Low melatonin can worsen insulin resistance! It regulates the expression of GLUT 4 transporter in your fat tissue and skeletal muscles and triggers phosphorylation of the insulin receptor. If melatonin is low, you’ve got glucose and insulin issues. Causes of low melatonin:

-High cortisol at night

-Alcohol

-Blue light from electronics

-Mutations in snps that make melatonin

-Low tryptophan

-Medications like aspirin, ibuprofen, Motrin, Alleve, Prozac (fluoxetine), beta blockers like 

propranolol and calcium channel blockers