Sandra Hassink, MD
Dupont Children’s Hospital
Thomas Jefferson University
Wilmington, DE
Jennifer Bass, MD
Oregon Health Science University,
Doernbecher Children's Hospital,
Portland, Oregon
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PRE-TEST (detailed explanations at the bottom):
Please pick best option or True/False
Q1. The Body Mass Index is calculated by:
A. Dividing the height in centimeters by the weight in kilograms.
B. Squaring the body surface area.
C. Dividing the weight in kilograms by the height in meters squared.
D. Dividing the height in inches by the weight in pounds cubed.
E. Multiplying the height times the weight.
Q2. A possible respiratory complication of obesity is:
A. Asthma
B. Upper airway obstruction
C. Restrictive lung disease
D. Pickwikian syndrome
E. All of the above
Q3. Laboratory studies you might order in an evaluation of an obese adolescent are listed below EXCEPT:
A. Lipid panel
B. Liver function tests
C. Androgens
D. Fasting insulin level
E. HgbA1C
Q4. In assessing potential lifestyle changes to encourage weight loss in an obese adolescent you would want information about: (Circle all that would apply)
A. The family system
B. The school environment
C. Peer interactions
D. Individual psychological issues
E. Family health behaviors
F. All of the above
OBJECTIVES
1. Understand how to calculate and plot Body Mass Index for the patient.
2. Be able to complete a comprehensive diagnostic assessment of an obese adolescent.
3. Be able to identify obesity related co-morbid conditions from the patient’s history and physical examination.
4. Understand the basis for the laboratory evaluation of the obese adolescent.
5. Identify an initial approach to address obesity in the context of the patient's psychological, physical, emotional, environmental and family circumstances.
FACILITATOR PREPARATION
1. Hassink, S. “Problems of the Obese Child” Office Management of Obesity, Ed George Bray, Saunders 2004 pg.73-91.
2. Dietz W. (1999 and 2005) Childhood obesity (in) Shils, ME, JA Olson, M Shike, and AC Ross. (eds) Modern nutrition in Health and Disease, 9th edition. Lippincott Williams and Wilkins, Baltimore, MD. pp 1071-1080 and..10th edition pp 979-990. Dr Dietz is Chair of the CDC obesity Section at the NIH. PubMed will provide his latest contributions to the literature.
3. Dietz WH and Robinson TN. Overweight Children and Adolescents. New England Journal of Medicine 2005; 352:2100-9.
4. Hassink, S. “Problems of the Obese Child” Office Management of Obesity, ed George Bray , Saunders 2004 pg.73-91.
CASE STUDY
Presentation:
Kamesha, a 13-year-old African American girl, comes to you for a yearly school physical. In the past year you note that she has gained 15 pounds with a current weight of 147 pounds and a height of 58.5 inches.
Her blood pressure was measured in her right arm at 122/80 mmHg.
Medical: In the past year she was seen by one of your partners for abdominal pain relieved by Zantac. She has no serious illnesses or accidents.
Questions:
1. What are the patient's weight and height percentiles?
2. Her BMI and BMI percentile?
3. Does she meet the classification for obesity?
Plot these values on the growth chart.
4. What is her blood pressure percentile? [Hyperlink to diet and hypertension]
5 Are there any other questions arising out of these measurements?
Answers
1. Her weight percentile is >95%, height 10%.
2. The Body mass index is weight in kilograms divided by the height in meters squared. You can also use weight in pounds; height in inches squared and multiply by 703. Her weight is 66.8 kg, (147lbs/2.2 lbs/kg), height is 148.5 cm (58.5in x 2.54 cm/in). Her Body Mass Index is 66.8 kg/ (1.48 m) 2 or 30.5.
3. This would classify her as obese.
4 Her blood pressure is just over the 95% for her height or for her age (95% is 120/79 mmHg).
5. As discussed in the module for Prader Willi Syndrome [Hyperlink], short stature is a warning sign that this may not be exogenous obesity. This information would raise the question of possible growth impairment/genetic problem. Previous growth data would be important to see if there was a linear growth deceleration, if so then an endocrinopathy such as Cushing’s disease, thyroid, or growth factor insufficiency. If the height has been steadily under the 10% then you may want to consider genetic factors such as Turner’s Syndrome, and other causes of short stature. In general it is unusual for a child to have a weight greater than the 95% and a height less than the 50% with normal height parents. Excess stimulus to growth with open epiphysis usually results in increased height unless endocrine, genetic or early pubertal epiphyseal closure intervenes. Knowing the parental height will also help put her height in context.
