Osteoporosis Prevention: Start Early!

A main focus of the osteoporosis literature is treatment by various drugs which are targeted toward prevention of post-menopausal fractures.  However, a recent review by physicians at New York University Medical Center in the journal Clinical Obstetrics & Gynecology stresses the view that "…no treatment is as effective as prevention."

The authors cite that by the age of 18, most women have 92 percent of their total bone mineral content, and by age 26, they have attained 99 percent.  This implies the importance of establishing behaviors, such as activity and nutrition that promote bone health early in life.  Take the following steps to prevent bone loss and promote bone strength:

1.      Exercise: Weight-bearing exercise is known to have a positive effect on bone strength. 

2.      Nutrition: Vitamin D and calcium intake is critical to for bone health.  An increase in the consumption of dairy products, as well as mushrooms and certain types of fish (including salmon, sardines and tuna) allow the body to maintain stronger bones.

3.      Lifestyle: Avoiding excessive alcohol intake (more than 3 drinks per day) and smoking can have a negative effect on bone maintenance.  Avoiding or reducing these behaviors will reduce the risk of bone density loss.

The bottom line is that many lifestyle choices before menopause can markedly reduce the risk of osteoporosis in later life. 

Find the abstract here.

How does a World-Class Female Triathlete Train?

Exercise tracking apps can allow us access to the training programs of our friends but it is quite rare to gain detailed insight into the workout schedule of a world-class athlete.  A recent article in the International Journal of Sports Physiology and Performance provided such an account of the preparation of a women triathlete for the 2012 London Olympic Games. 

During the 50 weeks leading up to the games, this athlete completed 796 training sessions  about 16 per week comprising  303 swimming, 194 biking, 254 running and 45 strength training sessions. Typical weekly totals were 15.5 miles of swimming, 9 hours of cycling, and 5 hours of running.  The intensity of the training program was monitored and modulated based on heart rate, speed, and power output together with measurements of blood chemistry (particularly lactate).  In addition to training, the athlete completed 15 races - 8 of which were Olympic distance triathlons.  There is no mention of injuries during the year.  The athlete placed 7th in London 2012 and her world ranking improved from 14th to 8th at the end of 2012.

This glimpse into the life of an Olympic athlete shows what it takes to compete at the highest level.  Sustaining such a high-intensity program obviously requires years of background preparation together with a very unusual genome!

Read more here.

Too Little Exercise during Pregnancy

Questions about too much exercise during pregnancy are often raised  - such as the current discussion on weightlifting at 38 weeks here.

But a recent study in the Maternal and Child Health Journal of more than 600 pregnant women in Canada found that only 58% of the women did 15 minutes or more exercise at least 3 days per week.  Only 23% of women met the Canadian guidelines for physical activity during pregnancy (30 or more minutes on at least 4 days of the week). Pregnant women were less likely to be meeting exercise guidelines if they were single, divorced, separated or widowed, a visible minority, had a household income between $20,000 and $80,000, and reported being in less than excellent health. Women who had completed high school were more likely to be meeting guidelines.

The bottom line here is that pregnancy is not a time to let your exercise habits slip.  In a healthy pregnancy and with physician approval, mother and baby will both be best served by a moderate exercise program as recommended in both Canadian and US guidelines.

It should be noted that the American Congress of Obstetricians and Gynecologists suggests that each potential sport activity should be reviewed individually for its potential risk.  They recommend that activities with a high risk of falling or those with a high risk of abdominal trauma should be avoided during pregnancy. They strongly recommend that scuba diving be avoided throughout pregnancy because the fetus is at an increased risk for decompression sickness during this activity.

Read more about the Canadian exercise in Pregnancy study here.

Young Women like Feedback!

You can now buy many devices to monitor your exercise program – ranging from cell phone Apps that work as long as you carry your phone to body-mounted sensors on the wrist, ankle, or waist.  But do they encourage you to exercise more or are they just a way of expressing your tech savvy?

