Energy deficiency, menstrual disorders and low bone mineral density in female athletes: a systematic review

Abstract

Low energy availability (LEA) may lead to menstrual disorders and low bone mineral density, predisposing to the female athlete triad. The primary aim of the present review was to systematically investigate the impact of chronic strenuous exercise on the energy status of professional female athletes compared to sedentary, recreationally active controls as concerns their menstrual status and bone mineral density (BMD). A secondary aim was evaluation of the combined prevalence of the components of the female athlete triad in athletes as compared to non-athletes. A systematic review was conducted from 2007 to February 2018. The inclusion and exclusion criteria of the studies were established in advance of the literature search according to the clinical inquiry and the study design. Four studies were included in this systematic review. The female athlete triad was more prevalent in professional athletes compared to non-athletes. The same results were obtained for both LEA and menstrual disorders. However, BMD and Z-scores showed high heterogeneity among the studies. Both female athletes and non-athletes are prone to LEA and subsequent menstrual disorders and low BMD or osteoporosis. Future studies are needed to examine energy availability in elite female athletes as well as in non-athletes.