The story most people have in their heads about type 2 diabetes is about someone who is overweight, maybe even a lot, and who slowly develops insulin resistance. They are then diagnosed and told to lose weight. It’s not really wrong. There are some gaps in it, though, and a new study from Finland is making it harder to ignore.
The University of Eastern Finland kept track of 3,539 adults in North Karelia who were diagnosed with type 2 diabetes for the first time between 2011 and 2014. They used electronic health records to keep track of BMI for a whole ten years. They didn’t find a single story. There were three separate ones, and the differences between them were very important.
About 78% of the people who took part in the study had a stable BMI during the follow-up. It didn’t make a big difference which way their weight went. This is how most people with type 2 diabetes look: they aren’t gaining or losing a lot of weight; they’re just staying about the same while managing their condition. About 15% had a BMI that went up over time, and their weight kept going up after they were diagnosed. The BMI of the last 8% or so of people went down over time, starting higher but going down over time. On the surface, that last group sounds like they did really well. Not all the time.
This is the really interesting and a little scary part of the research. The group whose BMI was going down had more heart and lung diseases, more memory problems, and a much higher death rate than the other two groups. The researchers are careful to point out that the register-based data didn’t exactly help them figure out why these patients’ BMI was going down.
It could be that they were trying to lose weight on purpose, but it could also be that the disease was getting worse, they were getting older, or they were physically weak and losing weight for no medical reason. In older diabetics, a falling BMI may be more of a warning sign than a sign of success. The study can’t say for sure, but the pattern is interesting.
The group with a higher BMI had its own unique burden. These patients got more long-term kidney disease, urinary tract problems, sleep apnea, and breathing issues than people whose weight stayed the same. Over time, they also started taking more diabetes medicines that help them control their weight. Reading through the results makes it seem like this group is made up of patients who are slowly falling behind—not in a big way, but by slowly getting more and more problems over time.
When it comes to weight, diabetes medicine has long relied on a single treatment suggestion: lose weight. That order is also correct. But this study shows that the weight story after being diagnosed is more complex than that frame lets on. Some patients get better. Some gain. Some people lose, and it’s not always for the best. That’s one reason why this finding is useful and not just interesting for academics: the right clinical response to each of those paths is probably not the same.
The University of Eastern Finland group has now done related work in several studies, and the main idea is the same: people who are newly diagnosed with type 2 diabetes are not all the same. In earlier studies from the same institution, it was found that only about 10% of patients were able to lose weight in the years after being diagnosed. A small percentage actually gained weight. This new ten-year study takes that view a lot further and adds data on comorbidity and mortality, which give the paths more clinical weight.
What’s still not clear is what these results mean for healthcare systems in real life. The researchers think that keeping an eye on a patient’s BMI over time and also looking at their overall health could help with more personalized care planning. For older patients in particular, a BMI that is going down might need just as much attention as one that is going up. The data shows that people whose weight is going up may not have to deal with the complications that come later if they get help earlier and more firmly. This could include medication, coaching, and structural support.
Taking care of diabetes has always been complicated. It needs a new layer, and this study adds one.
