June 8, 2015 -- Spouses or live-in partners of people newly diagnosed with diabetes were twice as likely to get the condition within a year later, a large study shows.
"We know that health-related risks tend to occur among people who are socially connected," said Mohammed K. Ali of Emory University. He reported the findings at the American Diabetes Association (ADA) 2015 Scientific Sessions.
Simply sharing the same home is linked to the higher risk, Ali said, even in two people who aren't genetically related.
"The take-home message is that it might push us [doctors] a bit more to say, if someone is newly diagnosed, what's happening with their partner?" he said. And instead of "waiting for years and years" for that partner to show up for their own blood sugar (glucose) test, doctors might want to check into that person's risk of diabetes sooner.
"It may not be going as far as doing a glucose test, it might just be weighing them, or doing a 'paper-pencil' test -- asking them a few questions about age, weight, etc. That might be the most prudent way, but it certainly seems necessary."
Having a family history of diabetes raises your risk of getting it, but this study "is showing how strong an environmental effect (can be)," said session chair Audrey C. Chu, PhD, from Brigham and Women's Hospital.
Dr. Bendix Carstensen, from the Steno Diabetes Center in Denmark, said this was the first time he had come across such a link and said he was intrigued by it.
But James B Meigs, MD, of Massachusetts General Hospital, said he fears this study has a shortcoming. "The researchers didn't account for (the participants') body mass index, and I believe that if you accounted for obesity, a lot of the effect would go away."
He said he's concerned that the researchers are making big statements "with data that might be wrong. If you get the data right, you might come to a different answer" that might still help doctors come up with ways to help someone's partner lower their risk of getting diabetes, too.
Ali said almost 30 million people have diabetes in the United States, and 86 million have "prediabetes," a warning sign that you're on the path to the disease. But 89% of people with prediabetes are unaware of that. And 1 in 4 of people with type 2 diabetes are also undiagnosed.
The American Diabetes Association recommends a blood sugar test for anyone over 45 years -- or at any age if their body mass index is 25 or higher (23 or higher in Asian Americans) and there are one or more risk factors for diabetes. Those include a first-degree relative with diabetes, physical inactivity, high blood pressure, or a history of gestational diabetes or polycystic ovary syndrome for women, among other things.
But, Ali wondered, could other things, like who you live with, raise your risk, even if you aren’t related by blood?
He and his colleagues analyzed years' worth of data from Kaiser Permanente Northern California covering more than 3 million members.
The researchers estimated the average annual rate of new diabetes cases among those ages 18 to 79. Whether it was type 1 or 2 diabetes wasn't specified, he said, but most newly diagnosed diabetes among adults would be type 2.
They also estimated annual rates of new cases among the spouses and domestic partners of members diagnosed with diabetes in the previous year. Finally, they compared both of these figures with those from the general U.S. population, as reported by the CDC.
The rate of new diabetes cases among Kaiser Permanente members was similar to that reported in the general U.S. population.
But the rate was much higher among their spouses or live-in partners compared with Kaiser Permanente's overall population -- it was double when all ages were combined.
Women with newly diagnosed spouses or domestic partners had 90% higher risks than women in the overall Kaiser Permanente population. And the risk was even higher for men whose spouses or partners had new cases of diabetes.
There was no difference across different racial groups.
And there were a number of same-sex partners in the analysis, but the numbers are too small so far to draw meaningful conclusions, Ali said.
He acknowledged that the data are based on observations, and that there may be an effect where spouses of those newly diagnosed were encouraged to seek a blood sugar test themselves following their partner's diagnosis, thereby explaining some of the increased risk. The next analysis Ali and his co-researchers do will take that into consideration, he said.