Transcript Bone Risks and Lifestyle Factors

Bone Risks and Lifestyle
Factors
Barbara Hastings-Asatourian
MSc, BNurs, Cert Ed, RN, RM, RHV, NDN
Cert, SP General Practice Nursing
Pre and Post Natal AIM Module Leader
Copyright Barbara HastingsAsatourian 2002
A presentation about how
lifestyle can influence the
development of osteoporosis
and osteopaenia
Copyright Barbara HastingsAsatourian 2002
Definitions
• Osteoporosis
• “A systemic skeletal disease characterised
by low bone mass and micro-architectural
deterioration of bone tissue with an
increase in bone fragility and susceptibility
to fracture.” I.e. Bone mineral density of
more than 2.5 standard deviations below
the young adult mean.
• Osteopaenia
• Bone density lies between 1 and 2.5
standard deviations below the mean for
young adults.
Copyright Barbara HastingsAsatourian 2002
Definitions (2)
• Primary Osteoporosis
• Type One
– Mainly affects trabecular bone characterised by
vertebral and Colles (wrist) fractures. E.g. Postmenopause
Type Two
– Age related, over 80 years characterised more
by hip, humerus, and tibia fractures
• Secondary Osteoporosis
Associated with medical conditions and
certain drugs Copyright Barbara HastingsAsatourian 2002
Other medical causes
• Premature menopause
• Hysterectomy and oopherectomy (removal of
womb and ovaries)
• Hyper-prolactinaemia
Rheumatoid arthrtis
• Inflammatory bowel disease (colitis or Crohn’s)
• Chronic liver or kidney disease
• Hyperthyroidism (excess of the thyroid hormone
thyroxine)
Hyperparathyroidism
• Treatment with corticosteroids (more than 7.5mg
prednisolone per day for over 6 months) inhibits
Barbara Hastingsosteoblast activity Copyright
Asatourian 2002
The shape of osteoporosis
Copyright Barbara HastingsAsatourian 2002
The UK Context
• Every year there are an estimated
–230,000 osteoporotic fractures each
year
–Approx 60,000 hip
–120,000 vetebral compression fractures,
of which 2 thirds may go undetected
–50,000 wrist fractures
Copyright Barbara HastingsAsatourian 2002
(DoH 1999)
• The fundamental problem in the
osteoporosis is the imbalance of
osteoblast and osteoclast activity
Copyright Barbara HastingsAsatourian 2002
Bone growth
• From conception to teen years, a
balanced diet containing sufficient
calcium and vitamin D is critical for
proper growth and development
• Children who are accustomed to
nutritious diets tend to make healthy
promoting food choices as adults,
• This provides the means of achieving
optimal health, enabling a buildup of
bone mass that can be drawn from
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Asatourian 2002
Bone growth into adulthood
• During teens, the hormones oestrogen and
testosterone affect bone size and strength
• By 17, < > 90% of the adult bone mass will be
established.
• By 21, calcium is no longer added to bones
• By 30 loss of calcium from bones begins
• In a recent survey in US the recommended calcium
intakes were achieved by only
35.1% of males age 12-19,
14.4% of females age 12-19,
45% of males 20-29,
17.8% ofCopyright
females
age 20-29
Barbara HastingsAsatourian 2002
The Role of Nutrition
• “Given the fact that approximately
30% of bone mass is influenced by
exogenous factors (with nutrition
clearly being one of the key factors
open to modification), careful
consideration as to the effect of
nutrition on the skeleton is fully
justified”
Source:Susan
New 2001
Copyright
Barbara HastingsAsatourian 2002
Calcium Intake
• Recommended Intake/ Ages *Amount mg/day
Birth - 6 months
210
6 months - 1 year
270
1-3
500
4-8
800
9-13
1300
14-18
1300
19-30
1000
31-50
1000
51-70
1200
1200
70 or older
(Source: National Dairy Council)
Copyright Barbara HastingsAsatourian 2002
Vitamin D
• Vitamin D facilitates calcium transfer from to
intestine to bloodstream.
• Vitamin D acts in the kidneys resorbing calcium
preventing its excretion in the urine.
• Food sources of vitamin D are vitamin Dfortified dairy products (e.g. margarine), egg
yolks, saltwater fish and liver.
• Some calcium supplements and most
multivitamins contain vitamin D.
• Recommended daily intake is 400 - 800
international unitsCopyright
(IU).
Barbara HastingsAsatourian 2002
Sunshine source
• Vitamin D is derived from exposure of the
skin to solar ultraviolet B radiation
• Vitamin D is manufactured in the skin
following direct exposure to sunlight,
depending on time of day, season, latitude
and skin pigmentation.
• 10-15 minutes exposure of hands, arms and
face two to three times a week (depending
on skin sensitivity) is enough.
Copyright Barbara HastingsAsatourian 2002
Dress Style
• Some studies of “hypovitaminosis D in a
sunny country” have shown significant
problems in population groups who restrict
their skin exposure for cultural and religious
reasons
• Dress covering the whole body has adverse
effects on vitamin D status and the potential
for causing secondary hyperparathyroidism
in the long term.