The Case study continued.
Further history reveals that she has a mother who is 5’ 6” tall
and father who is 6 feet tall. The next step is to complete a thorough review of systems and physical examination looking for obesity related co-morbidities.
Review of Systems:
Head: She complains of occasional self-limited headaches, usually when she is “stressed”.
Eyes: She wears glasses for myopia, denies any visual disturbance or ocular injury.
Ears: As an infant she had frequent otitis and tympanostomy tubes, hearing is normal.
Nose: No epistaxisis
Pharynx: She has occasional strep throat. Her dental care has been routine.
Pulmonary: She has some shortness of breath on exercise; she cannot say whether she experiences any feeling of “tightness” in her chest but notes it takes her “a long time” to get her breathing back to normal. Her mother says she does snore (as does her father) and there do seem to be “pauses” in her breathing at night.
Cardiac: She denies any chest pain or previous cardiac problems. She does note that she has trouble “keeping” up physically.
GI: She has occasional stomach pain treated with Zantac. No unusual vomiting, diarrhea or constipation.
GU: She is occasionally enuretic. She has had 1-2 urinary tract infections in the past. She had her first menstrual period at age 10. Her periods are still irregular with a fair amount of cramping. On examination she is in Tanner stage IV.
Musculoskeletal: She has some aching of her legs on exercise but denies any hip or knee pain or limping.
Skin: She has moderately severe acne and a history of eczema.
Question for residents:
What are you going to focus on for her physical exam?
TABLE 1. Findings of Physical Examination of an Obese Child Anthropometrics:
1. Plot Height, Weight, and BMI.
2. Look at growth pattern as well as magnitude.
3. Measure waist/hip ratio
4. Measure skin folds if possible
5. Manual blood pressure with correct size cuff
Skin
Evaluate for acanthosis nigricans, striae, hirsuitism, hydrandenitis supperativa, skin infections between skin folds, and skin picking.
HINT
Note adipose tissue distribution i.e. cervical fat pad, evaluation airway, examine thyroid and check fundi for any signs of papilledema and/or arteriolar nicking.
Chest and Abdomen
Note any gynecomastia, increased work of breathing, depth of ventilation, resting heart rate, murmurs, and liver size.
Extremities
Examine hip for slipped capital femoral epiphysis and knee for Blounts disease. Check for scoliosis.
GU
Note Tanner stage, penile size.
TEACHING CAPTION: Obesity has a pervasive impact on multiple body systems.
Physical Examination
Her weight was 147 pounds and height of 58.5 inches. Her heart rate is 84 bpm, Respiratory rate 20bpm.
Her blood pressure was measured in her right arm at 122/80 mmHg. Her leg blood pressure was 125/84. Her waist hip ratio was .99.
Head: Normocephalic with no scalp lesions.
Eyes: Pupils were equal and reactive, extra ocular muscles intact, fundiscopic examination was normal with flat disc margins and no arteriolar nicking.
Ears: Tympanic membranes slightly retracted, without fluid.
Nose: Clear with no obstruction
Pharynx: Tongue and palate midline and mobile. Tonsils 2+ without hyperemia.
Neck: No masses, no thyromegaly.
Lungs: Clear to auscultation.
Heart: Normal rhythm and no murmurs were heard.
Abdomen: No masses, tenderness, liver was palpated 1 cm below the right costal margin.
Tanner stage IV.
Musculoskeletal: Full range of motion of all joints without pain or tenderness.
Skin: Acanthosis nigricans of her neck crease with ridging. The axilla and groin are also affected.
Neurologic exam: No cranial nerve deficits or focal neurologic abnormalities.
Question for residents
Based on your evaluation of the patient, what obesity-related co-morbidities would you need to assess further and/or treat?
Table 2 provides a listing of systems related co-morbidities and their signs and symptoms.
