I recently was fortunate enough to visit a Shiva temple in a village called KOYIL VENNI, which is on the Tanjavur Tiruvarur road about 26 Km from Tanjavur, Tamil Nadu.

Shiva here is said to reduce or cure diabetes. Shiva is called Venni Karumbeshwarar. There is a special offering of Rava & sugar mix that is offered to Shiva to reduce the effect of diabetes. This mix is then spread around the temple to be consumed by ants.

This temple also happens to be a "padal petra sthlam". The original name was TIRUVENNIYUR in olden days. See link :http://www.templenet.com/Tamilnadu/s265.html.
Both Thiru Gnanasambandhar & Appar have visited and sung hymns on Lord Shiva here.

Due to less number of visitors & poor patronage the temple is open for a short period of time (8 Am - 10 Am, 5:30 PM - 7:30 PM). Visitors can contact the priest, Raja Gurukkal at +91 9626769424 prior to visiting to ensure the temple is open for pooja. There is a display board on the highway to indicate the turn off.

if you know someone suffering from acute diabetes please ask them to visit & perform a pooja here.

OM NAMA SIVAYAH!! OM NAMO NARAYANAYAH!!