A recent study from Murray Edwards College in the United Kingdom recruited almost 900 male and female adolescents - mean age 14.5 years – and monitored their activity over four days.  Half of the subjects also wore a pedometer from which they could get feedback about their own exercise history.

Girls who wore the pedometers were more active than girls who did not.  There was no such difference among the boys.

The bottom line is that self-monitoring of activity may be an effective way to motivate young women to exercise.  So an exercise App or a body-mounted sensor might be a healthy gift for your daughter!

Read more about the study here.

Hypermobility and ACL Injury

People with hypermobility can move their joints well beyond the normal range.  A group of researchers at a hospital in New Dehli, India studied the association between hypermobility and injury to the anterior cruciate ligament.  They examined 135 men and 75 women who had experienced an ACL injury giving each a rating on a standard test of hypermobility called the Beighton score. There are nine components to this score including the ability to put the hands flat on the floor with knees straight, to bend the elbow backwards, and to bend the thumb back onto the front of the forearm.  The injured group was compared to a comparable group who had never had knee injury.

The investigators found that the women in their samples were more likely to be hypermobile than men but the dramatic finding was that people with an ACL injury were 4.5x more likely to be hypermobile than those without an ACL injury.

If this research is confirmed by others, the results suggest that active women who are hypermobile should consider a training program to decrease their risk of injury or consider protective bracing in at-risk settings.

The original paper can be accessed here.

What is Next in Osteoporosis Treatment?

Postmenopausal osteoporosis (low bone mass) is a huge global problem. The National Osteoporosis Foundation estimates that about one in two women over the age of 50 will break a bone due to osteoporosis. By 2020, half of all Americans over age 50 are expected to have low bone density.  A recent paper from the Musculoskeletal Research Program at the University of Aberdeen, UK reviewed the present and future drug treatments for osteoporosis.

While exercise is often prescribed for prevention and treatment many women end up taking drugs on a regular basis to prevent further bone loss.  The mainstay of drug treatment since 1995 are a class of drugs called oral bisphosphonates – such as Fosamax, Actonel, or Didronel.  These drugs have been shown to prevent loss of bone (resorption) but they need to be taken frequently and the side effects can include gastrointestinal upset or, more rarely, femoral fracture.  Bisphosphonates can also be administered intravenously.  A bone-building drug (as opposed to a loss-prevention drug) has also been available since 2002 (Forteo). This drug requires sub-cutaneous injection and frequent administration.  The latest addition to treatment is an anti-resorptive called demosumab (Prolia) which has a different mode of action than the bisphosphonates and requires only one subcutaneous injection every 6 months.  All of the above products are FDA approved for the treatment of osteoporosis.

There are number of very promising new products in the pipeline.  Among the most important is a class of drugs called anti-sclerostin antibodies.  These have been shown to be dramatically successful in mice and human trials are under way.

The bottom line of the paper from Aberdeen is that there are now several drug treatment options for osteoporosis that have been shown to be effective.  In the future, drugs with fewer side effects and less frequent administration are likely to be available. This will increase compliance and reduce the risk of fracture.

Read details of the paper here.

Hip Injuries in Female Rowers

Early morning rowers on the lake are a common sight in our hometown of Seattle. Most prior studies of rowing overuse injuries have focused on high rates of minor injuries to the lumbar spine, knee, wrist, and ribs. However, a recent paper in the journal Clinical Orthopaedics and Related Research examined injuries to the hip in adolescent and young adult rowers. In a retrospective review, clinicians from the Blue Ridge Bone and Joint Clinic, Asheville, NC, identified 21 hips in 18 rowers, mean age of 18.5 years, with significant hip joint pathology. Most of the patients (85%) were female prep school or collegiate rowers, and they exhibited isolated groin pain and physical findings consistent with impingement. Eighteen of the 21 hips (85%) eventually underwent arthroscopic surgery to repair labral tears and other pathology.  However, only 10 of the patients returned to rowing after surgery (2 were lost to follow-up). The authors believe that the mechanism of injury may be the repeated hyperflexion of the hip which compresses the hip as the seat slides up and the blade is placed in the water at the catch. The hips both go from extreme flexion to extension thousands of times during practice and competition.

