Population-specific IGF Levels and Relationship between Serum IGF1 and IGFBP3 Levels, Obesity, Hypertension, Diabetes and Biochemical Variables

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: SUN 758-779-Cardiometabolic Risk & Vascular Biology
Sunday, June 16, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board SUN-770
Ilhan Satman*, Nese Colak Ozbey, Harika Boztepe, Aysegul Telci, Beyhan Omer, Yildiz Tutuncu, Ferihan Aral and Faruk Alagol
Istanbul University Istanbul Faculty of Medicine, Istanbul, Turkey
Objective: To define age and sex-specific IGF1 levels in adult Turkish population, to identify relationship between serum IGF1 and IGFBP3 levels, hypertension, obesity, diabetes and biochemical variables.

Study Design: Study included 16,242 women and 9,061 men from the TURDEP-II (2010) survey representing age-specific adult Turkish population.

Results: Median (1-99 percentile) IGF1 levels in the reference population composed of 2,455 healthy men and women were 149 (36.1-384.3) and 143 (30.4-384.3) ng/mL, respectively. IGF1 levels were higher in men than women in all 5-yr age intervals, and decreased with age in both sexes, whereas IGFBP3 levels and IGF1/IGFBP3 ratios were higher in women than men and decreased with age in both sexes (p<0.001, for all). People living in the East part had lower IGF1 than all other regions (p<0.001).

Correlation analysis controlled for region, rural/urban, age, sex, alcohol, tobacco, BMI, waist and blood pressure (BP) revealed that serum IGF1 levels positively correlated with IGFBP3, creatinine, HDL-chol, FT4, insulin, HOMA-IR, vitB12, pholates, cystatin-C and eGFR, and inversely correlated with hsCRP levels. Whereas serum IGFBP3 levels positively correlated with FPG, OGTT-1hPG, HbA1c, HOMA-IR, creatinine, cystatin-C, triglycerides, LDL-chol, nonHDL-chol, FT4, insulin, vitB12, pholates and vit25(OH)D; and inversely correlated with eGFR, hsCRP and PTH levels.

Serum IGF1 levels corrected for region, rural/urban, age, sex, tobacco, alcohol, BMI, waist, BP, creatinine and serum lipids showed decreasing trend from normal glucose tolerance through known diabetes. IGF1 levels were even more reduced if hypertension and/or obesity accompanied to diabetes.

Comparison of lowest and highest quintiles of IGF1 indicated that obesity, hypertension and diabetes were more prevalent in the lowest quintile (obesity: 45.5% vs. 20.8%, central obesity: 63% vs. 34%, known hypertension: 27.9% vs. 7.3%, new hypertension: 17.6% vs. 7.9%, new diabetes: 11.2% vs. 3.5%, total diabetes: 24.8% vs. 7.2%, and pre-diabetes: 32.7% vs. 26.9%). 

Conclusion:  IGF1 levels decreased with age. Low IGF1 associated with higher risk of obesity, hypertension and diabetes.

Nothing to Disclose: IS, NCO, HB, AT, BO, YT, FA, FA

*Please take note of The Endocrine Society's News Embargo Policy at http://www.endo-society.org/endo2013/media.cfm

Sources of Research Support: This study was supported by Istanbul University Scientific Research Fund, The Society of Endocrinology and Metabolism of Turkey (SEMT), Turkish Scientific and Technical Research Council (TUBITAK), The Association of Diabetes Obesity and Metabolism (DOM), and a pooled grant from pharmaceutical industry.