Bone Mineral Density, Osteoporosis, and the Risk of Fracture in Celiac Disease Kathleen Wildasin, MA

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Bone Mineral Density, Osteoporosis, and the Risk
of Fracture in Celiac DiseaseKathleen Wildasin,
MAMedical/science writer
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We Have Celiac Disease Why Are We Talking About
Bones?

• People with celiac disease (CD) can experience a
  variety of signs and symptoms that involve
  multiple organ systems, including the skeleton
• Numerous studies in the US and elsewhere have
  investigated the bone health of children and
  adults with CD
• The following three questions are of interest to
  me and may be of interest to you
• ? What do the experts currently know
  about the effect of treated and untreated CD on
  bones in children, adolescents, and adults?
• ? Should people with CD monitor their
  bone health and take extra steps to keep bones as
  healthy as possible?
• ? Should people with seemingly
  unexplained osteoporosis be tested for CD?

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The Boot A Good Reason for Bone Chatter
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A Vocabulary Checklist

• Lets take a minute to review the following
  definitions
• ? Bone mineral density
• ? Osteoporosis
• ? Osteopenia
• ? Dual energy x-ray absorptiometry (DEXA
  or DXA)
• ? T-score
• ? Z-score

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What is Bone Mineral Density and How is it
Measured?

• Bone mineral density (BMD) refers to the amount
  of calcium and other minerals contained in a
  segment of bone
• ? The higher the bone mineral content,
  the denser the bone
• BMD can be measured in several ways
• ? The goal standard for measuring BMD is
  dual energy x-ray absorptiometry (DEXA or DXA)
• Source Mayo Clinic website

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Why is Bone Mineral Density Measured?

• Doctors measure BMD to determine if a patient
  hasor is at risk of developingosteoporosis
• A DEXA scan can be used to
• ? Screen for the presence of osteoporosis
• ? Quantify the severity of osteoporosis
• ? Predict future fracture risk
• ? Monitor the progression of osteoporosis
• But, what is osteoporosis?
• Sources Mayo Clinic website National
  Osteoporosis Foundation

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What is Osteoporosis?

• Osteoporosis means porous bones
• Osteoporosis is a skeletal disease characterized
  by the deterioration of the microarchitecture of
  bone
• Osteoporosis can lead to brittle bones, bone
  fragility, and increased risk of fracture
• Sources American College of Obstetricians and
  Gynecologists Dorlands Medical Dictionary Mayo
  Clinic website

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How is DEXA Performed?

• DEXA scans measure bone density in the hip and
  spine
• During the test, the patient lies on a padded
  table while an imager passes over the body
• The imager does not touch the patients body, but
  the test does emit radiation
• The radiation emitted during DEXA is usually
  about 1/10 of the amount emitted during a regular
  chest x-ray
• DEXA is painless, noninvasive, and does not
  require any preparation prior to testing
• Source Mayo Clinical website

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How Are the Results of DEXA Quantified?

• BMD measured by DEXA scanning is expressed in
  units of g/cm2 and is compared to two reference
  populations
• ? A young normal population
• ? An age-matched population
• Young normal
• ? Your BMD value is compared with that
  of a healthy 30-year-old person
• ? The comparison is expressed as a
  T-score
• Age-matched
• ? Your BMD value is compared with that
  of someone your age and body size
• ? The comparison is expressed as a
  Z-score
• Source National Osteoporosis Foundation

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How Are DEXA Results Interpreted?

• The World Health Organization (WHO) has devised
  definitions of osteoporosis based on T-scores
• To understand the WHO definitions, you will need
  to know the meaning a statistical term standard
  deviation (SD)
• Standard deviations are commonly used to describe
  the spread or distribution of datain the case of
  T-scores, standard deviation describes the spread
  between your score and that of a healthy young
  adult
• Source National Osteoporosis Foundation

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WHO Definitions of Osteoporosis

• The WHO definitions of osteoporosis are as
  follows
• ? Normal bone density is within 1 SD of
  the young adult average
• ? Osteopenia (low bone mass) bone density
  is 1 to 2.5 SD below the young adult average
• ? Osteoporosis bone density is 2.5 SD or
  more below the young adult average
• ? Severe (established) osteoporosis bone
  density is more than 2.5 SD below the young adult
  average and the patient has experienced one or
  more osteoporotic fractures
• Source National Osteoporosis Foundation

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Who is at Risk of Developing Osteoporosis?

