High sitting time or obesity: Which came first? Bidirectional association in a longitudinal study of 31,787 Australian adults.

Obesity (Silver Spring, Md.)

PubMedID: 24943057

Pedisic Z, Grunseit A, Ding D, Chau JY, Banks E, Stamatakis E, Jalaludin BB, Bauman AE. High sitting time or obesity: Which came first? Bidirectional association in a longitudinal study of 31,787 Australian adults. Obesity (Silver Spring). 2014;.
OBJECTIVE
Evidence on the direction of the association between sitting time and obesity is limited. The prospective associations between baseline total sitting time and subsequent changes in body mass index (BMI), and baseline BMI and subsequent changes in sitting time were examined.

METHODS
BMI, from self-reported height and weight, and a single-item measure of sitting time were ascertained at two time points (3.4?±?0.96 years apart) in a prospective questionnaire-based cohort of 31,787 Australians aged 45-65 years without severe physical limitations.

RESULTS
In a fully adjusted model, baseline obesity was associated with increased sitting time among all participants (adjusted odds ratio [aOR]?=?1.20 [95% CI, 1.11-1.30]; P?
CONCLUSIONS
Our findings support the hypothesis that obesity may lead to a subsequent increase in total sitting time, but the association in the other direction is unclear.