Childhood Obesity: Assessments,
Cardiometabolic Risk, and
Interventions
Can We Predict Prediabetes
and Cardiac Risk Profile in
Overweight African
American Adolescents
Patricia A. Cowan, PhD, RN
University of Tennessee Health Science Center
Funded by NIH-NINR and GCRC
Obesity: A Worldwide
Concern



Worldwide there are 1 billion
overweight or obese adults.
In the United States, 65% of adults are
overweight or obese---The prevalence
has doubled since 1980.
Parental obesity associated with
childhood obesity.
(2004). Obesity—Big is beautiful? The Globalist: retrieved March 1, 2003
from www.theglobalist.com/DBWeb/printStoryId.aspx?StoryId=3326
Obesity Trends: U.S. Adults
BRFSS, 1990
(*BMI ≥30, or ~ 30 lbs overweight for 5’ 4” person)
No Data
<10%
10%–14%
Obesity Trends: U.S. Adults
BRFSS, 2008
TN
#2 –Adult
obesity
#6 –Childhood
obesity
(*BMI ≥30, or ~ 30 lbs overweight for 5’ 4” person)
No Data
<10%
10%–14%
15%–19%
20%–24%
25%–29%
≥30%
Prevalence of Overweight &
Obesity Among Youth in the
United States (1999-2008)
Overweight
Obese
(BMI for age ≥85%)
(BMI for age≥ 95%)
1999-2000
28.2
13.9
2001-2002
30.0
15.4
2003-2004
33.6
17.1
2007-2008
31.7
16.9
Year
Ogden, C.L., et al. (2006). JAMA, 295 (13), 1549-1555 and Ogden et al (2010)
JAMA, 303(3):242-249.
Disparities in Obesity and
Overweight Among 6-19 Year
Olds in 2007-2008
Groups
Boys
Girls
Overweight
%
Obese
%
Overweight Obese
%
%
Total
35.3
20.1
34.1
17.3
Caucasian
33.4
18.2
31.6
15.6
African
American
34.4
18.9
43.3
25.9
Hispanic
American
43.1
26.7
40.5
19.5
Ogden, C.L., et al. (2010). JAMA, 303(3):242-249
Why the Concern?




Childhood obesity persists into adulthood
Linked to subsequent morbidity &
mortality, including type 2 diabetes and
cardiovascular disease
Costly--$129 billion directly attributed to
obesity
Escalation in costs if development of
diabetes and cardiovascular diseases
Evolution of Childhood Type 2 Diabetes
in the Greater-Memphis Area
120
100
80
60
40
20
Since 1990, in the Memphis area, 10-fold increase in
diagnosis of type 2 diabetes mellitus in children.
In children, shorter latency period from prediabetes
to diabetes.
The NHANES 1999-2000 data revealed an 11%
prevalence of prediabetes in children.
ADA estimates 2 million teens (or 1 in 6 overweight
adolescents) aged 12-19 have pre-diabetes.
0
1990
1992
1994
1996
1998
2000
2002
2006
2008
Cardiovascular Risk (CVR)
Factors in Obese Youth



Current screening recommendations for
obese youth include fasting insulin and
glucose, blood pressure, and lipid profile
if family history of hyperlipidemia.
Typically clinicians refer older, more
severely obese youth with a family history
of diabetes for metabolic evaluation
Perception that diabetes drove the
development of CVR factors in youth.
Who Should be Screened?



Inadequate resources to screen all
overweight youth for diabetes and CVR
factors.
Need to identify which youth are at
greater risk for developing metabolic and
cardiovascular abnormalities.
Determine whether current screening
recommendations relevant across ethnic
groups.
Diabetes Screening: 150
Overweight or Obese Children
155
145
135
GLU0
125
Ctrl
115
OB-NGT
105
OB_IGT
95
85
75
65
80
100
120
140
160
180
200
220
GLU120
66% of youth who had IGT (pre-diabetes or diabetes
based on OGTT) had normal fasting blood glucose
Similar Cardiovascular Risk Factors in Obese AA
Teens with T2DM and Obese AA Non-DM Teens
60
T2DM
Non-DM
Percent
40
*
20
0
FIB >400
CRP >0.5
BP>95th%
*p<0.05 between groups
Chol >170
LDL>110
TRI >150
HDL <35
Purpose

