Skip to content

Diabetes is a diverse group of metabolic diseases involving disorders of the pancreas and increased blood glucose levels. There are several types of diabetes. The main ones are type 1, type 2, and gestational diabetes. The most common type is type 2 diabetes.

Type 1 diabetes results from autoimmune inflammation of the insulin-producing beta cells in the islets of Langerhans of the pancreas. This leads to beta cell dysfunction and gradual depletion of insulin production.

In type 2 diabetes, the effect of insulin on tissues decreases, or in other words, insulin resistance develops, years before blood glucose levels rise. Other signs of insulin resistance are central obesity, fatty liver disease, hypertension, hyperlipidemia, and lowering of HDL cholesterol (good cholesterol). Insulin resistance is also known as metabolic syndrome.

Diagnosing diabetes

Diabetes can be diagnosed based on its typical symptoms (tiredness, weight loss, urinating a lot, dehydration and thirst) and high blood glucose levels as shown by a laboratory test. Other tests include haemoglobin A1c (glycosylated haemoglobin) and a glucose tolerance test.

The normal upper limit for blood glucose is 6.0 mmol/L in the morning after at least 8 hours fasting. A blood glucose level of between 6.1 and 6.9 mmol/L is termed impaired fasting glucose. A fasting blood glucose level of 7.0 mmol/L is the diagnostic threshold value for diabetics.

After a meal the blood glucose level can rise by 2 to 3 mmol/L in healthy people, after which it returns to its pre-meal level in 2 to 4 hours. In laboratory testing of a venous blood sample, a blood glucose value below 7.8 mmol/L is considered normal two hours after eating or as shown by the glucose tolerance test. A blood glucose level of between 7.8 and 11.0 mmol/L signifies impaired glucose tolerance. A blood glucose level of 11.1 mmol/L (in a laboratory test) is the diagnostic threshold value for diabetics.

Treatment of diabetes

In all types of diabetes, treatment is based on weight control, blood glucose control and healthy lifestyle habits that promote cardiovascular health. The main goal is to keep blood glucose levels as close to normal as possible. The blood glucose level should mainly be between 4 and 7 mmol/L beforeeating, and below 8 to 10 mmol/L after eating.

In type 1 diabetes, the lack of insulin is managed with multiple daily injections therapy or an insulin pump, and patients adjust the insulin doses as required by themselves.

In type 2 diabetes, treatment focuses on weight control, a healthy diet, and physical activity. If blood glucose levels do not normalize with lifestyle changes, the patient will be put on the appropriate medication.

In addition to blood glucose levels, blood pressure and blood lipid levels should also be as close to the normal range as possible, as diabetes increases the risk of arterial diseases. Poor diabetes control may lead to several complications over the years. These include diabetic retinopathy, diabetic neuropathy, and diabetic kidney disease.

Preventing diabetes

There is currently no treatment for the prevention of type 1 diabetes. Type 2 diabetes can be prevented very effectively through weight control, healthy eating and physical activity. Keeping to a normal weight may delay the onset of type 2 diabetes for several decades.

Data sources: Duodecim: Terveysportti health portal, Lääkärin tietokanta doctor’s database
FSHS General practitioner / 23 June 2023