Download Cystic Fibrosis - Lindsay Esposito

Cystic Fibrosis & Vitamin D
Lindsay Esposito
Evidence-Based Medicine
Integration of the best research evidence with clinical
expertise, and the patient’s unique values and circumstances
• Purpose: improve patient outcomes by providing clinicians with highest
grade evidence available
• Pros: results have been shown in a large number of people
• Cons: individuals are different, funding issues, outdated, unsupported
claims, constant change
Ask relevant question
Acquire best evidence
Appraise validity
Apply results to patients
Assess effectiveness
CF: Background
• Inherited autosomal recessive disorder
• Epithelial cells and exocrine glands secrete
abnormal mucus
• Affects respiratory tract, sweat, salivary,
intestine, pancreas, liver, reproductive tract
CF: Symptoms
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Increase number of greasy stools
Abdominal Cramping
EFAD
High risk for malnutrition
Increased energy expenditure
Individualize throughout life span
CF: MNT Focus
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Enzyme therapy
Energy
Macronutrients
Antioxidants
Vitamins/Minerals
Feeding Strategies
CF: Treatment
• Airway Clearing Techniques
– Postural drainage and percussion
• Pancreatic enzyme supplements
• Inhaled medications
• Antibiotics
• Implanted devices
– Ports and PICCs
Cystic Fibrosis
• Most common lethal autosomal-recessive genetic
disease among Caucasian
• Affects 60,000 individuals worldwide, occurs in 1 in
every 2500 live births
• Leads to death or lung transplantation in more than
1000 people annually
Cystic Fibrosis
• Greatest single cause: respiratory disease
• Medical improvements/treating pulmonary
infections
• Recognition of bone disease which increases
with age
• Vitamin D: maximizes calcium absorption from
the lumen of the gut
Possible Causes of Low Vitamin D
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Decreased GI absorption
Impaired hydroxylation
Reduced sun exposure
Increased use of sunscreen
Season influence
Geographical location
Diminished and erratic absorption of ergocalciferol in
adult cystic fibrosis patients
Robert K Lark, Gayle E Lester, David A Ontjes, Angelina D Blackwood, Bruce W Hollis, Margaret M
Hensler, Robert M Aris
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Osteoporosis diminishes quality of life
Vitamin D and low bone mineral density
10 Control and 10 CF
CF patients matched with control based on age, gender, sex
2500 micrograms Vit D2 with meals
CF took pancreatic enzymes
Baseline blood samples at specific hour intervals
Results
• Vitamin D absorption significantly lower and variable in CF
• Ergocalciferol (D2) vs. cholecalciferol (D3)
• Large dose of vitamin D2 did not raise serum 25(OH)D
significantly
• Don’t absorb vitamin D2 efficiently less substrate for 25hydroxylase enzyme
• Rapid metabolic clearance
• CF: absorbed less than ½ oral vit D2 than controls over time
Discussion
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Vitamin D malabsorption correlated to low BMD
Do not convert into more active form like controls
>25 micrograms oral Vit D/d for adequate repletion
Individualize dosage
More vitamin D analogs
Further research needed
Study 1 Rating
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A
Randomized, well-controlled study
Generalizable
Other studies mentioned confirm results and
conclusions
– Need more research on exact dose
– Current dose of 20 micrograms vit D/day not
adequate
Cholecalciferol significantly increases 25hydroxyvitamin D concentrations in adults with cystic
fibrosis
Anne Stephenson, Michelle Brotherwood, Ronalee Robert, Eshetu Atenafu, Mary Corey, Elizabeth
Tullis
• Guidelines for Vit D not proven and effectiveness
untreated
• 360 adults with CF
• Determine prevalence of 25(OH)D and effectiveness of
supplementation with cholecalciferol
• Counseled on compliance or additional oral
cholecalciferol
• Baseline 25(OH)D less than or equal to 50 nmol/L
Results
• 69% had 25(OH)D baseline concentrations less than
or equal to 50 nmol/l, despite already having
cholecalciferol
• Current dosage 400-800 IU cholecalciferol/d
inadequate to normalize serum concentrations
• Lowest 25(OH)D seen in young: Lower BMI and less
pulmonary function (more at risk)
• Cholecalciferol increases with maximum response in
those with lowest baseline concentrations
Discussion
• Recent recommendations from CFF: 25(OH)D greater
than 75 nmol/L
• Highest risk in those with severe CF
• Brief, casual exposure to sun
• Additional 1000 IU/d
• Most effective way to normalize concentrations is
uncertain
Study 2 Rating
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B
Well-conducted cohort study
Large population size
Retrospective study design, not randomized
controlled
• Exact date of intervention not recorded
• Dosage results not recorded
• Randomized clinical trial needed to determine
dosage and treatment duration
References
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Lark, Robert K., Gayle E. Lester, David A. Ontjes, Angelia D. Blackwood, Bruce W.
Hollis, Margaret M. Hensler, and Robert M. Aris. “Diminished and erratic
absorption of ergocalciferol in adult cystic fibrosis pateints1’2’3.” The American
Journal of Clinical Nutrition 73.3 (2001): 602-606. American Society for Clinical
Nutrition, March 2001. Web. 24 Oct. 2015.
Stephenson, Anne, Michelle Brotherwood, Ronalee Robert, Eschetu Atenafu, Mary
Corey, and Elizabeth Tullis. “Cholecalciferol Significantly Increases 25hydroxyvitamin D Concentrations in Adults with Cystic Fibrosis1,2.” The American
Journal of Clinical Nutrition 85.5 (2007): 1307-1311. American Society for Clinical
Nutrition, May 2007. Web. 24 Oct. 2015.
Questions