HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: CJN.02870707v1 3/2/348    most recent Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Baxmann, A. C. Articles by Heilberg, I. P. Search for Related Content PubMed PubMed Citation Articles by Baxmann, A. C. Articles by Heilberg, I. P.

Influence of Muscle Mass and Physical Activity on Serum and Urinary Creatinine and Serum Cystatin C

Alessandra Calábria Baxmann^*, Marion Souza Ahmed, Natália Cristina Marques^*, Viviane Barcellos Menon^*, Aparecido Bernardo Pereira, Gianna Mastroianni Kirsztajn, and Ita Pfeferman Heilberg

^* Nutrition Program, Universidade Federal de São Paulo, and Nephrology Division, Universidade Federae Federal de São Paulo, São Paulo, Brazil

Correspondence: Dr. Ita Pfeferman Heilberg, Universidade Federal de São Paulo, Nephrology Division, Rua Botucatu 740, Vila Clementino, São Paulo, SP, 04023-900, Brazil. Phone: 55-11-5574-6300; Fax: 55-11-5573-9652; E-mail: ipheilberg{at}nefro.epm.br

Background and objectives: For addressing the influence of muscle mass on serum and urinary creatinine and serum cystatin C, body composition was assessed by skinfold thickness measurement and bioelectrical impedance analyses.

Design, setting, participants, & measurements: A total of 170 healthy individuals (92 women, 78 men) were classified as sedentary or with mild or moderate/intense physical activity. Blood, 24-h urine samples, and 24-h food recall were obtained from all individuals.

Results: Serum and urinary creatinine correlated significantly with body weight, but the level of correlation with lean mass was even greater. There was no significant correlation between body weight and lean mass with cystatin C. Individuals with moderate/intense physical activity presented significantly lower mean body mass index (23.1 ± 2.5 versus 25.7 ± 3.9 kg/m²) and higher lean mass (55.3 ± 10.0 versus 48.5 ± 10.4%), serum creatinine (1.04 ± 0.12 versus 0.95 ± 0.17 mg/dl), urinary creatinine (1437 ± 471 versus 1231 ± 430 mg/24 h), protein intake (1.4 ± 0.6 versus 1.1 ± 0.6 g/kg per d), and meat intake (0.7 ± 0.3 versus 0.5 ± 0.4 g/kg per d) than the sedentary individuals. Conversely, mean serum cystatin did not differ between these two groups. A multivariate analysis of covariance showed that lean mass was significantly related to serum and urinary creatinine but not with cystatin, even after adjustment for protein/meat intake and physical activity.

Conclusions: Cystatin C may represent a more adequate alternative to assess renal function in individuals with higher muscle mass when mild kidney impairment is suspected.