[论文解读] Impact of Weight Loss on Brain Age: Improved Brain Health Following Bariatric Surgery

Yashar Zeighami, Mahsa Dadar+10 more|arXiv (Cornell University)|Dec 12, 2021

Cardiovascular Disease and Adiposity被引用 4

一句话总结

本研究调查了减重手术引起的体重减轻是否能逆转与肥胖相关的脑老化。通过基于MRI的体素形态测量脑年龄预测模型，研究显示在术后12个月和24个月时，脑年龄显著减少了2.9至5.6年，表明脑健康改善与体质指数（BMI）、血压和胰岛素抵抗的代谢改善相关。

ABSTRACT

Overweight and obese individuals tend to have increased brain age, reflecting poorer brain health likely due to grey and white matter atrophy related to obesity. However, it is unclear if older brain age associated with obesity can be reversed following weight loss and cardiometabolic health improvement. The aim of this study was to assess the impact of weight loss and cardiometabolic improvement following bariatric surgery on brain health, as measured by change in brain age estimated based on voxel-based morphometry (VBM). We used three datasets: 1) CamCAN to train the brain age prediction model, 2) Human Connectome Project to investigate whether individuals with obesity have greater brain age than individuals with normal weight, and 3) pre-surgery, as well as 4, 12, and 24 month post-surgery data from participants (n=87) who underwent a bariatric surgery to investigate whether weight loss and cardiometabolic improvement as a result of bariatric surgery lowers the brain age. Our results from the HCP dataset showed a higher brain age for individuals with obesity compared to individuals with normal weight (p<0.0001). We also found significant improvement in brain health, indicated by a decrease of 2.9 and 5.6 years in adjusted delta age at 12 and 24 months following bariatric surgery compared to baseline (p<0.0005). While the overall effect seemed to be driven by a global change across all brain regions and not from a specific region, our exploratory analysis showed lower delta age in certain brain regions at 24 months. This reduced age was also associated with post-surgery improvements in BMI, systolic/diastolic blood pressure, and HOMA-IR (p<0.05). In conclusion, these results suggest that obesity-related brain health abnormalities might be reversed by bariatric surgery-induced weight loss and widespread improvements in cardiometabolic alterations.

研究动机与目标

• 确定肥胖是否与脑年龄增加相关，反映脑健康状况较差。
• 评估减重手术引起的体重减轻及心血管代谢改善是否能逆转脑老化。
• 检查减重手术后脑年龄减少与脑区变化的关系。
• 识别代谢改善与脑年龄减少之间的关联。

提出的方法

• 利用剑桥衰老与神经科学中心（CamCAN）数据集训练脑年龄预测模型。
• 使用人类连接组计划（HCP）数据验证正常体重与肥胖个体之间脑年龄的差异。
• 从87名减重手术患者中收集术前及术后4、12、24个月的MRI扫描数据。
• 应用体素形态测量（VBM）从结构MRI扫描中估算脑年龄。
• 计算年龄差值（预测脑年龄减去实际年龄）以评估随时间推移的脑健康变化。
• 将年龄差值的变化与术后体质指数（BMI）、血压和HOMA-IR的改善进行相关性分析。

实验结果

研究问题

• RQ1 与正常体重者相比，肥胖个体的脑年龄是否更高？
• RQ2 减重手术是否导致脑年龄降低，表明脑健康改善？
• RQ3 减重手术后脑年龄减少是否与脑区变化相关？
• RQ4 体质指数（BMI）、血压和胰岛素抵抗的改善在多大程度上与脑年龄减少相关？

主要发现

• 基于HCP数据，肥胖个体的脑年龄显著高于正常体重个体（p < 0.0001）。
• 减重手术后12个月，脑年龄平均较基线减少2.9年（p < 0.0005）。
• 术后24个月，脑年龄较基线减少5.6年（p < 0.0005）。
• 脑年龄的减少与体质指数（BMI）、收缩压和舒张压以及HOMA-IR的改善相关（p < 0.05）。
• 探索性分析显示，术后24个月时特定脑区的年龄差值降低，尽管整体效应为全局性。
• 观察到的脑年龄减少表明，与肥胖相关的脑健康衰退可能通过减重和代谢改善实现逆转。