What is the connection between screen time and lifestyle factors important for bone health? Findings from the Hertfordshire Intergenerational Study.

Screen time was inversely associated with physical activity, with the strongest association observed among males.

• Among males, each SD increase in screen time was associated with a -0.58 SD difference in physical activity (95% CI -0.82, -0.35)
• Among individuals aged 21-52, each SD increase in screen time was associated with a -0.47 SD difference in physical activity (95% CI -0.71, -0.22)
• Physical activity was ascertained using the International Physical Activity Questionnaire
• Analyses were adjusted for education and number of comorbidities and stratified by sex and age tertiles

Greater screen time was associated with higher BMI among individuals aged 60-69.

• Each SD increase in screen time was associated with a 0.25 SD increase in BMI among those aged 60-69 (95% CI 0.03, 0.48)
• BMI was derived from self-reported height and weight
• This association was specific to the oldest age tertile (60-69 years) and was not reported as significant in younger age groups

Greater screen time was associated with reduced odds of ever smoking among males.

• Among males, each SD increase in screen time was associated with an odds ratio of 0.30 for ever smoking (95% CI 0.10, 0.89)
• Smoking status (ever smoking) was self-reported
• This association was observed only in males and not reported as significant in females

The study sample had a median age of 56 years and a median screen time of 249 minutes per day.

• Overall, 67 males and 136 females aged 21-69 were analysed
• Median (lower quartile, upper quartile) age was 56 (42, 60) years
• Median screen time was 249 (152, 377) min/day
• Screen time referred to the past 7 days and was self-reported

Screen time was not significantly associated with diet quality or high alcohol intake in the overall sample.

• The study examined screen time in relation to BMI, physical activity, diet quality, ever smoking, and high alcohol intake (>14 units/week)
• Diet quality score was derived using principal component analysis from a food frequency questionnaire
• No significant associations between screen time and diet quality or high alcohol intake were highlighted in the results