Thursday, May 02, 2013
HRT comes in from the cold
HRT 'boosts muscles': Women taking the treatment after the menopause stay stronger, study claims
Hormone replacement therapy could do your muscles a power of good, according to researchers. They found it significantly improves muscle function, right down to the muscle fibre level.
A study which put muscle fibres under the microscope found cells were arranged differently in post-menopausal women taking HRT compared with those who did not.
The difference reduced age-related changes and improved muscle function, the researchers said.
An estimated one million women in the UK are prescribed HRT in their 50s to replace oestrogen lost in the menopause. It can combat symptoms such as hot flushes and mood changes.
HRT is known to slow bone loss and increase bone density, and reverse declining levels of skin collagen, which is responsible for the stretch in skin and muscle.
Previous studies have suggested HRT reduces the drop in muscle mass and strength in post-menopausal women, improving the ability to jump higher and walk faster than those not taking drugs.
The latest study, in Sweden, is the first to explore these effects at cellular and molecular levels to find how the changes are occurring.
Researchers at Uppsala University Hospital observed six pairs of post-menopausal identical twins – of whom only one of each pair was receiving HRT – to rule out genetic differences. They then examined muscle biopsies taken from them, says a report published in The Journal of Physiology.
They found HRT had a significant effect on slow-twitch muscle fibres, enabling cells to work more efficiently. Dr Lars Larsson, from Uppsala University Hospital, said negative publicity over the past decade has made many women reluctant to use HRT, but the study shows a positive outcome.
He said: ‘Even though individual muscle fibres did not change in size, the muscles of HRT users showed greater strength by generating a higher maximum force compared to non-HRT users. It is thought that using HRT, at least in part, reduces modifications of muscle contractile proteins that are linked to ageing.
‘HRT is also associated with a more efficient organisation of myonuclei, which are essential components for muscle fibre function.’
Experts last year reappraised HRT risks after claims that users were at higher risk of breast cancer, heart disease and strokes – contrary to previous research suggesting oestrogen protected them from heart problems.
Re-analysis of data from the US Women’s Health Initiative found the extra health risks applied to older patients in their 60s and 70s, who do not normally use HRT but were given it for research purposes. It showed women taking HRT at the start of the menopause for ten years can reduce their risk of heart failure, heart attacks and premature death.
Effects of Iodine deficiency on children
Iodides are normally added to table salt if not naturally present (as in sea salt). It is the unfounded horror of salt that leads to iodine deficiency
Children deprived of iodine in the womb are worse at literacy especially in spelling, a new study warned.
But lack of the chemical had no effect on a child's maths skills, suggesting the deficiency affects the development of auditory pathways and auditory working memory.
Scientists say expectant mums could prevent long-term neurological impairment by taking supplements as part of their daily diet.
Iodine is absorbed from food and plays a key role in brain development, but even a mild deficiency during pregnancy can harm the baby's brain development.
The nutrient can be found in a variety of foods and is especially rich in shellfish, but pregnant women should not eat this food.
The study examined standardised test scores of 228 children whose mothers attended The Royal Hobart Hospital's antenatal clinics in Tasmania between 1999 and 2001.
The children were born during a period of mild iodine deficiency in the population, but conditions were reversed when bread manufacturers began using iodised salt in October 2001 as part of a voluntary iodine fortification programme.
Results showed inadequate iodine exposure was associated with lasting effects with nine-year-olds - the children who received insufficient iodine in the womb - gaining lower scores on their literacy tests particularly in spelling.
However researchers from the University of Tasmania found that low iodine intake had absolutely no effect on maths scores.
They suggest iodine deficiency may take more of a toll on the development of auditory pathways and consequently, auditory working memory.
They say the results are preventable if pregnant women take daily dietary supplements containing iodine.
Dr Kristen Hynes said: 'Our research found children may continue to experience the effects of insufficient iodine for years after birth.
'Although the participants' diet was fortified with iodine during childhood, later supplementation was not enough to reverse the impact of the deficiency during the mother's pregnancy.
'Fortunately, iodine deficiency during pregnancy and the resulting neurological impact is preventable.
'Pregnant women should follow public health guidelines and take daily dietary supplements containing iodine.
'Public health supplementation programs also can play a key role in monitoring how much iodine the population is receiving and acting to ensure at-risk groups receive enough iodine in the diet.'
The results are published in the Journal of Clinical Endocrinology & Metabolism.
Posted by jonjayray at 12:24 AM