• Several factors play a role
• ? Age (risk increases with age in both men
  and women)
• ? Sex (women face a greater risk than men)
• ? Family and personal history of fracture
  as an adult
• ? Race (Asian and white women face a
  greater risk than African American and Hispanic
  women white men seem to be at greater risk than
  men of all other races)
• ? Bone structure and body weight
  (small-boned and thin women are at greater risk)
• ? Menopause/menopausal history in women
  (early or normal menopause increases risk)
• ? Undiagnosed low levels of testosterone in
  men
• ? Lifestyle (cigarette smoking, excessive
  alcohol, inadequate calcium, or lack of
  weight-bearing exercise increases risk)
• ? Medications to treat chronic medical
  conditions may increase risk (e.g.,
  glucocorticoids, antacids containing aluminum,
  methotrexate for cancer)
• ? Chronic diseases, including celiac
  disease
• Source National Osteoporosis Foundation

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Applying the Definitions

• John, a 42-year-old white accountant, has been a
  heavy smoker and moderate drinker for 20 years
  and has taken several medications known to damage
  bone. He is 62, weighs 240 pounds, and
  exercises daily. John acknowledges having a bad
  diet and cannot consume dairy products because he
  is lactose intolerant. After breaking his leg
  from a minor fall while walking to get the mail,
  his doctor ordered DEXA scanning. John was
  surprised that his T-score was -2.4.
• What is Johns diagnosis?

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BMD in Children and Effect of a GF Diet Study
Conducted in Turkey

• BMD was measured in 34 children with CD at
  diagnosis, 28 children who had been on a GF diet
  for 1 year, and 64 healthy children
• The average values of BMD in the newly diagnosed
  children were significantly lower than those of
  both the treated children and the healthy
  children
• The average values of BMD in the treated children
  were not significantly different than those in
  the healthy children
• The researchers concluded that a strict GF diet
  improves bone health even in a short period of
  time (in this case, 1 year) and that early
  diagnosis and treatment of CD in childhood may
  protect a child from the development of
  osteoporosis
• Source Kavak et al. J Pediatr Gastroenterol
  Nutr. 200337434-436.

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BMD in Children and Adolescents and Effect of a
GF Diet Study Conducted in Portugal

• BMD was measured in 17 children with CD, 13
  adolescents with CD, and 23 healthy children and
  adolescents
• All of the children and adolescents with CD were
  on a GF diet a greater number of adolescents
  than children started the GF diet after the age
  of 2
• BMD in adolescents with CD who were on a GF diet
  was significantly less than that in healthy
  adolescents
• BMD in children with CD who were on a GF diet was
  not different from that in healthy children
• Does the key to success lie in early initiation
  of the GF diet?
• Source Carvalho et al. J Pediatr (Rio J).
  200379303-308.

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BMD in Children and Effect of a GF Diet Study
Conducted in Argentina

• BMD was measured in 24 children at diagnosis of
  CD and about 1 year after treatment with a GF
  diet
• Average age of the children was 4.9 years 16
  children were younger than age 4 years, and 8
  children were older than age 4 years
• At diagnosis of CD, Z-score was 1 SD below normal
  in 58 of the children
• After about 1 year of treatment with a GF diet,
  Z-score increased by more than 1 SD in 15 of the
  16 children who were younger than age 4 years,
  but in only 4 of the 8 children who were older
  than age 4 years
• The researchers noted that the younger children
  all followed the GF diet strictly, whereas some
  of the older children did not
• Source Tau et al. Eur J Clin Nutr.
  200660358-363.

