Association of changes in commute mode with body mass index and visceral adiposity: a longitudinal study

Background Prospective data are sparse for active commuting to work and body weight in Asia. We assessed the association of 5-year changes in commuting mode with body mass index (BMI) and the indicators of abdominal obesity in Japanese working adults. Methods In this longitudinal study, we studied 29,758 participants (25,808 men and 3950 women) in Japan aged 30 to 64 years at baseline who underwent further health examination 5 years after the baseline examination. Changes in BMI were calculated from objectively measured body height and weight at baseline and follow-up examination. Visceral and subcutaneous fat areas and waist circumference measured by computed tomography scans were used as indicators for abdominal adiposity. Linear regression was applied to estimate the association of changes in commuting mode with the obesity outcomes. Results Within the 5-year study period, adults who maintained inactive commuting gained weight, and compared with this group, adults who switched to inactive commuting had higher weight gain; conversely, adults who switched to active or public transportation commuting and especially those who maintained active or public transportation commuting experienced less weight gain. Subgroup analysis showed similar tendency across the different transitions of leisure-time exercise or occupational physical activity. For example, among adults who maintained no exercise (n = 16,087), the adjusted mean (95% confidence intervals) of the BMI change over 5 years in kg/m(2) were 0.27 (0.24 to 0.30) for maintained inactive commuting group (reference), 0.34 (0.30 to 0.38) for switching to inactive commuting group (P = 0.046), 0.20 (0.18 to 0.22) for switching to active commuting or public transportation group (P = 0.001), and 0.09 (0.06 to 0.13) for maintained active commuting or public transportation group (P < 0.001). Maintained inactive commuting tended to be associated with larger gain in abdominal adiposity indicators. Conclusion Switching from inactive commuting mode to more physically active commuting mode and maintaining active commuting can promote body weight control among working adults across different levels of occupational or leisure-time physical activity.

背景 在亚洲，关于通勤方式积极与否与体重之间的前瞻性数据较为稀少。我们评估了日本在职成年人通勤方式5年的变化与体重指数（BMI）以及腹部肥胖指标之间的关联。 方法 在这项纵向研究中，我们对日本29758名参与者（基线时男性25808名，女性3950名）进行了研究，他们在基线检查时年龄为30 - 64岁，并在基线检查5年后接受了进一步的健康检查。BMI的变化是根据基线和随访检查时客观测量的身高和体重计算得出的。通过计算机断层扫描测量的内脏和皮下脂肪面积以及腰围被用作腹部肥胖的指标。采用线性回归来估计通勤方式的变化与肥胖结果之间的关联。 结果 在5年的研究期间，保持消极通勤方式的成年人体重增加，与该组相比，转变为消极通勤方式的成年人体重增加更多；相反，转变为积极通勤或使用公共交通通勤的成年人，尤其是那些保持积极通勤或使用公共交通通勤的人，体重增加较少。亚组分析显示，在休闲时间运动或职业体力活动的不同转变中，存在类似的趋势。例如，在保持不运动的成年人（n = 16087）中，保持消极通勤组（参照组）5年中BMI变化的调整后均值（95%置信区间）为0.27（0.24 - 0.30）kg/m²，转变为消极通勤组为0.34（0.30 - 0.38）kg/m²（P = 0.046），转变为积极通勤或公共交通组为0.20（0.18 - 0.22）kg/m²（P = 0.001），保持积极通勤或公共交通组为0.09（0.06 - 0.13）kg/m²（P < 0.001）。保持消极通勤往往与腹部肥胖指标的更大增加有关。 结论 从消极通勤方式转变为体力活动更积极的通勤方式并保持积极通勤，能够促进不同职业或休闲时间体力活动水平的在职成年人控制体重。