The prevalence of prediabetes is high and has rapidly increased, independent of the degree of obesity, in Finnish children with overweight or obesity

Objectives: The global increase in obesity predisposes individuals to prediabetes and type 2 diabetes, but data on their prevalence, temporal trends, and associated factors in children remain limited. We examined these issues in well-defined patient and population cohorts. Methods: Data were collected from 602 patients aged 6–16 years, who were examined in healthcare for overweight/obesity once in 2002–2020. Controls comprised 483 population-representative children aged 7–16, who participated in 1–3 prospective visits. Prediabetes signified fasting glucose 5.6–6.9 mmol/L or 2h-post-challenge glucose 7.8–11.0 mmol/L, and diabetes as values ≥7.0 mmol/L or ≥11.1 mmol/L, respectively. Factors associated with prediabetes in patients were studied using logistic regression. The prevalence of prediabetes was compared between patients having their first healthcare visit in different years between 2002 and 2019. Results: Altogether, 89.2% of patients and 3.3–4.7% of controls had obesity. The prevalence of prediabetes was 34.2% and of type 2 diabetes 1.3% among patients, and 6.9% and 0% in controls respectively, with prediabetes increasing significantly with age and stage of puberty. Both conditions were associated with presence of metabolic dysfunction-associated steatotic liver disease (OR 1.69, 95% CI 1.01–2.80) and acanthosis nigricans (1.83, 1.05–3.21), after adjusting for age. Prevalence of prediabetes increased steeply over time from 11.4% in patients examined in 2002–2004 to 50.0% in patients examined in 2017–2019 (OR 1.16, CI 1.10–1.21 p < 0.001) without concurrent changes in the degree of obesity, body mass index, other metabolic conditions, age, sex, or gestational/neonatal factors, except for an increase in maternal prepregnancy/pregnancy overweight (20.0–68.8%, OR 1.14, CI 1.08–1.21, p < 0.001). Conclusions: Prediabetes was decidedly prevalent in pediatric patients with obesity and was associated particularly with steatotic liver disease. Its prevalence increased steeply over time, independent of the degree of obesity.