How long do you usually use a computer in your free time? While a little relaxation here and there is good, many health experts worry about sedentary behaviors. Sedentary activities involve extended periods of sitting, reclining or laying. A prolonged amount of time engaging in sedentary behaviors, such as watching television and using a computer, has increased the risk of heart disease.
Among some common sedentary behaviors, watching TV seems to be strongly associated with developing heart disease. An epidemiological explanation is that leisure time spent watching TV is associated with fewer and shorter breaks, lower total energy expenditure, and different snacking behaviors. These characteristics may increase the adverse effects of prolonged sitting. Leisure time spent using a computer does not seem to be associated with an increased risk of heart disease.
To identify genetic determinants associated with sedentary leisure behaviors and whether they are a causal risk factor for CAD, researchers performed a genome-wide association study (GWAS) of three phenotypes of sedentary behaviors in 408,815 study participants. The specific types of sedentary activities examined in the study were leisure time spent watching television, using a computer, and driving. Participants were asked “On a typical day, how many hours do you spend using the computer? (Do not include using a computer at work)” to assess the time spent using a computer in their leisure time. The GWAS revealed 193 variants in 169 loci associated with one or more sedentary traits. In addition, they found 37 independent variants in 36 loci associated with leisurely computer use, including rs6744254 in the KCNJ3 gene and rs1448355 in the NTM gene.
Interestingly, the association study using a Mendelian randomization (MR) approach revealed that computer use was not significantly associated with CAD nor any obesity-related trait measured. In addition, they found the highest genetic correlations between sedentary behaviors and educational traits. These traits were negatively associated with television watching and driving and positively associated with computer use.
One of the limitations of this study is that the questionnaire did not include occupational sedentary behaviors, meaning conclusions cannot be generalized to total sedentary behavior. Therefore, future research efforts should be directed at expanding the current set of analyses to total sedentary behavior, physical activity, and sleep behaviors, including motor data.. Read more about the study here:
Are you interested in learning more about your genetic tendency for leisure time spent using a computer? You can login to your Genomelink TRAITS to see this new genetic trait.