Micronutrient Intake, Menstrual History, and Bone Mineral Density in Female Collegiate Runners

Abstract

An increasing number of young women in ts has shifted much research attention to bone health and the female athlete. One purpose of this investigation was to use the menstrual index (MI), an objective measure of menstrual history, to compare bone mineral density (BMD) measurements of female collegiate runners with a history of menstrual regularity to those with irregular menstrual patterns. A second purpose was to examine the relationship between BMD and calcium and magnesium intake among these two groups. Eleven regular runners with a MI ≥ 10 and 12 irregular runners with a MI < 10 underwent dual-energy X-ray absorptiometry (DEXA) measurements of the lumbar spine (L1-L4), total hip, femoral neck, trochanter, Ward's triangle and total body. Calcium and magnesium intakes were assessed with a food frequency questionnaire. Although BMD values were lower at all sites among the irregular runners, a MANOVA indicated that there was no statistically significant difference in BMD at L1-L4, total hip, femoral neck, trochanter, or Ward's triangle between the two groups. Total body BMD was significantly lower in the irregular (1.114±0.068g/cm2) group compared to regularly menstruating runners (1.180±0.068g/cm2). Pearson product-moment correlation confirmed that there was no significant relationship between BMD at any site and calcium or magnesium intake in either group. Irregular runners have a lower total body BMD than their eumenorrheic counterparts. Identifying athletes that are at high risk for low BMD could help reduce the medical costs associated with fracture development, the psychological consequences attributed to the premature end of an athlete's career, and the detrimental effects of irreversible bone loss.