OBJECTIVES To establish the effect of different degrees and kinds of physical activity on bone marrow fat (BMAT) content at different anatomical locations in a population-based cohort study undergoing whole-body MR imaging. METHODS Subjects of the KORA FF4 study without known cardiovascular disease underwent BMAT fat fraction (FF) quantification in L1 and L2 vertebrae and femoral heads/necks (hip) via a 2-point T1-weighted VIBE Dixon sequence. BMAT-FF was calculated as mean value (fat image) divided by mean value (fat + water image). Physical activity was determined by self-assessment questionnaire regarding time spent exercising, non-exercise walking, non-exercise cycling, and job-related physical activity. RESULTS A total of 385 subjects (96% of 400 available; 56 ± 9.1 years; 58% male) were included in the analysis. Exercise was distributed quite evenly (29% > 2 h/week; 31% ~ 1 h/week (regularly); 15% ~ 1 h/week (irregularly); 26% no physical activity). BMAT-FF was 52.6 ± 10.2% in L1, 56.2 ± 10.3% in L2, 87.4 ± 5.9% in the right hip, and 87.2 ± 5.9% in the left hip (all p < 0.001). Correlation of BMAT-FF between spine and hip was only moderate (r 0.42 to 0.46). Spinal BMAT-FF, but not hip BMAT-FF, was inversely associated with exercise > 2 h/week (p ≤ 0.02 vs. p ≥ 0.35, respectively). These associations remained significant after adjusting for age, gender, waist circumference, and glucose tolerance. No coherent association was found between BMAT-FF and physical activity in the less active groups. CONCLUSIONS In our study, exercise was inversely correlated with vertebral BMAT-FF, but not hip BMAT-FF, when exercising for more than 2 h per week. Physical activity seems to affect the spine at least preferentially compared to the hip. KEY POINTS • In our population-based cohort, at least 2 h of physical activity per week were required to show lower levels of bone marrow adipose tissue fat fraction in MRI. • Physical activity seems to affect bone marrow adipose tissue at least preferentially at the spine in contrast to the proximal femur.

中文翻译：

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与身体活动有关的骨髓脂肪分数评估：基于人群的队列中的 KORA FF4-3-T MR 成像。

目的 在进行全身 MR 成像的基于人群的队列研究中，确定不同程度和类型的身体活动对不同解剖位置的骨髓脂肪 (BMAT) 含量的影响。方法 没有已知心血管疾病的 KORA FF4 研究对象通过 2 点 T1 加权 VIBE Dixon 序列对 L1 和 L2 椎骨和股骨头/颈（臀部）进行 BMAT 脂肪分数 (FF) 量化。BMAT-FF 计算为平均值（脂肪图像）除以平均值（脂肪 + 水图像）。身体活动是通过关于锻炼、非锻炼步行、非锻炼骑自行车和与工作相关的体育活动所花费的时间的自我评估问卷确定的。结果 共有 385 名受试者（400 名可用受试者中的 96%；56 ± 9.1 岁；58% 为男性）被纳入分析。运动分布相当均匀（29% > 2 小时/周；31% ~ 1 小时/周（定期）；15% ~ 1 小时/周（不定期）；26% 没有体育活动）。BMAT-FF 在 L1 中为 52.6 ± 10.2%，在 L2 中为 56.2 ± 10.3%，在右髋为 87.4 ± 5.9%，在左髋为 87.2 ± 5.9%（所有 p < 0.001）。脊柱和髋部之间 BMAT-FF 的相关性仅为中等（r 0.42 至 0.46）。脊柱 BMAT-FF，而非髋部 BMAT-FF，与运动 > 2 小时/周呈负相关（分别为 p ≤ 0.02 vs. p ≥ 0.35）。在调整年龄、性别、腰围和葡萄糖耐量后，这些关联仍然显着。在较不活跃的组中，BMAT-FF 与身体活动之间没有发现一致的关联。结论 在我们的研究中，当每周锻炼超过 2 小时时，锻炼与椎骨 BMAT-FF 呈负相关，但与髋部 BMAT-FF 无关。与臀部相比，身体活动似乎至少优先影响脊柱。要点 • 在我们基于人群的队列中，每周至少需要进行 2 小时的体力活动才能在 MRI 中显示较低水平的骨髓脂肪组织脂肪分数。• 与股骨近端相比，体力活动似乎至少优先影响脊柱的骨髓脂肪组织。