Elecsys igf 1

After at least 8 h of fasting, 5 cc peripheral venous blood samples were collected into three blood collection tubes (2 EDTA-containing and 1 gel-included biochemistry tubes) from all participants.
Serum fasting blood glucose (FBG), alanine aminotransaminase (ALT), creatinine, uric acid, total cholesterol (TC), triglyceride (TG), and high-density lipoprotein cholesterol (HDL-C) were measured using a Beckman Coulter AU 5800 chemistry analyzer (Beckman Coulter, Brea, CA, USA). Low-density lipoprotein cholesterol (LDL-C) was calculated with the Friedewal formula [LDL-C= TC - (HDL-C+ (TG/5)].
Serum IGF-1 and GH levels were measured by electro-chemiluminescence immunoassay (Elecsys IGF-1; Roche Diagnostics, Mannheim, Germany). The normal range of serum IGF-1 was evaluated by sex and age. Age and sex-normalized levels of IGF-1, rare GH< 0.4 ng/mL in oral glucose tolerance test (OGTT) after surgery and random GH<1 ng/mL when treating with SSA were accepted criteria for cure or good biochemical control [14].

Serum IGF-1 was measured by electrochemiluminescence immunoassay (Elecsys IGF-1; Roche Diagnostics, Tokyo, Japan), which was calibrated against the WHO International Standard 02/254. The values of serum IGF-1 were transformed into SDs, according to the established reference ranges of the assay for sex and calendar age^{12 (link)}. GH was measured by immunoenzymometric assay (E Test TOSOH II HGH; Tosoh Co., Ltd., Tokyo, Japan), which was standardized against the WHO International Standard 98/574. According to the manufacture's datasheet, the intra- and interassay coefficients of variation (CV) for IGF-1 was < 10% and < 20%, and those for GH was < 10% and < 15%. As GH was measured in the hospital, we tested for intra-assay CV for GH in our hospital and found that it was 2% on average. Interassay CV for GH in our hospital was not tested. IGF-1 was measured by the testing company.