Introduction: Sedentary behaviours (including sitting) may increase risk of mortality independently of physical activity level. Little is known about how fidgeting behaviours might modify the association. Methods: Data were drawn from the UK Women’s Cohort Study. In 1999/2002, 12,778 women (age 37 to 78) provided data on average daily sitting time, overall fidgeting (irrespective of posture), and a range of relevant covariates including physical activity, diet, smoking status and alcohol consumption. Participants were followed for mortality over a mean of 12 years. Proportional hazards Cox regression models were used to estimate the relative risk of mortality in the high (vs. low) and medium (vs. low) sitting time groups. Results: Fidgeting modified the risk associated with sitting time (p value for interaction = 0.04), leading us to separate groups for analysis. Adjusting for a range of covariates, sitting for 7+ hours/day (vs. <5 hours/day) was associated with 30% increased risk of all-cause mortality (HR = 1.30, 95% CI 1.02, 1.66) only among women in the low fidgeting group. Among women in the high fidgeting group, sitting for 5/6 (vs. <5 hrs/day) was associated with decreased risk of mortality (HR = 0.63, 95% CI 0.43, 0.91), adjusting for a range of covariates. There was no increased risk of mortality from longer sitting time in the middle and high fidgeting groups. Conclusions: Fidgeting may reduce the risk of all-cause mortality associated with excessive sitting time. More detailed and better validated measures of fidgeting should be identified in other studies in order to replicate these findings and identity mechanisms, particularly measures that distinguish fidgeting in a seated from standing posture.
CORE (COnnecting REpositories)
CORE (COnnecting REpositories)