Transcript IBD: Growth & Nutrition

PEDIATRIC IBD
Growth and Nutrition
By
Karla Au Yeung, MD
MAJ, MC, USAR
3 November 2000
Objectives
• Epidemiology/Definition
• Complications/ Mechanisms
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Malnutrition
Medication effects
Micronutrient deficiencies
Effects unique to pediatrics
• Specific Nutritional Therapy
Definition of Failed Growth
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Kleinman, et al
Dec Ht > 0.3 SD per year
growth velocity <5cm/yr
Dec ht velocity > 2cm from preceding yr
(during early to mid-puberty)
• Bone age and pubertal staging
Our Situation
• 25% of all IBD are pediatric --> infants
– CD > UC 4:1
• Growth failure is unique to pediatric IBD
– 30-50% of CD ped. Pts
– 10% of UC ped. Pts
• Malnutrition/micronutrient deficiencies
more likely due to increased metabolic
needs for growth
Our Situation cont.
• Sole manifestation of IBD in 5% of pts
• Resemble anorexia nervosa
– wt loss/anorexia sx more prevalent than GI sx
• IBD pts do not have disordered body image
or fear becoming fat
• Problem: heights (weights) do not get
recorded regularly for school-age kids
Problems We Face in This
Situation
• 1. Growth/Nutrition is a problem before we
meet the pt.
– Possible direct effects of inflam. mediators
– Anorexic effects of inflam. Mediators
• 2. Patients don’t feel well
– Post-prandial pain --> dec. intake
– anorexia (intake 55-80% of RDA of cal. Needs)
Complications cont.
• 3. Malabsorption
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Protein Losing Enteropathy
Bacterial Overgrowth
Dec. surf. Area for absorption
Lactose intolerance
Micronutrient deficiencies
Rapid transit
Micronutrient Deficiencies
• Iron deficiency anemia is most common
– Tx with iron dextran if resistant to oral Fe Tx
• Folate and B12
• Zinc deficiency (est. up to 40% pts)
– lower in growth impaired teens with CD
– Zinc repletion does not accelerate growth.
• Ca, Mg, Phos, Vit D - esp in adolescent pts.
Complications Cont.
• 3. Chronic Dec Energy and Protein intake
– not able to keep up with needs
– endocrine functions altered
– 56% RDA was mean caloric intake in one study
Complications Cont.:
Medications
• Steroids
– alter linear growth
– proteolytic/ osteolytic
– inhibit bone growth
• Sulfasalazine
– use folic acid
Complications Cont.
• 6. Time is our enemy
– Eventual closure of the epiphyses
– Stunted growth in 17% of pts with early delay
in growth
– Especially important in the peripubertal age
• 7. Elemental Formulas
– Can restore growth velocity
– Bad taste, need for NGT/G-tube
Growth Failure at Presentation
“Prepatterned”
• Motil, et al Gastroenterology 1993
• Regardless of pubertal development, at dx,
23-39% of pts had delayed growth
• Delay in linear growth persisted through
puberty and was not reversed by surgery
• Sig. Neg. assoc. between linear growth and
disease activity, but not medication Tx
Ht Velocity According to
Severity of Symptoms
• Severity GI Sx- Griffiths, et al Gut 1993
Severe
Moderate
Mild
Ht Vel.
Quiescent
Cm/yr
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Growth In Pediatric IBD
Gender Difference
• Sentongo, et al. JPGN 2000
• Prospective Study to measure
anthropometry, DEXA, genetic potential,
PCDAI, lifetime steroid use in relation to
gender and disease activity
• Results:
– Ht age Z inc. in male control compared to CD
pt. This difference not seen in females
Endocrinologic Issues
• Short stature evaluation:
– secondary to IBD
– constitutional delay
– genetically short stature
• Other hormones
– thyroid/growth hormone - non-contributory
– gonadotropins/estrogen- affected by
malnutrition --> delayed pubertal maturation
Endocrine Cont.
• Insulin-like growth
factor I
– mediates growth
– nutritionally modulated
– low levels during
fasting and quickly
return to nl w/ feeding
– low in CD who are
nutritionally
impaired
Factors Affecting Bone Mass in
IBD
• Hyams and others showed mouse calvarium
and serum from active CD had impaired
mineralization - not in UC or controls
• Osteoblast impaired by cytokine in CD
serum: IL-1B, TNFa, IL-6
• STEROID
– Dec. Formation (inhibit osteoblast)
– Inc. Resorption (dec. gut absorption, Inc. PTH)
Risk Factors for Low Bone
Mineral Density
• Semeao, et al J. Ped 1999
• Life long risk of frax related to peak bone
mass
• Peak bone mass is achieved during pubertyearly adulthood
• Reports of up to 70% CD children with dec.
