Study Of Correlation Between Fat And Muscle Content Of Obesity Patients And Obesity-Related Complication

Background:In recent years, with rising living standard, changing lifestyle with more fat in our diet, as well as reducing labor intensity and physical activities, more and more people are becoming overweight and obese. According to researches, the number has amounted to 2.1 billion, which is 30% of the earth population. Obesity has become a global health problems. Timely and effective treatment for obesity is very important.The definition and diagnosis of obesity is a controversial issue. The diagnosis of obesity has multiple standards, which mainly include the armpit fat thickness, body mass index (BMI), waist circumference, waist-hip ratio and other indexes. Previous diagnosis of obesity is defined with body mass index (BMI) as the core index, and body mass index (BMI) higher than 24 kg/m2 is commonly regarded as obesity diagnosis standard. WHO-WPR2000 obesity diagnosis standard is also based on body mass index (BMI) classification. Body mass index less than 23 kg/m2 is not obesity, body mass index (BMI) from 23 to 24.9 kg/m2 is pre obesity, body mass index from 25 to 29.9 kg/m2 is period I obesity, and body mass index above 30 kg/m2 is period II obesity. Obese people often have other kinds of diseases, even those with lower body mass index (BMI) still have a higher risk of cardiovascular disease compared with people with normal weight. But BMI cannot effectively reflect different body composition levels, so BMI is not a good standard of obesity classification. Therefore, in 2014, according to weight and relevant complications, the American Society of Clinical Endocrine (AACE) and the American Association of Endocrine (ACE) divided obesity into 5 levels:normal weight, overweight, level 0 obesity, level 1 obesity, and level 2 obesity, along with respective intervention suggestions to each degree of obesity. Therefore, obesity is a disease which can be complicated by severe symptoms, and intervention should be carried out in a timely manner.Obesity often leads to the damage of the patients’ physical beauty, which can cause certain social discrimination in life and work. This will not only affect the normal work and life of the patients, but also cause many kinds of psychological problems, and thus reduce the patients’ life quality. Worse still, obesity cause a variety of complications and diseases, such as diabetes, NAFLD, high blood pressure, stroke, osteoarthritis, cancers, etc., which can seriously affect health and even endanger life. So effective prevention and control of obesity and its related complications to improve health and life quality of the patients is of great significance. The pathogenesis of insulin resistance, type2 diabetes, NAFLD foundation, influence each other...So insulin resistance, type2 diabetes, NAFLD are selected as the research objects.Patients in different obesity level have different complications rates. An important feature of obesity is increasing body fat content and decreasing muscle content. And people with different body mass index (BMI) have different levels of muscle and fat. Researches findings show that human body composition and metabolic diseases, such as insulin resistance, diabetes, NAFLD are closely related. Therefore, the content of fat, muscle and other body composition of obese people also may be related to the insulin resistance, diabetes, NAFLD and other related metabolic diseases. Investigating the relationship between muscles, fat level of different obesity level patient with insulin resistance, diabetes, and NAFLD may guide the prevention and treatment of obesity related complications, contribute to the improvement of the life quality and prognosis of obese people. Yet there is no precious study about relationship between muscles, fat with insulin resistance, diabetes, and NAFLD in different levels of obesity patients. So, this is an issue that is worth exploring. Objective:This study intends to compare body fat, muscle content in different WHO-WPR2000 grading obesity patients and their relationship with insulin resistance, diabetes, NAFLD and other obesity relates diseases, aiming to provide guidance for prevention and treatment of insulin resistance, diabetes, NAFLD and other common obesity complications in WHO-WPR2000 different grading obesity patients, so as to improve the effect of obesity prevention and treatment, life quality and prognosis.Methods:(1) research subjects:362 cases of overweight and obese patients with body mass index greater than 23 kg/m2 were selected. They were patients chosen from physical check-up in our hospital from September 2012 to December 2015. According to the WHO-WPR2000 obesity classification standard,22 cases of pre obese patients (23 kg/m2≤BMI≤24.9kg/m2) formed the pre obese group,201 cases of period I obese patients (25 kg/m2≤BMI≤29.9kg/m2) formed the period I group, 139 cases of period II obese patients (BMI≥30kg/m2) formed the period II group.(2) observation indicators:① Body fat, visceral fat, muscle contents and other body composition was detected by body composition detector, and muscle/fat ratio was calculated out.② Routine plasma fasting glucose (FPG) and fasting insulin (FINS) were detected for patients. And the insulin resistance indexes (HOMA IR) [HOMA-IR= (FINS×FPG)/22.5] and insulin sensitive index (ISI) [ISI=1/(FPG×FINS) were calculated.③According to The Chinese type 2 diabetes prevention guidelines for diabetes (2013), three standard groups were diagnosed. According to Guidelines for management of nonalcoholic NAFLD disease(2010) from the Chinese National Liver Disease Association for NAFLD diagnosis and the rate of NAFLD in three groups was calculated.