Menstrual Irregularity
Conditions
Keywords
Amenorrhea, Energy deficiency, Resting energy expenditure, Bone metabolism, Bone mineral density, Exercise
Brief summary
The purpose of this study is to examine the effects of increased food intake on the menstrual cycle and bone health in physically active women who have irregular or absent menstrual cycles. This study will examine whether a 12 month period of increased food intake will cause menstrual cycles to resume and help bones get stronger.
Detailed description
Low levels of estrogen found in physically active, premenopausal women with irregular or absent menstrual periods is likely caused by insufficient energy (calorie) intake compared to energy expenditure. Premenopausal women with menstrual disturbances and amenorrhea suffer from reductions in bone mineral density, particularly in the lumbar spine. Bone loss observed in amenorrheic women may be serious enough to result in osteoporotic fractures, but is also associated with a high prevalence of stress fractures. Increased calorie intake should help improve energy status, menstrual status, and bone health. Comparison: Premenopausal women with irregular or absent menstrual periods will be assigned to either receive additional calories or serve as controls. A group of premenopausal women with normal menstrual periods will also be used for comparison.
Interventions
During the 12 month intervention, volunteers in the Increased calorie intake group will follow a modified dietary plan designed to achieve and maintain a target level of 20-30% above their previously determined baseline, in an effort to achieve a chronic energy surplus of +20-30% over their baseline energy requirements.
Sponsors
Study design
Eligibility
Inclusion criteria
for Ovulatory Control Volunteers: * 18-35 years * BMI 16-25 kg/m2 * At least 2 hr/wk of aerobic exercise * Gynecological age \>/= 5 years * Weight stable (+/- 2 kg) last 6 months * History of regular menses for 6 months Inclusion Criteria for Women with Irregular or Absent Menses: * 18-35 years * BMI 16-25 kg/m2 * At least 3 hr/wk of aerobic exercise * Gynecological age \>/= 5 years * Weight stable (+/- 2 kg) last 6 months * No menses within past 3 months or 6 or less menses in last 12 months * Low to normal bone mass (L1-L4 Z score \</=0)
Exclusion criteria
for all participants: * Hormonal contraceptives in last 6 months * Smoking currently * Current clinical diagnosis of an eating disorder * Use of medications incompatible with measurement of reproductive or metabolic hormones, including thyroid medications that may interfere with any of the study outcomes. * Dietary habits incompatible with prescribed diet for study * Any metabolic, reproductive or bone disease * Sedentary individuals with less than 120 minutes (2 hrs) of activity per week
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Reproductive hormones | 1 year |
| Metabolic hormones | 1 year |
| Metabolic bone markers | 1 year |
| Bone mineral density | 1 year |
Secondary
| Measure | Time frame |
|---|---|
| Eating Disorder Inventory-2 (EDI-2) | 1 year |
| Three Factor Eating Questionnaire | 1 year |
Countries
United States