Diabetes: risk factors

There are different risk factors depending on the type of diabetes.

Type 1 Diabetes

The exact mechanisms that cause type 1 diabetes are not fully understood. Autoimmune mechanisms (the development of antibodies directed at the body's own tissues) lead to the destruction of the beta cells in the pancreas that produce insulin. It has been suggested that infectious agents may play a role, though no specific organism has been identified. There is a strong genetic component as the risk of developing Type 1 diabetes is greater where there is a family history of diabetes. It is thought that environmental or viral factors can trigger the onset in those with a genetic predisposition to developing type 1 diabetes.

Type 2 Diabetes

Type 2 diabetes becomes more common with increasing age, although it may also occur in young people. Risk factors for type 2 diabetes include overweight and obesity: the risk is around 4-10 times higher among those with obesity (a body mass index (BMI) over 30) (1), depending on their metabolic profile. Not all people with type 2 diabetes are overweight or have obesity: type 2 diabetes is also more common in the families of those with type 2 diabetes, and a number of genetic markers of increased risk have been identified. Type 2 diabetes is more common in people with African, Asian and Caribbean backgrounds, compared with European populations.

Diabetes among Minority Ethnic Groups in Scotland

The Scottish Government have produced a report outlining the higher risk of type 2 diabetes amongst people of South Asian and Black African and Caribbean descent, even if born in the UK. As well as increased risk, the onset of type 2 diabetes occurs around 10-12 years earlier than other ethnicities, on average.

A cohort study of people newly diagnosed with type 2 diabetes in Scotland found lower receipt of diabetes care including HbA1c (2) monitoring and diabetic eye screening in African, Caribbean or Black, Indian, and other ethnicity groups compared to those in the White ethnicity group.

(1) Body mass index (BMI) is a measure of obesity, calculated as a person's weight in kilograms divided by the square of their height in metres (kg/m2). Waist circumference has been proposed as a more useful measure of central obesity, which is also linked with the risk of type 2 diabetes.

(2) The hemoglobin A1c (HbA1c) test measures the amount of blood sugar (glucose) attached to your hemoglobin. Hemoglobin is the part of your red blood cells that carries oxygen from your lungs to the rest of your body. A HbA1c test gives an average of blood sugar over the last 2-3 months. However, as it is an average, it does not reflect fluctuations in blood glucose that may be having a significant impact on quality of life.

Gestational Diabetes

Gestational diabetes is maternal high blood glucose that develops during pregnancy and generally disappears after giving birth. It can develop at any stage during pregnancy but is more common in the second or third trimester. Risk factors include overweight and obesity, older maternal age, having a history of gestational diabetes, or family history of type 1 or type 2 diabetes, or being south Asian, Black, African-Caribbean or Middle Eastern origin (even if you were born in the UK). While gestational diabetes can occur with an otherwise healthy pregnancy, it can lead to problems as outlined here.

Having gestational diabetes also increases the risk of developing Type 2 diabetes in the future.

 Diabetes and Inequality

There is no strong evidence for a link between prevalence of type 1 diabetes and living in an area of high deprivation. However, a 2021 UK study showed that 45% of those developing type 2 diabetes came from the most deprived areas (using deprivation quintiles). There is also evidence of lower uptake of supportive technology to manage both type 1 and type 2 diabetes in the most deprived areas which could impact diabetes management and prevention of complications. A person’s ethnicity, where they live and their income impact the risk of getting type 2 diabetes, care received for type of diabetes and long-term outcomes (Diabetes UK, 2023).