Caffeine and diuresis during rest and exercise: A meta-analysis

Details

• Alternative Title:
  J Sci Med Sport
• Personal Author:
  Zhang, Yang ; Coca, Aitor ; Casa, Douglas J. ; Antonio, Jose ; Green, James M. ; Bishop, Phillip A.
• Description:
  Objectives
  
  Although ergogenic, acute caffeine ingestion may increase urine volume, prompting concerns about fluid balance during exercise and sport events. This meta-analysis evaluated caffeine induced diuresis in adults during rest and exercise.
  
  Design
  
  Meta-analysis.
  
  Methods
  
  A search of three databases was completed on November 1, 2013. Only studies that involved healthy adults and provided sufficient information concerning the effect size (ES) of caffeine ingestion on urine volume were included. Sixteen studies met the inclusion criteria, providing a total of 28 ESs for the meta-analysis. Heterogeneity was assessed using a random-effects model.
  
  Results
  
  The median caffeine dosage was 300 mg. The overall ES of 0.29 (95% confidence interval (CI) = 0.11-0.48, p = 0.001) corresponds to an increase in urine volume of 109 ± 195 mL or 16.0 ± 19.2% for caffeine ingestion vs. non-caffeine conditions. Subgroup meta-analysis confirmed exercise as a strong moderator: active ES = 0.10, 95% CI = −0.07 to 0.27, p = 0.248 vs. resting ES = 0.54, 95% CI = 0.22–0.85, p = 0.001 (Cochran's Q, p = 0.019). Females (ES = 0.75,95% CI = 0.38–1.13, p< 0.001) were more susceptible to diuretic effects than males (ES = 0.13,95% CI = −0.05 to 0.31, p = 0.158) (Cochran's Q, p = 0.003).
  
  Conclusions
  
  Caffeine exerted a minor diuretic effect which was negated by exercise. Concerns regarding unwanted fluid loss associated with caffeine consumption are unwarranted particularly when ingestion precedes exercise.
  
  
• Subjects:
  Adult Article Caffeine Central Nervous System Stimulants Coffee Dehydration Diuresis Diuretic Exercise Female Fluid Balance Humans Male Methylxanthine Models, Statistical Rest Water-Electrolyte Balance

  More +
• Source:
  J Sci Med Sport. 18(5):569-574.
• Pubmed ID:
  25154702
• Pubmed Central ID:
  PMC4725310
• Document Type:
  Journal Article
• Funding:
  CC999999/Intramural CDC HHS/United States
• Volume:
  18
• Issue:
  5
• Collection(s):
  CDC Public Access
• Main Document Checksum:
  urn:sha256:c33f1a49884131106b0c3369d48bf4547f91b0eabc426d167b3162b3b365c861
• Download URL:
  https://stacks.cdc.gov/view/cdc/37638/cdc_37638_DS1.pdf
• File Type:
  [PDF - 187.46 KB ]