The relationship between some selected indicators of body composition and VO2 max with blood pressure among female students aged 14 to 17 years.

Academic Thesis for Master's Degree

Abstract

Hypertension is a non-communicable chronic disease that has become an epidemic in recent decades. Studies show that this disease is more and more pronounced among obese, overweight and sedentary people. The purpose of this study is to investigate the correlation between some indices of body composition and VO2max with blood pressure. For this purpose, 510 teenage female students with an average age of 15.36±0.944 years, an average height of 160.18±6.28 cm and an average weight of 55.73±10.35 kg were randomly selected and BMI, WHR, WSR, WC, BF% and VO2max indicators and blood pressure were measured and calculated using standard methods. The results showed that there is a positive and significant relationship between BF%, WC, BMI and WSR indices with systolic blood pressure (p ? 0.05) and also between VO2max, BMI and BF% with diastolic blood pressure (p ? 0.05). Mean arterial blood pressure also showed a significant correlation with WC, BF%, BMI and VO2max indices (p ? 0.05). The result of the present research indicates that BMI has the strongest relationship and WHR has the weakest relationship with blood pressure. Also, BMI and VO2max have the strongest predictors with cardiovascular disease risk factors. Therefore, it is recommended to perform regular and sufficient physical activity to reduce harmful fat and increase useful fat, control weight and reduce high blood pressure in order to improve the level of health. style="direction: rtl;"> 

The first chapter

     Due to the urbanization life, industrialization of societies, increased economic growth and globalization of the market, rapid changes have been made in the diet pattern and lifestyle of people (6). At least 60% of the world's population does less than the amount of physical activity required for their health (5). The reason is that in their free time they generally do things that are not associated with physical activity. Sedentary behavior during work activities, urbanization, use of vehicles, lack of proper muscle activity and spending less energy have reduced physical activity and led to an increase in the prevalence of obesity, a decrease in infectious diseases, and an increase in lifestyle-related diseases among people (61, 19, 34). Since the 1990s, physical inactivity has been proposed as one of the main risk factors for cardiovascular diseases in adults and young people (19). Obesity and overweight are one of the main causes of many diseases, including cardiovascular disease, blood pressure, diabetes and cancer (61,19). Today, obesity has been raised as a global crisis (37) and in many countries as well as families, money is spent to reduce the prevalence of obesity and treat related diseases (8). Surveys and studies indicate that in developed and developing countries, 25% of children aged 6 to 14 years are overweight, ranging from 11 to 29% (124). In Iran, overweight and obesity among children and adolescents is also on the rise, and its relationship with lifestyle, including inactivity, has been shown (37,19). style="direction: rtl;">1. Hypertension is (37). According to statistics, almost half of heart and brain strokes occur due to high blood pressure, and it has caused that out of every eight deaths that occur in the world; One case is due to high blood pressure (58,37). This is the reason why this disease is considered a global challenge and caused the 2013 global slogan from the World Health Organization 1 (WHO) to be (high blood pressure) (37).Lamonte2 states that diastolic blood pressure is higher in the sedentary group than the active group (12). Experts say

that blood pressure is twice as much in overweight young people and 50% more in elderly people than normal weight people (154). Therefore, it is very possible that adolescents with high blood pressure will face a decrease in cardio-respiratory fitness 3 (CRF) as a risk factor for the development of cardiovascular complications in the future (168).

On this basis and considering the importance of preventing the occurrence of hypertension, the need to identify people with primary problems and develop considerations in order to improve physical activities in children and adolescents and prevent the increase of obesity in childhood seems important. (138). Therefore, the present study is conducted with the aim of investigating the blood pressure status and determining its relationship with some anthropometric indicators and maximum oxygen consumption among teenagers. increase On the other hand, the prevalence of obesity in developed and developing countries is significantly increasing; So that in some world forums it is referred to as an epidemic (19). According to a study conducted on 2125 students aged 9 to 17, the rate of high blood pressure was 9.6% in girls and 2.8% in boys (53). The presence of a negative and significant correlation between physical activity and blood pressure makes people with high blood pressure have a poor attitude towards physical activities compared to people with normal blood pressure (53,168), which makes people prone to overweight and obesity and its complications. In the study of the trend of obesity in West Azarbaijan among male and female students in urban and rural areas at different levels of education during the years 1987 to 1991, it was observed that the amount of overweight in girls is more than boys (24). In similar studies, it seems that girls are more prone to overweight and obesity and its complications than boys, and this situation in Iranian girls is due to special cultural, social and economic restrictions on mobility and physical activity. World Health Organization 2. Lamonteh 3. Cardio respiratory fitness

have less; It becomes more visible. Therefore, it is important to pay attention to the physical condition of girls, timely diagnosis with easy and accessible screening methods, prevention and adoption of useful strategies to overcome weak body composition, high blood pressure and reduced cardio-respiratory fitness. Therefore, in order to obtain an estimate of the blood pressure status in teenage girls in Khoi city and at the same time to screen for people who are likely to have cardio-respiratory problems in the future, this research examines the correlation between some anthropometric indicators and the maximum oxygen consumption with blood pressure among students aged 14 to 17 years in Khoi city. For evaluation, in order to carry out this research, the systolic, diastolic and average blood pressures are measured and calculated at rest. To evaluate anthropometry1, various anthropometric indices have been introduced to predict the risk of cardiovascular diseases, the most common of which is body mass index (BMI) as an index recommended by the World Health Organization, which measures overall obesity in the body (14,19,58). Although BMI has been studied more than other indicators in relation to the risk of chronic diseases and its consequences for health, there are limitations that affect its use. For example, BMI does not provide information about fat distribution in the body (19). Most studies show that the pattern of fat distribution in the body has a more decisive role in identifying the risk factors of diseases (31,74,78). Other indicators that have been mentioned more for fat distribution in the body are waist circumference 3 (WC), ratio of waist circumference to hip circumference 4 (WHR), ratio of waist circumference to standing height 5 (WSR) and body fat percentage 6 (%BF).