Well, both are related to nutrition and both can be prevented or helped by the same foods and supplements.  Type 2 diabetes is normally preceded by decades of slowly increasing insulin, blood sugar, and belt-size (.. and it is always healthier to sit on your fat than have your fat sit on you).  Early prevention is very effective but there come a point when insulin production permanently breaks down.  Smart nutrition (and portion control) can first prevent overweight and diabetes, and eventually heart disease.

Both conditions are epidemic with 1 in 13 Americans and 1 in 3 of those over age 60 developing 'adult' diabetes.  Most will develop heart, kidney, nerve and blood vessel diseases for an amazing 1/4th of total "health" costs!  Other countries have similar increasing rates.  Later-in-life diabetes (or during pregnancy) is a slow but eventually one-way track to heart disease.

What makes a diabetic?  Simply put: when your pre-breakfast blood sugar (plasma glucose) gets over 126 mg/dL (7 mmol/L).  Another measure is when 2 hours after taking a dose of glucose the blood level is still over 200 mg/dL (11.1 mmol/L), with over 140 (7.8) starting to suggest a problem.  This is how diabetes currently is defined [BMJ or ADA].  Fasting 95 (5.3) is good [ADA], under 36 (2) is seriously low blood sugar, while above 180 (10) a safety-valve opens that sends glucose to the urine.  To confuse anybody, the numbers changed from mg to the 18 times smaller mmole, they increase by 14% between 'blood' and 'plasma' in syringe samples -but the numbers for 'blood drop' and 'syringe-plasma' are similar.  However, it's the big picture that counts, not the decimal points of the reading.  This is one area where a blood test is important since serious organ or foot damage can happen early.

In early-age 'type 1' diabetes the body stops making insulin needed to process sugar and starch.  Type 1 represents under 5% of total diabetes.  There is no cure and insulin, a protein, must be dosed by injection in relation to sugar and starch intake.  Type 1 can possibly be prevented with vitamin B-3 in people with declining insulin -which can show years before irreversible damage [see ENDIT, an earlier study or theory].

In the now exploding 'type 2' diabetes, which develops in obese kids or at a more 'mature' age [Non Insulin Dependent Diabetes Mellitus, NIDDM or maturity-onset], the problem is initially not a lack of insulin but body cells became insensitive (resistant) to its effects.  Increasing amounts of insulin try to "push the gas pedal" but the system doesn't react (by taking fuel, glucose, into the cells).  In type 2, both blood-insulin and blood-sugar (glucose) become high which is a double problem.

This double problem is that:
1.) Insulin, as it always did, still changes excess blood-sugar into fat [in blood and around the belly, and it keeps it there].  So, insulin tends to make and keep you fat;
2.) High blood-sugar makes blood vessels and blood components "sticky".
Both effects reduce blood flow to all areas of the body especially to the feet, eyes and kidneys.  Fat, around the body or as triglycerides in the blood does nothing to promote blood circulation.  Good circulation is 50%-of-good-health.  This is why weight control, "shaking-up-the-fat" (exercise), a good multi-vitamin with minerals, omega-3 [n-3 and here] oils and high-fiber, low glycemic index foods are all-important.  Unhelpful are high omega-6 oils like corn, soy or sunflower while vitamin D works better than insulin drugs!  High waist size (belt length, regardless of your height) with high blood triglycerides (fats), high sugar, high insulin and high blood pressure, all lead to ill-health.  This group of symptoms is known as Syndrome X, the Metabolic Syndrome.

I remind you that this author is not a doctor and knows absolutely nothing about your specific situation.  Keeping this in mind, here are some ideas that will help you see the global picture of diabetes (kidney, leg, eye and heart disease) more clearly.