A Mendelian randomization-based study of the causal relationship between leisure sedentary behavior and delirium

BACKGROUND

Delirium is an acute or subacute change in mental status caused by various factors. We evaluated the causal relationship between leisure sedentary behaviors (LSBs) and delirium.

METHODS

A two-sample Mendelian randomization (MR) study was performed to evaluate the causal relationship between sedentary behaviors (time spent watching television, time spent using computer, and time spent driving) and delirium. Statistical information for the associations between single nucleotide polymorphisms (SNPs) and the traits of interest was obtained from independent consortia that focused on European populations. The dataset for LSBs was acquired from genome-wide association studies (GWAS) comprising a substantial sample size: 437887 samples for time spent watching television, 360,895 for time spent using computer, and 310,555 for time spent driving. A GWAS with 1269 delirium cases and 209,487 controls was used to identify genetic variation underlying the time of LSBs. We used five complementary MR methods, including inverse variance weighted method (IVW), MR-Egger, weighted median, weighted mode, and simple mode.

RESULTS

Genetically predicted time spent watching television (odds ratio [OR]: 2.921, 95 % confidence interval [CI]: 1.381-6.179) demonstrated significant association with delirium (P = 0.005), whereas no significant associations were observed between time spent using computer (OR: 0.556, 95 % CI: 0.246-1.257, P = 0.158) and time spent driving (OR: 1.747, 95 % CI: 0.09-3. 40, P = 0.713) and delirium. Sensitivity analyses supported a causal interpretation, with limited evidence of significant bias from genetic pleiotropy. Moreover, our MR assumptions appeared to be upheld, enhancing the credibility of our conclusions.

LIMITATIONS

Larger sample sizes are needed to validate the findings of our study.

CONCLUSION

Time spent watching television is a significant risk factor for delirium. Reducing television time may be an important intervention for those at higher risk of delirium.

Association between leisure sedentary behaviors and hypertension risk: A prospective cohort study and two-sample Mendelian randomization analysis in Europeans

OBJECTIVE

This study aimed to investigate the potential causal relationship between domain-specific sedentary behaviors (including television watching, computer use, and driving) and hypertension risk in European populations.

METHODS

Initially, we conducted a multivariable Cox regression analysis to evaluate the associations between domain-specific sedentary behaviors and the risk of developing hypertension using data from 261,829 hypertension-free participants in the UK Biobank. To validate the findings of observational analysis, we employed two-sample univariable mendelian randomization (UVMR) analysis utilizing summary statistics from genome-wide association study conducted on European populations. We then performed multivariable mendelian randomization (MVMR) analysis to account for the influence of the risk factors for hypertension.

RESULTS

In this prospective observational analysis, individuals who spent >3 h per day watching television had significantly higher risk of developing hypertension (HR = 1.24, 95% CI: 1.20-1.29, P < 0.001) compared to those who watched television for 0-1 h per day. The mendelian randomization analysis provided consistent evidence for a causal relationship between prolonged television watching time and hypertension risk (OR = 1.45, 95% CI: 1.25-1.69, P < 0.001; all PMVMR < 0.05) in both UVMR and MVMR results. No significant associations were found between computer use, driving behaviors and the risk of hypertension in either the observational or UVMR/MVMR analyses.

CONCLUSIONS

These findings provide evidence for a causal effect specifically linking higher television watching time to an increased risk of hypertension and indicate the potential effectiveness of reducing television viewing time as a preventive measure to mitigate the risk of hypertension.

Potential causal associations between leisure sedentary behaviors, physical activity, sleep traits, and myopia: a Mendelian randomization study

BACKGROUND

Myopia is the most prevalent refractive error and a growing global health concern that significantly affects visual function. Researchers have recently emphasized considerably on the influence of lifestyle on myopia incidence and development. This study investigates the relationship between leisure sedentary behaviors (LSB)/physical activity (PA)/sleep traits and myopia.

METHODS

LSB, PA, and sleep trait-associated genetic variants were used as instrument variables in a Mendelian randomization (MR) study to examine their causal effects on myopia. Summary genome-wide association studies (GWASs) statistical data for LSB and PA were obtained from UK Biobank, and the data of sleep traits was obtained from UK Biobank, UK Biobank and 23andMe, and FinnGen. We used summary statistics data for myopia from MRC IEU. The MR analyses was performed using the inverse variance-weighted (IVW), MR-Egger, weighted median, and MR Pleiotropy RESidual Sum and Outlier methods.

