Page 84 |
Save page Remove page | Previous | 84 of 172 | Next |
|
small (250x250 max)
medium (500x500 max)
Large (1000x1000 max)
Extra Large
large ( > 500x500)
Full Resolution
All (PDF)
|
This page
All
|
73
Chapter 3 INFLUENCE OF PHYSICAL ACTIVITY AND SEDENTARY
BEHAVIOR ON METABOLIC SYNDROME IN MINORITY YOUTH
3.1 INTRODUCTION
The metabolic syndrome (MetS) refers to a cluster of cardiovascular and Type 2
diabetes risk factors which include: elevated triglycerides, low high-density lipoprotein
(HDL)-cholesterol, abdominal adiposity, hyperglycemia, and elevated blood
pressure.(199) Based on current estimates from the National Health and Nutrition
Examination Survey (NHANES) from 1999 to 2002, the prevalence of MetS in youth
aged 12-19 years old varies widely from 2.0-9.4% reaching 44.2% among obese
children.(35) Our group has shown that over 30% of overweight Latino children in the
Los Angeles area have MetS.(39) We also have shown that children with persistent MetS
were at progressively greater risk for Type 2 diabetes.(211) This is especially important
in light of the fact that other research has found that MetS in childhood predicted adult
MetS and Type 2 diabetes mellitus as much as 25 to 30 years later.(143) Thus, to reduce
the increasing prevalence of such chronic diseases in adults, it is important to identify
lifestyle behaviors that can be modified during childhood.
Two of the key modifiable lifestyle factors which influence metabolic health are
physical activity(159) and sedentary behavior.(67) Lower levels of physical activity and
higher levels of sedentary behavior are known to be associated with progression toward
MetS in adults.(53, 67) However, little is known regarding these relationships in youth,
Object Description
| Title | The vicious cycle of inactivity, obesity, and metabolic health consequences in at-risk pediatric populations |
| Author | Hsu, Ya-Wen |
| Author email | ywxxbirdy@yahoo.com; yawenhsu@usc.edu |
| Degree | Doctor of Philosophy |
| Document type | Dissertation |
| Degree program | Preventive Medicine (Health Behavior) |
| School | Keck School of Medicine |
| Date defended/completed | 2011-03-09 |
| Date submitted | 2011 |
| Restricted until | Restricted until 26 Apr. 2012. |
| Date published | 2012-04-26 |
| Advisor (committee chair) |
Chou, Chih-Ping Spruijt-Metz, Donna |
| Advisor (committee member) |
Unger, Jennifer B. Azen, Stanley Paul Palinkas, Lawrence A. |
| Abstract | PURPOSE: This dissertation examined the associations between physical activity, sedentary behavior, overweight, and the metabolic syndrome (MetS) in at-risk pediatric populations in the United States and in China. Study 1 identified the independent influences of physical activity, sedentary behavior, and other weight-related correlates on overweight status in Chinese youth. Study 2 explored the influences of physical activity and sedentary behavior on MetS in US minority youth. Study 3 compared the longitudinal trends of physical activity and sedentary behavior between youth with and without MetS in a sample of US minority female youth.; METHODS: Participants were youth (ages 8-18 years) in the United States and in China. Study 1 used baseline data from of a longitudinal smoking prevention and health promotion study conducted in the 7 large cities in China for Chinese youth ages 11-18 years. Study 2 used baseline data from three related pediatric obesity studies that share a set of common methods and measures (US Latino and African American youth ages 8-18 years). Data for Study 3 are from a longitudinal, observation study for Latina and African American female youth ages 8-11 years at baseline.; RESULTS: In Study 1, Chinese youth were more likely to be overweight if they spent more time being sedentary, slept <7 hours/night, were male, were younger, participated more in vigorous physical activity, had higher levels of parental education, better self-perceived health status, a higher frequency of vegetable intake, and a lower frequency of sweet/fast food intake. In Study 2, lower levels of moderate-to-vigorous physical activity (by accelerometry) and higher levels of sedentary behavior (by 3-day physical activity recall) are associated with increased the metabolic risk independent of each other and body composition. In Study 3, a significant decline in MVPA and an increase in sedentary behavior were observed over one year. Sedentary behavior as measured by accelerometry increased 23.42 minutes/per quarterly visit, adding up to 93.68 minutes/per year more in youth with MetS than in those without.; CONCLUSION: Overweight-related correlates seem to play different roles in the Chinese culture than in Western cultures. Findings from this dissertation support a vicious cycle of increasing inactivity, obesity, and metabolic complications. These findings, coupled with longitudinal evidence of the effects of activity levels on obesity and MetS, suggests that physical activity and sedentary behavior could function as antecedents as well as consequences of overweight or MetS in youth. |
| Keyword | Chinese youth; metabolic syndrome; minority youth; obesity; physical activity; sedentary behavior |
| Geographic subject (country) | USA; China |
| Coverage date | 1970/2010 |
| Language | English |
| Part of collection | University of Southern California dissertations and theses |
| Publisher (of the original version) | University of Southern California |
| Place of publication (of the original version) | Los Angeles, California |
| Publisher (of the digital version) | University of Southern California. Libraries |
| Provenance | Electronically uploaded by the author |
| Type | texts |
| Legacy record ID | usctheses-m3779 |
| Contributing entity | University of Southern California |
| Rights | Hsu, Ya-Wen |
| Repository name | Libraries, University of Southern California |
| Repository address | Los Angeles, California |
| Repository email | cisadmin@lib.usc.edu |
| Filename | etd-Hsu-4455 |
| Archival file | uscthesesreloadpub_Volume23/etd-Hsu-4455.pdf |
Description
| Title | Page 84 |
| Contributing entity | University of Southern California |
| Repository email | cisadmin@lib.usc.edu |
| Full text | 73 Chapter 3 INFLUENCE OF PHYSICAL ACTIVITY AND SEDENTARY BEHAVIOR ON METABOLIC SYNDROME IN MINORITY YOUTH 3.1 INTRODUCTION The metabolic syndrome (MetS) refers to a cluster of cardiovascular and Type 2 diabetes risk factors which include: elevated triglycerides, low high-density lipoprotein (HDL)-cholesterol, abdominal adiposity, hyperglycemia, and elevated blood pressure.(199) Based on current estimates from the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2002, the prevalence of MetS in youth aged 12-19 years old varies widely from 2.0-9.4% reaching 44.2% among obese children.(35) Our group has shown that over 30% of overweight Latino children in the Los Angeles area have MetS.(39) We also have shown that children with persistent MetS were at progressively greater risk for Type 2 diabetes.(211) This is especially important in light of the fact that other research has found that MetS in childhood predicted adult MetS and Type 2 diabetes mellitus as much as 25 to 30 years later.(143) Thus, to reduce the increasing prevalence of such chronic diseases in adults, it is important to identify lifestyle behaviors that can be modified during childhood. Two of the key modifiable lifestyle factors which influence metabolic health are physical activity(159) and sedentary behavior.(67) Lower levels of physical activity and higher levels of sedentary behavior are known to be associated with progression toward MetS in adults.(53, 67) However, little is known regarding these relationships in youth, |
