Osteoporosis – And Who Is At Risk

What is osteoporosis?

Osteoporosis is a bone-thinning condition but it is by no means new.  The Romans were referring to non-healing hip fractures and other similar-sounding conditions in the 6^th century.  By the early 19^th century, physicians were concerned about the ‘spongy’ texture of bones in old age, even before they were able to see them on X-ray.

Osteoporosis is a silent insidious disease linked to hormonal changes at the time of the menopause.  Inevitably as we age there will be some bodily changes, such as the natural thinning of the bones in both men and women’s skeletons and weaker muscles less able to support the bones. Changes may also occur in the joints with arthritis, rheumatism and backpack being painful reminders of the passing years.

Today osteoporosis is regarded in many cases as a preventable disease although there is still a great deal we don’t know about it.  Despite its association with ageing and the menopause, the condition can also affect younger women and men.  Although more cases are being diagnosed, it doesn’t necessary follow that osteoporosis is on the increase bu that more of us are living longer, and so the chance of osteoporosis increases with longevity and the condition is more recognisable as osteoporosis by doctors who are fully aware of the effects of bone thinning.  Other reasons why many women present with osteoporosis include excessive dieting, poor nutrition, sedentary lifestyles and lack of exercise and young women who miss or have irregular periods or suffer from anorexia. A study of young women suffering from anorexia and missing periods for a year showed 77% has spinal bone loss caused by poor nutrition, weight loss and loss of ovarian function.   Young women athletes who train excessively are at risk if they become underweight and their periods stop. They can lose 5% of bone density in a year.

Lets’ bone up on the facts

• Bone consists of the compound calcium phosphate embedded in collagen fibres. The calcium gives strength and hardness, the fibres make for flexibility.

• Bone itself is not dead, but a living tissue full of little cavities looking not unlike a honeycomb
• Bone changes constantly with new bone repairing and replacing old bone throughout our lifetime
• Bone is liable to fracture, however the skeleton does replace itself every 7 –10 years
• Bone mass decreases gradually and naturally in both women and men after the age of 35
• Genetic inheritance and other factors also contribute to bone loss in some people
• Fast bone losers will have lost as much as 30% of bone within ten years of the menopause (average age 51)
• A woman who has an early menopause (before 45 years old) can experience bone loss even earlier (she will have been without bone-protective oestrogen for a longer period of her life.)
• For the same reason fast bone loss can also be expected after a premature menopause (possibly brought about by hysterectomy).

• The likelihood of fast bone loss is even greater if one or both ovaries were removed at the time (oophorectomy).

Your weight a 1 year of age could predict bone strength in adult life.  In a study of 230 women whose weight at a year old was traced from old medical records it was found that those underweight infants did not develop as strong skeletons in adulthood as those who were bigger infants.

 There are two types of bone: trabecular and cortical. 

• A woman will lose about 50% of trabecular bone and 35% of cortical bone in her lifetime.
• Trabecular bone is most likely to be lost in the 10 years or so around the menopause.
• Cortical bone is associated with slower, gradual bone loss later in life.
• The forearms and spinal column are made up largely of trabecular bone, and fractures in these areas are a sign of post-menopausal osteoporosis.
• Hip and shoulder bones are both cortical and trabecular (fractures here are associated with later ageing.)

Taking the oral contraceptive pill over a long period may protect against bone loss because the hormones they contain may stimulate a substance called calcitonin that inhibits bone breakdown.  Bone tissue is continually replacing itself, most rapidly in the young and more moderately in adulthood.  Peak bone mass is reached during the early 20s, and after that, if you want to look at it pessimistically, things begin to go downhill.  In women, bone loss at around the age of 30 is up to 1% a year, in men the rate is slower.  This gradual loss of bone density is common to everyone and part of the ageing process.  But in some women, the loss accelerates to between 2% and 3% a year at the onset of the menopause, and by the age of 70, a third of bone mineral mass can have disappeared.  You can see the results in the skinny ankles and so-called ‘dowager’s hump’ or stoop of some elderly women.  That stoop is the result of what are known as crush fractures in the spine.

Overweight women gain some protection from the disease because  greater body weight puts more stress on her bones and after the menopause her excess fat will store more estrogen in the fat cells.  Something  larger ladies can smile about?

What happens at the time of the menopause?

Menopause is a normal stage in a woman’s life.  It isn’t an illness although some women do have very real problems at this time and need help.  Other women sail through the mid life changes with ease.   It can be divided into three stages:

Perimenopause

• Signifies the transitional stage, a gradual process
• Ovaries produce less and less oestrogen.
• Can be 3 to 5 years, until the final cessation of the periods at menopause which for most women is between the ages of 45 and 55
• Average age of menopause being 51 years of age. (But recent research indicates that the menopause is occurring at an increasingly younger age.)

Menopause

• Menopause signifies a woman’s last menstrual period
• Her ovaries finally cease to function
• Her menstrual periods stop
• Reproduction comes to an end.

Postmenopause

• Signifies the many years of a woman’s life left after her last menstrual period and monthly bleed. (Possibly another 1/3^rd of her life)

The hormonal fluctuations during the time of the menopause can cause physiological changes which effect metabolism and emotions.