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BMD in Adults and the Effect of a GF Diet Study
Conducted in England

• BMD was studied in 21 adults in the first year
  after diagnosis of CD and initiation of a GF diet
  and compared with BMD measurement 1 year later
• The initial measurement of BMD at the lumbar
  spine and femoral neck was significantly lower in
  the adults with CD than in a comparator group of
  healthy adults
• After 1 year, the adults with CD had a gain in
  BMD at the lumbar spine of 16.6 and in the
  femoral neck of 15.5 no significant change in
  BMD was observed in the comparator group
• Although treatment of CD with a GF diet led to
  significant increases in BMD, the adults with CD
  still had lower BMD than those in the comparator
  group
• Source McFarlane et al. Gut. 199639180-184.

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Should People with CD be Screened for
Osteoporosis?

• According to researchers, results of a study
  conducted in England do not support the screening
  of BMD at diagnosis of CD
• In 43 newly diagnosed patients with CD who
  underwent DEXA scanning, osteoporosis was found
  at the hip in 7 of patients and at the spine in
  14 of patients
• Mean Z-scores were not significantly reduced
• BMD did not seem to be associated with duration
  of gluten exposure, symptoms, degree of villous
  atrophy, or smoking
• Source Lewis and Scott. Eur J Gastroenterol
  Hepatol. 2005171065-1070.

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Should People with Osteoporosis be Screened for
CD? One Study Says Yes

• According to researchers, results of a study
  conducted at the Washington University Bone
  Clinic (St. Louis) justify serologic CD screening
  in all people with osteoporosis the prevalence
  of CD was higher in people with than without
  osteoporosis
• People with osteoporosis (n266) and without
  osteoporosis (n574) were evaluated by serologic
  CD screening
• Twelve people with osteoporosis (4.5) and 6
  people without osteoporosis (1.0) tested
  positive for CD by serologic screening
• Subsequent biopsies were performed in all but 2
  of the serologically positive individuals the
  prevalence of biopsy-proven CD was 3.4 in those
  with osteoporosis and 0.2 in those without
  osteoporosis
• Antitissue transglutaminase levels were
  associated with the severity of osteoporosis
  measured by T-score (i.e., the more severe the
  CD, the more severe the osteoporosis)
• Source Stenson et al. Arch Intern Med.
  2005165393-399.

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Should People with Osteoporosis be Screened for
CD? An Editorialist Commenting on the Previous
Study Says No

• Alan L. Buchman, MD, of the Feinberg School of
  Medicine at Northwestern University, says of the
  previous study
• The cost to prevent a single fracture in a
  patient with celiac disease and osteoporosis
  would be 43,000. This cost would be far greater
  for a patient with osteopenia, to say nothing of
  a population screen . . . Not all investigations
  have reported an increased prevalence of celiac
  disease in individuals with osteoporosis or an
  increased fracture risk in patients with celiac
  disease . . . As is often the case, further study
  is indicated.
• Source Buchman AL. Arch Intern Med.
  2005165370-371 and a public press release of
  his comments.

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Risk of Fracture in People with CD Study
Conducted in Argentina

• Researchers compared 148 people with a wide
  clinical spectrum of CD with 296 age- and
  sex-matched individuals who had gastrointestinal
  disease
• People with classical CD symptoms had an
  increased number of fractures compared with both
  the age- and sex-matched population and people
  with CD who had subclinical/silent disease
• Femoral neck Z-score was also better in patients
  with subclinical/silent CD than in those with
  classical CD symptoms
• Source Moreno et al. Clin Gastroenterol Hepatol.
  20042127-134.

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Risk of Fracture in People with CD Study
Conducted in England

• Researchers used the General Practice Research
  Database to compare fracture risk in 4732 people
  with celiac disease and 23,620 age- and
  sex-matched individuals
• Analysis of the data showed that people with CD
  had only a small increased risk of fracture
  compared with the reference population
• The researchers concluded that concerns regarding
  a markedly increased fracture risk in CD are
  unwarranted
• West et al. Gastroenterology. 2003125429-436.

