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Childhood Obesity and Device‐Measured Sedentary Behavior: An Instrumental Variable Analysis of 3,864 Mother–Offspring Pairs
Author(s) -
Hamer Mark,
Chastin Sebastien,
Viner Russell M.,
Stamatakis Emmanuel
Publication year - 2021
Publication title -
obesity
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.438
H-Index - 199
eISSN - 1930-739X
pISSN - 1930-7381
DOI - 10.1002/oby.23025
Subject(s) - offspring , obesity , body mass index , medicine , instrumental variable , demography , cohort , longitudinal study , pregnancy , endocrinology , biology , machine learning , genetics , pathology , sociology , computer science
Objective Intergenerational data on mother–offspring pairs were utilized in an instrumental variable analysis to examine the longitudinal association between BMI and sedentary behavior. Methods The sample included 3,864 mother–offspring pairs from the 1970 British Cohort Study. Height and weight were recorded in mothers (age 31 [5.4] years) and offspring (age 10 years) and repeated in offspring during adulthood. Offspring provided objective data on sedentary behavior (7‐day thigh‐worn activPAL) in adulthood at age 46 to 47 years. Results Maternal BMI, the instrumental variable, was associated with offspring BMI at age 10 (change per kg/m 2 , β = 0.11; 95% CI: 0.09 to 0.12), satisfying a key assumption of instrumental variable analyses. Offspring (change per kg/m 2 , β = 0.010; 95% CI: −0.02 to 0.03 h/d) and maternal BMI (β = 0.017; 95% CI: 0.001 to 0.03 h/d) was related to offspring sedentary time, suggestive of a causal impact of BMI on sedentary behavior (two‐stage least squares analysis, β = 0.18 [SE 0.08], P = 0.015). For moderate‐vigorous physical activity, there were associations with offspring BMI (β = −0.010; 95% CI: −0.017 to −0.004) and maternal BMI (β = −0.007; 95% CI: −0.010 to −0.003), with evidence for causality (two‐stage least squares analysis, β = −0.060 [SE 0.02], P = 0.001). Conclusions There is strong evidence for a causal pathway linking childhood obesity to greater sedentary behavior.