scholarly journals Quantitative analysis of serum sodium concentration after prolonged running in the heat

2008 ◽  
Vol 105 (1) ◽  
pp. 91-99 ◽  
Author(s):  
Lindsay B. Baker ◽  
James A. Lang ◽  
W. Larry Kenney

This study compared measured serum [Na+] (S[Na+]; brackets denote concentration) with that predicted by the Nguyen-Kurtz equation after manipulating ingested [Na+] and changes in body mass (ΔBM) during prolonged running in the heat. Athletes (4 men, 4 women; 22–36 yr) ran for 2 h, followed by a run to exhaustion and 1-h recovery. During exercise and recovery, subjects drank a 6% carbohydrate solution without Na+ (Na+0), 6% carbohydrate solution with 18 mmol/l Na+ (Na+18), or 6% carbohydrate solution with 30 mmol/l Na+ (Na+30) to maintain BM (0%ΔBM), increase BM by 2%, or decrease BM by 2% or 4% in 12 separate trials. Net fluid, Na+, and K+ balance were measured to calculate the Nguyen-Kurtz predicted S[Na+] for each trial. For all beverages, predicted and measured S[Na+] were not significantly different during the 0%, −2%, and −4%ΔBM trials (−0.2 ± 0.2 mmol/l) but were significantly different during the +2%ΔBM trials (−2.6 ± 0.5 mmol/l). Overall, Na+ consumption attenuated the decline in S[Na+] (−2.0 ± 0.5, −0.9 ± 0.5, −0.5 ± 0.5 mmol/l from pre- to postexperiment of the 0%ΔBM trials for Na+30, Na+18, and Na+0, respectively) but the differences among beverages were not statistically significant. Beverage [Na+] did not affect performance; however, time to exhaustion was significantly shorter during the −4% (8 ± 3 min) and −2% (14 ± 3 min) vs. 0% (22 ± 5 min) and +2% (26 ± 6 min) ΔBM trials. In conclusion, when athletes maintain or lose BM, changes in S[Na+] can be accurately predicted by changes in the mass balance of fluid, Na+, and K+ during prolonged running in the heat.

2021 ◽  
Vol 12 ◽  
Author(s):  
Kai Schenk ◽  
Simon Rauch ◽  
Emily Procter ◽  
Katharina Grasegger ◽  
Simona Mrakic-Sposta ◽  
...  

Overdrinking and non-osmotic arginine vasopressin release are the main risk factors for exercise-associated hyponatremia (EAH) in ultra-marathon events. However, particularly during ultra-marathon running in mountainous regions, eccentric exercise and hypoxia, which have been shown to modulate inflammation, hormones regulating fluid homeostasis (hypoxia), and oxidative stress, could contribute to serum sodium changes in a dose-dependent manner. To the best of our knowledge, the contribution of these factors, the extent of which depends on the duration and geographical location of the race, has not been well studied. Twelve male participants (11 finishers) of the short (69km, 4,260m elevation-gain) and 15 male participants (seven finishers) of the long (121km, 7,554m elevation-gain) single-stage Südtirol Ultra Sky-Race took part in this observational field study. Venous blood was drawn immediately before and after the race. Analyses included serum sodium concentration, copeptin (a stable marker for vasopressin), markers of inflammation, muscle damage and oxidative stress. Heart rate was measured during the race and race time was obtained from the race office. During the short and the long competition two and one finishers, respectively showed serum sodium concentrations >145mmol/L. During the long competition, one athlete showed serum sodium concentrations <135mmol/L. Only during the short competition percent changes in serum sodium concentrations of the finishers were related to percent changes in body mass (r=−0.812, p=0.002), total time (r=−0.608, p=0.047) and training impulse (TRIMP) (r=−0.653, p=0.030). Data show a curvilinear (quadratic) relationship between percent changes in serum sodium concentration and body mass with race time when including all runners (short, long, finishers and non-finishers). The observed prevalence of hypo- and hypernatremia is comparable to literature reports, as is the relationship between serum sodium changes and race time, race intensity and body mass changes of the finishers of the short race. The curvilinear relationship indicates that there might be a turning point of changes in serum sodium and body mass changes after a race time of approximately 20h. Since the turning point is represented mainly by non-finishers, regardless of race duration slight decrease in body mass and a slight increase in serum sodium concentration should be targeted to complete the race. Drinking to the dictate of thirst seems an adequate approach to achieve this goal.


