👤 Matty P Weijenberg

The timing of physical activity may influence metabolic health through interactions with circadian rhythms, yet its role in type 2 diabetes mellitus (T2DM) development is unclear. We investigated associations between time-of-day-specific physical activity and incident T2DM, and whether theoretically reallocating activity from morning to later in the day was associated with changes in T2DM risk. We included 4615 participants from The Maastricht Study cohort without diabetes (age 59.2 ± 8.6 years; 56.3% women). Device-based physical activity was measured over 7 days using activPAL monitors and classified into light-intensity physical activity (LPA) and moderate-to-vigorous intensity physical activity (MVPA), for morning (06:00-11:59 AM), afternoon (12:00-17:59 PM), evening (18:00-23:59 PM) and night (00:00-05:59 AM). Incident T2DM was assessed during a median 8.2-year follow-up. Cox proportional hazard and isotemporal substitution models were used, adjusted for sociodemographic and lifestyle factors, including diet, employment and sleep duration. During follow-up, 168 participants (3.6%) developed T2DM. Each additional 10 min/day of afternoon LPA or MVPA was associated with lower T2DM risk (LPA: hazard ratio [HR] 0.82, 95% confidence interval [CI] 0.70-0.97; MVPA: HR 0.85, 95% CI 0.72-1.00). Evening MVPA was also inversely associated with T2DM risk (0.65; 0.45-0.93), whereas night-time MVPA was associated with an increased risk (3.64; 1.30-10.17). No significant associations were found of morning LPA and MVPA or evening and night LPA with T2DM incidence. Substitution analyses indicated that reallocating 10 min of morning LPA to afternoon LPA (HR 0.71; 0.54-0.95) or morning MVPA to evening MVPA (HR: 0.64; 0.43-0.96) was associated with a lower T2DM risk, while no other significant associations were observed. Later-day physical activity, particularly in the afternoon, was associated with a lower incidence of T2DM, independent of intensity. This highlights the potential relevance of activity timing in relation to T2DM incidence. Show less

Disrupted diurnal rest-activity rhythms (RAR), that is, daily 24-h patterns of rest and activity, have been associated with fatigue and decreased quality of life among survivors of colorectal cancer (CRC). To identify potential targets for interventions to improve RAR, we investigated longitudinal associations of time spent in sedentary behavior and physical activity with RAR parameters after CRC treatment. In a prospective cohort study, repeated measurements were performed among 268 survivors of stage I-III CRC at 6 weeks, 6 months, and 1, 2, and 5 years after treatment. Thigh-worn accelerometers were used to determine hours/day spent in sedentary behavior, standing, and total physical activity during waking time, as well as RAR parameters including mesor, amplitude, circadian quotient (CQ), dichotomy index (I < O) and 24 h-autocorrelation (R24). Self-reported light-intensity physical activity (LPA) and moderate-to-vigorous physical activity (MVPA) were determined via the validated SQUASH questionnaire. Longitudinal associations were analyzed using confounder-adjusted linear mixed models. More sedentary time was statistically significantly associated with a lower mesor, amplitude, I < O and R24 over the 5-year post-treatment period. More standing time was associated with a higher mesor, amplitude, CQ, and I < O but not with R24. Higher levels of objectively assessed total physical activity as well as self-reported MVPA were associated with higher values for all RAR parameters. LPA was not associated with any of the RAR parameters. In the years after CRC treatment, less sedentary behavior and more standing and physical activity were generally associated with higher RAR parameters indicating a more robust rhythm. Future studies should provide more insight into causality of these associations as RAR may be a potential new target for interventions to reduce fatigue after CRC.Trial registration: EnCoRe study NL6904 (https://www.Onderzoekmetmensen.nl/). Show less