A Multicenter, Open label, Randomized, Comparative Study to Evaluate the Efficacy and Safety of Electric Smart Insulin Pen DIA:CONN P8 in patients with Type 1, Type 2 or Pancreatogenic Diabetes Mellitus under Multiple Dose Insulin Therapy

[Blind CGM Period] All eligible participants who voluntarily provide informed consent to participate in this clinical trial and are determined suitable for trial inclusion/exclusion criteria undergo a blind CGM before the baseline visit (randomization). During this period, every subjects is provided with two DIA:CONN P8 devices for continuous glucose monitoring (CGM), basal insulin, and bolus insulin administration.

Throughout this period, subjects receive training on fundamental insulin pen usage and CGM operation. They use the DIA:CONN P8 specifically for insulin dosage entry and administration, functioning similarly to a conventional insulin pen, only utilizing the injection and injection recording function.

Insulin injection dosages and timing (time stamps) recorded on the DIA:CONN P8 and the participant's blood glucose data logged in the CGM app are collected.

[Application Period] The subject allocated to the intervention or control group through randomization will visit hospital maximun 5 times during the 12-week application period, including the baseline visit, in the following process.

1. Treatment Group: For the treatment group, education sessions will be conducted during the baseline visit on carb counting and bolus calculator methods, installation, and usage instructions for DIA:CONN P8 and DIA:CONN app, as well as CGM and CGM app.
2. Control Group: The control group will receive education on insulin pen and CGM usage, maintaining their conventional multiple dose insulin therapy while implementing CGM.

Inclusion Criteria:

1. Age between 19 and 75 years old.
2. Confirmed diagnosis of Type 1 or Type 2 diabetes or post-pancreatectomy(total or partial) diabetes at least 1 year prior to screening.
3. Currently using multiple dose insulin therapy at least 3 months prior to screening, regardless of Continuous Glucose Monitoring(CGM) usage.
4. HbA1c levels between 7.5% and 12.0% at screening.

Exclusion Criteria:

1. Who have administered medications affecting glucose metabolism within 3 months before screening(e.g., corticosteroids, immunosuppressants) (Candidate with stable, ongoing dosage for over 6 months before screening are exempted from this criterion).
2. Diagnosed with clinically significant cardiovascular disease within 6 months prior to screening.
3. Exhibiting an estimated glomerular filtration rate(eGFR)<15 mL/min at the screening.
4. Unable to engage in study education due to severe systemic disorders(e.g., end-stage renal failure requiring dialysis, liver cirrhosis of Child-Pugh Class C or higher, etc)
5. Participants with severe diabetic complications(e.g., diabetic foot, diabetic retinopathy, etc)
6. Pregnant or lactating women