REN and endothelial dysfunction: In previous studies using the SHIP cohort, endothelial dysfunction was linked to different exposures, including lower serum total and free testosterone levels [34], high plasma aldosterone concentrations and the aldosterone-to-renin ratio [62], increased serum haemoglobin A(1c) levels [63], lower serum Insulin-like growth factor-1 levels [64], and impaired renal function [65].