Obesity in Childhood and Adolescence (Pediatric and Adolescent Medicine)

280 Pages·2004·1.87 MB·English

by  Wieland Kiess

Obesity in Childhood and Adolescence
Pediatric and
Adolescent Medicine
Vol.9
Series Editors
David Branski Jerusalem
Wieland Kiess Leipzig
Obesity in Childhood
and Adolescence
Volume Editors
Wieland Kiess Leipzig
Claude Marcus Stockholm
Martin Wabitsch Ulm
24 figures, 2 in color, and 24 tables, 2004
Basel·Freiburg·Paris·London·New York·
Bangalore·Bangkok·Singapore·Tokyo·Sydney
Prof.Wieland Kiess Prof.Claude Marcus
Hospital for Children and Adolescents Children’s Hospital
University of Leipzig Huddinge University Hospital
Leipzig, Germany Stockholm, Sweden
Prof.Martin Wabitsch
Department of Paediatrics and
Adolescent Medicine
University Hospital of Ulm
Ulm, Germany
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© Copyright 2004 by S. Karger AG, P.O. Box, CH–4009 Basel (Switzerland)
www.karger.com
Printed in Switzerland on acid-free paper by Reinhardt Druck, Basel
ISSN 1017–5989
ISBN 3–8055–7730–3
Contents
VII Preface
Kiess, W. (Leipzig); Marcus, C. (Stockholm); Wabitsch, M. (Ulm)
1 Defining Childhood Obesity
Lahti-Koski, M. (Helsinki); Gill, T. (Sydney)
20 Body Composition Measurements
Ellis, K.J. (Houston, Tex.)
30 Examination and Diagnostic Procedure
Wabitsch, M.; Denzer, C. (Ulm)
41 Epidemiology of Obesity in Childhood and Adolescence
Ege, M.J.; von Kries, R. (Munich)
63 Obesity Research and the Physiology of Energy Homeostasis
Ristow, M. (Potsdam-Rehbrücke/Berlin); Tschöp, M.H. (Cincinnati, Ohio)
80 Genetic Aspects
Hebebrand, J.; Wermter, A.; Hinney, A. (Marburg)
91 Role of Environmental Factors in Childhood Obesity
Tauber, M.; Jouret, B. (Toulouse)
103 Nutrition
Czerwinski-Mast, M.; Müller, M.J. (Kiel)
112 Physical Activity in Obese Children
Chiarelli, F.; Blasetti, A.; Verrotti, A. (Chieti)
V
124 Some Psychological Viewpoints on Obesity
Butor, P.M. (Stockholm)
137 Musculoskeletal Consequences of Obesity in Youth
Günther, K.-P. (Dresden)
148 Lipids and Lipoproteins in Childhood Obesity
Zwiauer, K. (St. Poelten)
160 Childhood Obesity and Coronary Heart Disease
Freedman, D.S. (Atlanta, Ga.)
170 Type 2 Diabetes mellitus in Children and Adolescents:The European
Perspective
Blüher, S.; Kiess, W.; Böttner, A.; Raile, K.; Kapellen, T.;
Blüher, M. (Leipzig)
181 Type 2 Diabetes mellitus in Children and Adolescents:The New Epidemic
Saenger, P. (Bronx, N.Y.)
194 Multidisciplinary Management of Obesity in Children
and Adolescents – Why and How Should It Be Achieved?
Kiess, W.; Raile, K.; Kapellen, T.; Pfaeffle, R.; Keller, E.; Blüher, S.;
Böttner, A. (Leipzig)
207 Bariatric Surgery
Marcus, C. (Stockholm)
211 Pharmacological Treatment of Childhood Obesity
Marcus, C. (Stockholm)
219 Transfer into Adulthood
Hauner, H. (Munich)
229 Health Economics of Overweight and Obesity in Childhood
Böhler, T. (Heidelberg)
243 Prevention of Overweight and Obesity
Müller, M.J.; Danielzik, S.; Spethmann, C. (Kiel)
264 Author Index
265 Subject Index
Contents VI
Preface
An epidemic of obesity already at a young age is being observed in most
societies around the world. The level of fatness of a child or an adolescent at
which morbidity acutely and/or later in life increases is determined on an
individual basis. However, overall obesity substantially increases the risk of
subsequent morbidity. The definition and diagnosis of obesity in children and
adolescents are difficult and controversial. In children and adolescents the
degree of body fat mass depends upon ethnic background, gender, develop-
mental stage and age. Waist circumference, skinfold thickness and body mass
index are the most useful noninvasive clinical measures to define obesity.
Waist circumference and waist-to-hip ratio are helpful to assess upper body fat
deposition but do not provide for measuring visceral(cid:1)intra-abdominal fat
accumulation. Direct measurements of body fat content, e.g. hydrodensitome-
try, bioimpedance, or DEXA are useful tools in scientific studies. However,
body mass index (BMI) (weight in kilograms divided by the square of the
height in meters) is easy to calculate and is correlated sufficiently with direct
measures of fatness. Recently, it has been proposed that the adult body
mass index (BMI) cut-off points (25 and 30kg/m2) should be related to BMI
percentiles in children and adolescents to provide for cut-off points at younger
ages. Accordingly, age and gender specific BMI values for 2–18 years corre-
sponding to BMI values of 25 and 30kg/m2 at 18 years of age have been
published.
Projected obesity rates for obesity (BMI (cid:2)30kg/m2) in the adult population
of the United States are 30% for the year 2015 and over 40% for the year 2025.
The Bogalusa heart study found that 22% of the children surveyed in 1990 had
VII
a body mass index greater than the 85th percentile established in a similar
survey conducted in 1980. There was little change in the cohorts of children
with a BMI less than the 50th percentile. In contrast, there was a large increase
in BMI in the cohorts with a BMI greater than the 50th percentile. In summary,
over time, obese children have a tendency towards even more excessive weight.
It has become clear that childhood obesity has reached epidemic proportions in
all industrialized countries around the world. The current age-adjusted
prevalence may be as high as 20–30% in some populations. For example, data
from a nationally representative sample of 2,630 English children in 1999 show
