Studies involving patients with increased cardiovascular risk or studies of healthy patients with aims of detecting changes in cardiovascular risk with sauna activity used some of the same physiological parameters mentioned above as well as serum lipid profiles (total cholesterol, LDL, HDL, and triglycerides), fasting plasma glucose levels, serum levels of uric acid (potential marker of insulin resistance and metabolic syndrome), plasma levels of ghrelin, serum levels of leptin, plasma levels of Hb (hemoglobin) and HCT (haematocrit), and urinary prostaglandin levels [37, 47, 49, 63, 66, 67]. This evidence concerns the gene GHRL and metabolic syndrome.