Opposite associations of age-dependent insulin-like growth factor-I standard deviation scores with nutritional state in normal weight and obese subjects.
OBJECTIVE
Insulin-like growth factor-I (IGF-I) has been suggested to be a prognostic marker for the development of cancer and, more recently, cardiovascular disease. These diseases are closely linked to obesity, but reports of the association of IGF-I with measures of obesity are divergent. In this study, we assessed the association of age-dependent IGF-I standard deviation scores with body mass index (BMI) and intra-abdominal fat accumulation in a large population.


METHODS
A cross-sectional, epidemiological study.


METHODS
IGF-I levels were measured with an automated chemiluminescence assay system in 6282 patients from the DETECT study. Weight, height, and waist and hip circumference were measured according to the written instructions. Standard deviation scores (SDS), correcting IGF-I levels for age, were calculated and were used for further analyses.


RESULTS
An inverse U-shaped association of IGF-I SDS with BMI, waist circumference, and the ratio of waist circumference to height was found. BMI was positively associated with IGF-I SDS in normal weight subjects, and negatively associated in obese subjects. The highest mean IGF-I SDS were seen at a BMI of 22.5-25 kg/m2 in men (+0.08), and at a BMI of 27.5-30 kg/m2 in women (+0.21). Multiple linear regression models, controlling for different diseases, medications and risk conditions, revealed a significant negative association of BMI with IGF-I SDS. BMI contributed most to the additional explained variance to the other health conditions.


CONCLUSIONS
IGF-I standard deviation scores are decreased in obesity and underweight subjects. These interactions should be taken into account when analyzing the association of IGF-I with diseases and risk conditions.
Schneider
Harald Jörn
HJ
Institute of Clinical Psychology and Psychotherapy, Technical University of Dresden, Germany. schneider@mpipsykl.mpg.de
Saller
Bernhard
B
Klotsche
Jens
J
März
Winfried
W
Erwa
Wolfgang
W
Wittchen
Hans-Ullrich
HU
Stalla
Günter Karl
GK
D050153:Abdominal Fat; D000328:Adult; D000368:Aged; D000375:Aging / Q000378:metabolism*; D015415:Biomarkers; D015992:Body Mass Index; D001835:Body Weight; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009752:Nutritional Status; D009765:Obesity / Q000453:epidemiology / Q000378:metabolism*; D011379:Prognosis; D012307:Risk Factors
D015415:Biomarkers; D007334:Insulin-Like Growth Factor I