that the frequency of overweight ranged from 22% at age 6 years to 31% at
age15 years and that of obesity ranged from 10% at age 6 years and 17% at age
15years.
The genetic basis of obesity has been elucidated to some extent through
the discovery of leptin, the ob gene product, and the increasing knowledge on
the role of neuropeptides such as for example proopiomelanocorticotropin
(POMC), the orexins, neuropeptide Y (NPY) and the melanocyte concentrat-
ing hormone and its receptors (MSH and MCR). Environmental/exogenous
factors largely contribute to the development of a high degree of body fatness
early in life. Twin studies suggest that approximately 50% of the tendency
towards obesity is inherited. Exogenous factors such as overconsumption of
fat-rich diets, the excessive use of modern media and in particular television
viewing and lack of physical activity (sedentary life style) heavily contribute
to the development of obesity particularly in childhood and adolescence. In
fact, four cross-sectional studies from national samples in the United States
demonstrated a statistically significant correlation between adiposity and tele-
vision viewing among children. 8- to 18-year-old children and adolescents
spend an average of about 4.5h per day watching television and videotapes and
playing video games. Those demographic groups at highest risk for obesity,
such as African-Americans and Latinos and children from families with low
income, tend to watch even more television than other US children. In addi-
tion, socioeconomic factors as such may heavily contribute to the development
of obesity of children and adolescents: in one recent study, teenagers in fami-
lies with low income were significantly more likely to be overweight than chil-
dren and adolescents in families with high income. Nutrition and diet early in
infancy is thought to influence growth rate and body fatness beyond infancy.
Whether obesity is mainly caused by excess energy intake or a reduction in
energy expenditure or physical activity is unclear. Some authors have sug-
gested that intrauterine growth retardation actually predisposes for the devel-
opment of obesity and syndrome X later in life. However, the evidence for fat
patterning resulting from differences in fetal or early postnatal nutrition is still
open to question.
Preface VIII
There are numerous disorders including a number of endocrine dis-
orders (Cushing’s syndrome, hypothyroidism etc.) and genetic syndromes
(Prader-Labhard-Willi syndrome, Bardet-Biedl syndrome, Cohen syndrome,
etc.) that can present with obesity at a very young age. A simple diagnostic
algorithm allows for the differentiation between primary or secondary obesity.
Among the most common sequelae of obesity in the adolescent are hyperten-
sion, dyslipidemia, back pain and psychosocial problems. The definition of
obesity in childhood and adolescence is not easy. However, BMI is now gener-
ally accepted to be used to define obesity in children and adolescents clinically.
Only in preadolescent boys does BMI relate to muscle mass as well and has to
be used for the definition of fat mass with great caution. An increased risk of
death from cardiovascular disease in adults has been found in subjects whose
BMI had been greater than the 75th percentile as adolescents. Therapeutic
strategies include psychological and family therapy, lifestyle/behavior modifi-
cation and nutrition education. The role of regular exercise and exercise
programs is emphasized. Surgical procedures and drugs used in adult obesity
are still not generally recommended for obese adolescents.
Obesity is the most common chronic disorder in the industrialized soci-
eties. Its impact on individual lives as well as on health economics has to be
recognized by physicians and the public alike: Obesity at a young age is a major
burden for the economy. The annual economic costs due to medical expenses
and lost income as a result of complications of adult obesity is estimated to
be as high as approximately 70 billion dollars in the USA. At least another 30
billion dollars are thought to be spent on diet foods, products and programs to lose
weight. If one is to calculate the prospective costs of obesity forms that have
started at an early age, the prospective financial costs are even higher. On the
other hand, sales and profits of the obesity treatment industry have already
reached an enormous sum. Therefore, obesity in childhood and adolescence has
already become a major factor in health care planning systems and within the
health care industry as such. However, in addition to the prospect of diminished
health, obese people are often stigmatized both socially and in the workplace.
This fact also contributes to the economic cost of obesity albeit in an unknown
and almost incalculable way.
This book aims to increase physicians’knowledge and understanding of
obesity in childhood and adolescence as well as to further public awareness of
the health burden and economic dimension of obesity at a young age. Several
chapters deliver insight into the basic understanding of which factors contribute
or prevent the development of overweight and obesity in young people. Other
contributions provide tools for the clinician to manage the care of the child and
adolescent with overweight/obesity. In addition, knowledge from the latest
scientific studies on the molecular biology of obesity is also presented.
Preface IX