1Department of Family and Preventive Medicine, University of California, San Diego, San Diego, CA; and 2Department of Epidemiology, University of Pittsburgh, Pittsburgh, PA.
Med Sci Sports Exerc. 2014 Mar;46(3):520-8. doi: 10.1249/MSS.0b013e3182a77220.
Increased sedentary behavior predicts greater cardiovascular morbidity and mortality and does so independently of physical activity (PA). This association is only partially explained by body mass index (BMI) and overall body fat, suggesting mechanisms besides general increased adiposity. The purpose of this study was to explore associations of self-reported leisure PA and sitting time with regional fat depositions and abdominal muscle among community-dwelling older adults.
Participants were 539 diverse adults (mean age = 65 yr) who completed a study visit in 2001-2002. Areas of pericardial, intrathoracic, subcutaneous, visceral, and intermuscular fat, as well as abdominal muscle, were measured using computed tomography. Leisure PA and sitting hours were entered simultaneously into multivariate regression models to determine associations with muscle and fat areas.
After adjusting for demographics, smoking, diabetes, hypertension, triglycerides, and cholesterol, greater PA was associated with less intrathoracic, visceral, subcutaneous, and intermuscular fat (for all P < 0.05), while greater sedentary time was associated with greater pericardial and intrathoracic fat (for both P < 0.05). After further adjusting for BMI, each hour of weekly PA was associated with 1.85 cm less visceral fat (P < 0.01) but was not associated with other fat depositions. Conversely, each hour of daily sitting was associated with 2.39 cm more pericardial fat (P < 0.05) but was not associated with any other fat depositions. There were no associations with abdominal muscle area. Adjusting for common inflammatory markers had little effect. Associations between fat and PA were stronger for men.
Sitting and PA have distinct associations with regional fat deposition in older adults. The association between sitting and pericardial fat could partially explain the link between sitting and coronary heart disease.
久坐行为增加与更大的心血管发病率和死亡率相关，并且独立于体力活动（PA）。这种关联仅部分通过体重指数（BMI）和总体体脂肪来解释，表明除了普遍增加的肥胖外，还有其他机制。本研究的目的是探讨社区居住的老年人中自我报告的休闲体力活动（PA）和坐姿时间与局部脂肪沉积和腹部肌肉的关系。
参与者为 539 名不同的成年人（平均年龄为 65 岁），他们在 2001-2002 年完成了一次研究访问。使用计算机断层扫描测量心包、胸腔内、皮下、内脏和肌间脂肪以及腹部肌肉的区域。将休闲 PA 和坐姿时间同时输入多元回归模型，以确定与肌肉和脂肪区域的关联。
在调整了人口统计学、吸烟、糖尿病、高血压、甘油三酯和胆固醇后，更大的 PA 与更少的胸腔内、内脏、皮下和肌间脂肪相关（所有 P<0.05），而更大的久坐时间与更多的心包和胸腔内脂肪相关（两者均为 P<0.05）。在进一步调整 BMI 后，每周 PA 每增加一小时与内脏脂肪减少 1.85cm（P<0.01）相关，但与其他脂肪沉积无关。相反，每天坐姿每增加一小时与心包脂肪增加 2.39cm（P<0.05）相关，但与其他任何脂肪沉积无关。与腹部肌肉面积没有关联。调整常见炎症标志物几乎没有影响。PA 与脂肪之间的关联在男性中更强。
坐姿和 PA 与老年人的局部脂肪沉积有明显的关联。坐姿与心包脂肪的关联部分解释了坐姿与冠心病之间的联系。
