Patients will be randomized and data interpreters will be blinded to two alternating six-day protocols where the patients will be advised verbally and by written instruction to inject insulin in sites of subclinical lipohypertrophy or normal subcutaneous tissue. Patients will be asked to monitor and record their capillary blood glucose with meals and prior to bedtime using their own capillary blood glucose monitor. A trained research nurse at the Diabetes Centre will instrument each patient with an iPro 2 glucose sensor (Medtronic Canada). These sensors continuously measure blood glucose for periods of up to 7 days. A trained nurse will clean the skin with a superficial disinfectant and a small catheter will be inserted in the subcutaneous tissue at a non-lipohypertrophic site. The catheter will then be attached to a glucose sensor. Patients will wear this sensor for two periods of 6 days each at different sites. At the end of each of the two six day periods, the sensor will be removed.