TABLE 2. Obesity Related Co-morbid conditions —
Signs and Symptoms
Neurologic
Pseudotumor Cerebri Headache, vomiting, visual changes, particularly visual field cuts
Pulmonary
1. Upper Airway Obstruction, Sleep apnea, enuresis
2. Orthopnea, daytime tiredness, napping, poor school performance
3. Obesity related reactive Chest tightness, cough, shortness of breath on airway disease/exercise induced exercise asthma
Cardiovascular
1. Cardiomyopathy of obesity Dyspnea on activity, cardiac enlargement
2. Poor ventricular function
3. Hypertension Elevated blood pressure, left ventricular enlargement
4. Dyslipidemia Elevated cholesterol, Triglycerides, low HDL cholesterol
Orthopedic
1. Slipped Capital Femoral Epiphysis Limp, limitation of motion of hip, hip and or knee pain
2. Blount Disease Tibia Vera, knee pain
Gastrointestinal
1. Non alcoholic fatty liver disease Elevated ALT, AST, enlarged liver
2. Progression to fibrosis, cirrhosis
3. Gastroesophageal Reflux Abdominal discomfort, vomiting
Endocrine
1. Type II diabetes may present with diabetic ketoacidosis, polyuria
2. Polydipsia or discovered on routine exam. Rarely may present with Hyperosmolar, hyperglycemic state
3. Polycystic Ovary Syndrome Irregular menses, hirsuitism, acanthosis nigricans
Psychological
1. Depression Depressed affect, poor school performance
Suicidal ideation
2. Anxiety Excessive worries, emotional eating pattern
3. Poor self-esteem. Decreased participation in social/school, history of being teased
TEACHING CAPTION: Obesity in adolescence carries with it high risk for multiple interrelated co-morbidities. Of note, risk decreases and the co-morbidities often disappear with successful weight reduction Table from Hassink, S. “Problems of the Obese Child” Office Management of Obesity, ed George Bray , Saunders 2004 pg.73-91.
Q5. Which of these pertain to Kamesha?
1. Based on the patient’s complaints of shortness of breath on exercise you would want to investigate the possibility of exercise-induced asthma particularly since she has delayed recovery after exercise. The differential here would be exercise asthma versus deconditioning. You could document pulmonary function with PFT’s and treat for exercise induced asthma if diagnosed. This has implications for treatment since increasing activity will be on of your goals. A cardiac exercise test would document extent of deconditioning.
Upper airway obstruction needs to be considered here, with a history of snoring with pauses, 2 plus tonsils, a family history of sleep apnea. Her occasional enuresis might also be a symptom of untreated OSA. A sleep study is the only definitive way of making this diagnosis and treatment is weight loss in the long term and BiPAP in the short term. If severe and tonsils are large, referral to ENT for a Tonsillectomy and Adenoidectomy which may be helpful in the short term. It is interesting that school performance has declined, this may also be a sign of sleep apnea as children with sleep apnea have been documented to have short-term memory loss and defects in concentration.
Her irregular menses 3 years after onset of menses acne and acanthosis nigricans point to a possible Polycystic ovarian syndrome. This is commonly found in obese, insulin resistant adolescents. Diagnosis would be confirmed with measurement of elevated serum androgens and elevated fasting insulin. Ultrasound of her ovaries may show cysts. Treatment is aimed at regulating menses usually with oral contraceptives or glucophage, and lowering insulin resistance with weight loss.
This patient has several of the hallmark signs and symptoms of the dysmetabolic syndrome. The diagnosis of this syndrome in an adolescent would include 3 or more of the following 1) Obesity (BMI >95% for age and gender, 2) Elevated blood pressure (systolic and/or diastolic pressure >90% for age and gender), 3) Abnormal lipids (HDL-C <40 mg/dl, and /or Triglycerides >150 mg/dl, LDL .130 mg/dl 4) Impaired glucose tolerance (fasting glucose >110mg/dl, random glucose >200 mg/dl).
She meets the definition of obesity and hypertension. You do not yet know her lipid values but she does have a family history of dyslipidemia. She has signs of insulin resistance suggested by irregular menses, acanthosis nigricans, and a family history of type II diabetes and should be evaluated for elevated fasting insulin and impaired glucose tolerance. Kamesha has acanthosis nigricans, as do many obese, pre-diabetic, teenagers. The acanthosis often resolves with successful weight reduction at least in its early stages. The finding of ridging as well as darkening in axilla and groin are ominous signs.
You palpated her liver 1-cm below the right costal margin. Fatty infiltration of the liver is common in obese adolescents and 10% of patients will have elevation of liver enzymes indicating inflammation and possible fibrosis of the liver know as NASH (non alcoholic steatohepatitis). [Hyperlink to module] All obese patients should have liver enzymes measured. The only treatment is weight loss. For some of these patients, fibrosis will progress and liver transplantation for cirrhosis may be necessary.
Her blood pressure is >95% for age and gender and the incidence of hypertension is increased in obese patients, as is the increased incidence of insulin resistance in normal weight patients with essential hypertension.
Other co morbidities found in obese adolescents whom you evaluated this patient for but did not find are:
Slipped capital femoral epiphysis
Blount's disease
Pseudo tumor Cerebri
Q6. What laboratory/imaging studies would you order?
