Childhood obesity, childhood exposures, and adult

morbiditiesFrank Biro

Division of Adolescent Medicine

Cincinnati Children’s Hospital

Source: CDC Behavioral Risk Factor Surveillance System.

1998

Obesity Trends* Among U.S. AdultsBRFSS, 1990, 1998, 2007

(*BMI 30, or about 30 lbs. overweight for 5’4” person)

2007

1990

No Data <10% 10%–14% 15%–19% 20%–24% 25%–29% ≥30%

Trends in overweight for girls (BMI > 95%tile), by age and study

02468

1012141618

per

cen

tag

e o

verw

eig

ht

6-11 yo girls 12-19 yo girls

NHANES I

NHANES II

NHANES III

NHANES99

NHANES06

NHANES I ’71-74; NHANES II ’76-80; NHANES III ’88-94; NHANES ’99-00; NHANES ’03-6

Prevalence of “obesity” (BMI > 30) in girls 12-19 yo, by race and

ethnicity

0

5

10

15

20

25

30p

erce

nta

ge

ob

ese

non-Hispanic

white

non-Hispanic

black

Mexican-American

NHANES III

NHANES99

NHANES03

NHANES III: 1988-94; NHANES 1999-2000; NHANES 2003-2006

What is the impact of childhood obesity? What are the contributing

factors?• Most agree that onset of breast

development in girls has declined over the past 30 years in US– Greater decline in African American, contrasted

to white females, suggesting race (genetics) and environment interaction

– Does puberty serve as a sensitive and early indicator of genetic/ environmental interaction? (Parent 2004)

Pubertal onset in girls

Authors Year Age breast stage II

Reynolds & Wines 1948 10.8

Marshall & Tanner 1969 11.2

Harlan (NHES) 1980 12.8

Herman-Giddens (PROS)

1997 8.9/10.0

Sun (NHANES III) 2002 9.5/10.4

Biro (NGHS) 2006 9.8/10.4

Factors that contribute to age of pubertal onset

• 4-5 year variability in onset of puberty• Genetic• Behavioral/ environmental factors

– Health, public health issues – Nutrition/ overnutrition– (Lack of) physical activity– Environmental exposures

Factors impacting onset of puberty

• Genetic factors account for 30-70% of variability– Selective advantage in lower age of maturation

• Age of menarche as fitness trait• Advantage conferred in past, disadvantage contemporary• Cultural changes faster than genetic accommodations• “Stone Age genes in Space Age times” (Eaton)

– Thrifty phenotype (feast/famine, activity/rest; insulin resistance)

– Early menarche with later risk of hormone-dependent cancers

Factors impacting onset of puberty

• Single most important environmental factor is nutritional– Up to 25% of variance– Caloric density; carb sources; omega 6:3

• Studies suggest interaction between genetics and environment; studies have shown an interaction between BMI and race on age of onset of puberty

Physical (in)activity patterns

• YRBS has noted decreased physical activity among adolescents; odds of being inactive 1.3-1.6 more likely in 2003 contrasted to 1993– Inactivity rose by year; by grade; females >

males; more likely with lower SES

• Increased time in sedentary behaviors (TV, video games, computers); boys > girls for all

Environmental factors impacting pubertal onset

• Stress; nonbiologic adult male in household• Endocrine disruptors

– Androgen skin cream; shampoo w/ placenta extract– DDT-like pesticides and feminization of male gators;

immigrants to Europe/ precocious puberty/ DDE levels

– Food contamination in MI, flame retardant PBB– Earlier thelarche in PR; association with phthalates– Lead levels and delay in maturation– Phytoestrogens: agonists or antagonists?– BPA and LHRH pulse generator

Structure of xenoestrogens

EstradiolDibutylphthalate (DBP)

DES

Adapted from Kobayashi 2006

BPA

Sources of phthalates

• DEP: shampoo, scents, soap, cosmetics, medications;

• DEHP: soft plastics, food containers, packaging film/clear food wrap

Sources of phenols

• Phenols: parabens in personal care products – Triclosan: microbicide, including hand

sanitizers and toothpaste

• BPA: polycarbonate (Nalgene; liners for metal cans), dental sealant

Costs of childhood obesity

• Earlier maturation in girls– Data less clear in boys

• Body composition and BMI in adulthood• Association with insulin resistance,

metabolic syndrome• Puberty as a window of susceptibility to

environmental exposures• Adult morbidity and mortality

Costs of earlier maturation to contemporary teens

• Lower self esteem during adolescence and lower levels of body satisfaction

• Greater likelihood of depression• Greater likelihood of eating disorders• Greater perceived stress• Greater vulnerability to peer pressures• Younger ages sexual initiation, smoking,

drug use

Costs of earlier maturation to contemporary women

• Poorer adjustment in relationships• Lower lifelong academic achievement• Greater weight and BMI• Increased likelihood insulin resistance and

cardiovascular disease• Breast cancer with younger age of menarche• Relationship of childhood diet and physical

activity on subsequent adult morbidity

FFMI and FMI, by BMI group at age 9, and by age, NGHS girls

02468

101214161820

9 10 11 12 13 14 15 16 17 18

age

BM

I co

mp

on

en

t

FFMI hi

FFMI mid

FFMI lo

FMI hi

FMI mid

FMI lo

Biro, in press

We are changing human biology: Correlation of onset of puberty to age of

menarche, by study and year of birth

00.10.20.30.40.50.60.70.80.9

1

1933 1940 1947 1954 1961 1968 1975

year of birth

co

rrela

tio

n

12

3

4

5

67

1 Reynolds; 2 Bielicki; 3 Largo; 4 Taranger; 5 Marshall; 6 deRidder; 7 NGHS

Childhood diet and physical activity on subsequent adult

morbidity• Metabolic syndrome and childhood BMI• Cancer incidence and BMI

– Men: esophageal, thyroid, colon, renal– Women: endometrial, esophageal, gallbladder,

renal; breast (postmenopausal)

• Dietary intake and cancer (fiber, fish, fruit, bad fat)

• Physical activity and risk of cancer– Physical activity at ages 14-20 may be most

beneficial (Kruk 2007)

Potential mechanisms for childhood diet, activity, and morphology on

adult morbidity• Lifestyle patterns (diet, activity,

tobacco)• Tracking of obesity • Fat patterning • Role of insulin resistance• Adipocytokines

What can you recommend?• Dietary practices

– Limiting consumption of sugar-sweetened beverages; eating breakfast daily; limiting meals at fast food restaurants; encouraging family meals, eating together

• Physical activity patterns– Limit screen time to 2 hours daily; removing TV and

computers from bedrooms; participating in vigorous physical activity daily (AAP, NFL: 60 minutes daily)

• Recs similar to prevention of childhood obesity

What can you recommend?

• Eighty companies produce phthalate-free cosmetics– Lists available on line

• “Not too pretty”• “Skin Deep”

• Use products in moderation and with appropriate intention; avoid clear plastic wrap in microwaves; sun screen important, limit sun exposure

• Use of “organic” products

It’s Greek to me, but the Goddesses of Yesteryear lived well, though not long, and Today live longer

but…

Greece 2000 BC

USA 2000 AD

Age of menarche 17 12

Interval menarche-first birth

3 years 12 years

Number of children 6 1.8

Duration of breast feeding

3 years 0-6 months

Daily energy expenditure

20 kcal/kg/day

<5 kcal/kg/day

Age at death 40 years 75 years

Risk of breast cancer Unknown (low)

1:8

Stone Age genes in Space Age times (Eaton)

From J Pediatr Adolesc Gynecol. 2009; 22:3-6