Copyright Barbara Hastings-Asatourian 2002
Bone Risks and Lifestyle Factors
Barbara Hastings-AsatourianMSc, BNurs, Cert Ed, RN, RM, RHV, NDN
Cert, SP General Practice NursingPre and Post Natal AIM Module Leader
Copyright Barbara Hastings-Asatourian 2002
A presentation about how lifestyle can influence the
development of osteoporosis and
osteopaenia
Copyright Barbara Hastings-Asatourian 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 Hastings-Asatourian 2002
Definitions (2)• Primary Osteoporosis• Type One
– Mainly affects trabecular bone characterised by vertebral and Colles (wrist) fractures. E.g. Post-menopause
Type Two– Age related, over 80 years characterised
more by hip, humerus, and tibia fractures
• Secondary OsteoporosisAssociated with medical conditions and certain drugs
Copyright Barbara Hastings-Asatourian 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 osteoblast activity
Copyright Barbara Hastings-Asatourian 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(DoH 1999)
Copyright Barbara Hastings-Asatourian 2002
• The fundamental problem in the osteoporosis is the imbalance of osteoblast and osteoclast activity
Copyright Barbara Hastings-Asatourian 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 later
Copyright Barbara Hastings-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 only35.1% of males age 12-19,
14.4% of females age 12-19, 45% of males 20-29,
17.8% of females age 20-29
Copyright Barbara Hastings-Asatourian 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 Hastings-Asatourian 2002
Calcium Intake
• Recommended Intake/ Ages * Birth - 6 months6 months - 1 year1-34-89-1314-1819-3031-5051-70
70 or older
(Source: National Dairy Council)
Amount mg/day210270500800130013001000100012001200
Copyright Barbara Hastings-Asatourian 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 D-fortified 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 units (IU).
Copyright Barbara Hastings-Asatourian 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 Hastings-Asatourian 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.
El-Hajj Fulleihan 1999
Copyright Barbara Hastings-Asatourian 2002
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 low-dose 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 Hastings-Asatourian 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 Hastings-Asatourian 2002
Other Nutritional Factors
• High Protein Diets increase acidity and increase calcium loss from bone
• Salt promotes urinary excretion of calcium
Copyright Barbara Hastings-Asatourian 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 Hastings-Asatourian 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 Hastings-Asatourian 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.
Source: Chen et al 2001
Copyright Barbara Hastings-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 Hastings-Asatourian 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 may have higher levels of calcium, but lacks fat soluble vitamins.
Copyright Barbara Hastings-Asatourian 2002
• 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 osteoporosis throughout their life.
Copyright Barbara Hastings-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 10 years after diagnosis.
Copyright Barbara Hastings-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 Hastings-Asatourian 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 Hastings-Asatourian 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 Hastings-Asatourian 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 Hastings-Asatourian 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 Community Health.
Copyright Barbara Hastings-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 long-
term effect of high oestrogen levels of pregnancy on bone health.
• Calcium requirements of growing baby are suggested to be the cause of the loss.
(Kolthoff et al 1998)
Copyright Barbara Hastings-Asatourian 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, rings.
Copyright Barbara Hastings-Asatourian 2002
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 Hastings-Asatourian 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 Hastings-Asatourian 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 Hastings-Asatourian 2002
Exercise and HRT Study (Kapsabelis et al, 2001)
• A Greek study examined the influence 6-months high-strain exercise on bone mass of the tibia in 56 postmenopausal women
Copyright Barbara Hastings-Asatourian 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 Hastings-Asatourian 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 Hastings-Asatourian 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 Hastings-Asatourian 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 stretching.
Copyright Barbara Hastings-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 Hastings-Asatourian 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 Hastings-Asatourian 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 Hastings-Asatourian 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.
(Ward and Klesges 2001)