A6. A reasonable screening evaluation for an obese adolescent would include:
Fasting cholesterol, HDL-C, Triglycerides, glucose, insulin, HgbA1C, thyroid function, liver enzymes, cortisol.
Based on these patients findings additional studies are warranted. Her relative short stature might lead you to order IGF-1, and IGFBP3, as well as the cortisol level above. Genetic studies such as subtelomeric probes and evaluation for Turner’s Syndrome would not be unreasonable. Prader Willi Syndrome is the most common mono genetic disorder associated with obesity and would usually present with a neonatal history of failure to thrive, poor feeding followed by hyperphagia around age 1-2, developmental delay and behavior problems with compulsive eating.
Possible exercise induced asthma would be confirmed with pulmonary function testing.
A sleep study is the “gold standard” for diagnosing upper airway obstruction.
Polycystic ovarian syndrome [formerly Stein Leventhal Syndrome] would be confirmed with elevated fasting insulin, elevated androgen levels, an ultrasound of the ovaries may also demonstrate ovarian cysts.
This patient has several of the hallmark signs and symptoms of the dysmetabolic syndrome. The diagnosis of this syndrome in an adolescent would include three or more of the characteristics shown in Table 3.
TABLE 3. Characteristics of the Dysmetabolic Syndrome in Adolescents
1. Obesity - BMI >95% for age and gender
2. Elevated blood pressure - systolic and/or diastolic pressure >90% for age and gender
3. Abnormal lipids – HDL-C <40 mg/dl
4. Abnormal lipids - Triglycerides >150 mg/dl
5. Impaired glucose tolerance - fasting glucose >110mg/dl or random glucose >200 mg/dl
TEACHING CAPTION: While not on this list, a waist > hip circumference in a boy (>0.84) in a girl), or an LDL of >130 mg/dL, or an insulin to a glucose ratio of greater than 1:7 (insulin > 14% of glucose) would be suggestive of the Dysmetabolic Syndrome. Intervention would be warranted.
If there are elevated liver function studies, further Evaluation of NASH would include studies to rule out other liver pathology (GGT, Hepatitis B surface Ag, Hepatitis C Ab, IGG, ANA, Copper assay, Alpha 1 antitypic phenotype, liver/kidney microtonal Ab and ultrasound of the liver to document fatty infiltration).
Q7. How would you address the life-style issues facing Kamesha?
A7. As you begin to identify obesity related co morbid conditions, all of which respond to weight loss, you also need to begin to organize a plan of lifestyle intervention encompassing the domains of nutrition, activity and inactivity. You need to gather enough information about her nutritional environment, activity/inactivity level and resources for change to begin working on her obesity.
You need to assess nutrition, activity and inactivity. The best way to do this is to ‘walk’ with your patient through a typical day.
Q8. What factors do you need to assess with regard to her nutritional environment? Her activity/inactivity environment and her resources for change?
A8. These are listed below in the categories of diet, physical activity, life at school, interaction with peers and her family history.
Diet: Kamesha is skipping breakfast and eating a school lunch with occasional snacks from the vending machines at school. After school she says she eats “whatever I can find” which is often snack food or leftovers. She generally eats a cooked dinner with her family, eating out about once/week. She often has an evening snack of cereal or ice cream. She drinks regular soda or juice between meals.
Physical Activity: She does not have physical education this term. She does not participate in any regular physical activity and seldom goes outside after school.
Inactivity: She watches 5-6 hours of TV/Computer/day during the school week and 7-8 hours/day on the weekend.
School: Her school performance has declined since last year, and she is having some trouble focusing in class and on her homework.
Peers: She is not participating in any extracurricular activities, but she has friends in school and keeps in touch with mainly by e-mail after school.
With this data in hand you need to assess Kamesha and her family’s motivation for change. A family history can often provide motivation for change in health behavior. You find that:
Family History: Her mother is 49 years old and is 5 feet 6 inches tall with a weight of 190 lbs. and has been recently diagnosed with Type II diabetes. Her father is 6 feet tall and weighs 225 lbs. and has hypertension and dyslipidemia. Her 15-year-old brother is in good health but was diagnosed with ADHD in 4th grade. The paternal grandfather died at age 60 of a myocardial infarction. The maternal grandfather died in an accident in his 40’s. Both grandmothers are living; the maternal grandmother also has Type II diabetes.
Q8 How would you begin working on a lifestyle intervention?
