Although we learn to share many things when living with a partner, type 2 diabetes is not usually on the list. But new research from McGill University Health Centre in Canada suggests that if a person has type 2 diabetes, their partner is more likely to have or develop it.

This is according to a study published in the journal BMC Medicine.

Type 2 diabetes – the most common form of diabetes – occurs when the body develops insulin resistance. This is when the body is unable to use insulin properly.

The risk of developing diabetes can increase if a person follows an unhealthy lifestyle. For example, if they have a diet high in fat and do not participate in regular exercise.

If a person is biologically related to someone with diabetes, this also increases their risk of developing the condition. According to the American Diabetes Association, this biological risk is higher for type 2 diabetes.

However, the research team notes that very few studies have analyzed type 2 diabetes risk for spouses who are not biologically related, even though diabetes risk can be influenced by lifestyle factors – which are often very similar for partners.

With this in mind, the investigators analyzed six studies involving a total of 75,498 couples.

The researchers assessed the risk of diabetes for each individual and took into consideration other factors including age, socioeconomic status and how diabetic individuals were diagnosed with the condition.

The team found that for individuals with a history of type 2 diabetes, their partner has a 26% increased risk of developing the condition.

Furthermore, from studies that performed their own blood tests and detected undiagnosed diabetes, the researchers found that the risk of developing type 2 diabetes doubles for those with partners who have the condition.

The investigators hypothesize that this increased risk could be a result of “social clustering.”

This means that even though spouses are not biologically related, they live in the same environments, adopt the same social habits, follow similar eating patterns and carry out similar levels of exercise – all factors that can determine the risk of developing type 2 diabetes.

Additionally, the research team says “assortative mating” may play a part. This is when people seek out partners who possess similar characteristics to themselves.

Commenting on the findings, Kaberi Dasgupta, of the Research Institute at McGill University and senior author of the study, says:

When we talk about family history of type 2 diabetes, we generally assume that the risk increase that clusters in families results from genetic factors. What our analyses demonstrate is that risk is shared by spouses.

This underscores the effects of shared environments, attitudes, and behaviors, which presumably underlie the shared risk. Our results are not the finding of a single study but rather a synthesis of the existing studies.”

The researchers say that although further research is needed to better understand the shared risk factor of diabetes between couples, their findings suggest that interventions that engage both partners in adopting healthier lifestyles may help to lower diabetes risk.

Last year, Medical News Today reported on a study suggesting that when a spouse is in pain, this can have an impact on their partner by causing lack of sleep and even increasing the risk of health problems.