Copyright Barbara HastingsAsatourian 2002
El-Hajj Fulleihan 1999
Seasons and latitudes
• Winter months in northern latitudes increase
the risk of vitamin D deficiency and
consequent bone loss.
• Woitge et al from the University of
Heidelberg, Germany, reported that lowdose supplementation with calcium (500
mg/day) and vitamin D (500 IU/day) during
the winter months prevented bone loss in a
group of 10 men and 20 women.
Copyright Barbara HastingsAsatourian 2002
Sunscreens
• Use of sunscreen markedly diminishes
the manufacture of vitamin D in the
skin, as do window glass, clothing and
air pollution.
• Skin colour also affects vitamin D
production; the fairer the more
Vitamin D is made
Copyright Barbara HastingsAsatourian 2002
Other Nutritional Factors
• High Protein Diets increase acidity
and increase calcium loss from bone
• Salt promotes urinary excretion of
calcium
Copyright Barbara HastingsAsatourian 2002
• One hypothesis linked the average diet
to the development of osteoporosis.
• The higher incidence of osteoporosis
with age may represent production of
acid related to nutritional intake.
Kidney function reduces with age and
older people are therefore more acidic
(Wachman and Bernstein 1968)
Copyright Barbara HastingsAsatourian 2002
Fruit and Vegetable Trial
• 459 subjects were given a diet for 8
weeks:
(1) Control
(2) A diet rich in fruits and vegetables
(3) A combination diet rich in fruits and
vegetables with low-fat dairy
products.
Copyright Barbara HastingsAsatourian 2002
Findings
• An increase in fruit and vegetable intake
from 3.6 to 9.5 daily servings decreased
urinary Calcium excretion
• Fruit and vegetable diet provided a
reduced acid load compared with the
control diet.
Copyright
Barbaraet
HastingsSource:
Chen
al 2001
Asatourian 2002
Body Image
• In spite of evidence about the relationship
between bone health and BMI it is still
fashionable in the West to have a low BMI
• “Fat” is still used as a derogatory term
• Does our industry have a role here?
• Has the industry perpetuated the current
negative view of BMI > 19 when up to 25 is
healthy?
Copyright Barbara HastingsAsatourian 2002
Dieting
• Weight loss has been shown to be associated
with increased bone resorption
• Teenagers with a history of eating disorders
can develop osteoporosis
• Young girls and teenagers are the most
deficient in calcium and vitamin D.
• Uninformed dieters tend to cut out dairy
products because they consider them too
fatty
• Low fat milk mayCopyright
have
higher
levels
of
Barbara HastingsAsatourian
2002
calcium, but lacks fat
soluble
vitamins.
• Milk is a high source of calcium and girls
often find it difficult to make up the amount
through other food
• There are plenty of other sources (see
handout)
• The most important time to ensure calcium
and vitamin D levels are adequate is while the
bones are being formed. Peak bone mass is
achieved by the age of 30
• Diet and exercise could protect people from
Copyright Barbara Hastingsosteoporosis throughout
their life.
Asatourian 2002
Eating Disorders
• Eating disorders and over-exercise syndrome
may suppress of hormones controlling
menstruation (Low body mass index - less
than 19kg/m sq)
• The disorders may impair the achievement of
peak bone mass and cause early bone loss.
• Danish study. Those with anorexia nervosa
and bulimia were 2-3 times more likely to
suffer a fracture than other women.
• Increased fracture risks persisted for up to
Copyright Barbara Hastings10 years after diagnosis.
Asatourian 2002
Older people and diet
• Older people are at risk of vitamin D
deficiency is older people, particularly
those in residential homes.
• Elderly people need nutritious food to
optimise bone health
• Older people become more “acid”
Copyright Barbara HastingsAsatourian 2002
Ageing and Vitamin D
• As adults age, the ability to make
vitamin D through the skin decreases.
• People who are housebound and
experience no sunlight exposure are
unable to make vitamin D, and get
little weight bearing exercise.
Copyright Barbara HastingsAsatourian 2002
Hormonal effects
• Circulating oestrogen is very significant
• Menopause and amenorrhoea (absent
menstrual periods) pose serious risks
• The longer the time between a woman's first
period and the onset of menopause, the
better her chances of surviving a broken hip.
• Having children later in life and being
overweight also appear to cut the risk of
death as the result of a fracture
Copyright Barbara HastingsAsatourian 2002
• The study:
• 63,000 women over a 29 year period.
• Of these, 465 died as a result of a hip
fracture in the course of the study.
• If gap between first menstrual period and
menopause is less than 30 years increases
they were found to be twice as likely to die
from the fracture than those with a 38 year
gap.
• If mothers age at birth of first baby was
over 35 there was also a lower risk of a fatal
hip fracture.
Copyright Barbara HastingsAsatourian 2002
Risk factors
• Few of the women had used hormone
replacement therapy.
• Women with more reproductive years were
exposed to oestrogens for longer
• Oestrogens maintain bone strength.