Here is an opportunity for a role playing exercise in which each character is given 2 possible slips of paper and then picks one: Cooperative/Uncooperative Kamesha; Cooperative/Uncooperative Mom; Cooperative/Uncooperative Dad. Other persons can be added to the mix: The grandmother, the babysitter, and the school principle. Mix characters’ slips in a hat. Every participant picks a role at random. They then draw one of two cards for that character – Cooperative or Uncooperative. Play out roles for a while. The Resident or physician leader tries to bring everyone to a cooperative role. See what you can do if the principle dad and mother of Kamesha both want help.
Here’s one scenario for a starter: You ask Kamesha how her weight is a concern for her. She says she is not concerned at all, has no trouble with teasing or physical activity. Her mother however states that she (mother) is worried about diabetes particularly because of her recent diagnosis as well as a strong family history.
Intervention strategies:
1. Identify a goal
2. Determine how you are going to help the family make change
3. Provide ongoing support for change.
A methodology for constructing interviews is presented in the Introduction to the case studies [hyperlink]
1. Listen
You ask your patient what her current concerns are and she says she is worried about her schoolwork and feels “stressed”. You ask about the stress and she says that it has been hard for her to keep her mind on her work and she is having trouble keeping up. Mom chimes in and says that she doesn’t understand why her daughter doesn’t want to “do more” and seems to want to come home from school and “tune out” with the TV.
2. Reflect and connect the concerns
You ask Mom if she is concerned about her daughters school work and she says she is. You note that her daughter is finding it hard to focus, and mother says is the same problem her son has. You wonder with the patient if there might be a connection between her stress after school and her eating and TV. She says, “There might be”.
3. Provide information
You note that many children with Attention problems are not hyperactive and the diagnosis is often delayed in girls. You also note that children with ADD perform best when they have a structured setting and an organized plan. You say that it is not uncommon for children and adolescents who feel stress to turn to TV/Computer and food as relief and that if there is high calorie food around they will eat it. You note that peer activities, outdoor time, and family activities are often helpful alternatives.
4. Focus on implementation
You ask mom how she thinks she might help her daughter and she says she will talk to the school and ask for help and possible testing for ADD. You offer to help her with a schedule for her daughter’s after school time, which would include outside time and limit TV. You also work with mom to provide alternative foods to the high calorie snack foods and beverages she has been eating. You ask your patient what else she can do that would help her feel less stressed; she is puzzled at first but says she might be interested in joining a school club.
5. Monitor the outcome
You schedule another visit in 2-3 weeks to see if they were able to make any of these changes and measure the impact on her weight as well as to monitor your ongoing intervention into the co morbid conditions. On that follow up visit you begin the intervention cycle again.
In looking at the end point of this intervention, what are the patient’s and family’s goals and what are your goals as her doctor?
In this case, Kamesha was not worried about the weight, but was feeling problems at school and home. Related to this, she was willing to make behavioral changes: better scheduling of schoolwork and TV and looking for a school activity. Her mother was worried about diabetes, her school performance, and her inactivity at home. Her mother could provide healthier snacks and talk to school about testing for ADD. Of course, as her pediatrician, you are worried about her weight and the possible medical consequences of her weight, but for this family, behavior change goals are probably the most helpful at this time.
Other possible goals include the following:
Table 4: Maintaining treatment with obese children at whatever level of success they achieve
1. Slowing of weight gain
2. Weight stability
3. Weight loss
4. Metabolic Fitness
5. Treatment of a co morbid condition
6. Arresting the progress of a co morbidity
TEACHING CAPTION: It is worth noting that 90% of reduction in co-morbidities is achieved with 10% of weight loss. Success means being able to lead a healthy life with self-confidence in their appearance.
ANNOTATED ANSWERS
A1. The answer is C – weight in kg divided by the square of the height in meters. The changes seen with this particular ration seem to match metabolic processes quite well. Weight over height cubed (the Ponderal index) has been used in infants, and for small children we continue to use weight for height curves adjusted for age on a curve rather than with a number.
A2. The answer is D – all of the above. Obese children have substantial respiratory difficulties associated perhaps with the shear mass of the weight borne.
A3. The answer is C. While it is true that there is an early puberty with chronic obesity, it is not necessary or appropriate to measure androgens or other sex hormones unless there is true premature puberty. Obesity is associated with hepatic and coronary heart diseases as well as Type 2 DM.
A4. The answer is F. No single factor in predicting or sustaining obesity should be singled out. Anything affecting the life of an obese child should be considered as either a direct or indirect antecedent.