This hormonal imbalance caused by the natural drop in oestrogen levels can result in symptoms such as:

• Hot flushes
• Irritability
• Anxiety
• Poor concentration.

A natural drop in levels of hormone oestrogen at the menopause triggers an accelerated loss of calcium from the bone.  One of the mysteries surrounding osteoporosis is that though all women lose oestrogen at the menopause, not all of them suffer bone loss.  There are certain risk factors that make some women more vulnerable than others. The increased loss occurs at whatever age the menopause takes place, either naturally around the age of 51,or unnaturally through removal of the womb and ovaries for medical reasons at an earlier age.

The earlier the menopause the earlier the risk of thinning bones. On average women who smoke experience menopause 3 years earlier and if you live with a smoker (even though you don’t smoke) you too are at a disadvantage.

Who is most at risk of osteoporosis?

According to the National Osteoporosis Society the risk factors are:

• Heavy drinking and smoking
• Heavy caffeine intake
• Slight build, low weight
• Early menopause before the age of 45
• Family history of osteoporosis, especially in close female relatives, (i.e. mother or grandmother)
• Lack of exercise
• Prolonged bed rest or immobility
• Fair skin
• Lack of sufficient calcium in diet throughout life
• High protein diet (which increases calcium loss)
• Vitamin D deficiency (which reduces body’s ability to utilise calcium)
• Long course cortisone or thyroid treatment
• Women who have over dieted especially anorexia or bulimia sufferers)
• Women who over-exercise such as marathon runners (periods diminish or disappear)

Studies in the US show that black women have stronger, thicker, larger bones than white.  Black women also tend to lose bone more slowly  and lose less calcium in their urine than white women.  Both black and white men lose bone and calcium in similar amounts.

What are the effects of bone loss?

There may be nothing noticeable at first.  It’s what happens in the long run that counts.  A typical sign is the broken wrist, a Colles fracture (which I experienced when I fell ice-skating – ouch)  You know the scenario: the person slips and falls on an outstretched hand.  Her average age will be 60, and I use the word ‘she’ advisedly, because it happens much more often to women than to men.

Fracture of the femur, the thighbone is another indicator.  It can happen through quite a minor fall.  The incidence rises with increased age in both men and women, but again its women who are statistically more prone to these injuries.

And then there are fractures of the vertebrae, or spine that become more frequent from the age of 50, again primarily in women.  These can cause loss of height through a concave or wedging effect of the weakened bones, or the spinal column may collapse because the bones are actually crushed.  One estimate suggests that about 60% of elderly women will experience wedging of bones in the spine.

Keep your  black coffee intake down.  An American study shows that drinking more than 2 cups a day reduces bone density, though coffe drinkers who also drank at least one glass of milk a day lost less bone than those who did not.

Hip fractures increase after the age of 70, and are the most serious of the four types of fracture connected with osteoporosis.  While the other kinds may cause pain they rarely need much medical care.  But hip fractures are associated with hospitalisation, permanent disability and death in old age. In the UK in 2004 we’re talking in terms of 300,000 cases of osteoporosis every year resulting in 70,000 hip fractures, 40,000 Colles fractures, and 40,000 fractures of the spine. And then there’s the financial burden, some £1.7 billion a year cost to the NHS.  Not to mention the cost in human misery and pain.   Some 14,000 people will die as a result of fractures.  And, yet again I say, some osteoporosis is preventable.

All fall down?

Fractures follow falls.  Even a minor impact can lead to a fracture when bones reach a certain stage of brittleness.  Why do people fall down more as they get older?  For a number of reasons, some medical:

• They could be on a course of drug treatment that makes them drowsy or lose balance (tranquillisers for instance.)
• They may suffer from muscular weakness through illness or lack of exercise.
• Vision may not be as keen so there is a danger of tripping over (where lighting is not too good, for instance in a hall or on stairs).
• Blackouts or fainting due to a physical condition.

A minimum of 2 or 3 units of alcohol a day (preferably less) will not affect bones directly.  But women who drink excessive amounts of alcohol may stumle and fall!

Prevention is better than cure

Not everyone has the opportunity, or the positive determinations to regain full mobility after an accident as I did.   But women with fragile bones have a lot to lose; both their physical independence and quality of life are at risk. Many accidents leading to nasty falls occur around the house, so be aware of potential hazards:

• loose rugs
• slippery floors
• spilt liquids
• Snake like flexes.

I find my visiting grandchildren, and other people’s pets are often the cause of “accidents just waiting to happen!”  Objects get moved from their familiar spots, toys get left in unexpected places as their bored little owners abandon treasured possessions in the most inconvenient places! Accidents in my kitchen are best avoided by keeping things in more accessible places, it’s too easy to lose one’s balance and tumble off the kitchen steps.  For people suffering from osteoporosis, handrails and non-slip mats in bathrooms can stop nasty falls on slippery surfaces, which could have such devastating consequences.

And cold weather can take it’s toll.  One study of elderly women admitted to hospital with fractures showed there was a mid winter peak.  But they weren’t slipping on icy pavements, most of the accidents took place indoors.  It was noted a large proportion of the women were thin, possibly suffering from poor nutrition which triggered low body temperatures, hypothermia and subsequent lack of co-ordination.