Changes in insulin resistance, body mass index and degree of obesity among junior high school students: A comparison before and after the outbreak of the COVID-19 pandemic.

This study aimed to investigate how the COVID-19 pandemic since 2020 has affected the homeostasis model assessment of insulin resistance (HOMA-IR), body mass index (BMI) and degree of obesity among Japanese children. HOMA-IR, BMI and degree of obesity were calculated for 378 children 14-15 years old (boys/girls, 208/170) who underwent checkups during 2015-2021. Changes in these parameters over time and correlations between parameters were assessed, and the proportions of participants with IR (HOMA-IR ≥2.5) were compared. HOMA-IR values increased significantly over the study period (p < 0.001), with a significantly large proportion of participants with IR in 2020-2021 (p < 0.001). Conversely, BMI and degree of obesity did not change significantly. HOMA-IR did not correlate with BMI or degree of obesity during 2020-2021. In conclusion, the COVID-19 pandemic may have had an impact on the increase in the proportion of children with IR, regardless of BMI or degree of obesity.