High Prevalence of Iron Deficiency Exhibited in Internationally Competitive, Non-Professional Female Endurance Athletes-A Case Study

Parenteral Iron Therapy: Examining Current Evidence for Use in Athletes

A high prevalence of iron deficiency exists in athlete populations. Various mechanisms, including increased losses through sweat, haemolysis, haematuria, and gastrointestinal micro-ischemia; inadequate dietary intake; and transient exercise-induced increases in the regulatory hormone, hepcidin, contribute to the increased prevalence in athletes. Indeed, hepcidin has been shown to peak around 3-6 hours post-exercise, limiting iron absorption from the gut. As the practitioner's ability to control losses is limited, the key to treatment of iron deficiency in athletes is optimal timing of dietary and oral iron supplementation around these periods of reduced gut absorption. While timing and dosing schedule strategies might be sufficient to treat iron deficiency non-anaemia, the significant lag to impact iron status is relatively long. Therefore, in iron deficiency anaemia, the use of parenteral iron has the benefit of rapid repletion of iron stores and normalisation of haemoglobin status, while bypassing the action of hepcidin at the gut. Furthermore, newer intravenous formulations can be administered as a single total dose over 15-60 min and have a similar safety profile to oral treatment. This review discusses the existing evidence for parenteral iron use in athletes and the unique context for consideration when choosing the parenteral route in this population.

Nutritional Modulation of Hepcidin in the Treatment of Various Anemic States

Twenty years after its discovery, hepcidin is still considered the main regulator of iron homeostasis in humans. The increase in hepcidin expression drastically blocks the flow of iron, which can come from one's diet, from iron stores, and from erythrophagocytosis. Many anemic conditions are caused by non-physiologic increases in hepcidin. The sequestration of iron in the intestine and in other tissues poses worrying premises in view of discoveries about the mechanisms of ferroptosis. The nutritional treatment of these anemic states cannot ignore the nutritional modulation of hepcidin, in addition to the bioavailability of iron. This work aims to describe and summarize the few findings about the role of hepcidin in anemic diseases and ferroptosis, as well as the modulation of hepcidin levels by diet and nutrients.

Prevalence of iron-deficient but non-anemic university athletes in Japan: an observational cohort study

BACKGROUND

Iron deficiency (ID) and iron deficiency anemia (IDA) are long-standing health problems in athletes, affecting both performance and health. ID prevalence in young athletes remains high and a matter of concern. ID and IDA can lead to fatigue, reduced endurance, and decreased oxygen transport, potentially compromising athletic performance. We hypothesized that ID would still be a major health concern in university athletes across sports clubs in Japan.

PURPOSE

The study aimed to investigate the prevalence of ID and IDA in athletes participating in Kendo, badminton, baseball, and handball at the University of Tsukuba (Tsukuba, Ibaraki Prefecture, Japan). The study also examined the correlation between hypoferritinemia and other variables, such as previous use of iron supplements, body mass index (BMI), energy intake, and years of athletics.

METHODS

Between January and December 2019, 126 university athletes, consisting of 79 males and 47 females, underwent physical measurements and blood tests. The blood test included complete blood count, levels of serum ferritin, serum iron, and total iron-binding capacity. The anemia was defined in accordance with the WHO criteria. Daily energy and iron intake were estimated with the food frequency questionnaire in Japanese (FFQg). Thirty-four female athletes responded to a survey about their menstruation and low-dose estrogen-progestin (LEP) usage.

RESULTS

While none of the athletes had anemia, 22 (47%) female athletes exhibited serum ferritin levels of 30 ng/mL or less, defining them as hypoferritinemia. The multivariate logistic regression model revealed that a shorter duration of the athletic experience (adjusted odd ratio [95% confidence interval]: 0.62 [0.43-0.90]), lower energy intake (0.994 [0.989-0.999]), and higher dietary iron intake (4.40 [1.12-17.26]) were associated with hypoferritinemia. Seventeen (50%) female athletes reported a decline in subjective performance during menstruation, albeit two took LEP regularly.

CONCLUSIONS

This study reveals that ID is a prevalent health concern among young female athletes across sports clubs. It underscores the need for their education on the importance of assessing ID status. Limitation includes the nature of single-site and observational study, the absence of hepcidin measurement, and an unspecified amount of exercise. Comprehensive investigations are needed to elucidate the causes and optimal treatments for ID in young athletes.

Nutritional Strategies for Endurance Cyclists - Periodized Nutrition, Ketogenic Diets, and Other Considerations

ABSTRACT

Cycling is a growing sport worldwide since the COVID-19 pandemic. With the growing availability and interest in long distance events, professional and amateur cyclists are pushing themselves further and harder than ever before. Training and nutrition should be understood by the sports medicine professional in order to guide counseling toward proper fueling to avoid health consequences. This article reviews macronutrients and micronutrients, periodized training and nutrition, and the relevance of the ketogenic diet for endurance cyclists riding greater than 90 min.