'Screen Time' Is Risk Factor For Low Bone Density In Teenage Boys
Most parents don't consider that their teenagers are at risk for osteoporosis; teens certainly don't think about it. But with teens spending more time with their screens - computer, notepad, TV, and smart phone - than in athletic activities, researchers are starting to look into how these sedentary habits are affecting teen development - particularly their bone development. The findings are not encouraging....
The results of a Norwegian study of bone fitness levels of more than 1,000 teenage boys and girls, ages 15 to 18, were presented at this year's meeting of the World Congress of Osteoporosis, Osteoarthritis, and Musculoskeletal Diseases on April 4, 2014. The boys (484) and girls (463) had participated in a 'Fit Futures' study in 2010 - 2011 that assessed more than 90 percent of first year high school students in the Tromsø region of Norway.
As part of the assessment, bone mineral density (BMD) was measured for each child at the hip and femoral neck, and total body body mass index (BMI) was also measured. Lifestyle questionnaires and interviews provided data about the number of leisure hours spent in front of computer screens and TV; diet, physical activity, and other lifestyle information was also compiled.
Results showed that boys spent more time in front of a screen than girls. In both boys and girls, higher sedentary time correlated with a lower BMD and a higher BMI, as one would expect. However, in boys the negative effects on BMD were much higher than in girls; in fact, girls who spent 4-6 hours in front of a computer a day had higher BMD than boys who spent only 1.5 hours of screen time a day. This was not explained by other lifestyle factors which were factored out.
This study is very significant for young persons, because full skeletal maturity is reached in one's teens and peak mone mass - one's maximum strength and size - is reached in early adulthood; a sedentary lifestyle at such an early age can have a significant effect on one's ability to reach his physical potential. Perhaps more importantly, as this study shows, more men will be susceptible to fractures and to osteoporosis at an earlier age. Currently, osteoporosis is more common in women, particularly after menopause.
Low awareness of osteoporosis and bone health among men has prompted the International Osteoporosis Foundation to focus on osteoporosis in men during this year's World Congress.