'Type 2 diabetes runs in the family'
A simple fact. If someone in your family has type 2 diabetes, you are at increased risk of developing the disease.
A review by Australian Diabetes Council of a diverse range of international studies shows that family history is an important predictor of type 2 diabetes. Type 1 and type 2 diabetes have different causes. Type 1 diabetes is an autoimmune disease, which affects the pancreas and stops the body producing insulin. Type 2 diabetes, is a metabolic disease that develops when the body doesn’t produce enough insulin and the insulin is not working effectively.
Type 2 diabetes is strongly linked to lifestyle and more closely associated with genetic inheritance than type 1 diabetes. If one identical twin has type 2 diabetes, the chance of glucose intolerance is up to 90%.
The closer the relative, the greater the risk. It’s estimated that people with one parent with diabetes have double the risk, while both parents increase the risk up to six times.
Where both parents have diabetes, the average age of diagnosis is 39, compared to 48 years of age for people where neither parent has the disease.
Having a brother or sister with type 2 diabetes increases the risk more than four times. Mothers present a greater risk than fathers.
Research at the Diabetes Centre at Sydney’s Royal Prince Alfred Hospital found that diabetes was twice as common when the mother had diabetes.
The more relatives with the disease the greater the odds for other family members. For instance, three or more relatives increase the risk almost 15 times.
No safety in numbers
New Australian research found type 2 diabetes develops earlier in families where there are more cases of the disease. The average age of diagnosis when six relatives have diabetes was found to be 42 years, compared with 52 years of age when only one family member had it.
In turn, age increases risk. The younger the person is when they develop type 2 diabetes will help determine the level of risk their children face.
The American Diabetes Association estimates that a child has a 1 in 7 chance of developing diabetes if the parent is diagnosed before the age of 50, compared to a 1 in 13 chance if the parent is diagnosed after that age.
Lifestyle plays a role
Another risk factor associated with family history is lifestyle.
A study in the United Kingdom and in the United States found obese and overweight adults were more likely to have a family history of diabetes.
They are almost twice as likely to have diabetes, while obese adults are nearly four times as likely.
Australians not aware of family risk
Despite mounting evidence, the Australian public does not yet believe that family history is a serious risk factor for diabetes.
A survey by Australian Diabetes Council found only 22% of people in Australia are aware of the risk associated with family history.
This matches American studies that reveal only a third of parents with diabetes thought it likely their children would develop the disease. Only 38% of brothers and sisters of people who had diabetes, thought they, themselves, would develop it.
Campaign to alert people
Based on this overwhelming evidence, Australian Diabetes Council has decided to use National Diabetes Week, July 10 –16 to launch an awareness campaign alerting Australians to the genetic link with type 2 diabetes.
The campaign will highlight the importance of family history for prevention and early detection of type 2 diabetes.
Get to know your family medical history
The ‘type 2 diabetes runs in the family’ campaign presents the ideal time for people to sit down with relatives to talk about any health problems in the family and to create a ‘Family Health History Report’.
Dr Neville Howard, President of Australian Diabetes Council says because type 2 diabetes is known to run in families, along with other common illnesses such as high blood pressure, heart disease and cancer, it’s important that people learn as much as possible about the health history of their relatives.
“It could save a life.”
American studies show that while two thirds of people know they have type 2 diabetes in their family, only a third actively collect health information to develop a family medical history.
An ‘Action Plan’ to reduce your family’s risk
For those with a family history of type 2 diabetes, the good news is that you can reduce your family’s risk.
A number of international landmark studies have found that after adopting simple lifestyle changes, people with pre-diabetes reduced their risk of developing type 2 diabetes by 58%.
As part of the family history awareness campaign, Australian Diabetes Council has produced an ‘Action Plan’ brochure that tells people with diabetes, pre-diabetes families and the general community how to prevent type 2 diabetes and reduce the risk of complications.
The brochure along with a poster and a risk assessment tick test, are being distributed to doctors, pharmacies, hospitals and other health professionals.
- June 14 2005
References
1. Preventing Chronic Disease, CDC. Family History, Diabetes and other Demographic and Risk Factors among participants of the National Health and Nutrition Examination Survey 1999-2002
2. Strong family History Predicts a younger age of onset for subjects diagnosed with type 2. Molyneaux, Constantino, Yue
3 American Diabetes Association. The Genetics of Diabetes
4. Sergeant LA. European Prospective Investigation into Cancer.
5. Jones Donald. Impact and Evaluation of Recent campaigns run by Diabetes Australia. 2004
6. 2004 HealthStyles Survey. CDC
7 Characterisation of subjects with early abnormalities of glucose tolerance in the Stockholm Diabetes Prevention Program/ Kuhl. Diabetologia