Hyponatremia among Runners in the Boston Marathon

• Published in: The New England journal of medicine Vol. 352; no. 15; pp. 1550 - 1556
• Main Authors: Almond, Christopher S.D, Shin, Andrew Y, Fortescue, Elizabeth B, Mannix, Rebekah C, Wypij, David, Binstadt, Bryce A, Duncan, Christine N, Olson, David P, Salerno, Ann E, Newburger, Jane W, Greenes, David S
• Format: Journal Article
• Language: English
• Published: United States Massachusetts Medical Society 14.04.2005
• Subjects: Analysis of Variance; Beverages; Body Mass Index; Cohort Studies; Drinking - physiology; Female; Fluids; Humans; Hyponatremia - etiology; Logistic Models; Male; Marathons; Multivariate analysis; Risk Factors; Running - physiology; Sex Factors; Sodium - blood; Time Factors; Track & field; Urine; Water - administration & dosage; Weight Gain; Boston Massachusetts; United States > US
• ISSN: 0028-4793; 1533-4406
• DOI: 10.1056/NEJMoa043901

The development of hyponatremia during a marathon may have grave consequences. In this study of 488 runners in the 2002 Boston Marathon, 13 percent had hyponatremia, and 0.6 percent had critical hyponatremia (serum sodium concentration, <120 mmol per liter). Weight gain during the race, longer racing time, and body-mass-index extremes were associated with hyponatremia. Better efforts to monitor and regulate fluid balance may reduce the frequency of this largely preventable condition. The development of hyponatremia during a marathon may have grave consequences. In this study of 488 runners in the 2002 Boston Marathon, 13 percent had hyponatremia, and 0.6 percent had a serum sodium concentration of <120 mmol per liter. As marathon running has surged in popularity during the past quarter-century, 1 reports have emerged of serious illness and death from hyponatremia, 2 – 8 as in the case of a 28-year-old woman who died after the 2002 Boston Marathon. 2 The incidence of hyponatremia among marathon runners is unknown, since previous studies have been small and limited to runners presenting for medical attention. 4 , 5 , 7 , 9 – 11 Excessive fluid intake is believed to be the primary risk factor for hyponatremia, on the basis of observations of marathon runners who have collapsed 2 – 5 , 7 , 11 , 12 and studies of elite athletes. 13 – 17 However, other . . .