General Information for Diabetes

Diabetes is a disorder of the sugar metabolism that occurs when the body cannot produce enough insulin (the hormone that regulates blood sugar) or/and cannot effectively use the insulin it produces.

There are mainly 2 types of diabetes; their characteristics are shown in table 1. Type 1 diabetes is due to an autoimmune destruction of the insulin-producing cells in the pancreas. Type 1 diabetes usually appears in people who have one or more genes that make them susceptible to the disease, with or without a family history of type 1 diabetes. Type 2 diabetes is much more common and has several predisposing factors such as genetic causes (family history, increased risk in certain ethnic groups) and environmental conditions (unhealthy diet, obesity, lack of physical activity).

Table. Characteristics of type 1 and 2 diabetes

Diabetes represents a growing public health problem and its prevalence increases with age. Currently, 382 million people worldwide have diabetes and this number is expected to rise to 592 million by 2035. What appears to be especially worrisome is that some cases of type 2 diabetes begin to present as early as in childhood and adolescence and this fact is mainly linked to the increasing prevalence of childhood obesity.

Healthy diet, regular physical activity, maintaining a normal body weight and avoiding smoking can prevent or delay the onset of type 2 diabetes. These measures can also facilitate the control of blood sugar and help in the prevention of complications in people with diabetes.

Typical symptoms include excessive excretion of urine (polyuria), extreme thirst (polydipsia), dry mouth, constant hunger, weight loss, blurred vision, drowsiness and fatigue. These symptoms may occur suddenly (type 1 diabetes) or gradually (type 2 diabetes). In some cases, type 2 diabetes is asymptomatic and a delayed diagnosis is made only when complications develop.

Diabetes can lead to several complications, either acute such as diabetic coma, or chronic due to the high blood sugar damaging the large (macrovascular) and small (microvascular) arteries. The latter complications include coronary heart disease (myocardial infarction), stroke, peripheral arterial disease, retinopathy leading to blindness, nephropathy leading to kidney failure and the need for dialysis, neuropathy, ulceration of the foot (diabetic foot) leading to amputation.

The main diagnostic criteria include:

• Symptoms of diabetes and a random blood sugar of 200 mg/dL (11.1 mmol/L) or higher.
• A fasting (no eating/drinking for at least 8 hours, usually overnight) blood sugar level of 126 mg/dL (7.0 mmol/L) or higher.
• A blood sugar of 200 mg/dL (11.1 mmol/L) or higher two hours after an oral glucose tolerance test (this is performed by drinking a glucose solution containing 75 gr of glucose).
• An hemoglobin A1C (HbA1c) test (this blood test measures your average blood sugar level over the past two to three months) of 6.5% or higher.

The blood tests should be repeated on another day to confirm the diagnosis of diabetes. The same blood test can also recognize categories of increased risk for diabetes (also known as prediabetes).

These include:

• A fasting blood sugar level between 100 mg/dL (5.6 mmol/L) and 125 mg/dL (6.9 mmol/L).
• A blood sugar between 140 mg/dL (7.8 mmol/L) and 199 mg/dL (11 mmol/L) two hours after an oral glucose tolerance test.
• HbA1c test between 5.7 and 6.4%.