Prospective association of daily ambulatory activity with metabolic syndrome in middle-aged and older Japanese adults: the Toon Health Study

Background This cohort study aimed to examine the relationship between objectively measured daily ambulatory activity (AA) variables and the onset of metabolic syndrome (MetS) in middle-aged and older Japanese individuals. Methods A total of 1,034 participants (women, 76.8%; mean age, 56.9 years) who were initially free from MetS, underwent objective assessment of daily AA using a uniaxial accelerometer at baseline. The number of steps, time accumulated in light-intensity AA (LIAA), moderate-to-vigorous intensity AA (MVAA), and total AA (LIAA + MVAA) were calculated. The diagnostic criteria outlined by the Japanese standards were employed to define the presence of MetS. To explore the association between AA variables and MetS onset, both multivariate logistic regression and a restricted cubic spline model were used while controlling for variables such as age, sex, education, alcohol habit, smoking habit, energy intake, and the number of MetS components present at baseline. Results Over the course of the 5-year follow-up period, 116 participants (11.2%) developed MetS. In terms of the number of steps, LIAA, and total AA, the third quartile had significantly lower multivariate adjusted odds ratios for MetS onset than the first quartile. The odds ratios (95% confidence intervals) were 0.386 (0.197–0.755), 0.527 (0.285–0.975), and 0.392 (0.206–0.745), respectively. In the spline model, an L-shaped association with MetS was observed for the number of steps (p for nonlinearity = 0.066), LIAA (p for nonlinearity = 0.034), and total AA (p for nonlinearity = 0.040). Conclusions Among the variables related to AA, the index of daily amount AA, in particular, may be linked to the onset of MetS.