RESULTS

Computer use was genetically predicted to increase the myopia risk [IVW odds ratio (OR) = 1.057; 95% confidence interval (CI), 1.038-1.078; P = 7.04 × 10- 9]. The self-reported moderate-to-vigorous physical activity (MVPA) (IVW OR = 0.962; 95% CI, 0.932-0.993; P = 1.57 × 10- 2) and television watching (IVW OR = 0.973; 95% CI, 0.961-0.985, P = 1.93 × 10- 5) were significantly associated with a lower myopia risk. However, genetically predicted sleep traits or accelerometer-measured physical activity had no significant associations with myopia.

CONCLUSION

Our results indicated that computer use is a risk factor for myopia, whereas television watching and MVPA may protect against myopia. These findings shed new light on possible strategies for reducing the prevalence of myopia.

Causal relationship between leisure sedentary behaviors and low back pain risk: a Mendelian randomization study

PURPOSE

This study aims to assess the causal associations of leisure sedentary behaviors with low back pain (LBP).

METHODS

A Mendelian randomization (MR) study was carried out utilizing genetic instruments to determine whether leisure sedentary behaviors (including leisure television watching, leisure computer use, and driving) are causally associated with LBP. All instrumental variables were selected from publicly available genetic summary data. The inverse variance weighted (IVW) was used as the main method to conduct univariable MR analyses. Further sensitivity analyses were utilized to test the stability of the results. Moreover, multivariable MR was performed to evaluate the independent causal relationship between leisure sedentary behaviors and LBP when body mass index (BMI), waist circumference, smoking initiation, and vigorous physical activity were taken into account.

RESULTS

The MR analyses showed evidence that television watching increased the risk for LBP (OR: 1.97, 95% CI 1.45, 2.66; P = 1.19 × 10-5). Genetically determined computer use is causally associated with a decreased risk of LBP (OR: 0.53, 95% CI 0.41, 0.68; P = 4.79 × 10-7). However, no evidence was found of a causal relationship between driving and LBP (OR: 2.27, 95% CI 0.75, 6.81; P = 0.145). After adjusting for BMI, waist circumference, smoking initiation, and vigorous physical activity, only television maintained its causal effect on LBP.

CONCLUSIONS

This study indicated that genetically predicted television watching was a risk factor for LBP independent of BMI, waist circumference, smoking initiation, and vigorous physical activity. This finding may be helpful for the diagnosis and management of LBP.

Causal association of leisure sedentary behavior with arthritis: A Mendelian randomization analysis

OBJECTIVES

This study aimed at exploring the potential causal effects of leisure sedentary behavior (LSB) on common types of arthritis.

METHOD

Two-sample Mendelian randomization (MR), including both univariable MR (UVMR) and multivariable MR (MVMR) analysis, was performed to explore the effects of LSB on the risk of several common types of arthritis, including osteoarthritis, rheumatoid arthritis (RA), and psoriatic arthritis (PsA). Genetic variants from genome-wide association studies (GWAS) of LSBs for time spent on television watching, computer use, and driving were obtained from the UK Biobank. Summarized GWAS data of OA [overall, OA of the hip (HOA), and OA of the knee (KOA)], RA [overall, seronegative RA (nRA) and seropositive RA], and PsA was also acquired from the FinnGen Biobank Analysis. Causal Analysis Using Summary Effect Estimates (CAUSE) were further applied to verify the causality.

RESULTS

UVMR results provided evidence for the causal relationship of time spent on watching TV with overall OA [odds ratio (OR) = 1.80, 95% confidence interval (CI) = 1.45-2.23], KOA (OR = 1.86, 95% CI = 1.45-2.39) and HOA (IVW-fixed: OR = 1.65, 95% CI =1.20-2.26). Similar associations were observed in the TV-overall RA and TV-pRA, and TV-PsA, but the CAUSE method results only supported the causal association of time spent TV watching with OA and KOA. Moreover, MVMR results showed indicated an independent causal effect of TV watching on OA (overall, KOA, and HOA).

CONCLUSION

This study demonstrated the genetic causal association of prolonged TV watching time with overall OA and KOA risks.