Examine the interaction of severity
of obesity, physical activity (fitness),
diet, insulin resistance and family
history in predicting pre-diabetes
and a cardiac risk profile in
overweight-obese AA adolescents.
Design & Sample



Descriptive, correlational
122 overweight-obese 11-18 year
African-American (AA) adolescents
(age=14.8 ± 2.1 yr), 57% female
Non-diabetic, no medications that
affect glucose tolerance, femalesnegative pregnancy test. 97% had
acanthosis nigrican
Methods: Demographics
and Family History

Age

Gender

Tanner Stage

Parental report of family history of
type 2 diabetes or early myocardial
infarction in child’s parents or
blood relatives.
Methods: Obesity Severity

Body Mass Index (BMI)
BMI= Weight in kg
Height in m²
Relative BMI= BMI
50th% BMI

x 100
Whole body DXA scan (Hologics)
with segment measures of fat,
bone, and lean mass.
Methods: Prediabetes

Oral glucose tolerance test

Prediabetes =
75 gm maximum)


(1mg/kg,
Fasting blood glucose > 100 mg/dl or
2-hr post load glucose > 140 mg/dl
Methods: Insulin Resistance

Fasting and OGTT derived indices

QUICKI = 1/(log FI μU/ml+ log FBG)

CISI= 10000 / [SQRT (FI x FBG) x
(mean insulin (0-120 min) x mean
glucose (0-120 min)]
Methods: CVR Factors
Fasting blood samples for







Homocysteine (>12 mcg/M)
High-sensitivity C-reactive Protein (>2 mg/L)
Fibrinogen (>350 mg/dl)
PAI-1 (>43 ng/ml)
Standard lipid profile: triglycerides >150 mg/dl;
cutpoints for total cholesterol, LDL-cholesterol,
HDL-cholesterol based on age and gender
normative data (Jolliffe 2006)
Lp(a) (>20 mg/dl)
LDL particle size (<25.9=Pattern B)
Blood pressure (per NHLBI guidelines)
Self-report of tobacco use.
Methods: Dietary Intake


3-day diet diary analyzed for micro
and macronutient content using
Nutribase Clinical Nutritional
dietary software program.
Multi-pass approach with the use of
food models and queries.
Methods: Activity/Fitness

7-Day physical activity recall



Days/week of > 30 minutes of
moderate or more intense physical
activity
Sit hours per day
Maximal cardiopulmonary exercise
testing (VO2 peak)
Statistical Analysis




Data log-transformed if not normally
distributed
Logistic regression to predict prediabetes
Multiple regression to predict cardiac risk
profile
Substitution of DXA for BMI measures of
obesity severity and fitness for physical
activity in models.
Results: Anthropometrics

BMI
36.4 ± 7.9

Relative BMI
185.1 ± 40.4

Percent fat mass
42.4 ± 7.4
Percent trunk mass
activity (day/week)
42.2 ± 8.3

Physical Activity and Fitness

VO2peak
(mg/kg/min):
21.5 ± 6.3
> 30 min moderate+
activity (day/week)
2.6 ± 1.8

Sit (hours/day)
10.5 ± 2.7

Walk
81.9 ± 62.8



(min/day)
Only 4 youth (3.3%) engaged in
recommended amounts of physical activity.
97% had very poor or poor levels of fitness
Results: Macronutrients
Energy intake 1791 ± 626 kcal/day;
estimated underreporting of 940 kcal/day
Kcal/day
(Mean ± SD)
Percent of
Intake
268 ± 99
15.2 ± 3.1
Carbohydrates
865 ± 333
48.3 ± 6.2
Fat
657 ± 246
36.5 ± 5.5
Protein
Physical Activity and Fitness

VO2peak
(mg/kg/min):
21.5 ± 6.3
> 30 min moderate+
activity (day/week)
2.6 ± 1.8

Sit (hours/day)
10.5 ± 2.7

Walk
81.9 ± 62.8



(min/day)
Only 4 youth (3.3%) engaged in
recommended amounts of physical activity.
97% had very poor or poor levels of fitness
Results: Pre-diabetes

