Kuswanto C N, Sum M Y, Yang G L, Nowinski W L, McIntyre R S, Sim K
Research Department, Institute of Mental Health, Singapore.
Biomedical Imaging Laboratory, Singapore Bioimaging Consortium, Agency for Science, Technology and Research, Singapore.
Psychol Med. 2014 Feb;44(3):533-41. doi: 10.1017/S0033291713000858. Epub 2013 Apr 26.
Obesity is increasingly prevalent in bipolar disorder (BD) but data about the impact of elevated body mass index (BMI) on brain white-matter integrity in BD are sparse. Based on extant literature largely from structural magnetic resonance imaging (MRI) studies, we hypothesize that increased BMI is associated with decreased fractional anisotropy (FA) in the frontal, temporal, parietal and occipital brain regions early in the course of BD.
A total of 26 euthymic adults (12 normal weight and 14 overweight/obese) with remitted first-episode mania (FEM) and 28 controls (13 normal weight and 15 overweight/obese) matched for age, handedness and years of education underwent structural MRI and diffusion tensor imaging scans.
There are significant effects of diagnosis by BMI interactions observed especially in the right parietal lobe (adjusted F(1,48) = 5.02, p = 0.030), occipital lobe (adjusted F(1,48) = 10.30, p = 0.002) and temporal lobe (adjusted F(1,48) = 7.92, p = 0.007). Specifically, decreased FA is found in the right parietal (F(1,48) = 5.864, p = 0.023) and occipital lobes (F(1,48) = 4.397, p = 0.047) within overweight/obese patients compared with normal-weight patients with FEM. Compared with overweight/obese controls, decreased FA is observed in right parietal (F(1,48) = 6.708, p = 0.015), temporal (F(1,48) = 10.751, p = 0.003) and occipital (F(1,48) = 9.531, p = 0.005) regions in overweight/obese patients with FEM.
Our findings suggest that increased BMI affects temporo-parietal-occipital brain white-matter integrity in FEM. This highlights the need to further elucidate the relationship between obesity and other neural substrates (including subcortical changes) in BD which may clarify brain circuits subserving the association between obesity and clinical outcomes in BD.
肥胖在双相情感障碍（BD）中越来越普遍，但关于体重指数（BMI）升高对BD患者脑白质完整性影响的数据却很少。基于主要来自结构磁共振成像（MRI）研究的现有文献，我们假设在BD病程早期，BMI升高与额叶、颞叶、顶叶和枕叶脑区的各向异性分数（FA）降低有关。
共有26名缓解期首发躁狂症（FEM）的心境正常成年人（12名体重正常，14名超重/肥胖）和28名年龄、利手和受教育年限相匹配的对照组（13名体重正常，15名超重/肥胖）接受了结构MRI和弥散张量成像扫描。
观察到诊断与BMI交互作用有显著影响，尤其在右侧顶叶（校正F(1,48)=5.02，p = 0.030）、枕叶（校正F(1,48)=10.30，p = 0.002）和颞叶（校正F(1,48)=7.92，p = 0.007）。具体而言，与体重正常的FEM患者相比，超重/肥胖患者右侧顶叶（F(1,48)=5.864，p = 0.023）和枕叶（F(1,48)=4.397，p = 0.047）的FA降低。与超重/肥胖对照组相比，FEM超重/肥胖患者右侧顶叶（F(1,48)=6.708，p = 0.015）、颞叶（F(1,48)=10.751，p = 0.003）和枕叶（F(1,48)=9.531，p = 0.005）区域的FA降低。
我们的研究结果表明，BMI升高会影响FEM患者颞顶枕脑白质的完整性。这凸显了进一步阐明BD中肥胖与其他神经基质（包括皮层下变化）之间关系的必要性，这可能会阐明肥胖与BD临床结局之间关联的脑回路。
