Mood Disorders Centre, University of British Columbia, Vancouver, Canada.
Biol Psychiatry. 2011 Aug 15;70(4):381-7. doi: 10.1016/j.biopsych.2011.02.025. Epub 2011 Apr 17.
Compared with normal-weight patients, obese patients with bipolar I disorder (BD) suffer more manic and depressive episodes and make more suicide attempts. In the general population, obesity is associated with reduced total brain volume (TBV) and gray matter volume (GMV), but the neurobiology of obesity in BD has not been investigated.
We used magnetic resonance imaging to examine TBV, GMV, white matter volume (WMV), as well as frontal, parietal, occipital, and temporal lobe volumes, in 55 healthy subjects (17 overweight/obese and 38 normal weight) and 57 patients with BD following their first manic episode (20 overweight/obese and 37 normal weight).
Linear regression analyses demonstrated that when other predictors of brain volume were accounted for, increased body mass index (BMI) in healthy subjects was significantly associated with decreased TBV and GMV. In contrast, increased BMI in patients with BD was significantly associated with decreased WMV and temporal lobe volume, areas of known vulnerability in early BD.
This is the first published report to show a relationship between elevated BMI and reduced brain volumes in BD, or any psychiatric illness. Our results suggest that obesity is associated with unique neurobiological changes in BD. They further imply a possible biological mechanism underlying the association between obesity and a more severe illness course in BD.
与正常体重患者相比，患有双相情感障碍 I 型（BD）的肥胖患者经历更多的躁狂和抑郁发作，并尝试更多自杀。在普通人群中，肥胖与总脑容量（TBV）和灰质体积（GMV）减少有关，但 BD 中肥胖的神经生物学尚未得到研究。
我们使用磁共振成像检查了 55 名健康受试者（17 名超重/肥胖和 38 名正常体重）和 57 名首次躁狂发作后的 BD 患者（20 名超重/肥胖和 37 名正常体重）的 TBV、GMV、白质体积（WMV），以及额叶、顶叶、枕叶和颞叶体积。
线性回归分析表明，当考虑到脑容量的其他预测因子时，健康受试者的体重指数（BMI）增加与 TBV 和 GMV 减少显著相关。相比之下，BD 患者的 BMI 增加与 WMV 和颞叶体积减少显著相关，这是 BD 早期已知的脆弱区域。
这是首次发表的报告，表明 BD 或任何精神疾病中 BMI 升高与脑容量减少之间存在关联。我们的研究结果表明，肥胖与 BD 中的独特神经生物学变化有关。它们进一步暗示了肥胖与 BD 中更严重疾病过程之间关联的可能生物学机制。
