DENVER — When women athletes eat more, they can recover menstrual cycles that have been suppressed by intense exercise, results from a pioneering clinical trial on the syndrome suggest.
More than half the women diagnosed with female athlete triad began menstruating in the year after a caloric increase that was 20% to 30% of baseline energy expenditure.
The finding suggests that athletes can recover from the syndrome without changing their exercise regimen.
“We’re very excited,” said Mary Jane De Souza, PhD, from Pennsylvania State University in State College. “It’s important to know we can get these women to eat and resume menses.”
Dr De Souza presented preliminary results from REFUEL (NCT00392873), the groundbreaking randomized clinical trial of the female athlete triad, here at the American College of Sports Medicine 2017 Annual Meeting.
REFUEL Trial
Women affected by the female athlete triad exercise so intensely that their energy consumption does not meet their needs. Some athletes unknowingly burn more calories than they consume, others deliberately try to lose body mass, and still others have eating disorders.
This energy imbalance can disrupt or suppress menstruation, reducing the production of estrogen and increasing the risk for bone loss and stress fractures.
Although clinicians have typically encouraged women with the syndrome to eat more, the approach has not been tested before in a randomized trial, Dr De Souza told Medscape Medical News.
For their study, she and her colleagues recruited exercising women who had no eating disorders, hormonal abnormalities, other medical concerns, or high body mass indexes.
The 42 women in the intervention group had exercise-related menstruation abnormalities and increased their calorie intake by 20% to 30%. The 36 women in the control group had exercise-related menstruation abnormalities and did not change their calorie intake. The 40 women in the healthy control group had normal menstruation and ovulation and did not change their calorie intake.
There were significant differences among the groups at baseline. Average age was 21 years in the intervention and control groups, but 23 years in the healthy control group. And age at menarche followed the same pattern: 14 years in the intervention and control groups, but 12 years in the healthy control group.
To determine resting energy expenditure, the researchers used indirect calorimetry. To determine 7-day purposeful energy expenditure, they relied on heart rate monitors, exercise logs, and accelerometers.
In the intervention group, daily intake was increased by up to 580 kilocalories. Most of the women ate power bars provided by Nestlé to achieve this increase, but some worked with the researchers to change the foods they normally ate. Pilot studies showed that just adding food to increase calories would have been “extremely difficult,” Dr De Souza explained.
Women whose consumption of vitamin D or calcium was inadequate received supplements.
All the women were asked to maintain their baseline exercise levels. Women in the intervention group who increased their energy expenditure ate more food to compensate.
Of the 47 women who dropped out of the study early on, seven did not to adhere to the study regimen. After 6 months, another 16 women dropped out, one of whom did not adhere to the regimen. “It was very, very difficult to keep these women compliant with our protocols,” Dr De Souza reported.
Sometimes women said they couldn’t eat a whole power bar, so the researchers cut the bars into thirds and had them to eat one piece every few hours.
Weight Gain
The women in the intervention group gained more weight at 6 and 12 months than the women in the other two groups. In addition, they increased energy availability (the amount of energy not consumed by exercise) more than the other women, levels of leptin (a hormone that helps regulate energy balance), and levels of insulin-like growth factor (IGF)-1 (a protein with insulin-like effects).
Of the 19 women who remained in the intervention group at 12 months, eight resumed menstruating 2 to 3 months after increasing calorie consumption, one resumed 4 to 6 months after, and two resumed 10 to 12 months after.
In the control group, only one woman resumed menstruating, and that was at 4 to 6 months.
More women in the intervention group than in the control group showed signs of estrogenic activity (10 vs 1) and ovulation (4 vs 0).
Table. Biometric Changes From Baseline to 12 Months
| Variable | Intervention Group, % (n = 19) | Control Group, % (n = 16) | Healthy Control Group, % (n = 20) | P Value (Intervention vs Control Group) |
|---|---|---|---|---|
| Body weight | 5.6 | 0.8 | –0.6 | .07 |
| Energy intake | 34.5 | 0.1 | –4.5 | .04 |
| Energy availability | 31.0 | –6.0 | –6.0 | <.02 |
| Leptin | 85.7 | 0.7 | 3.9 | <.01 |
| IGF-1 | 15.2 | 0.8 | –3.6 | .034 |
There were signs of improved bone health in the women who ate more, Dr De Souza told Medscape Medical News. However, she did not present those data because “bone recovery will take longer.”
The researchers are planning to follow-up with as many participants as possible to see how their health, exercise, and eating habits have changed, she noted.
One menstrual cycle does not indicate recovery from the female athlete triad, she stressed, advising that clinicians treating these women wait two or three consecutive cycles before they relax their supervision.
The women willing to participate in the study were prepared to make changes in their health, which might set them apart from other women with the female athlete triad, she acknowledged.
After the presentation, several members of the audience spoke about their struggles to convince patients to eat more. One reported that a woman returned again and again with stress fractures but still rejected advice to balance her energy needs.
Study participants were not really worried about broken bones or missed menstruation, Dr De Souza explained, but warnings about infertility and reduced performance caught their attention.
For women on sports teams, restricting participation can motivate them to eat more, said Elizabeth Joy, MD, president of the Female Athlete Triad Coalition. “My experience with the older athletes out of college is that it’s about relationship building. If you can lead her to water, sometimes she just might sip.”
This controlled trial is “where we need to go,” said session moderator Aurelia Nattiv, MD, from the UCLA Medical Center in Santa Monica, California.
“It’s huge progress in science,” she told Medscape Medical News.
For a long time, researchers thought exercise itself was the cause of the female athlete triad. So it comes as good news that athletes with this problem “can continue to exercise as long as they increase their energy consumption,” she said.
This study was funded by the Department of Defense. Nestlé provided the power bars. Dr De Souza and Dr Nattiv have disclosed no relevant financial relationships.
American College of Sports Medicine (ACSM) 2017 Annual Meeting: Abstract 64. Presented May 31, 2017.
Follow Medscape Ob/Gyn on Twitter @MedscapeOb/Gyn and Laird Harrison @LairdH
Tidak ada komentar:
Posting Komentar