REN and obesity due to melanocortin 4 receptor deficiency: One of the known causes of elevated BP during obesity is impaired renal natriuresis which increases renal sodium retention in obesity.[5] Other factors contributing to obesity induced sodium retention are increased sympathetic nervous system activity, increased renin-angiotensin-aldosterone system (RAS) activity, decreased levels of natriuretic peptides, fat compression of the kidney, and an increase in inflammatory cytokines.[6,7] However, our understanding of all the factors involved is far from comprehensive.