BMD
• Evaluated several parameters for risks
Risk Factors for Low Bone
Mineral Density
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Inc. # hosp. Days
Inc. PCDAI
Hypoalbuminemia
NGT/TPN
Flagyl/Asacol
– unreliable because
such routine use
• 6MP (32% pts)
• >7.5 mg/day of
steroid exposure
• >5000mg accum
steroid use
• Duration of steroid
>12 mos
Low BMD Risks cont.
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NOT Correlated
Site of Dz
Age Dx
Duration DZ
H/o surgery
• Conclusion:
– Use this as criteria to
decide who needs
DEXA and when
– Risk of dec. bone mass
is not just due to
steroid use.
Labs to Evaluate Osteopenia
• Serum Ca, Phos, Alk Phos
• Vit D, Vit D metabolites, Alk phos
isoenzymes, GGT, PTH
• BONE AGE
– Impt for interpreting BMD
– Impt for estimating growth delay
• Dual Xray Densitometry/absorptiometry
– 1SD below mean = osteopenia
Treatment of Osteopenia
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Tx underlying disorder
Nutritional rehabilitation
Consider malabsorption and tx
Bone is mineralized at max dose of steroid
of 0.3mg/kg qod
• Substitute steroid for immunomod. Asap
• Ca supplement when well
Treatment of Osteopenia
• Vit D supplement: no evidence that excess
beyond RDA is needed
– except liver dz, deficiency, dietary restriction
• Weight Bearing exercise helps mineralize
bone
• Bisphosphonates
– dec. turnover of bone
– side effects/ longterm effects on growing bones
RDA for Calcium
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0-6 months
6-12 months
1-3 years
4-8 years
9-13 years
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210mg
270 mg
500 mg
800 mg
1300 mg
Dietary Calcium Sources
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Dairy products
Meat, fish with bone
Broccoli
Bok choy
Kale
Enteral Nutrition: Intro
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Possible Mechanisms:
1. Dec. Antigen load to the GI tract
2. Alter intestinal microbial flora
3. Dec. intestinal synthesis of inflammatory
mediators via reduction of dietary fat
• 4. Provision of micronutrients to diseased
bowel
Enteral Nutrition cont.
• Formula composition for protein and/or fat
source have not proven to make a difference
in studies
– Common practice for remission is elemental or
semi-elemental formula
• Dec. ratio of n-6 to n-3 polyunsat fatty acids
– dec. precursors for arachidonate-derived
eicosanoid synthesis (n-6) (fish-oil tx)
Enteral Nutrition Intro cont.
• Factors for Relative Benefit of Enteral
Nutrition as Primary Therapy
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Mostly small bowel dz
Prepubertal
Acute Malnutrition/Growth Failure
Motivated patient/family
• Not as good as steroid compared in metaanalysis (relapse 70% in one year)- but
growth improved on nutrition tx.
Enteral Nutrition Support
• Three possible strategies
• 1. Begin with nutritional therapy alone
– elemental formula only for 4-6 wks
• 2. Nutritional supplement to increase caloric
intake and reverse growth delay
• 3. Prevent relapses
– intermittent administration
Supplementary Enteral Nutrition
Maintains Remission
• Wilschanski, et al Gut 1996
• Tx 65 pts active CD with elemental formula
overnight 4-6 weeks: 72% remission
– 43% relapse by 6 mos
– 60% relapse by 12 mos
• If continued NGT fdg with daytime reg.
diet, even less relapse rate
• Suggest macro/micronutrient effect vs. Ag
Chronic Intermittent Elemental
Diet
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Belli, et al Gastroenterology 1988
7 boys/ 1 girl CD/growth delayed
1st year observe
2nd year, elemental diet group/control grp
– E. diet q 4months for 1 month
• Treat prn with medication (sulfa/pred)
RESULTS
• No pt dropped out
• Ave caloric intake of 133% during ED Tx
compared to 106% between tx.
• ED grp grew 7cm the 2nd year
• ED grp gained more weight
• ED grp dec. prednisone intake (22vs89
mg/kg/year)
• ED grp CDAI dec. significantly
Absolute Height Changes
7
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5
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Cm/yr
Obs yr
Exp yr
3-D Column 3
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2
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Elemental
Control
Conclusion to This Study
• This is tolerable and effective method for
maintaining remission with nutrition tx
• Not only did pts have increased height and
weight, but they also had dec. steroid use.
• In past studies, even though pts achieve
longer remission with steroids, linear
growth was not improved much
• problem: small study
Conclusions
• Growth delay is something intrinsic to
Crohn’s disease in addition to malnutrition
from a multitude of reasons.
• Induce remission and minimize daily
steroids ASAP - consider nutritional tx
• Improve energy/nutrient deficiencies
• Account for catch up growth
• Limited time available in puberty pt.