Endocrine and clinical correlates of myostatin serum concentration in men--the STRAMBO study.
BACKGROUND
Myostatin is expressed mainly in skeletal muscle cells and acts as an inhibitor of muscle growth and differentiation. However, data on the determinants of serum myostatin concentrations in humans are limited.


OBJECTIVE
The aim of the study was to assess the correlates of serum myostatin concentrations in men.


METHODS
We conducted a cross-sectional analysis of the STRAMBO cohort.


METHODS
Men holding private health insurance coverage with Mutuelle de Travailleurs de la Région Lyonnaise were included in the study.


METHODS
A total of 1121 male volunteers aged 20-87 yr participated in the study.


METHODS
Nonfasting blood samples were collected.


METHODS
We measured the association of the investigated variables with circulating myostatin levels.


RESULTS
Serum myostatin levels increased slightly with age until 57 yr and then decreased. Circulating myostatin levels showed circannual variation, with the highest concentration in spring. In men older than 57 yr, serum myostatin levels decreased across increasing quartiles of body mass index and of total central and peripheral fat mass (P<0.05 to <0.001). Serum myostatin levels were positively correlated with serum levels of 25-hydroxycholecalciferol (25OHD), even after adjustment for season. Average myostatin levels were 0.47 sd higher in men with 25OHD above 40 ng/ml, compared with those with 25OHD below 20 ng/ml (P<0.05). Current smokers had lower myostatin concentration. Neither current physical activity nor serum levels of PTH, testosterone, and 17β-estradiol were associated with myostatin concentrations.


CONCLUSIONS
In men, circulating myostatin levels show seasonal changes and are associated with age, body mass index, fat mass, smoking, and 25OHD levels.
INSERM UMR 1033, University of Lyon, Hospices Civils de Lyon, Hôpital Edouard Herriot, Pavillon F, Place d'Arsonval, 69437 Lyon, France. pawel.szulc@inserm.fr
Pawel
P
Szulc
Michael
M
Schoppet
Claudia
C
Goettsch
Martina
M
Rauner
Thomas
T
Dschietzig
Roland
R
Chapurlat
Lorenz C
LC
Hofbauer
D000273:Adipose Tissue / Q000502:physiology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000378:metabolism*; D015992:Body Mass Index; D002112:Calcifediol / Q000097:blood; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D004703:Endocrine System / Q000502:physiology*; D006801:Humans; D008019:Life Style; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology; D018482:Muscle, Skeletal / Q000502:physiology*; D055435:Myostatin / Q000097:blood*; D012621:Seasons; D012907:Smoking / Q000378:metabolism; D055815:Young Adult
C525911:MSTN protein, human; D055435:Myostatin; D002112:Calcifediol