A recent study by the University of Eastern Finland identified three distinct body mass index (BMI) trajectories among people with type 2 diabetes. Over the ten-year follow-up period, the BMI trajectories were associated with significant differences in comorbidities, diabetes medication and healthcare service use.
The study included 3,539 adults living in North Karelia, Finland, who were diagnosed with type 2 diabetes between 2011 and 2014. The data were based on electronic health records, which were used to examine BMI trajectories over the ten years following diagnosis.
The researchers identified three distinct BMI trajectories. Of the people with type 2 diabetes, 77.7% had a stable BMI trajectory, 14.6% had an increasing BMI trajectory and 7.7% had a decreasing BMI trajectory. Among those with an increasing BMI trajectory, BMI rose steadily during the follow-up, whereas among those with a decreasing BMI trajectory, BMI was high at baseline but decreased over the follow-up period to a level close to that seen in those with a stable trajectory.
Increasing BMI was associated with a clustering of comorbidities
During the follow-up, those with an increasing BMI trajectory had more chronic kidney and urinary tract diseases, sleep disorders, sleep apnoea and chronic respiratory diseases than those with other BMI trajectories. The use of diabetes medications that support weight management also became more common during the follow-up, particularly among people with an increasing BMI trajectory.
“The findings show that people with type 2 diabetes do not form a homogeneous group. Based on BMI trajectories, it is possible to identify individuals who may have an increased risk of developing comorbidities and requiring more care,” says University Lecturer Suvi Koivunen , the first author of the study.
Weight loss does not always indicate better health
People with a decreasing BMI trajectory differed from those with the other BMI trajectories in that they had higher healthcare service use and higher mortality. They also had a higher prevalence of memory disorders as well as cardiovascular and pulmonary diseases than those with the other trajectories.
Weight loss may be due to several factors. It may reflect successful weight management, but it may also be related to diseases, ageing and frailty. According to the researchers, the register-based data did not allow the reasons for weight loss to be determined with sufficient confidence.
“Weight changes should be considered as part of the patient’s overall situation. Particularly in older patients and those with multimorbidity, it is important to carefully assess the underlying causes of weight changes,” Koivunen says.
Weight changes should be considered as part of comprehensive diabetes care
The findings highlight the importance of long-term monitoring in type 2 diabetes. Different BMI trajectories were associated with comorbidities, diabetes medication use and healthcare service utilisation. The findings also highlight the importance of weight management as part of comprehensive type 2 diabetes care, alongside other forms of treatment.
According to the researchers, the findings may support the development of individualised care pathways and the planning of long-term management of type 2 diabetes.
Diabetes Research and Clinical Practice
BMI trajectories and their relation to medication, comorbidities, and healthcare service use among people with type 2 diabetes mellitus
22-Aug-2026