INS and type 2 diabetes mellitus: Another mechanism may involve energy imbalance through the upregulation of appetite (via decreased leptin and increased ghrelin)10 or reduced total energy expenditure due to day-time fatigue11 that predispose to weight gain and risk of type 2 diabetes.6 7 Other hypothesised pathways to impaired glycaemic control and insulin resistance involve increased evening cortisol levels and increased sympathetic tone which inhibits insulin release.12