Diabetes and Complications

Many diseases are more common in people with diabetes, for two reasons.

Reason 1: Something puts people at risk of developing both diabetes and other diseases.

Reason 2: Diabetes causes other diseases.

With sort of cross between them being

Reason 1.5: Something causing diabetes (tendency towards high blood sugar) also causes another dysfunction.

The diseases in the first category will usually be more common in relatives of people with diabetes as well as in diabetics themselves. Almost all autoimmune diseases fall into the first category for people with type 1 diabetes and their families.
Diabetes does not cause other autoimmune diseases, but both the genes and the unknown environmental factors leading to type 1 diabetes put people at higher risk of other autoimmune diseases.

The diseases from reason 2 and generally called "complications" of diabetes.

These include:

-glomerular nephropathy, or kidney disease. This develops in 60% of men with type 1 diabetes and 40% of women with type 1 diabetes. Risk is much higher for those diagnosed with diabetes during or after puberty, compared to those diagnosed prepubertally. Other factors affecting risk of nephropathy include diabetes control, genes (there is a gene that is strongly protective against diabetic kidney disease, and it is more common in people with diabetes), c-peptide levels, and blood pressure (low normal is best).
The good news about diabetic kidney disease is that the majority of cases never progress into symptomatic kidney disease. Especially in men, diabetic kidney disease tends to progress slowly. If it is in early stages, it sometimes even gets better.

-Atherosclerosis, or hardening of the arteries, is found in almost everybody with diabetes. Looking for studies to back up this assertion, I found this blurb studying children with type 1 diabetes and children without diabetes- there wasn't even any overlap between the two groups in terms of the flexibility of their arteries. Not a single of the thirty two children with diabetes had arteries as flexible as the least flexible of the fourty seven children without diabetes.
Arterial disease is part of why heart disease is assumed to be present in all people with diabetes and heart healthy activities and diet are important.

-neuropathy or nerve disease includes a whole bunch of diseases of the nerves. Some degree of neuropathy is present in 90% of type 1 diabetics after 20 years, but how much neuropathy, and whether it is enough that it makes any difference in the person's life, is affected by numerous factors, including unknown ones, but primarily blood sugar control.
Autonomic neuropathy can cause problems with hypoglycemia awareness, blood pressure, sexual function, continence, and digestion.

-gastroparesis is a disease of the stomach causing fewer contractions and impaired digestion with delaying of digestion. While some studies claim that more than half of type 1 diabetics have delayed gastric emptying, I believe that this is an error due to the fact that delayed gastric emptying is seen with high blood sugar in just about everybody (I think that's the body's way of stopping itself from going even higher). I think the actual portion of people getting gastroparesis after long term type 1 diabetes is probably more like 1 in 5. Blood sugar control affects risk of gastroparesis a lot.
Diabetics account for more than half of all people with gastroparesis.

-Numerous eye diseases are more common in people with diabetes but the most problematic and common is retinopathy. In retinopathy, the small veins in the retinas break and bleed, and the bleeding causes problems. In proliferative retinopathy, the eyes grow new veins to replace the broken ones, but the new baby veins are even more fragile and when they break there's even more bleeding.
Some degree of retinopathy develops in about 80% of type 1 diabetics. Getting severe retinopathy is more likely the longer you've had diabetes, the worse the blood sugar, and if you get pregnant (one in three women who has retinopathy at the beginning of her pregnancy will see a progression in the disease within that year).

-Although they are not generally thought of as complications, dementia, strokes, and hearing loss are more common in seniors with insulin dependent diabetes.

-The acute complication of type 1 diabetes is diabetic ketoacidosis, which is mostly preventable. It most commonly happens in three circumstances: undiagnosed diabetes, insulin discontinuation (which can happen on purpose, through poverty, or when an insulin pump or pump site or insulin pen breaks), or illness. In situations of illness, ketoacidosis is still usually preventable but when the insulin needs go drastically up, many people do not know how to raise their doses appropriately and will go into ketoacidosis.

-Diabetic mammopathy or breast disease is about the most benign diabetes complication I can think of. It happens in about 1 in 7 women who develop diabetes before menopause and the disease consists of getting dense masses in the breasts that are impossible to tell apart from cancer without a biopsy. Diabetic mammopathy therefore results in lots of breast biopsies.

-Other: Fatty liver disease is found primarily in people with type 2 diabetes and is rarely symptomatic in type 1 diabetics. Blood formation may be accelerated in people with higher blood sugar due to higher rates of blood cell death. Urinary tract and bladder infections are more common in people who pee sugar, including the majority of diabetics and occasionally nondiabetics. Gum disease can be caused by diabetes. Ermm... I believe that's all, folks.

Next up: genetics of diabetes.