The prevalence of prediabetes has increased significantly in recent years among Finnish children living with overweight or obesity, a recent study by Tampere University and the University of Eastern Finland shows. In the early 2000s, 11 per cent of those studied had prediabetes, whereas 20 years later, the prevalence of prediabetes was 50 per cent. The prevalence of obesity remained unchanged during the study period, but prediabetes became more common among children, which could, in part, be due to a simultaneous increase in maternal overweight.

The study included 602 children aged 6–16 who had been assessed for overweight or obesity in primary health care or specialised health care in Tampere between 2002 and 2020. The study also included a control group of 483 children aged 7–16, which had been drawn from the Physical Activity and Nutrition in Children (PANIC) study, underway at the University of Eastern Finland.

According to the study, 34 per cent of children who had been assessed for overweight or obesity had prediabetes, and one per cent had type 2 diabetes. In the control group, 7 per cent had prediabetes, while type 2 diabetes was not observed. Prediabetes was more common in older children and those in more advanced stages of puberty. Its prevalence was also associated with fatty liver disease and acanthosis nigricans, a skin condition often linked to overweight and disturbances in glucose metabolism.

Notably, the prevalence of prediabetes increased substantially during the study period. Between 2002 and 2004, prediabetes was diagnosed in 11 per cent of patients, while in 2017–2019, its prevalence had reached 50 per cent. No significant changes occurred in other factors, such as the prevalence or degree of obesity, body mass index or other metabolic disorders.

The foetal period may play a role

The only other significant change found during the study period was a marked increase in maternal overweight, rising from 20 per cent to 69 per cent.

“The rise in the prevalence of prediabetes without changes in children’s weight may partly be explained by factors related to pregnancy and the foetal period. Changes in children’s body composition, physical activity or diet might also play a role. Further research into these factors is needed,” says researcher Hanna Riekki, MD, from Tampere University.

Professor Kalle Kurppa and Linnea Aitokari, MD, PhD, from Tampere University, together with Professor Timo Lakka, the director of the PANIC study at the University of Eastern Finland, consider the findings concerning. “The results show that even if the prevalence or degree of obesity does not change, obesity-related comorbidities may still become more common.”

Prediabetes increases the risk of developing type 2 diabetes and many other cardiometabolic disorders such as fatty liver disease and cardiovascular diseases. A metabolic disorder that begins in childhood may progress more rapidly and cause more complications than a disorder beginning in adulthood. It is therefore essential to actively screen for obesity-related comorbidities such as disturbances in glucose metabolism in children with increased adiposity, so that interventions can be implemented early.

Research article:

Riekki, H., Aitokari, L., Saari, A. et al. The prevalence of prediabetes is high and has rapidly increased, independent of the degree of obesity, in Finnish children with overweight or obesity. Int J Obes (2025). https://doi.org/10.1038/s41366-025-01950-y