OGTT on 119

28 (23.5%) had prediabetes


8 of these youth had normal fasting, but
abnormal 2 hr glucose
Thus, 29% of youth with prediabetes
would have been missed if the OGTT had
not been performed.
Results: Insulin Resistance

CISI < 2.0
77 (69.4%)

QUICKI <0.3
68 (57.1%)

Some degree of acanthosis nigricans in
97%.
Results: CVR factors
CVR Factor
CVR Factor
Lp(a)
Abnormal
N (%)
94 (78.3)
CRP-hs
71 (59.2)
Homocysteine
7 (5.8)
Fibrinogen
71 (59.2)
LDL-cholesterol
7 (5.8)
PAI-1
60 (50.4)
4 (2.3)
HDLcholesterol
Hypertension
58 (47.5)
Total
cholesterol
Small LDL
particle size
Triglycerides
32 (29)
Tobacco Use
Abnormal
N (%)
9 (7.3)
1 (0.8)
1 (0.8)
Results: CVR Factors

# of CVR factors 3.9 ± 1.6

36% had five or more CVR factors
Model: Pre-diabetes



Logistic regression to predict
prediabetes
Variables entered: Obesity severity
(BMI, RBMI or fat mass), physical
activity or fitness, family history, insulin
indices, diet, adjusting for tanner stage,
age, and gender
Model did not predict prediabetes
Model: Cardiac Profile



Backwards multiple regression for
cardiac profile.
Higher severity of obesity and positive
family history of MI predicted cardiac
profile retained in all models.
Age (younger), Tanner score (lower),
obesity severity, insulin resistance
(greater), and positive family history of
MI predicted 33% of the variance in the
cardiac profile.
Discussion
Compared to NHANES data:


prediabetes was more common in these
predominantly sedentary, overweight
AA adolescents.
emerging cardiac risk factors were more
prevalent
Contrary to the literature, fitness and
physical activity did not predict prediabetes nor the cardiac profile.
Research Conclusions


Current screening recommendation
underestimate metabolic and cardiac
risk of obese AA adolescents.
Because neither age, severity of obesity,
or family history of T2DM predicted
prediabetes in overweight AAA, these
demographics should not be used to
limit screening for prediabetes in this
population.
Research Conclusions

Future studies are needed to determine
the interactions between biomarkers,
behaviors, and obesity severity to
predict early CVD in obese AA
adolescents.
Childhood Obesity
Treatments
Target Factors Contributing
to Obesity in Youth


Nutritional Factors
Physical Inactivity
Consider Other Factors
Contributing to Childhood
Obesity

Medical Conditions

Pharmacological Treatments

Genetic Conditions

Other (Abuse, etc)
Lifestyle and Behavioral
Interventions



Family-based behavioral weight-management
interventions have generally yielded positive results
in children (McLean, 2003; Epstein, 1994; Reinehr,
Brylak, Alexy, Kersting, and Andler, 2003).
Parents strongly influence their children’s dietary
intake and level of activity through modeling and
reinforcement of eating and lifestyle habits.
Additionally parents determine food options and
opportunities for physical activity (Morgan, 2002 ).
Dietary-Behavioral-Physical
Activity Interventions
• Three month duration effectively decreased BMI
• Exercise minimally 3 x week 45 minutes
• Balanced hypocaloric diet
• Counseling
• Modest BMI reductions -1.7 vs. a gain of 0.6
for the control group
Inpatient (Immersion)
Programs?

2006 study

Diet-based on RDA for age and low fitness level

Physical activity-90 minutes 3x week or more


Cognitive behavioral therapy: modificationindividual and group sessions
Impressive BMI decline!!
-Girls-38.4 ± 4.1 down to 28.4 ± 4.1
-Boys-34.5 ± 3.2 down to 25.5 ± 2.3

2011 review: 191% greater reductions in %
overweight at post-treatment and 130%
greater reduction at 12month follow-up
Kelly, K. P., & Dirschenbaum, D. S. (2011). Obesity Reviews, 12(1):37-49.
Challenges with Home
Lifestyle Behavioral
Treatments
Portion Sizes
How Much Exercise Is
Needed?



