Relationship between Blood Myostatin Levels and Kidney Function:Shimane CoHRE Study.
OBJECTIVE
Myostatin (MSTN), a member of TGF-β superfamily, is produced in the skeletal muscle to inhibit myocyte differentiation. MSTN expression is increased in the skeletal muscle in patients with chronic kidney disease (CKD), which may play a role in the pathogenesis of sarcopenia or in the protein energy wasting (PEW). This observation implies that the plasma MSTN level may be correlated with kidney function. Thus, we conducted a cross-sectional study to evaluate the association between the plasma MSTN concentration and the estimated glomerular filtration rate (eGFR).


METHODS
Subjects were 781 participants of a health examination performed in a rural area in Japan. Among them, 124 subjects were selected by stratified random sampling according to eGFR. Creatinine clearance (ClCr) by the Cockcroft-Gault equation was used as a measure of kidney function. Plasma concentration of MSTN was determined by ELISA.


RESULTS
The plasma MSTN level was not different between men (3.42±1.61 ng/mL) and women (3.27±1.43 ng/mL). In a simple regression analysis, the MSTN level was significantly correlated with eGFR (r = -0.25, p<0.01) and ClCr (r = -0.20, p<0.05) but not with age and BMI. In a multiple linear regression analysis, the MSTN level showed a negative correlation with eGFR (standardized β = -0.31, p<0.01) and ClCr (standardized β = -0.35, p<0.01) under the adjustment with age, sex, BMI and LDL-C. Weak correlation was observed between the MSTN level and BMI / the serum LDL-C level. When the subjects were stratified into 4 groups according to eGFR, MSTN was significantly greater in the groups with the lowest and the 2nd lowest eGFR (3.55±1.79 and 3.76±1.75 ng/mL, respectively) than the level in the group with the highest eGFR (2.77±0.85 ng/mL).


CONCLUSIONS
Plasma MSTN level was elevated in an early stage of CKD, which could be involved in the progression of sarcopenia.
Department of Laboratory Medicine, Shimane University Faculty of Medicine, Shimane, Japan; The Center for Community-based Health Research and Education (CoHRE), Shimane University, Shimane, Japan.
Shozo
S
Yano
Department of Laboratory Medicine, Shimane University Faculty of Medicine, Shimane, Japan.
Atsushi
A
Nagai
Department of Functional Pathology, Shimane University Faculty of Medicine, Shimane, Japan; The Center for Community-based Health Research and Education (CoHRE), Shimane University, Shimane, Japan.
Minoru
M
Isomura
Department of Environmental and Preventive Medicine, Shimane University Faculty of Medicine, Shimane, Japan; The Center for Community-based Health Research and Education (CoHRE), Shimane University, Shimane, Japan.
Masayuki
M
Yamasaki
Department of General Medicine, Shimane University Faculty of Medicine, Shimane, Japan; The Center for Community-based Health Research and Education (CoHRE), Shimane University, Shimane, Japan.
Tsunetaka
T
Kijima
The Center for Community-based Health Research and Education (CoHRE), Shimane University, Shimane, Japan.
Miwako
M
Takeda
The Center for Community-based Health Research and Education (CoHRE), Shimane University, Shimane, Japan.
Tsuyoshi
T
Hamano
Department of Laboratory Medicine, Shimane University Faculty of Medicine, Shimane, Japan; The Center for Community-based Health Research and Education (CoHRE), Shimane University, Shimane, Japan.
Toru
T
Nabika
D000368:Aged; D003430:Cross-Sectional Studies; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology; D006801:Humans; D007668:Kidney / Q000378:metabolism* / Q000473:pathology; D016014:Linear Models; D008297:Male; D055435:Myostatin / Q000097:blood*; D051436:Renal Insufficiency, Chronic / Q000097:blood
D055435:Myostatin