Browsing by Author "Konzok, Julian"

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    Association between circadian physical activity patterns and mortality in the UK Biobank
    (2023-09-01) Stein, Michael J.; Baurecht, Hansjörg; Sedlmeier, Anja M.; Konzok, Julian; Bohmann, Patricia; Fontvieille, Emma; Peruchet-Noray, Laia; Bowden, Jack; Friedenreich, Christine M.; Fervers, Béatrice; Ferrari, Pietro; Gunter, Marc J.; Freisling, Heinz; Leitzmann, Michael F.; Viallon, Vivian; Weber, Andrea
    Abstract Background The benefit of physical activity (PA) for increasing longevity is well-established, however, the impact of diurnal timing of PA on mortality remains poorly understood. We aimed to derive circadian PA patterns and investigate their associations with all-cause mortality. Methods We used 24 h PA time series from 96,351 UK Biobank participants aged between 42 and 79 years at accelerometry in 2013–2015. Functional principal component analysis (fPCA) was applied to obtain circadian PA patterns. Using multivariable Cox proportional hazard models, we related the loading scores of these fPCs to estimate risk of mortality. Results During 6.9 years of follow-up, 2,850 deaths occurred. Four distinct fPCs accounted for 96% of the variation of the accelerometry data. Using a loading score of zero (i.e., average overall PA during the day) as the reference, a fPC1 score of + 2 (high overall PA) was inversely associated with mortality (Hazard ratio, HR = 0.91; 95% CI: 0.84–0.99), whereas a score of -2 (low overall PA) was associated with higher mortality (1.69; 95% CI: 1.57–1.81; p for non-linearity < 0.001). Significant inverse linear associations with mortality were observed for engaging in midday PA instead of early and late PA (fPC3) (HR for a 1-unit increase 0.88; 95% CI: 0.83–0.93). In contrast, midday and nocturnal PA instead of early and evening PA (fPC4) were positively associated with mortality (HR for a 1-unit increase 1.16; 95% CI: 1.08–1.25). Conclusion Our results suggest that it is less important during which daytime hours one is active but rather, to engage in some level of elevated PA for longevity.
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    Diurnal timing of physical activity and risk of colorectal cancer in the UK Biobank
    (2024-09-18) Stein, Michael J.; Baurecht, Hansjörg; Bohmann, Patricia; Fervers, Béatrice; Fontvieille, Emma; Freisling, Heinz; Friedenreich, Christine M.; Konzok, Julian; Peruchet-Noray, Laia; Sedlmeier, Anja M.; Leitzmann, Michael F.; Weber, Andrea
    Abstract Background Physical activity reduces colorectal cancer risk, yet the diurnal timing of physical activity in colorectal cancer etiology remains unclear. Methods This study used 24-h accelerometry time series from UK Biobank participants aged 42 to 79 years to derive circadian physical activity patterns using functional principal component analysis. Multivariable Cox proportional hazard models were used to examine associations with colorectal cancer risk. Results Among 86,252 participants (56% women), 529 colorectal cancer cases occurred during a median 5.3-year follow-up. We identified four physical activity patterns that explained almost 100% of the data variability during the day. A pattern of continuous day-long activity was inversely associated with colorectal cancer risk (hazard ratio (HR) = 0.94, 95% confidence interval (CI) = 0.89–0.99). A second pattern of late-day activity was suggestively inversely related to risk (HR = 0.93, 95% CI = 0.85–1.02). A third pattern of early- plus late-day activity was associated with decreased risk (HR = 0.89, 95% CI = 0.80–0.99). A fourth pattern of mid-day plus night-time activity showed no relation (HR = 1.02, 95% CI = 0.88–1.19). Our results were consistent across various sensitivity analyses, including the restriction to never smokers, the exclusion of the first 2 years of follow-up, and the adjustment for shift work. Conclusions A pattern of early- plus late-day activity is related to reduced colorectal cancer risk, beyond the benefits of overall activity. Further research is needed to confirm the role of activity timing in colorectal cancer prevention.