Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, THE NETHERLANDS.
MRC Epidemiology Unit, Institute of Metabolic Science, University of Cambridge, Cambridge, UNITED KINGDOM.
Med Sci Sports Exerc. 2021 Nov 1;53(11):2309-2317. doi: 10.1249/MSS.0000000000002712.
It remains unclear to what extent habitual physical activity and sedentary time (ST) are associated with visceral fat and liver fat. We studied the substitution of ST with time spent physically active and total body fat (TBF), visceral adipose tissue (VAT), and hepatic triglyceride content (HTGC) in middle-age men and women.
In this cross-sectional analysis of the Netherlands Epidemiology of Obesity study, physical activity was assessed in 228 participants using a combined accelerometer and heart rate monitor. TBF was assessed by the Tanita bioelectrical impedance, VAT by magnetic resonance imaging, and HTGC by proton-MR spectroscopy. Behavioral intensity distribution was categorized as ST, time spent in light physical activity (LPA), and moderate to vigorous physical activity (MVPA). To estimate the effect of replacing 30 min·d-1 of ST with 30 min·d-1 LPA or MVPA, we performed isotemporal substitution analyses, adjusted for sex, age, ethnicity, education, the Dutch Healthy Diet index, and smoking.
Included participants (41% men) had a mean ± SD age of 56 ± 6 yr and spent 88 ± 56 min in MVPA and 9.0 ± 2.1 h of ST. Replacing 30 min·d-1 of ST with 30 min of MVPA was associated with 1.3% less TBF (95% confidence interval = -2.0 to -0.7), 7.8 cm2 less VAT (-11.6 to -4.0), and 0.89 times HTGC (0.82-0.97). Replacement with LPA was not associated with TBF (-0.03%; -0.5 to 0.4), VAT (-1.7 cm2; -4.4 to 0.9), or HTGC (0.98 times; 0.92-1.04).
Reallocation of time spent sedentary with time spent in MVPA, but not LPA, was associated with less TBF, visceral fat, and liver fat. These findings contribute to the development of more specified guidelines on ST and physical activity.
目前尚不清楚习惯性体力活动和久坐时间（ST）与内脏脂肪和肝脂肪之间的关联程度。我们研究了在中年男女中，用活跃时间和全身脂肪（TBF）、内脏脂肪组织（VAT）和肝甘油三酯含量（HTGC）代替 ST 的情况。
在荷兰肥胖症流行病学研究的这项横断面分析中，使用组合加速度计和心率监测仪评估了 228 名参与者的体力活动情况。TBF 通过 Tanita 生物电阻抗法评估，VAT 通过磁共振成像评估，HTGC 通过质子-MR 光谱法评估。行为强度分布分为 ST、轻度体力活动（LPA）时间和中等到剧烈体力活动（MVPA）时间。为了估计用 30 分钟·d-1 的 LPA 或 MVPA 代替 30 分钟·d-1 的 ST 的效果，我们进行了等时替代分析，调整了性别、年龄、种族、教育程度、荷兰健康饮食指数和吸烟情况。
纳入的参与者（41%为男性）平均年龄（±标准差）为 56 ± 6 岁，MVPA 时间为 88 ± 56 分钟，ST 时间为 9.0 ± 2.1 小时。用 30 分钟·d-1 的 ST 代替 30 分钟·d-1 的 MVPA，与 TBF 减少 1.3%（95%置信区间为 -2.0 至 -0.7）、VAT 减少 7.8 cm2（-11.6 至 -4.0）和 HTGC 减少 0.89 倍（0.82 至 0.97）相关。用 LPA 替代与 TBF 无关（-0.03%；-0.5 至 0.4）、VAT（-1.7 cm2；-4.4 至 0.9）或 HTGC（0.98 倍；0.92 至 1.04）无关。
用 MVPA 代替 ST 时间，而不是 LPA 时间，与 TBF、内脏脂肪和肝脂肪减少有关。这些发现有助于制定更具体的 ST 和体力活动指南。
