Too much computer time hits bone health in adolescents

Researchers have found that in boys, higher screen time was adversely associated to bone mineral density (BMD) at all sites even when adjusted for specific lifestyle factors.

Results of a study showed that the skeleton grows continually from birth to the end of the teenage years, reaching peak bone mass - maximum strength and size- in early adulthood. Along with nutritional factors, physical activity can also greatly impact on this process.

The Norwegian study explored the hypothesis that greater computer use at weekends is associated with lower BMD. The data was obtained from 463 girls and 484 boys aged 15-18 years in the Tromso region of Norway. The students participated in the Fit Futures study from 2010-2011 which assessed more than 90 per cent of all first year high school students in the region.

BMD at total hip, femoral neck and total body was measured by DXA (dual-energy X-ray absorptiometry). Lifestyle variables were collected by self-administered questionnaires and interviews, including questions on time per day during weekends spent in front of the television or computer, and time spent on leisure time physical activities. The associations between BMD and screen time were analyzed in a multiple regression model that included adjustment for age, sexual maturation, BMI, leisure time physical activity, smoking, alcohol, cod liver oil and carbonated drink consumption.