Concentrations of GH, IGF-1 and insulin in CSF of healthy people

Growth hormone (GH), insulin-like growth factor-1 (IGF-1) and insulin are involved in brain development, and also act as neuroprotective factors. The values of these hormones in healthy population have not been published so far. We measured GUI, IGF-1 and insulin concentrations in cerebrospinal fluid (CSF) of 57 healthy people (35 male and 22 female) undergoing lumbar puncture for spinal anesthesia before surgery of the knee joint. In men, the mean (SD; min-max) CSF concentrations of GH, IGF-1 and insulin were 0.67 (0.11; 0.50-0.90) mu U/mL; 7.49 (0.92; 6.00-9.00) mu g/L and 0.71 (0.13; 0.40-0.90) mu U/mL, respectively. In women, the mean CSF concentrations of GH, IGF-1 and insulin were 0.69 (0.10; 0.50-0.90)mu U/mL; 7.32 (0.95; 6.00-9.00) mu g/L and 0.68 (0.13; 0.40-0.90) mu U/mL, respectively. None of the study hormones showed a statistically significant sex difference. There was no significant bivariate correlation between GH, IGF-1 and insulin. The hormones did not correlate with age either. Determination of the normal range of GH, IGF-1 and insulin in CSF could help identify deviations in CSF hormone status in particular neurologic diseases. These values could prove important in the screening, diagnosis and management of various diseases involving the central nervous system.