• Association between hepatic steatosis and serum IGF1 and IGFBP-3 levels in a population-based sample.

      Völzke, Henry; Nauck, Matthias; Rettig, Rainer; Dörr, Marcus; Higham, Claire E; Brabant, Georg E; Wallaschofski, Henri; Institute of Community Medicine Institute of Clinical Chemistry and Laboratory Medicine Institute of Physiology Department of Internal Medicine B, University of Greifswald, Greifswald D-17487, Germany. voelzke@uni-greifswald.de (2009-11)
      CONTEXT: It is assumed that hepatic steatosis plays a role in the development and progression of the metabolic syndrome and its cardiovascular sequelae. Low serum IGF1 levels might mediate these associations. OBJECTIVES: The aims of this study were i) to investigate the associations of hepatic steatosis with serum IGF1 and IGF binding protein-3 (IGFBP-3) levels using ultrasound and serum alanine aminotransaminase (ALT) data to define hepatic steatosis, and ii) to analyze the specific role of alcohol consumption in this context. DESIGN: We analyzed data from the population-based Study of Health in Pomerania. METHODS: We used data from 3863 subjects (1971 women) aged 20-79 years who had no history of viral hepatitis, liver cirrhosis, or malignant diseases. Liver hyperechogenicity was diagnosed using ultrasound. Serum IGF1 and IGFBP-3 levels were determined by automated two-site chemiluminescence immunoassays. RESULTS: Hyperechogenic liver pattern was associated with low serum IGF1 levels and low serum IGF1/IGFBP-3 ratios. The lowest serum IGF1 and IGF1/IGFBP-3 values and highest IGFBP-3 levels were present in subjects who had a hyperechogenic liver pattern and increased serum ALT levels. All of these associations were independent of alcohol consumption. CONCLUSIONS: Our data show that hepatic steatosis is associated with low serum IGF1 levels. This association is independent of alcohol consumption.
    • Five commercially available insulin-like growth factor I (IGF-I) assays in comparison to the former Nichols Advantage IGF-I in a growth hormone treated population.

      Krebs, Alexander; Wallaschofski, Henri; Spilcke-Liss, Elisabeth; Kohlmann, Thomas; Brabant, Georg E; Völzke, Henry; Nauck, Matthias; Institute of Clinical Chemistry and Laboratory Medicine, Ernst Moritz Arndt University of Greifswald, Greifswald, Germany. alexander.krebs@uni-greifswald.de (2008)
      BACKGROUND: The serum insulin-like growth factor I (IGF-I) level is accepted to diagnose the growth hormone (GH) status. Here, we evaluated the DRG IGF-I 600 ELISA, DSL IGF-I ELISA, IDS OCTEIA IGF-I, Mediagnost IGF-I-ELISA, and the Siemens Immulite 2500 IGF-I in comparison to the former Nichols Advantage IGF-I assay. METHODS: Imprecision was determined by use of a serum pool and commercial control materials. Accuracy was evaluated by means of a method comparison to Nichols in 173 serum samples of GH deficient patients. RESULTS: The Siemens and the IDS IGF-I assays showed the lowest imprecision with coefficients of variation up to 3.6% and 6.9%, respectively. Both correlated best to Nichols (Siemens: y=0.667X+8.8 microg/L, r=0.950; IDS: y=0.527 X+4.6 microg/L, r=0.927) with the lowest dispersion of residuals from a linear equation. The DSL assay had the highest comparability to Nichols (y=1.000 X+35.5 microg/L, r=0.864), but with a considerable scattering. CONCLUSIONS: To yield IGF-I determination comparable to the former Nichols IGF-I, either the Siemens or the IDS assay should be applied, and the results should be converted by a linear method transformation. Where a conversion factor is not desired, the DSL assay should be selected.
    • Mortality and serum insulin-like growth factor (IGF)-I and IGF binding protein 3 concentrations.

      Friedrich, Nele; Haring, Robin; Nauck, Matthias; Lüdemann, Jan; Rosskopf, Dieter; Spilcke-Liss, Elisabeth; Felix, Stephan B; Dörr, Marcus; Brabant, Georg E; Völzke, Henry; et al. (2009-05)
      BACKGROUND: Previous studies provided conflicting results regarding the association of serum IGF-I or IGF-binding protein-3 (IGFBP-3) and mortality. The aim of this study was to assess the relation of IGF-I and IGFBP-3 levels with mortality from all causes, cardiovascular disease (CVD), and cancer in a prospective population-based study. METHODS: From the Study of Health in Pomerania (SHIP) 1988 men and 2069 women aged 20-79 yr were followed up on average 8.5 yr. Causes of deaths were coded according to the International Classification of Diseases, 10th revision. Serum IGF-I and IGFBP-3 levels were determined by chemiluminescence immunoassays and categorized into three groups (low, normal, high) according to the sex- and age-specific 10th and 90th percentiles. RESULTS: Adjusted analyses revealed that men with low but not high IGF-I levels had an almost 2-fold higher risk of all-cause mortality [hazard ratio (HR) 1.92 (95% confidence interval [CI] 1.35; 2.73)], CVD mortality [HR 1.92 (95% CI 1.00; 3.71)], and cancer mortality [HR 1.85 (95% CI 1.00; 3.45)] compared with men with normal IGF-I levels. In women, no association between IGF-I and mortality was found. Moreover, low IGFBP-3 levels were associated with higher all-cause mortality in men [HR 1.87 (95% CI 1.31; 2.64)] and women [HR 1.63 (95% CI 0.96; 2.76)]. CONCLUSIONS: The present study found inverse associations between IGF-I or IGFBP-3 levels and mortality from all causes, CVD, or cancer in men and between IGFBP-3 and all-cause mortality in women.