Low bone density is well known as the major risk in exercise-induced amenorrhea. But not everyone who has had hypothalamic amenorrhea will get osteopenia or osteoporosis, so what other causes might contribute to the condition? And how far can it be reversed?
After going on the record recently about overcoming hypothalamic amenorrhea on my blog, a renewed desire to search for answers and move forward led me to reflect on the long-term health consequences that might affect me now that most of the temporary symptoms of hypothalamic amenorrhea had subsided. I learned a couple of months ago that a recent blood test was on the low-side of normal for calcium, and given that a paper on the subject published in the BJSM in 20141 recommends that women who have had fewer than 6 menstrual cycles in 12 months have a DEXA bone-density scan carried out (regardless of any other risk factors), I decided I couldn’t settle for just hoping it was all okay and set about finding out if I could pay to have one done, since my request to my GP for one six months prior had been refused. It turned out I couldn’t even book an appointment at the private clinic without a referral from a doctor, so I went back to my GP surgery to ask them to kindly refer me to the private clinic for a scan. Even that request was met with doubt and scepticism, but after conferring with the other practice doctors, it was decided that a referral letter would be written so that I could arrange my appointment.
I had the test last week and preliminary results show I have osteopenia. To quote Wikipedia:
“Osteopenia is a condition in which bone mineral density is lower than normal. It is considered by many doctors to be a precursor to osteoporosis. However, not every person diagnosed with osteopenia will develop osteoporosis. More specifically, osteopenia is defined as a bone mineral density T-score between −1.0 and −2.5.” https://en.wikipedia.org/wiki/Osteopenia
I won’t go so far as to include my score here, for one it is so far provisional, but also I don’t think comparing numbers generally is that helpful, the story is enough.
The diagnosis came as a bit of shock, particularly as my doctor had been so doubtful that I would have any issues. But it’s better to know and to be able to do something about it, knowing that you are making changes for a reason and knowing that you can improve things than to just forget about it and hope for the best. It also means I’ll be doing a lot of reading and one of the best things about this whole experience is providing a channel for my information-hungry mind! Here are some quick facts about the skeleton to whet your appetite:
- The bones are made of living tissue which completely regenerates every 7 years. The two main cells responsible for this regeneration are osteoblasts, which create new bone cells, and osteoclasts, which break down old bone cells.
- Weight for weight, bone is five times stronger than steel, but it is very light. The skeleton makes up only one-sixth of an adult’s weight
- The hard matrix of bone is made of crystals of calcium phosphate and other minerals, and fibres of protein called collagen. The minerals make bone hard, while the collagen fibres are arranged lengthwise to make bone flexible. Both are produced by cells called osteocytes, found throughout the matrix.
- Not everyone who has had prolonged hypothalamic amenorrhea will get osteopenia, dietary intake of calcium, vitamin D and vitamin K and the type of exercise undertaken are key factors to consider, as is family history of osteoporosis.
Causes and factors in osteopenia
There are many factors that can lead to osteopenia, but I’ll keep it to the factors that have probably contributed to my low bone density.
- Low calcium intake
- I developed an intolerance to dairy products when I was twenty-one years old and although I discovered a few years later that I was only sensitive to cow’s and ewe’s milk products and I could consume dairy products made from goat’s milk, I don’t consume the recommended 2-3 portions of dairy per day. I supplemented for a few years but eventually decided I must be able to get sufficient from a good diet. As well goat’s milk, I also use soy milk and I always check it is supplemented with Calcium and Vitamin B12 and look for calcium triphosphate over calcium carbonate, but supplemented nutrients are generally absorbed less well. There is calcium in lots of other foods I eat, such as dark green vegetables, sesame seeds and tahini, tofu, almonds, chickpeas, but probably not enough. This is supported by the blood test I had in March that showed my calcium levels were on the low side. And there’s a good chance it’s been like this for around fifteen years.
- Hypothalamic amenorrhea / low energy availability
- This is two-fold. If you saw my blog post you will have read about overcoming hypothalamic amenorrhea (HA) recently. I brought about a state of prolonged energy-availability as a result of a lot of exercise and not compensating properly with the food I ate to support my training. This led to my hypothalamus shutting down the reproductive hormones which cause the ovaries to produce oestrogen but also meant that my body had too little energy coming in to make use of nutrients I was consuming to repair or build new tissue. Oestrogen is one of the most important mechanisms for building bone density in women and the rates of osteoporosis in post-menopausal women demonstrate that low oestrogen alone can lead to bone density. Add to this the low-energy state where the body has little energy to build new bone tissue and you start to understand how HA plays a major role in osteopenia and osteoporosis.
- The contraceptive pill
- I was on the contraceptive pill on and off, but mostly on, from the age of around 16 or 17 to control my bad skin and regulate my painful periods. This is a very common scenario here in the UK. For some time, doctors thought that taking the contraceptive pill would have a protective effect on bone density in women with HA on the assumption that the synthetic oestrogen would have similar effects to natural oestrogens. Unfortunately, research published in 20132 showed that was not the case. Additionally, new research published in 2015 and 20163 shows that in fact, when the pill is prescribed to healthy teenager girls, they will build less bone than their counterparts who were not on the pill – this is in their most important years for building strong bones.
