Weight gain from insulin treatment in type 2 diabetes linked to sedentary behaviour

Non-obese people with type 2 diabetes who gain weight after starting insulin therapy are more likely to do so because of sedentary behavior, research suggests.
A research team from the Netherlands randomly selected 40 people with type 2 diabetes and recorded a variety of health measurements. These included their body weight, waist-to-hip circumference, fasting blood sugar levels, and HbA1c levels. The same data was recorded again six to 12 months after.
The participants started using insulin as part of their treatment, and had their physical activity monitored through armband monitors.
The researchers captured each participants’ step count and assessed how much energy they used on a daily basis. They were also asked to write down what they ate every day.
Explaining the increase in sedentary behavior, the authors wrote: “Sedentary behavior, especially in non-obese type 2 diabetes patients, may contribute to body weight gain after initiation of insulin therapy. Sedentary behaviour assessment and intervention may be needed in type 2 diabetes management.”
The findings showed that the increase in sitting time and decrease in light activity only happened in the people who had a Body Mass Index (BMI) of less than 30 kg/m2, when compared with those with a higher BMI, after starting insulin.
The researchers added that the results may be because of a “ceiling effect in sedentary behavior in patients with BMI>30 kg/m2”.
“Indeed, the average sitting time of 12.5 hours [for this group] makes it practically difficult to further increase sedentary behavior,” they said.
The 12-month review also suggested those with the lower BMI spent less time sitting down and took part in more low-intensity exercise. But, after they started insulin their BMI increased; this did not occur in those with the higher BMI when the study began.
The study suggests that a change in activity levels may be at least partly responsible for weight gain upon starting insulin therapy.
Benedict Jephcote, Head of Diabetes Education at Diabetes.co.uk, said: “The results are interesting and it will be useful if further research can identify why non-obese people starting insulin therapy are more likely to reduce their activity levels.
“Is it because they are worried to exercise when starting insulin because of a fear of hypoglycemia? Do some patients feel a sense of resignation when they start insulin that leads to a decrease in motivation for exercise? These will useful questions to get answers to.”
The findings have been published in the journal Diabetes Care.