Dept. of Neuroscience, Chicago Medical School, Rosalind Franklin University of Medicine & Science, USA.
Dept. of Neuroscience, Chicago Medical School, Rosalind Franklin University of Medicine & Science, USA.
Neuroimage. 2016 Jan 1;124(Pt A):350-366. doi: 10.1016/j.neuroimage.2015.08.050. Epub 2015 Aug 31.
Hippocampal atrophy is found in many psychiatric disorders that are more prevalent in women. Sex differences in memory and spatial skills further suggest that males and females differ in hippocampal structure and function. We conducted the first meta-analysis of male-female difference in hippocampal volume (HCV) based on published MRI studies of healthy participants of all ages, to test whether the structure is reliably sexually dimorphic. Using four search strategies, we collected 68 matched samples of males' and females' uncorrected HCVs (in 4418 total participants), and 36 samples of male and female HCVs (2183 participants) that were corrected for individual differences in total brain volume (TBV) or intracranial volume (ICV). Pooled effect sizes were calculated using a random-effects model for left, right, and bilateral uncorrected HCVs and for left and right HCVs corrected for TBV or ICV. We found that uncorrected HCV was reliably larger in males, with Hedges' g values of 0.545 for left hippocampus, 0.526 for right hippocampus, and 0.557 for bilateral hippocampus. Meta-regression revealed no effect of age on the sex difference in left, right, or bilateral HCV. In the subset of studies that reported it, both TBV (g=1.085) and ICV (g=1.272) were considerably larger in males. Accordingly, studies reporting HCVs corrected for individual differences in TBV or ICV revealed no significant sex differences in left and right HCVs (Hedges' g ranging from +0.011 to -0.206). In summary, we found that human males of all ages exhibit a larger HCV than females, but adjusting for individual differences in TBV or ICV results in no reliable sex difference. The frequent claim that women have a disproportionately larger hippocampus than men was not supported.
海马体萎缩存在于许多在女性中更为普遍的精神疾病中。记忆和空间技能方面的性别差异进一步表明，男性和女性的海马体结构和功能存在差异。我们对基于健康参与者的 MRI 研究进行了首次男性与女性海马体体积（HCV）差异的元分析，以检验结构是否存在可靠的性别二态性。使用四种搜索策略，我们收集了 68 个男性和女性未校正 HCV（共 4418 名参与者）的匹配样本，以及 36 个男性和女性 HCV（2183 名参与者）的样本，这些样本校正了总脑体积（TBV）或颅内体积（ICV）的个体差异。使用随机效应模型计算了左、右和双侧未校正 HCV 以及校正了 TBV 或 ICV 的左、右 HCV 的合并效应大小。我们发现，未校正的 HCV 在男性中确实更大，左海马体的 Hedges'g 值为 0.545，右海马体为 0.526，双侧海马体为 0.557。元回归显示年龄对左、右或双侧 HCV 的性别差异没有影响。在报告该结果的研究子集中，TBV（g=1.085）和 ICV（g=1.272）在男性中都明显更大。因此，报告了校正了 TBV 或 ICV 个体差异的 HCV 研究，在左、右 HCV 中没有发现显著的性别差异（Hedges'g 值范围从+0.011 到-0.206）。总之，我们发现所有年龄段的男性都比女性具有更大的 HCV，但校正 TBV 或 ICV 的个体差异后，没有可靠的性别差异。女性的海马体比男性不成比例地大的常见说法并没有得到支持。
