將近半數(shù)西歐人攜帶的一種與肥胖有關(guān)的基因變異可能也與大腦退化有聯(lián)系,。
Paul Thompson及其同事生成了200多位健康的老年白人受試者的大腦3D圖,，結(jié)果發(fā)現(xiàn)了“與脂肪和肥胖相關(guān)”基因內(nèi)的一種特定的DNA序列的攜帶者比非攜帶者表現(xiàn)出了大腦容量減少的模式,。這種大腦差異可能無(wú)法直接歸結(jié)于其它肥胖相關(guān)因素,，例如膽固醇水平,、糖尿病或高血壓,。
此前的研究發(fā)現(xiàn)46%的西歐和中歐人以及16%的亞洲人攜帶這種與高于平均水平的體重和腰圍有關(guān)的等位基因,。肥胖是認(rèn)知功能衰退的已知風(fēng)險(xiǎn)因素,，而且此前科學(xué)家已經(jīng)把它和超重人群腦容量的可探測(cè)差異聯(lián)系了起來(lái),。
這組作者說(shuō)，這項(xiàng)研究并沒(méi)有發(fā)現(xiàn)這種等位基因攜帶者的腦萎縮的機(jī)制,，而且也無(wú)法確定這種DNA序列的遺傳影響是否處于決定肥胖的因素之中,。這組科學(xué)家提出，這種遺傳變異可能超出體重影響的大腦退化有貢獻(xiàn),。（生物谷Bioon.com）
關(guān)于肥胖基因的最新研究進(jìn)展
Nature：解析肥胖基因的蛋白結(jié)構(gòu)
Nature：嚴(yán)重肥胖可能由成段基因缺失導(dǎo)致
ISME Journal：基因與飲食和肥胖的關(guān)系
生物谷推薦原文出處：
PNAS doi: 10.1073/pnas.0910878107
A commonly carried allele of the obesity-related FTO gene is associated with reduced brain volume in the healthy elderly
April J. Hoa,1, Jason L. Steina,1, Xue Huaa, Suh Leea, Derrek P. Hibara, Alex D. Leowa,b, Ivo D. Dinova, Arthur W. Togaa, Andrew J. Saykinc, Li Shenc, Tatiana Foroudd, Nathan Pankratzd, Matthew J. Huentelmane, David W. Craige, Jill D. Gerbere, April N. Allene, Jason J. Corneveauxe, Dietrich A. Stephanf, Charles S. DeCarlig, Bryan M. DeChairoh, Steven G. Potkini, Clifford R. Jack Jr.j, Michael W. Weinerk,l, Cyrus A. Rajim, Oscar L. Lopezn, James T. Beckero,p,q, Owen T. Carmichaelr, Paul M. Thompsona,2, and the Alzheimer's Disease Neuroimaging Initiative?
A recently identified variant within the fat mass and obesity-associated (FTO) gene is carried by 46% of Western Europeans and is associated with an ~1.2 kg higher weight, on average, in adults and an ~1 cm greater waist circumference. With >1 billion overweight and 300 million obese persons worldwide, it is crucial to understand the implications of carrying this very common allele for the health of our aging population. FTO is highly expressed in the brain and elevated body mass index (BMI) is associated with brain atrophy, but it is unknown how the obesity-associated risk allele affects human brain structure. We therefore generated 3D maps of regional brain volume differences in 206 healthy elderly subjects scanned with MRI and genotyped as part of the Alzheimer's Disease Neuroimaging Initiative. We found a pattern of systematic brain volume deficits in carriers of the obesity-associated risk allele versus noncarriers. Relative to structure volumes in the mean template, FTO risk allele carriers versus noncarriers had an average brain volume difference of ~8% in the frontal lobes and 12% in the occipital lobes—these regions also showed significant volume deficits in subjects with higher BMI. These brain differences were not attributable to differences in cholesterol levels, hypertension, or the volume of white matter hyperintensities; which were not detectably higher in FTO risk allele carriers versus noncarriers. These brain maps reveal that a commonly carried susceptibility allele for obesity is associated with structural brain atrophy, with implications for the health of the elderly.
