Although there are several long-term effects of diabetes, some effects can develop after only 6 or 12 months of high levels of glucose in the blood.

Diabetes complications can cause major health problems such as blindness, heart disease, stroke and kidney failure.

A high level of glucose in the blood is the most important factor causing long-term complications of diabetes.

Tobacco smoking is the second single most important factor in the development of complications of the eyes, kidneys and blood vessels. It is extremely unusual of a person with diabetes to have a leg amputated due to blocked blood vessels unless they smoke.

Untreated high blood pressure accelerates the blockage of arteries and increases the risk of hear attack, stroke, peripheral vascular disease and retinopathy.

High blood fats and being overweight tend to accelerate the build up of fat in the lining of the blood vessels, accelerating the blockage of arteries.

Excess alcohol consumption aggravates nerve damage and causes high blood pressure, high blood fats and excess weight gain.