Sex differences in changes in BMI and blood pressure in Chinese school-aged children during the COVID-19 quarantine

There may be sex differences in BMI and blood pressure levels in school-age children, especially in the face of lifestyle changes. This study aimed to explore sex differences in changes in BMI and blood pressure in Chinese school-aged children during the COVID-19 quarantine. The cohort study of 445 school-aged children examined the change of BMI and blood pressure during the five-month quarantine. Multivariable Cox regression models were created to identify potential predictors of overweight, obesity, and elevated blood pressure (EBP). During the COVID-19 quarantine, the proportion of boys with overweight and obesity increased (P = 0.036), and the proportion of both boys and girls with Pre-EBP and EBP increased (P = 0.004 in boys; P < 0.001 in girls). The multivariate Cox regression analysis demonstrated that the setting, eating chili, parents’ perception of their child’s size and family doting were associated with overweight, obesity, and EBP. The study showed that BMI was more likely to increase in boys, and blood pressure increased in both boys and girls during the COVID-19 quarantine.