- Low vitamin D
- Vitamin D is well known to play an important role in building bones; growing rates of vitamin D deficiency amongst the UK population as a result of more time spent indoors by children is blamed for the unexpected uptick in Ricketts. Vitamin D can be produced by the body from sunlight and is also present in a small number of foods. I probably spent an average amount of time outdoors as a child as we had two dogs to take for walks and play with in the garden, however my main hobbies (dancing and playing the violin) were indoors. Once I started in the world of work, I routinely spent 10 hour days in an office and during winter would only see daylight briefly for part of my morning commute and for my 10-minute dashes to shops and cafes to buy lunch at midday. The Department of Health issued new advice to GPs in 2012 identifying at-risk groups who should supplement with vitamin D and the NHS states that in the UK between October and early March we cannot generate enough vitamin D from sunlight. So as a vegetarian the options are limited and it’s unlikely I can get enough from my diet and I haven’t spent as much time outside as people with other hobbies or jobs might have.
- Low impact exercise
- Since giving up dancing when I left school, most of my exercise has comprised yoga, running, swimming and cycling – with a year or so of weight training before I got into triathlon and I have picked this up again over the last three years. Yoga and running are both good for bone density, but they’re not necessarily the best activity for stimulating the production of new bone cells. There are masses of different studies looking at different forms of activity on bone density in different populations and my research has only scratched the surface, but it seems that the higher the impact, the better, frequency makes quite a difference and stress on the bones via tension in tendons when muscles contract and lengthen is also beneficial. For example, the best form of running for bone density would be short, fast, sprints with lots of power. This is the opposite to the type of running I have occupied myself with. Yoga has some benefits and is recommended to people with low-bone density, however it is almost always low-impact. Some of the advice on exercise to help people with low bone density can seem different from the advice given to healthy people to build good bone density, because high-impact, high-force exercise and weight training is high-risk for weak bones.
What am I going to do about it?
- Get medical help! This is number one and I’m waiting for speak to my GP to review the results and make an action plan or get referred to someone who can.
- Nourish my body, maintain the weight I’ve gained and keep the hormones flowing – if my cycle starts to lengthen or the signs I get about my cycle through the month begin to diminish, either take a step back on the activity levels, increase food intake or both. Despite the bleak outlook given by a study from 19974, more recent papers5,6 support the theory that bone density can be improved by restoring cycles and gaining/maintaining weight so these are key.
- Go back to strength training twice a week, with a view to gradually progressing to three times per week.
- Incorporate regular plyometric activity – maybe take up a new sport like netball, volleyball or parkour? Or keep working on my skipping skills and box jumps.
- Maybe try out vibration training? I always saw this as a fad and I have stood on one of these machines at the gym once, but a scientific literature review published in the Journal of Osteoporosis and Physical Activity in 20157 cited studies that had observed increases in bone density ranging from 1.5%-6.2%, which was largely dependent on the frequency and magnitude of vibrations (some very small magnitude vibrations were in fact too little to counteract the underlying bone loss that happened over the duration of the study).
- Supplement with calcium and vitamin D. I started taking vitamin D last winter but stopped once the clocks go forward. Given the low bone density diagnosis I am now taking it all year round. I know magnesium and vitamin K are also both important in bone health but most of the main sources of these nutrients both feature prominently in my diet already and they did not show up in a recent blood test as being low.
- Get more sleep! The body repairs and builds tissue when we are sleeping. I frequently get less than 8 hours and I’m not giving myself the best chance to build solid bones, new muscle tissue or to just repair damaged tissue such as a sprained ankle or bruises.
So, I’m very concerned but hopeful that I will be able to restore my bone density to a healthy level. It looks like sacrifices will probably have to be made but at this point there is no compelling reason not to make my long-term health a priority. Fingers crossed the doctor will be equally optimistic!
- De Souza MJ, Nattiv A, Joy E, et al, 2014 Female Athlete Triad Coalition Consensus Statement on Treatment and Return to Play of the Female Athlete Triad: 1st International Conference held in San Francisco, California, May 2012 and 2nd International Conference held in Indianapolis, Indiana, May 2013. Br J Sports Med 2014;48:289. http://bjsm.bmj.com/content/48/4/289
- Bergström I, Crisby M, Engström AM, Hölcke M, Fored M, Jakobsson Kruse P, Of Sandberg AM. Women with anorexia nervosa should not be treated with estrogen or birth control pills in a bone-sparing effect. Acta Obstet Gynecol Scand. 2013 Aug;92(8):877-80. doi: 10.1111/aogs.12178. Epub 2013 Jun 15. PubMed PMID: 23682675. https://www.ncbi.nlm.nih.gov/pubmed/23682675
- Update on Birth Control Pills / Oral Contraceptive Pills and Bone Density http://www.noperiodnowwhat.com/research/birth-control-pills
- Keen AD, Drinkwater BL. Irreversible bone loss in former amenorrheic athletes. Osteoporosis Int 1997;7:311–15. https://www.nds.ox.ac.uk/publications/400582
- Fredericson M, Kent K. Normalization of bone density in a previously amenorrheic runner with osteoporosis. Med Sci Sports Exerc. 2005 Sep;37(9):1481-6. PubMed PMID: 16177598. https://www.ncbi.nlm.nih.gov/pubmed/16177598
- Vescovi JD, Jamal SA, De Souza MJ. Strategies to reverse bone loss in women with functional hypothalamic amenorrhea: a systematic review of the literature. Osteoporos Int. 2008 Apr;19(4):465-78. doi: 10.1007/s00198-007-0518-6. Epub 2008 Jan 8. Review. PubMed PMID: 18180975. https://link.springer.com/article/10.1007%2Fs00198-007-0518-6
- Abazovic E, Paušic J, Kovacevic E (2015) Whole Body Vibration Training Effects on Bone Mineral Density in Postmenopausal Osteoporosis: A Review. J Osteopor Phys Act 3:150. doi:10.4172/2329-9509.1000150 https://www.omicsonline.org/open-access/whole-body-vibration-training-effects-on-bone-mineral-density-inpostmenopausal-osteoporosis-a-review-2329-9509-1000150.php