours are similar in both groups. The age of the respondents did not determine the respondents’ knowledge about the relationship between the consumption of energy drinks and coffee, and the incidence of diabetes. Almost 70% of the students aged 19-20 and 84.5% of those aged 21-23 believed that frequent smoking played a role in the pathogenesis of type 2 diabetes; differences were statistically significant. Senior students also declared that smoking up to 10 cigarettes a day is a determinant of T2DM (group II – 90.9% vs. group I – 80.8%). Similar observations involved the use of e-cigarettes and high consumption of alcoholic beverages. A significant percentage of respondents, regardless of age, emphasized that irregular physical activity, and especially sedentary lifestyle, are risk factors of type 2 diabetes. Another interesting issue was the perception of emotional stress as the cause of type 2 diabetes. The results show that university students are aware of the fact that stress is one of the causes of the increased risk of T2DM. This was declared by almost 44% of the students aged 21-23 and by over 29% of those aged 19-20 – in the case of chronic stress, and by 21.8% and 9.4%, respectively – in the case of short-term stress episodes; differences were statistically significant. In both age groups, the respondents considered the importance of sleep disorders in the pathogenesis of diabetes insufficient. More than 48% of male students and 58% of female students declared the relationship between insomnia and a disease involving chronic hyperglycaemia.

Although measuring glucose levels is recommended in elderly people (usually over 45 years of age), the incidence of obesity and hypertension among university students encourages their education about the possibilities of diagnosing diabetes (Table 3).

Almost all the respondents indicated the level of fasting venous blood glucose among diagnostic indicators of this metabolic disease. The correct answer about the normal level of glycated haemoglobin (HbA1c) in healthy individuals was given by 29.3% of women and by 23.3% of men. Almost 88% of the respondents indicated “testing glucose in urine” as an indicator of diabetes.

According to 25.0% of male students and 40.0% of female students, detection of ketones in urine is another test used to diagnose diabetes. As for the OGTT test (oral glucose tolerance test), only a small percentage of the respondents (9.2% of men and 8.0% of women) indicated the group in which the test should be performed (people with suspected diabetes, healthy but genetically predisposed individuals and those belonging to risk groups, the test is obligatory for pregnant women). Few respondents incorrectly pointed out the Wasserman reaction.

Taking into account the age of students and their knowledge about the diagnosis of type 2 diabetes, higher number of the respondents classified to group II than to group I indicated the correct level of glycated haemoglobin – HbA1c, 40.9% and 5.9%, respectively (χ² = 35.15, differences p < 0.05). Every fifth student aged 19-20 and almost every second student aged 21-23 declared that the measurement of the level of ketones in blood is used to diagnose T2DM (statistically significant differences). University students, regardless of their age, did not have the sufficient knowledge of the OGTT test, though a three times higher percentage of senior students indicated the need to perform this test; statistically significant differences (Table 4).

The knowledge of male and female students about the symptoms of hypoglycaemia is similar (Table 5). Among the somatic symptoms of low blood glucose levels, the respondents most often mentioned the feeling of hunger (92.5% of male students and 94.7% of female students), trembling hands (92.5% of male students and 94.7% of female students) and dizziness (91.7% of male students and 94.7% of female students). Over 89% of university students indicated weakness as a symptom of the low blood glucose level. Female respondents were more likely than male respondents to declare that heart palpitations were accompanied by hypoglycaemia, 82.7% and 66.7%, respectively (statistically significant differences, p<0.05). Almost all respondents mentioned drowsiness among the symptoms of hypoglycaemia related to the central nervous system. A significant percentage of the respondents declared that impaired concentration and the loss of consciousness are the signs of the low blood glucose level. In the opinion of 84.2% of men and 90.7% of women, visual impairment is another symptom of hypoglycaemia.

The comparison of the knowledge of hypoglycaemia symptoms depending on age showed that a higher percentage of students belonging to group II than to group I indicated trembling hands as one of the somatic symptoms of hypoglycaemia, 96.4 and 89.4, respectively (statistically significant differences). Almost 19% more senior students than junior students indicated heart palpitations as one of the symptoms of type 2 diabetes (χ²=8.31, statistically significant differences at the level of p<0.05). A similar trend was found for the loss of consciousness; over 96% of the respondents from group II and almost 84% of those from group I indicated the sudden loss of consciousness as a sign of diabetes. Fluctuations in glucose homeostasis can cause periodic vision problems. According to 84.0% of the students aged 19-20 and 96.4% of those aged 21-23, visual impairment is the sign of hypoglycaemia (Table 6).

