Association between serum insulin-like growth factor (IGF) I and IGF binding protein-3 and lung function.
BACKGROUND
There is strong evidence that IGF-I and IGF binding protein 3 (IGFBP-3), as central mediators of endocrine and finally metabolic or anabolic effects of GH, were associated with increased lung size in acromegaly or a decrease of respiratory muscle pressures in patients with GH deficiency. The aim of the present study was to further clarify the impact of IGF-I and IGFBP-3 levels on lung volumes and respiratory pressures in a general adult population.


METHODS
From the Study of Health in Pomerania, 1326 subjects aged 25 to 85 yr participated in standardized pulmonary function testing. IGF-I and IGFBP-3 levels were measured with the Immulite 2500 system. Multivariable linear regression analyses adjusted for age, sex, body mass index, physical activity, and smoking were performed.


RESULTS
In men, positive linear associations between IGF-I and IGF-I/IGFBP-3 ratio with forced expiratory volume in 1 sec (FEV1) as well as with forced vital capacity (FVC) were detected across all ages, whereas in women this positive association was only detectable above 50 yr. Furthermore, the analyses indicated positive linear relations of IGF-I/IGFBP-3 ratio with FEV1 and FVC, respectively. No significant relations between IGF-I or IGFBP-3 and maximal inspiratory pressure was detectable in both sexes.


CONCLUSIONS
In conclusion, higher IGF-I levels were associated with higher lung volumes in men, whereas in women this association was only detectable in subjects older than 50 yr. Higher IGF-I values were not associated with increased respiratory muscle strength measured as maximal inspiratory pressure.
Gläser
Sven
S
Department of Internal Medicine B, Pulmonary Medicine and Infectious Diseases, Ernst-Moritz-Arndt University Greifswald, D-17475 Greifswald, Germany. glaeser.sven@gmail.com
Friedrich
Nele
N
Ewert
Ralf
R
Schäper
Christoph
C
Nauck
Matthias
M
Dörr
Marcus
M
Völzke
Henry
H
Felix
Stephan B
SB
Krebs
Alexander
A
Wallaschofski
Henri
H
Koch
Beate
B
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006130:Growth Disorders / Q000097:blood / Q000503:physiopathology; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000032:analysis / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D008168:Lung / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D012129:Respiratory Function Tests; D012727:Sex Characteristics
D018972:Insulin-Like Growth Factor Binding Protein 3; D007334:Insulin-Like Growth Factor I