The PANIC study looked at how physical activity and dietary intervention affect fasting insulin levels and insulin resistance in children.
As the prevalence of type 2 diabetes and prediabetes increases worldwide, this increase is also seen in children and adolescents. Insulin resistance plays a critical role in the pathogenesis of diabetes and is a strong predictive factor for future risk of type 2 diabetes. Short-term studies have shown that combined physical activity and dietary modifications effectively reduced insulin resistance and improved glucose tolerance in children with overweight and obesity; however, there is limited evidence showing the effects of physical activity and dietary modification on insulin resistance and blood glucose in children categorized as normal weight.
The PANIC study examined the long-term effects of combined physical exercise and diet modification on fasting glucose and insulin resistance on a population of predominantly normal-weight children in Kuopio, Finland. The study included children between the ages of 6 – 9 starting 1st grade from 16 primary schools in the area between 2007 and 2009. The median follow-up time was 2.1 years. Students were randomized into the intervention group or the control group depending on the school they attended; 9 schools were included in the intervention group, and the remaining seven schools were in the control group. The study was non-randomized to prevent non-intentional intervention in the control group children while organizing interventions for the intervention group students. The schools were matched according to the location to reduce the sociodemographic differences between the groups.
Children in the treatment group participated in 6 intervention visits after baseline, which included 30 – 45 minutes of physical activity and dietary intervention over 18 months. The children and their parents received fact sheets on sedentary time, diet and physical activity, information on exercise opportunities in the area, individualized advice from a clinical nutritionist and exercise medicine specialist, and were encouraged to participate in after school exercise clubs that were established at the schools by the study. Children in the control group and their parents only received advice on health-improving physical activity and diet at baseline. They were not allowed to participate in the study established exercise clubs.
A total of 504 children were randomized at baseline, 306 participants in the intervention group, and 198 participants in the control group. Baseline characteristics were balanced between the two groups. 85% of the children had an average body weight at baseline. The change in the effect of physical activity and dietary modification on fasting glucose, fasting insulin, and insulin resistance (HOMA-IR) was studied on an IIT basis in all participants of the study. Participants were also assessed for physical activity, sedentary time, and dietary factors that reflected intervention goals. Data were adjusted for age, sex, and pubertal status.
Of the 504 children randomized at baseline, 261 and 177 children from the intervention and control groups completed two years of follow-up, respectively. Increases in fasting insulin levels were reduced in the intervention group compared to the control group at follow-up after adjustment (absolute change +8.96 vs. +13.61 pmol/L, p=0.026). Change in HOMA-IR was also reduced in the intervention group (fundamental change +0.31 vs. +0.49 units, p=0.023). The was no difference in the estimated change in fasting glucose between the two groups (β -0.03; 95% CI -0.07 – 0.02, p= 0.263).
Changes in fasting insulin levels and HOMA-IR were attributed to different mediators of effect, including total physical activity expenditure, light physical activity, moderate to vigorous physical exercise, total sedentary time, diet quality measured by the Finnish Children Health Eating Index (FCHEI), reported high-fat consumption, and vegetable oil-based spreads. Percent change in intervention effect was similar between fasting insulin levels and HOMA-IR in each subgroup. Changes in body fat percentage and lean body mass did not significantly impact the fasting insulin levels and HOMA-IR changes.
The PANIC study provided evidence that dietary modifications and physical activity changes can reduce the increase in HOMA-IR and fasting insulin levels long-term in predominately normal-weight children. It also demonstrated that increases in HOMA-IR and fasting insulin levels could be mediated by decreasing sedentary time and increasing physical activity at all levels. Implementing these lifestyle changes in childhood could help prevent type 2 diabetes for children who are overweight or obese and in the general pediatric population.
- Dietary modifications and physical activity changes can attenuate the increase in HOMA-IR and fasting insulin levels long-term in predominately normal-weight children.
- Changes in fasting insulin levels and HOMA-IR were not affected by body fat percentage changes and lean body mass.
- Lifestyle changes can be beneficial in preventing type 2 diabetes in the general pediatric population.
Lakka, Timo A. et al. “A 2 Year Physical Activity And Dietary Intervention Attenuates The Increase In Insulin Resistance In A General Population Of Children: The PANIC Study“. Diabetologia, vol 63, no. 11, 2020, pp. 2270-2281
Destiny Reed, PharmD. Candidate, Florida A&M College of Pharmacy and Pharmaceutical Sciences