Source: Journal of Epidemiology and
Copyright Barbara HastingsCommunity Health.
Asatourian 2002
Pregnancy and Lactation
• Pregnancy causes a low BMD with additional
losses in the first 5 months of lactation.
• There are little data examining the longterm effect of high oestrogen levels of
pregnancy on bone health.
• Calcium requirements of growing baby are
suggested to be the cause of the loss.
(KolthoffCopyright
et Barbara
al 1998)
HastingsAsatourian 2002
HRT
• HRT can significantly reduce the risk of
developing osteoporosis, but only if taken
long term at the optimum dose.
• Oestrogen HRT can prevent bone fracturing,
but its effect wears off within five years of
stopping it.
• HRT taken for more than five years has
shown 70% less likelihood of suffering bone
fractures than if no HRT taken
• Available as pills, patches, implants, gels,
Copyright Barbara HastingsAsatourian 2002
rings.
Exercise (1)
• Two principal mechanisms determine adult
bone health:
(1) the maximum attainment of peak bone
mass (PBM), which is achieved during growth
and early adulthood
(2) the rate of bone loss with advancing age,
with the menopausal years being a time of
considerable concern for women.
Copyright Barbara HastingsAsatourian 2002
Exercise (2)
• Physical activity
plays a crucial role in
both the attainment
of Peak Bone Mass in
the early years and
in the reduction of
bone loss in later
life.
Copyright Barbara HastingsAsatourian 2002
Exercise (3)
• X-ray of arms of a tennis
player, the bones in the
playing arm are bigger and
denser than the bones in the
other arm.
• Elite female athlete runners
have been shown to have
significalntly higher bone
mineral densities in their
lower limbs than rowers.
(Wolman et al 1991)
Copyright Barbara HastingsAsatourian 2002
Exercise and HRT Study
(Kapsabelis et al, 2001)
• A Greek study examined the influence 6months high-strain exercise on bone mass of
the tibia in 56 postmenopausal women
Copyright Barbara HastingsAsatourian 2002
• Subjects were grouped.
• 1 group undertook a 60-minutes of
aerobics, bench and rope jumping, and
resistance training, 3 times per week
over a 6-month period;
• 2 group acted as control, taking no
exercise. Results showed
improvements in total bone mass,
total bone density, subcortical bone
mass, and lean muscle area.
Copyright Barbara HastingsAsatourian 2002
• Subjects were also tested for
psychological well-being and functional
fitness. Results showed significant
improvements in the subjects who
undertook physical activity.
• High-impact exercise stimulates
accrual of bone mineral content in the
skeleton. Lower-impact exercises, such
as walking, have also been found to
have beneficial effects
Copyright Barbara HastingsAsatourian 2002
Resistance Training
• Resistance exercises use muscular strength
to improve muscle mass, improve posture and
balance and strengthen bone, e.g. using free
weights and / or machines.
• Layne and Nelson (1999) showed positive
effects on bone density of resistance
training
Copyright Barbara HastingsAsatourian 2002
Running, Tai chi, Stretching
• In a study of Chinese men and women
over 60 years of age
• Data was collected on past and
current physical activities, and the
length of time spent on recreational
activities. Results indicated that time
spent on was associated with
increased BMD.
• Most significant effect on bone
health included running, Tai Chi, and
Barbara Hastingsstretching. Copyright
Asatourian 2002
Weightlessness
• In a recent study examining bone loss in 15
Russian cosmonauts, cancellous bone mineral
density (BMD) loss at the weight-bearing
tibial site occurred after the first month in
space and deteriorated with mission
duration.
• With 6 months in space, losses ranged up to
23% - clearly a problem for long-distance
space travel.
Copyright Barbara HastingsAsatourian 2002
Caffeine Consumption,
• No conclusive evidence exists as yet
of an association between caffeine
consumption and rates of hip bone
loss
• So far there are no trends toward an
association between lifetime caffeine
consumption and risk for hip fracture
Source: Homan et al 2001
Copyright Barbara HastingsAsatourian 2002
Alcohol Intake
• positive effect of moderate alcohol
intake (2 units a day) on whole body
and spinal BMD, using wine
consumption
• negative effect of regular excessive
alcohol intake (> 14 units a week)
Source: Illich et al 2001
Copyright Barbara HastingsAsatourian 2002
Smoking
• Bone mass in smokers has been found to be
significantly lower than that of non-smokers
• Smoking increases the lifetime risk of
– vertebral fracture by 13% in women and 32% in
men
– hip fracture by 31% (for women) and 40% (for
men) Furthermore, they note that.
• Smoking has an independent, dose-dependent
effect on bone loss, which may be partly
reversed in part by stopping.
Copyright Barbara
Hastings- and Klesges 2001)
(
Ward
Asatourian 2002
UK Government
Recommendations
 Adopt a healthy lifestyle to maintain
bone health
 Stop smoking all together
 Avoid excessive alcohol (some is good!)
 Get an adequate calcium and Vitamin D
intake
 Exercise regularly
 Maintain a healthy body weight
Copyright Barbara HastingsAsatourian 2002