alexa Is specific gravity a good estimate of urine osmolality?
Diabetes & Endocrinology

Diabetes & Endocrinology

Journal of Obesity & Weight Loss Therapy

Author(s): Imran S, Eva G, Christopher S, Flynn E, Henner D

Abstract Share this page

Abstract CONTEXT: Urine specific gravity (USG) is often used by clinicians to estimate urine osmolality. USG is measured either by refractometry or by reagent strip. OBJECTIVE: We studied the correlation of USG obtained by either method with a concurrently obtained osmolality. DESIGN: Using our laboratory's records, we retrospectively gathered data on 504 urine specimens on patients on whom a simultaneously drawn USG and an osmolality were available. Out of these, 253 USG's were measured by automated refractometry and 251 USG's were measured by reagent strip. Urinalysis data on these subjects were used to determine the correlation between USG and osmolality, adjusting for other variables that may impact the relationship. The other variables considered were pH, protein, glucose, ketones, nitrates, bilirubin, urobilinogen, hemoglobin, and leukocyte esterase. The relationships were analyzed by linear regression. RESULTS: This study demonstrated that USG obtained by both reagent strip and refractometry had a correlation of approximately 0.75 with urine osmolality. The variables affecting the correlation included pH, ketones, bilirubin, urobilinogen, glucose, and protein for the reagent strip and ketones, bilirubin, and hemoglobin for the refractometry method. At a pH of 7 and with an USG of 1.010 predicted osmolality is approximately 300 mosm/kg/H(2)O for either method. For an increase in SG of 0.010, predicted osmolality increases by 182 mosm/kg/H(2) O for the reagent strip and 203 mosm/kg/H(2)O for refractometry. Pathological urines had significantly poorer correlation between USG and osmolality than "clean" urines. CONCLUSION: In pathological urines, direct measurement of urine osmolality should be used. © 2010 Wiley-Liss, Inc. This article was published in J Clin Lab Anal and referenced in Journal of Obesity & Weight Loss Therapy

Relevant Expert PPTs

Relevant Speaker PPTs

Recommended Conferences

  • 13th World Congress on Obesity
    Aug 24-25, 2017, Toronto, Canada
  • 13th Euro Obesity and Endocrinology Congress
    Sep 21-23, 2017, Madrid, Spain
  • 14th Global Obesity Meeting
    Oct 23-24, 2017 Dubai, UAE
  • 16th International Conference and Exhibition on Obesity & Weight Management
    November 13-15, 2017 Atlanta,Georgia, USA

Relevant Topics

Peer Reviewed Journals
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version