Physical activity 60
minutes everyday
Limit physical
inactivity
Issues with length of
school day, homework,
technology (computer,
gaming, TV), safety
concerns
Anti-Obesity Medications
•
•

Anti-obesity medications are usually
reserved for those patients who have
failed diet, exercise, and behavioral
interventions (Kaplan, 2005).
Approved by the Federal Drug
Administration for weight loss in adults:
appetite depressant (phentermine,
sibutramine), and inhibitors of fat
absorption (orlistat).
(Ionnides-Demos, Proietto, & McNeil, 2005)
In Overweight Youth with
Impaired Glucose Tolerance
Impaired glucose tolerance is characterized by insulin
resistance with high levels of insulin production (betacell function is preserved)
Treatment should be geared toward improving insulin
sensitivity (decreasing insulin resistance) while
preserving beta-cell function.
Treatment focus is on diet, weight loss, increase physical
activity, medications to improve insulin sensitivity…also
look at other risk factors that may need intervention
Additional Treatments if
Associated Co-Morbidities



Metformin and other insulinlowering drugs
Lipid-lowering drugs
High blood pressure medicines
Ornstein, R.M. & Jacobson, M.S. (2006). Adolescent Medicine
Clinics, 17 (3), 565-587.
Bariatric Surgery for Obese
Youth
Medically supervised weight loss management
Failed at ≥6 months
BMI
related
≥40 with serious obesityco-morbidities
co-
or BMI ≥ 50 with less severe
morbidities

Physiologic maturity
Attained or nearly attained

Medical and Psychological evaluations
Demonstrated commitment
before and after surgery

Agreement to avoiding Pregnancy
At 1 year postoperatively

Informed consent
Must provide

Decisional Capacity
Must provide

Family environment
Supportive





_____________________________________________________________________________
Inge et al., 2004. Serious obesity-related co-morbities (Diabetes type 2, obstructive sleep apnea, and pseudotumor cerebri);  less severe
co-morbidities (hypertension, dyslipidemia, nonalcoholic steatohepatitis, venous stasis disease, significant impairment in activities of daily
living, interiginous soft-tissue infections, stress urinary incontinence, gastroesophageal reflux disease, weight-related arthropaties that
impair physical activity, and obesity related psychosocial distress
Evidence for
Management





Multidisciplinary approach
Family involvement
Behavioral/Lifestyle remains key
component
Medication MAY be used as adjunct
Bariatric surgery—last resort
COFFEE
20 Years Ago
Today
Coffee
(with whole milk and sugar)
Mocha Coffee
(with steamed whole
milk and mocha syrup)
45 calories
8 ounces
How many calories
are in today's coffee?
COFFEE
20 Years Ago
Today
Coffee
(with whole milk and sugar)
Mocha Coffee
(with steamed whole
milk and mocha syrup)
45 calories
8 ounces
350 calories
16 ounces
Calorie Difference: 305 calories
Maintaining a Healthy Weight is a
Balancing Act: Calories In = Calories Out
How long will you have to walk in
order to burn those extra 305
calories?*
*Based on 130-pound person
Calories In = Calories Out
If you walk 1 hour and 20 minutes,
you will burn approximately 305
calories.*
*Based on 130-pound person
MUFFIN
20 Years Ago
210 calories
1.5 ounces
Today
How many calories
are in today’s
muffin?
MUFFIN
20 Years Ago
210 calories
1.5 ounces
Today
500
calories
4 ounces
Calorie Difference: 290 calories
Maintaining a Healthy Weight is a
Balancing Act: Calories In = Calories Out
How long will you have to vacuum in
order to burn those extra 290
calories?*
*Based on 130-pound person
Calories In = Calories Out
If you vacuum for 1 hour and 30
minutes you will burn approximately 290
calories.*
*Based on 130-pound person
CHICKEN CAESAR SALAD
20 Years Ago
390 calories
1 ½ cups
Today
How many calories are
in today’s chicken
Caesar salad?
CHICKEN CAESAR SALAD
20 Years Ago
390 calories
1 ½ cups
Today
790 calories
3 ½ cups
Calorie Difference: 400 calories
Maintaining a Healthy Weight is a Balancing Act
Calories In = Calories Out
How long will you have to walk the dog
in order to burn those extra 400
calories?*
*Based on 160-pound person
Calories In = Calories Out
If you walk the dog for 1 hour and 20
minutes, you will burn approximately 400
calories.*