The bottom line of this study is that rowing may cause significant overuse injury in the hip that can limit future participation in the sport.  If a rower has early signs of hip pain, she should proceed cautiously and seek qualified help from an orthopedic specialist. A young rower with a history of hip disorders should be particularly vigilant.

Read more about the study here.

Exercise is Associated with Better Eating Habits in Children

A recent study at Blaise Pascal University and Clermont University in France explored the relationship between poor eating behaviors and exercise in 278 children (147 girls) between the ages of 6 and 10. The researchers measured height, weight, body mass index, an adiposity index from skinfold measurements, and two measures of fitness: a 20-meter shuttle run and a squat jump test for height.  They identified the following eating behaviors as “high risk” when they occurred frequently: skipping breakfast; snacking; TV viewing during meals; and sweetened beverage consumption. Dietary habits were obtained from a validated questionnaire completed by parents in the present of the child.  106 children presented with one risk factor, 46 children had 2 eating risk factors, and 20 had at least 3 factors. Children who ate breakfast every day were fitter than those who ate breakfast sometimes or never.  Children who snacked everyday had significantly lower vertical jumps than those who rarely or never ate breakfast.  These results were independent of obesity.

The bottom line of this research is that unhealthy eating habits in elementary school children appear to be associated with poorer fitness. The authors believe that progressive lifestyle interventions which change a child's eating habits step by step may lead to progressive improvements in physical fitness.

Read more about the study here.

Running on the Moon

One of the key questions that remains unanswered as we prepare to send humans to other planetary surfaces is the degree to which living and exercising in these reduced gravity environments will provide an osteoprotective stimulus to prevent bone loss that is currently seen on International Space Station missions. 

With support from the National Space Biomedical Research Institute and the NASA Flight Opportunities Program, our research team from the Department of Orthopaedics and Sports Medicine at the University of Washington conducted a parabolic flight experiment to validate the activity monitoring system that was worn by subjects exercising in microgravity.  Nine subjects were tested as they performed a series of locomotor activities with the sensors positioned on the mid-lower back and around the ankle. Subjects were secured to the surface of the treadmill via a subject load device to provide loads similar to those experienced on Earth. Over two flight campaigns, activities were performed in three conditions:  zero, lunar, and Martian gravity.  An image of a subject running in zero-G with a simulated lunar load is shown below. 

With the acquired parabolic flight data, the team is developing classification software to autonomously recognize activities performed in reduced gravity.  Validation of this system would improve the ability to monitor exercise designed to preserve the bone health of astronauts aboard the ISS and on future exploration missions.  Similar methods could be applied to address the prevention of osteoporosis on Earth.

ACL Injury and the Menstrual Cycle

It has long been known that women have a highly elevated risk for rupture of the anterior cruciate ligament (ACL) in the knee compared to men engaged in the same activity. One of the many theories to explain this risk is that the increase in circulating estrogen and degrease in progesterone during the pre-ovulatory stage of the menstrual cycle reduces the strength of the ligament. A group of researchers from the Nollet Musculo-skeletal System Institute in Paris studied 172 pre-menopausal women (mean age 34 years) with regular cycles who tore their ACL while skiing. The accidents mainly occurred on blue (moderately difficult) slopes at medium speed and the ski bindings did not release in most patients.  The authors found that ACL injury was 2.4 times more likely to occur in a pre-ovulatory phase of the cycle compared to the post-ovulatory phase. This pattern was not affected by the use of oral contraceptives. 

Bottom Line:    The findings suggest that women engaged in risky recreational exercise during the pre-ovulatory stage of their menstrual cycles could decrease their risk of injury by taking special precautions.  In skiing this might involve skiing on less demanding runs and adjusting release bindings to a lower threshold.  Read more about the study published in the June 2013 issue of the journal Orthopaedics and Traumatology, Surgery and Research here.