(3)Data processing:Utility SPSS 19.0 statistical software for was used for data analysis, t test for data measurement, and chi-square test for counting data. Pearson correlation analysis and linear Spearman were used for relationship analysis. And P<0.05 was taken as the standard of significant difference for data analysis.Results:(1) Compared with the pre obesity group, the period Ⅰ group and the period Ⅱ group have higher fat rate, visceral fat rate, muscle content, insulin resistance index increases, the incidence of diabetes and NAFLD (P<0.05), while their muscle/fat ratio and insulin sensitivity index decreased (P<0.05). Compared with the period Ⅰ group, the period Ⅱ group has higher body fat rate, visceral fat rate, muscle content, insulin resistance index increases (P<0.05), the incidence of diabetes and NAFLD and lower muscle/fat ratio and insulin sensitivity index (P<0.05).(2) Body fat rate, visceral fat rate, insulin resistance index of pre obesity group combined with diabetics were higher than that of pre obesity group without diabetes, while muscle content, muscle/fat ratio, insulin sensitive index of pre obesity patient combined with diabetics were lower than that of pre obesity group without diabetes (P<0.05). Body fat rate, visceral fat rate, insulin resistance index of pre obesity group combined with NAFLD were higher than that of pre obesity group without diabetes, while muscle content, muscle/fat ratio, insulin sensitive index of pre obesity group combined with diabetics were lower than that of pre obesity group without NAFLD (P<0.05).(3) Body fat rate, visceral fat rate, insulin resistance index of period Ⅰ obesity group combined with diabetics were higher than that of period Ⅰ obesity group without diabetes, while muscle content, muscle/fat ratio, insulin sensitive index of period Ⅰ obesity group combined with diabetics were lower than that of period Ⅰ obesity group without diabetes (P<0.05). Body fat rate, visceral fat rate, insulin resistance index of period Ⅰ obesity group combined with NAFLD were higher than that of period Ⅰ obesity group without diabetes, while muscle content, muscle/fat ratio, insulin sensitive index of period Ⅰ obesity group combined with diabetics were lower than that of period Ⅰ obesity group without NAFLD (P<0.05).(4) Body fat rate, visceral fat rate, insulin resistance index of period Ⅱ obesity group combined with diabetics were higher than that period Ⅱ obesity group without diabetes, while muscle content, muscle/fat ratio, insulin sensitive index of period Ⅱ obesity group combined with diabetics were lower than that of period Ⅱ obesity group without diabetes (P<0.05). Body fat rate, visceral fat rate, insulin resistance index of period Ⅱ obesity group combined with NAFLD were higher than that of period Ⅱ obesity group without diabetes, while muscle content, muscle/fat ratio, insulin sensitive index of period Ⅱ obesity group combined with diabetics were lower than that of period Ⅱ obesity group without NAFLD (P<0.05). (5) Results of the Pearson correlation analysis show that, body fat rate, visceral fat rate of pre obese patients were positively correlated with insulin resistance index (r=0.852,0.847,P<0.05), while negatively correlated with insulin sensitive index (r=-0.869,-0.842,P<0.05), and the muscle content, muscle/fat ratio were negatively correlated with insulin resistance index (r=0-.872,-0.823,P<0.05), while positively correlated with insulin sensitive index (r=0.844,0.853,P<0.05). Body fat rate, visceral fat rate of period Ⅰ obese patients were positively correlated with insulin resistance index (r=0.862, 0.858, P<0.05), while negatively correlated with insulin sensitive index (r=-0.844,-0.868,P<0.05), and the muscle content, muscle/fat ratio were negatively correlated with insulin resistance index (r=-0.847,-0.866, P<0.05), while positively correlated with insulin sensitive index (r=0.878,0.842, P<0.05). Body fat rate, visceral fat rate of period II obese patients were positively correlated with insulin resistance index (r=0.853,0.862, P<0.05), while negatively correlated with insulin sensitive index(r=-0.874,-0.865, P<0.05), and the muscle content, muscle/fat ratio were negatively correlated with insulin resistance index (r=-0.855,-0.872, P<0.05), while positively correlated with insulin sensitive index (r=0.869,0.875, P<0.05). (6) Results of unconditional Spearman correlation analysis showed that, body fat rate, visceral fat rate of pre obese patients were positively correlated with diabetes incidence and the NAFLD incidence (body fat rate:r=0.818,0.842; visceral fat rate: r=0.858,0.896, P<0.05), while its muscle content, muscle/fat were negatively correlated with diabetes incidence and the NAFLD incidence (muscle content: r=-0.866,-0.763; muscle/fat:r=-0.815,-0.878, P<0.05). Body fat rate, visceral fat rate of period I obese patients were positively correlated with diabetes incidence and NAFLD incidence (body fat rate:r=0.832,0.857; visceral fat rate:r=0.869,0.923, P<0.05), while its muscle content, muscle/fat were negatively correlated with diabetes incidence and the NAFLD incidence (muscle content:r=-0.866,-0.866; muscle/fat:r=-0.844,-0.863,P<0.05). Body fat rate, visceral fat rate of period Ⅱ obese patients were positively correlated with diabetes incidence and NAFLD incidence (body fat rate:r=0.932,0.965; visceral fat rate:r=0.958,0.978, P<0.05), while its muscle content, muscle/fat were negatively correlated with diabetes incidence and the NAFLD incidence (muscle content:r=-0.896,-0.896; muscle/fat: r=-0.872,-0.848, P<0.05). Conclusion:(1)When patients get more and more obese, the fat rate will increase while the muscle rate will decrease. Body fat and muscle rate changes with the severity of obesity.(2)The more obese patients are, the more severe will their insulin resistance be, and the more risk will they have for type 2 diabetes and/or NAFLD. The severity of obesity is closely related to the increase of obesity related complications(3)Fat and muscle content in obese patients are closely to obesity related complications. When fat content increases and muscle content decreases in a patient, his risk of having obesity related complications will increase. Therefore, to prevent and control obesity related complications, timely measures should be taken to lower fat content and increase muscle content in obese patients.