Associations of Sedentary Time and Physical Activity From Childhood With Lipids: A 13-Year Mediation and Temporal Study.

Context: Among children, evidence on long-term longitudinal associations of accelerometer-measured sedentary time, light physical activity (LPA), and moderate to vigorous PA (MVPA) with lipid indices are few. The mediating role of body composition and other metabolic indices in these associations remains unclear and whether poor movement behavior precedes altered lipid levels is unknown.

Objective: This study examined the associations of sedentary time, LPA, and MVPA from childhood through young adulthood with increased lipids, the mediating role of body composition, and whether temporal interrelations exist.

Methods: Data from 792 children (58% female; mean [SD] age at baseline, 11.7 [0.2] years), drawn from the Avon Longitudinal Study of Parents and Children (ALSPAC) UK birth cohort, who had at least 2 time-point measures of accelerometer-based sedentary time, LPA, and MVPA during clinic visits at ages 11, 15, and 24 years and complete fasting plasma high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglyceride, and total cholesterol measured during follow-up visits at ages 15, 17, and 24 years were analyzed.

Results: Total fat mass partly mediated the inverse associations of LPA with low-density lipoprotein cholesterol by 13%, triglyceride by 28%, and total cholesterol by 6%. Total fat mass mediated the inverse associations of MVPA with low-density lipoprotein cholesterol by 37% and total cholesterol by 48%, attenuating the effect on total cholesterol to nonsignificance (P = .077). In the temporal path analyses, higher MVPA at age 15 years was associated with lower low-density lipoprotein cholesterol at 24 years (β = -0.08, SE, 0.01, P = .022) but not vice versa.

Conclusion: Sedentary time worsens lipid indices, but increased LPA had a 5- to 8-fold total cholesterol-lowering effect and was more resistant to the attenuating effect of fat mass than MVPA.