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Risk of Fracture in People with CD Study
Conducted in Sweden

• Researchers used a statistical model to estimate
  the future risk of hip fracture and fracture of
  any type in more than 13,000 people with celiac
  disease and 65,000 age- and sex-matched
  individuals
• The analysis showed that CD was positively
  correlated with subsequent hip fracture and
  fracture of any type in both children and adults
  and that CD may be positively associated with
  long-term risk of hip fracture
• Source Ludvigsson et al. Aliment Pharmacol Ther.
  200725273-285.

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Risk of Fracture in Men vs. Women with CD

• Risk of fracture due to secondary causes, such as
  CD or taking medications that can adversely
  affect the bones, is more likely in men than
  women
• In general, men do not experience rapid bone loss
  in their 50s in the way that women do
• Men are usually diagnosed with osteoporosis only
  after theyve fractured a bone
• At present, 10 million people in the US8 million
  women and 2 million menhave osteoporosis
• Osteoporosis in men remains underdiagnosed and
  underreported
• Sources National Institutes of Health Word on
  Health National Osteoporosis Foundation

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What do the experts currently know about
the effect of treated and untreated CD on bones
in children, adolescents, and adults?Should
people with CD monitor their bone health and take
extra steps to keep bones as healthy as
possible?Should people with seemingly
unexplained osteoporosis be tested for CD?
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The Jury is Still Out
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What Can I Do Right Now?

• Adequate amounts of calcium, vitamin D, and
  exercise are important for maintaining healthy
  bones
• ? Ask your doctor to map out a plan that is
  right for you
• Consult with your doctor about available
  pharmacologic options for preventing or treating
  osteoporosis

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Role of Calcium in Bone Health and Recommended
Daily Amount

• Getting the recommended amount of calcium is
  essential for maintaining bone strength and may
  aid in preventing osteoporosis-related fracture
• The National Osteoporosis Foundation recommends
  the following amount of calcium
• ? 1,000 mg/day in adults younger than
  age 50 years
• ? 1,200 mg/day in adults age 50 years
  and older

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Calcium
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Role of Vitamin D in Bone Health

• Vitamin D plays a critical role in calcium
  absorption and bone health
• Vitamin D3 (also called cholecalciferol), the
  form of vitamin D that best supports bone health,
  is manufactured in the skin after direct exposure
  to sunlight
• Food sources of vitamin D include fortified milk,
  egg yolks, saltwater fish, liver, and supplements
• Source National Osteoporosis Foundation

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Vitamin D
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Recommended Amount of Vitamin D

• The National Osteoporosis Foundation recommends
  the following amount of vitamin D
• ? 400 to 800 IU of vitamin D3 daily in
  adults younger than age 50 years
• ? 800 to 1,000 IU of vitamin D3 daily in
  adults age 50 years and older
• Source National Osteoporosis Foundation

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Exercise
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Role of Exercise in Bone Health

• Resistance exercise helps to strengthen the
  muscles and bones in your arms and upper spine
• ? Examples Free weights and weight
  machines
• Weight-bearing exercise primarily affects the
  bones in your legs, hips, and lower spine
• ? Examples Walking, jogging, dancing,
  stair climbing
• Swimming and cycling can provide a good
  cardiovascular workout, but are low impact and
  therefore not as helpful for improving bone
  health
• Always check with your doctor before beginning an
  exercise program
• Sources Mayo Clinic website National
  Osteoporosis Foundation

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Strict Adherence to the GF Diet
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Parting Thoughts

• Always try to put CD into perspective
• ? The treatment for CD is simple and
  requires no pills, no medical devices, no
  surgery, no chemotherapy, no transplants, and no
  injections
• ? The absence of pharmacologic
  treatment means that the potential for side
  effects, which are often worse than the disease
  itself, does not exist
• Find the discipline required to strictly adhere
  to a diet that is really not that bad anyway
• Try to avoid food envy and making normal
  eaters feel guilty
• Use the GF dietand the vast knowledge youve
  acquired to get thereto your advantage
  experiment with healthy new recipes and cuisines
  
• Remember that if you cheat on the GF diet, youre
  cheating on only one (very important) person