Discussion

In recent years, there has been an increasing interest in lifestyle medicine, which emphasizes the role of prevention in many diseases. Much importance is given to the decisions regarding health behaviours. This also applies to diabetes, which, in the light of scientific achievements, is considered a lifestyle disease of the 21st century. Alarming scientific reports call for wide-ranging actions dedicated to young people in order to prevent a significant increase in the percentage of patients with this metabolic disease syndrome (Płaczkowska, Kokot, Pawlik-Sobecka, Kołaczek, Małolepsza, 2013). The results of the study conducted by Barbosa et al. (2016) show that the incidence of insulin resistance in Brazilian students was 7.3% and the incidence of metabolic syndrome ranged from 13.3% (in women) to 32.2% (in men).

Modification of eating habits is emphasized among many measures to prevent type 2 diabetes. In the opinion of the vast majority of respondents, irregular eating times and a diet rich in highly processed foods are risk factors of type 2 diabetes. Almost 90% of university students accented the role of the method of preparing meals. As indicated by the research of Cahill et al. (2014), frequent eating fried foods, mainly eating out, is correlated with the risk of type 2 diabetes.

Vitamins are essential components responsible for the proper functioning of the human body. Female respondents more often than male students mentioned vitamin deficiencies, especially vitamin D deficiency as a factor predisposing to type 2 diabetes. This is consistent with the findings of Zhou et al. (2016) who reported that the intake of vitamin C exceeding 140 mg per day can reduce the incidence of diabetes up to 5%. According to the authors, an increased amount of this vitamin in the diet has a positive effect on oxidative stress and insulin resistance. As for the relationship between vitamin D and the risk of diabetes, this chemical compound can effectively reduce the incidence of this disease by 15% in adults diagnosed with prediabetes (Pittas et al., 2023).

University of Physical Education students declared that eating disorders had an influence on the development of type 2 diabetes. In this context, they usually mentioned binge eating disorder and night eating syndrome. These disorders correlate with the energy supply and glucose instability, as well as affect the body fat content (Raevuori et al., 2015).

According to many scientific reports, cigarette smoking is one of the risk factors of type 2 diabetes. Based on the data from 88 prospective studies involving almost 6 million participants, Pan et al. (2015) demonstrated that both active and passive smoking increase the risk of type 2 diabetes. According to these authors, 11.7% of the cases of type 2 diabetes in men and 2.4% of the cases in women (a total of approximately 27.8 million cases worldwide) are related to active smoking. In our research, 75.0% of male students and 82.4% of female students mentioned frequent smoking as a risk factor of T2DM. Young people are increasingly using e-cigarettes. According to literature, e-cigarettes may affect carbohydrate metabolism and increase the risk of prediabetes by 1.22-1.97% compared to the group of never smokers (Atuegwu et al., 2019, Zhanga et al., 2022).

Also, inadequate duration (less than 5-6 hours and more than 9 hours a day) and quality of sleep may cause abnormal blood glucose levels. Sleep disorders may reduce the sensitivity of tissues to insulin, promote the development of insulin resistance, increase the blood concentration of cortisol in the morning, and consequently lead to the development of T2DM (Tan, Chapman, Cedernaes, Benedict, 2018). The risk of type 2 diabetes is increased by 9% with every hour of sleep lost (Kolb, Martin, 2017).

Almost all respondents indicated the lack of regular physical activity among the risk factors of T2DM. Regular physical exercises promote the proper metabolism of glucose, reduce the risk of complications related to this disease and support weight reduction (Zielińska et al., 2018, Rietz, 2022). After analysing research results and conducting meta-analysis, Shah et al. (2021) concluded that physical activity has an impact on the value of glycated haemoglobin (reduction by 0.03%) and the fasting blood glucose level (decrease by almost 22 mg/dl). Physical exercises reduce the nervous tension of the human body, which is important for the prevention of diabetes, regardless of its type.

The research shows that university students have knowledge about diagnostic indicators of diabetes (except for the OGTT test) and that they can name the symptoms of hypoglycaemia. This is important given the future professional activity of the respondents, especially in the aspect of working with children and young people. Work with a given population requires from a physical education teacher or trainer to be familiar with health threats and to shape health-promoting attitudes in his/her students, emphasizing the role of physical activity in the prevention of lifestyle diseases.

Conclusions