Hydration to Optimize Metabolism

High plasma concentration of vasopressin (i.e. antidiuretic hormone) is a novel and independent risk factor for type 2 diabetes, the metabolic syndrome, cardiovascular disease and premature death. The main physiological role of vasopressin is to maintain constant plasma osmolality. Previous studies in rats and mendelian randomization studies in humans suggest causality between elevated vasopressin concentration and elevated plasma glucose concentration. As vasopressin can be suppressed by increasing water intake, we hypothesize that water supplementation in individuals with high vasopressin can lower plasma glucose and prevent diabetes. The aim of this project is to test in a single-centre randomized clinical trial (RCT), if water supplementation in subjects with high plasma levels of vasopressin (measured by a stable vasopressin marker of its precursor hormone called copeptin) can reduce fasting levels of glucose (primary outcome measure), risk of new-onset diabetes and other cardiometabolic risk factors (secondary outcome measures).