Diabetes existed even during the vedic period.
Vanaras force(army of monkeys) which invaded Lanka,
the abode of Ravana, developed diabetes after eating
sugar laden food items.–(Garuda Purana)
Garuda Purana describes abnormal sugar contained
in human body as the state of diabetes.
Lord Ganesha develops diabetes due to his eating spree,
obesity and sedentary lifestyle. Deeply disturbed Ganesha
approache Lord Shiva, who gives some medicines and advises
a regimen of healthy diet and regular exercise to get cured of
the disease–says Kapilamuni in Sankhya Darshan.