If you’re a man married to a woman who’s obese, it may “substantially increase” your risk of developing Type 2 diabetes, but the link does not appear the other way around.
That’s according to a new study, which is the first to investigate the sex-specific effect of obesity in married couples on diabetes risk.
The authors conducted research into whether obesity or Type 2 diabetes in one partner could lead to Type 2 diabetes in the other, due to the many risk behaviours that lead to diabetes shared by couples, such as poor eating habits and little physical activity.
Following the research, they suggested that men with obese wives may benefit from undergoing diabetes screening due to the heightened risk they identified.
People who are obese or have a family history of Type 2 diabetes are already known to have a much higher risk of Type 2 diabetes than the general population.
But the research also suggests that the over 55s with a spouse with Type 2 diabetes tend to be more obese than their peers without a diabetic partner.
The new research - divided into two studies - is the first to specifically analyse these links.
In the first of two studies, researchers from Aarhus University in Denmark examined the association of spousal diabetes and obesity with the risk of developing Type 2 diabetes in more than 3,000 men and 3,000 women living in England.
Participants were interviewed every 2.5 years between 1998-2015, and incidence of Type 2 diabetes was identified from self-reports or clinical examination.
The results were adjusted for potential factors that might contribute to the risk of developing Type 2 diabetes such as age, ethnicity, socioeconomic status, and an individual’s own obesity level (i.e., body mass index and waist circumference).
At the 11.5-year follow up, the new case rate for Type 2 diabetes was 12.6 per 1000 people per year among men and 8.6 per 1000 among women.
The researchers found no statistically significant indication overall that having a spouse with diabetes increases diabetes risk. However, further analysis showed that men with an obese wife were significantly more likely to develop Type 2 diabetes during follow-up.
Per 5kg higher BMI in his wife, the husband’s Type 2 diabetes risk was 21% higher, when accounting for the man’s own BMI.
Conversely, women with an obese husband had no additional risk beyond that of their own obesity level.
In a further study, the research team examined whether the development of obesity with age was different for people with and without a spouse with Type 2 diabetes in more than 7,000 men and women.
The analysis was restricted to opposite-sex couples and the researchers noted that while most people put on weight up to age 70, the results showed that in people over 55, individuals living with a spouse with Type 2 diabetes had much higher levels of obesity compared to those with no spousal diabetes.
The authors said: “This is the first study investigating the sex-specific effect of spousal obesity on diabetes risk. Having an obese wife increases a man’s risk of diabetes over and above the effect of his own obesity level, while among women, having an obese husband gives no additional diabetes risk beyond that of her own obesity level. Our results indicate that on finding obesity in a person, screening of their spouse for diabetes may be justified.
“Recognising shared risk between spouses may improve diabetes detection and motivate couples to increase collaborative efforts to eat more healthily and boost their activity levels. Obesity or Type 2 diabetes in one spouse may serve as a prompt for diabetes screening and regular weight checks in the other. In particular, men whose wives are obese may benefit from being followed more closely.”
The research is being presented at this year’s European Association for the Study of Diabetes (EASD) Annual Meeting in Lisbon, from 11-15 September.