SCIENCE FRIDAY FOR ATHLETES: SLEEP (AN 'ACTIONABLE' PREVENTION) & OSTEOPOROSIS

Nearly nighttime. Taken by PKSenagore. All rights reserved

MARY CAIN, A HIGH SCHOOL RUNNING STANDOUT ATHLETE, recently told her story in an opinion piece for the New York Times, also available as a video ("I Was the Fastest Girl In America Until I Joined Nike".  In it she reveals her experience training under the direction of Alberto Salazar in the Nike Oregon Project.  Regardless of whether her recounting of alleged abuse is accepted by readers/viewers, a health danger of training is highlighted: osteoporosis.
 
Female and male athletes (even Kenyan runners) are known to be at risk of this disease, especially those involved in endurance sports in which low body weight is seen as desirable and contributing to success.
 
Recreational runners, as well as cyclists and swimmers, who aren’t competing professionally don’t realize that they share this risk with elites. A number of factors influence bone health including diet, muscular strength, genes, and hormones. 

A recent study examining participants in the Women’s Health Initiative (WHI) indicates that sleep might also be included.
 
Sleep has been hyped in the news over the past couple years as essential for heart and brain health and the prevention of chronic diseases include obesity, type II diabetes, and depression.  The CDC warns that short sleep duration is reaching epidemic proportions in the US.
 
Age does not offer protection; teens who require 8-10 hours each night and adults who should get 7-8 hours have similar problems with too little sleep. Neither does gender (men and women have similar prevalence of short sleep duration). Additional information about sleep in the USA is available on the CDC sleep statistics page.
 
Very recently, in early November 2019, a study on postmenopausal women’s bone health was published that examined the association between self-reported sleep duration and sleep quality of more than 11,000 women (average age 63.3 years) and whole body, total hip, femoral neck and spine bone mineral density (BMD) measured by dual-Xray-absorptiometry (DXA) scan. The participants were part of a much larger group of nearly 162,000 women enrolled in the WHI between the ages of 50 and 79. Each had received a baseline DXA scan and completed a sleep data questionnaire about the preceding 4 weeks.
 
The results, adjusted for multiple factors not limited to but including age, body mass index (BMI), alcohol intake, smoking, education, and race, showed that women who “reported sleeping 5 hours or less each night had on average…significantly lower BMD at all four sites compared with women who reported sleeping 7 hours per night”.  Reporting sleep duration of 5 or less hours also increased the odds of osteoporosis.
 
So, there it is. Sleep is important for bone health in women over 50! It’s an actionable health measure according to experts.
 
However, this information can be disheartening to those who struggle with sleep issues.  Sleep is another aspect of daily living that should be under our control, but some feel powerless to change.  Like diet. Yes, it’s clearly important but frustrating when, after taking all recommended steps to obtain quality sleep, the body resists.   
 
The hopeful news in this study is that while short sleep duration was significantly associated with lower BMD and higher osteoporosis risk, sleep QUALITY WAS NOT! 
 
In addition to indicating how long they slept in the 4 weeks preceding the study, women participants answered 5 questions about sleep that concerned difficulty falling asleep, awakening during sleep, early waking and/or problems returning to sleep.  A score of 0-20 was possible; the higher score the greater the insomnia (>9 was the cut-off for insomnia).  Researchers could NOT find an association with BMD even though they had hypothesized it would matter at the start of their research effort.  It was thought that perhaps increased physical activity related to insomnia was protective (getting in and out of bed for example) or the findings were simply due to chance.
 
My interpretation of this study’s results is that as long as I make the effort to sleep 7-8 hours each night, regardless of interruptions and disturbances, my total time asleep may be sufficient to be bone-health-friendly, and maybe generally health-friendly. That last part is probably a leap of faith, but until my own sleep quality is completely under my control, that’s the story I’m going with.
 
Others may take heart from these findings about sleep quality. Work pressures, relationship worries, looming deadlines, family responsibilities and other stresses may not be able to totally derail our attempts at improving health with sleep. Worrying about poor sleep quality isn’t likely to help matters. I plan to work at getting the hours in and forget about the rest for the time being. For the sake of my bones, heart, brain, mental health, and metabolism, etc.
 
The WHI study did not involve men, younger ages, or athletes specifically and the results may not apply beyond this particular demographic.  But as long as scientific evidence continues to accumulate regarding the protective and potentially rejuvenating powers of sleep, the “fix” (getting adequate sleep) is not risky and seems only to be beneficial.
 
It seems easier to accomplish than diet manipulations or exercise prescriptions.
 
RUN & MOVE HAPPY!
 
https://www.msn.com/en-gb/sport/olympics/mary-cain-i-was-emotionally-and-physically-abused-by-alberto-salazar-at-nike/ar-BBWsRce#image=1
 
https://www.mayoclinic.org/healthy-lifestyle/adult-health/in-depth/bone-health/art-20045060

https://www.cdc.gov/sleep/about_sleep/index.html

https://www.sleepdr.com/the-sleep-blog/cdc-declares-sleep-disorders-a-public-health-epidemic/
 
https://www.cdc.gov/chronicdisease/resources/infographic/sleep.htm (tips to getting good sleep)

https://www.ncbi.nlm.nih.gov/pubmed/31692127

https://www.cdc.gov/chronicdisease/resources/infographic/sleep.htm