A Nutritional Intervention In Exercising Women With Oligo/Amenorrhea Improved Energy Availability

Abstract

Reduced energy availability (EA) suppresses reproduction and induces oligo/amenorrhea (O/A) in exercising women. Treatment goals are to increase energy intake (EI) to improve EA and restore menstrual function. PURPOSE: Determine if a nutritional intervention that increased EI in exercising women with O/A improved EA and energetic status. METHODS A 12 month randomized controlled trial designed to increase energy intake 20-30% above baseline energy needs in exercising women with O/A randomized participants into O/A+CAL (n=13) and Control (n=10) groups. EI and exercise energy expenditure (EEE) were assessed throughout the intervention. EA was calculated as EI-EEE/fat free mass (FFM). Fasting blood samples were collected to assess TT3 and leptin. Independent t-tests/Mann-Whitney U tests compared differences between groups and correlations were run between changes in energy and hormones. Data are mean ± SE. RESULTS Subjects were 22±1 yr, BMI 20.0±0.4 kg/m2. Menstrual recovery was observed and previously reported. There were no pre intervention differences in EI (1837±95 kcal/d), EEE (390±40 kcal/d), FFM (41.5±0.8 kg) or EA (37.2±2.7 kcal/kg FFM/d) between groups. During the intervention there were greater absolute and percent increases in EI in O/A+CAL vs Control (448±170 vs -117±147 kcal/d, p=0.02; 23.6±8.6 vs -4.6±8.4%, p=0.03). There were no differences between groups in absolute or percent change for EEE (133±46 kcal/d, p=0.07; 38.8±11.3%, p=0.10) or FFM (0.6±0.3kg, p=0.60; 1.6±0.7%, p=0.51). Absolute increase in EA was greater in O/A+CAL vs Control (10.8±5.5 vs -6.0±3.9 kcal/kg FFM/d, p=0.03), but no difference in percent change (29.2±13.4 vs -6.7±12.5%; p=0.07). Absolute and percent increase in fat mass (2.3±0.3 vs 0.7±0.5, p<0.01; 20.6±3.1 vs 5.4±3.2%, p<0.01) and body mass (3.2±0.3 vs 0.8±0.8, p<0.01; 6.1±0.7 vs 1.5±1.3%, p<0.01) were greater in O/A+CAL vs Control. O/A+CAL had larger absolute and percent increases in TT3 (10.3±5.0 vs -6.7±5.3 ng/dL, p=0.03; 17.2±7.4 vs -8.3±5.5%, p=0.02) and percent increase in leptin (85.1±24.0 vs -13.3±18.0%) vs Control. Changes in EI and EA were not associated with changes in hormonal markers. CONCLUSION An intervention designed to improve EI can be considered an effective nutritional intervention for managing oligo/amenorrhea in exercising women.