2010 ◽  
Vol 30 (8) ◽  
pp. 1137-1142 ◽  
Author(s):  
Mónica Guevara ◽  
María E. Baccaro ◽  
Jose Ríos ◽  
Marta Martín-Llahí ◽  
Juan Uriz ◽  
...  

2010 ◽  
Vol 42 (9) ◽  
pp. 1669-1674 ◽  
Author(s):  
MATTHEW D. PAHNKE ◽  
JOEL D. TRINITY ◽  
JEFFREY J. ZACHWIEJA ◽  
JOHN R. STOFAN ◽  
W. DOUGLAS HILLER ◽  
...  

2017 ◽  
Author(s):  
Richard H Sterns ◽  
Stephen M. Silver ◽  
John K. Hix ◽  
Jonathan W. Bress

Guided by the hypothalamic antidiuretic hormone vasopressin, the kidney’s ability to conserve electrolyte–free water when it is needed and to excrete large volumes of water when there is too much of it normally prevents the serum sodium concentration from straying outside its normal range. The serum sodium concentration determines plasma tonicity and affects cell volume: a low concentration makes cells swell, and a high concentration makes them shrink. An extremely large water intake, impaired water excretion, or both can cause hyponatremia. A combination of too little water intake with too much salt, impaired water conservation, or excess extrarenal water losses will result in hypernatremia. Because sodium does not readily cross the blood-brain barrier, an abnormal serum sodium concentration alters brain water content and composition and can cause serious neurologic complications. Because bone is a reservoir for much of the body’s sodium, prolonged hyponatremia can also result in severe osteoporosis and fractures. An understanding of the physiologic mechanisms that control water balance will help the clinician determine the cause of impaired water conservation or excretion; it will also guide appropriate therapy that can avoid the life-threatening consequences of hyponatremia and hypernatremia.


1980 ◽  
Vol 8 (3) ◽  
pp. 349-352 ◽  
Author(s):  
Luen Bik To ◽  
P. J. Phillips

Eighteen patients with hyperosmolar non-ketotic diabetic coma were studied retrospectively to identify factors affecting prognosis and to review treatment. This condition affected older women two-thirds of whom were unrecognised diabetics. Eight (44%) died. Mortality correlated with age above 60, uraemia and hyperosmolarity, but not with the degree or rate of fall of hyperglycaemia. Hyperglycaemia responded to rehydration and insulin, but in all patients serum osmolarity remained high for several days. In 14 patients (78%) the serum sodium concentration initially increased and in four (22 %) serum osmolarity increased. This persistence or worsening of the hyperosmolar state can be avoided without the risk of cerebal oedema by replacing the fluid and electrolyte deficits over 48 hours and using 5% dextrose for the water deficit.


2013 ◽  
Vol 98 (4) ◽  
pp. 289-291
Author(s):  
Ryota Iwase ◽  
Hiroaki Shiba ◽  
Takeshi Gocho ◽  
Yasuro Futagawa ◽  
Shigeki Wakiyama ◽  
...  

Abstract A 68-year-old man underwent pancreaticoduodenectomy with lymph nodes dissection for carcinoma of the ampulla of Vater. The patient had anxiety neurosis and had been treated with a selective serotonin reuptake inhibitor (SSRI). Postoperatively, SSRI was resumed on postoperative day 2. His serum sodium concentration gradually decreased, and the patient was given a sodium supplement. However, 11 days after the operation, laboratory findings included serum sodium concentration of 117 mEq/L, serum vasopressin of 2.0 pg/mL, plasma osmolality of 238 mOsm/kg, urine osmolality of 645 mOsm/kg, urine sodium concentration of 66 mEq/L, serum creatinine concentration of 0.54 mg/dL, and serum cortisol concentration of 29.1 μg/dL. With a diagnosis of syndrome of inappropriate secretion of antidiuretic hormone (SIADH), the antianxiety neurosis medication was changed from the SSRI to another type of drug. After switching the medication, the patient made a satisfactory recovery with normalization of serum sodium by postoperative day 20.


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