Relationship between 25-(OH) D3, the IGF-I system, leptin, anthropometric and body composition variables in a healthy, randomly selected population.
OBJECTIVE
This study prompted us to investigate the relationship between 25-(OH) D (3) and the IGF-I system, leptin, sex, age, anthropometric and body composition variables in healthy adults. We hypothesised that these variables would regulate 25-(OH) D (3) concentrations.


METHODS
We included 253 subjects--126 men and 127 women. Body mass index (BMI) and body composition was determined, along with serum leptin, total IGF-I, free IGF-I, IGFBP3 and plasma 25-(OH) D (3) concentrations.


RESULTS
25-(OH) D (3) deficiency was observed in 69 subjects. There was a difference between 25-(OH) D (3) values and season (summer vs. winter). We observed similar 25-(OH) D (3) concentrations in men to those in women. The differential characteristics in subjects without 25-(OH) D (3) deficiency were lower BMI, fat mass and body fat and higher free IGF-I. We observed that leptin increased in the last decades and IGF-I system decreased by decade in both men and women. In subjects without 25-(OH) D (3) deficiency, there was a correlation between free IGF-I and 25-(OH) D (3) in men, and a negative correlation between 25-(OH) D (3) and age, BMI, fat mass and leptin and a positive correlation with total IGF-I in women. The multivariate linear regression analysis explained 37.8 % of 25-(OH) D (3) variability in men and 39 % in women, and only season and free IGF-I made an independent contribution to 25-(OH) D (3) in men, and season and fat mass in women.


CONCLUSIONS
These data suggest that free IGF-I in men and fat mass in women could regulate 25-(OH) D (3) concentrations.
Gómez
J M
JM
Endocrinology Service and Hormonal Laboratory, Hospital Clínic, Barcelona, Spain. jmgs@csub.scs.es
Maravall
F J
FJ
Gómez
N
N
Navarro
M A
MA
Casamitjana
R
R
Soler
J
J
D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging; D000886:Anthropometry; D001823:Body Composition; D001824:Body Constitution; D015992:Body Mass Index; D002112:Calcifediol / Q000097:blood / Q000172:deficiency / Q000502:physiology*; D005260:Female; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000502:physiology*; D020738:Leptin / Q000502:physiology*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012621:Seasons; D012727:Sex Characteristics
D020738:Leptin; D007334:Insulin-Like Growth Factor I; D002112:Calcifediol