Circulating follistatin displays a day-night rhythm and is associated with muscle mass and circulating leptin levels in healthy, young humans.
OBJECTIVE
Follistatin may affect lean and fat mass and be implicated in metabolic diseases. We aimed to elucidate physiological predictors of circulating follistatin variation in healthy young humans.


METHODS
This was an observational, cross-sectional study with two additional prospective observational arms (circadian, seasonal sub-studies) and one prospective interventional arm (mixed meal sub-study). Healthy, young individuals of both sexes (n=122) were subjected to anthropometric and body composition measurements and their eating and exercise behavior profiles were assessed by validated questionnaires. Sub-groups were subjected to standardized meal ingestion (n=36), day-night rhythm (n=20) and seasonal variation (n=20) studies. Main outcome of the study were circulating follistatin levels.


RESULTS
At baseline follistatin levels were correlated with creatinine (r=0.24; p=0.01), creatine phosphokinase (rs=0.22; p=0.02), and with lean body mass (rs=0.19; p=0.04) and were higher in males than females (p=0.004) after adjustment for leptin, which was its major predictor. Follistatin levels showed a circadian (p<0.001), but not a seasonal, variation, and were also affected by the phase of menstrual cycle in females (p=0.034). Follistatin levels were not affected by dietary or exercise habits but levels increased after a standardized meal ingestion (250kcal) (p=0.002).


CONCLUSIONS
In healthy young individuals circulating follistatin levels are correlated with muscle mass. Follistatin levels are associated with circulating leptin levels and display a day-night rhythm and a menstrual cycle, but not a seasonal, variation.
Department of Endocrinology, 424 General Military Hospital, Thessaloniki, Greece. Electronic address: anastath@endo.gr.
Athanasios D
AD
Anastasilakis
Department of Medicine, Aristotle University of Thessaloniki, Ippokration General Hospital, Thessaloniki, Greece.
Stergios A
SA
Polyzos
Hellenic Military School of Medicine, Thessaloniki, Greece.
Elpida C
EC
Skouvaklidou
Hellenic Military School of Medicine, Thessaloniki, Greece.
Georgios
G
Kynigopoulos
Hellenic Military School of Medicine, Thessaloniki, Greece.
Zacharias G
ZG
Saridakis
Nutrition-Dietetics Department, Alexander Technological Education Institute of Thessaloniki, Central Macedonia, Greece.
Aggeliki
A
Apostolou
Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
Georgios A
GA
Triantafyllou
Nutrition-Dietetics Department, Alexander Technological Education Institute of Thessaloniki, Central Macedonia, Greece.
Thomai
T
Karagiozoglou-Lampoudi
Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
Christos S
CS
Mantzoros
D001823:Body Composition; D002940:Circadian Rhythm; D003402:Creatine Kinase / Q000097:blood; D003404:Creatinine / Q000097:blood; D003430:Cross-Sectional Studies; D004032:Diet; D005260:Female; D038681:Follistatin / Q000097:blood*; D064368:Healthy Volunteers; D006801:Humans; D020738:Leptin / Q000097:blood*; D008297:Male; D008597:Menstrual Cycle / Q000378:metabolism; D018482:Muscle, Skeletal / Q000033:anatomy & histology / Q000502:physiology*; D011446:Prospective Studies; D012621:Seasons; D012727:Sex Characteristics; D055815:Young Adult
C503233:FST protein, human; D038681:Follistatin; D020738:Leptin; D003404:Creatinine; D003402:Creatine Kinase
Circadian rhythm; Fat mass; Follistatin; Lean body mass; Leptin