Insulin-like growth factor-1 positively associated with bone formation markers and creatine kinase in adults with general physical activity.

BACKGROUND: The Insulin-like growth factor-1 (IGF-1) is primarily synthesized by hepatocytes in a growth hormone (GH)-dependent manner, it is also produced by bone and muscle. The effects of exercise on the associations between IGF-1 levels and bone turnover markers (BTM) were found in the previous studies. However, the associations between the levels of IGF-1 and BTM, liver function tests, and skeletal muscle markers in adults with general physical activity were not clear. METHODS: Ninety-four participants were recruited from healthy survey. Blood samples were collected to analyze the levels of IGF-1, total protein (TP), albumin (Alb), total bilirubin (T-Bil), direct bilirubin (D-Bil), aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), bone alkaline phosphatase (BALP), lactate dehydrogenase (LDH), creatine kinase (CK), creatinine (CRTN), and glucose. Urine samples were collected to analyze the CRTN and deoxypyridinoline (Dpd) levels. RESULTS: The positively significant associations were found between the IGF-1 levels and the levels of ALP, BALP, and CK, respectively. No significant associations were found between the IGF-1 levels and the levels of TP, Alb, A/G, T-Bil, D-Bil, AST, ALT, LDH, glucose, urinary CRTN, urinary Dpd, and Dpd/CRTN ratios, respectively. CONCLUSION: The serum IGF-1 levels associated with the levels of skeletal muscle and bone formation markers (BFM), not the bone resorption markers under general physical activity in the healthy adults. The physician needs to consider the effects of bone formation and skeletal muscle markers on the IGF-1 levels in the management of IGF-1-related disorders.

Increased Igf-I/Igfbp-3 Ratios in Postmenopausal Taiwanese with Breast Cancer, Irrespective of Er and Pr Statuses and Her2 Expression in a Case-Control Study.

BACKGROUND: In most research, there were positive associations between the insulin-like growth factor I (IGF-I) status, including IGF-I, insulin-like growth factor binding protein-3 (IGFBP-3), and ratio of IGF-I/IGFBP-3, and risks of breast cancer (BC), which was influenced by many factors, including hormone statuses and ethnicity. Therefore, the alterations of the IGF-I status in Taiwanese women with BC by menopausal statuses and hormone receptors were investigated. METHODS: The levels of IGF-I and IGFBP-3 were determined by the enzyme-labeled chemiluminescent immunometric assay, and the protein expression of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor 2 (HER2) on paraffin-embedded sections of tissues with BC were analyzed by the immunohistochemical method. RESULTS: The ratios of IGF-I/IGFBP-3 were significantly higher in the women with BC than those in the controls, but not of the levels of IGF-I and IGFBP-3; furthermore, the significantly higher ratios were found only in the postmenopausal status. In addition, there was no significant difference between the IGF-I status and ER and PR statuses, and HER2 expression, respectively, in the women with BC. CONCLUSIONS: The ratios of IGF-I/IGFBP-3 were increased in postmenopausal Taiwanese women with BC, irrespective of their ages, ER and PR statuses, and HER2 expression.