Manca Riccardo, Correro Anthony N, Gauthreaux Kathryn, Flatt Jason D
Department of Life Sciences, Brunel University London, Uxbridge, United Kingdom.
Mental Health Service, VA Ann Arbor Healthcare System, Ann Arbor, MI, United States.
Front Hum Neurosci. 2022 Sep 2;16:909868. doi: 10.3389/fnhum.2022.909868. eCollection 2022.
Sexual minority (SM) older adults experience mental health disparities. Psychiatric disorders and neuropsychiatric symptoms (NPS) are risk factors for cognitive decline. Although older people in same-sex (SSR) compared to mixed-sex relationships (MSR) perform more poorly on cognitive screening tests, prior studies found no differences in rates of dementia diagnosis or neuropsychological profiles. We sought to explore the role of NPS on neurocognitive outcomes for SM populations. We compared cognitive performance and structural brain parameters of older adults in SSR and MSR.
Data were originally collected at Alzheimer's Disease Research Centers (ADRCs). Inclusion criteria were: age of 55+ years, a study partner identified as a spouse/partner, and availability of T1-MRI brain volumes/thickness. Participants were labeled as either SSR or MSR based on their/their co-participant's reported sex. We identified 1,073 participants (1,037 MSR-555 cognitively unimpaired [CU]; 36 SSR-23 CU) with structural MRI data, Mini-Mental State Exam (MMSE), and Neuropsychiatric Inventory Questionnaire (NPI-Q) scores. A subset of the overall sample completed comprehensive neuropsychological assessment ( = 939; 908 MSR-494 CU; 31 SSR-22 CU). Covariates included in statistical models were age, sex, education, total intracranial volume, and apolipoprotein E genotype.
Multivariate general linear models showed significant diagnosis-by-relationship interaction effects on the left parahippocampal gyrus volume. After stratification by relationship group, only cognitively impaired (CI) MSR had significantly smaller left parahippocampal volumes than MSR-CU. The SSR group showed better episodic memory performance. Severity of neuropsychiatric symptoms was negatively associated with volume/thickness of bilateral fronto-temporal areas and with MMSE scores, predominantly in the MSR group.
In our study, MSR participants presented with a more compromised cognitive profile than SSR participants. MSR-CI participants showed significantly smaller left medio-temporal volumes, a neural signature of AD. Neuropsychiatric symptoms predicted smaller fronto-temporal volumes in the MSR more consistently than in the SSR group. These findings may be due to unexplored protective factors against cognitive decline in SM elders. Indeed, social support has been proposed as a protective factor warranting future investigation.
性少数群体（SM）中的老年人存在心理健康差异。精神疾病和神经精神症状（NPS）是认知能力下降的风险因素。尽管与异性恋关系（MSR）中的老年人相比，同性关系（SSR）中的老年人在认知筛查测试中的表现更差，但先前的研究发现痴呆症诊断率或神经心理学特征并无差异。我们试图探讨NPS对SM人群神经认知结果的作用。我们比较了SSR和MSR中老年人的认知表现和脑结构参数。
数据最初在阿尔茨海默病研究中心（ADRCs）收集。纳入标准为：年龄55岁及以上、有一名被认定为配偶/伴侣的研究对象以及有T1-MRI脑容量/厚度数据。根据参与者或其共同参与者报告的性别，将参与者标记为SSR或MSR。我们确定了1073名参与者（1037名MSR - 555名认知未受损[CU]；36名SSR - 23名CU），他们有结构MRI数据、简易精神状态检查表（MMSE）和神经精神问卷（NPI-Q）评分。总体样本中的一个子集完成了全面的神经心理学评估（n = 939；908名MSR - 494名CU；31名SSR - 22名CU）。统计模型中纳入的协变量包括年龄、性别、教育程度、总颅内体积和载脂蛋白E基因型。
多变量一般线性模型显示，在左侧海马旁回体积上存在诊断与关系的显著交互作用。按关系组分层后，只有认知受损（CI）的MSR的左侧海马旁回体积显著小于MSR - CU。SSR组表现出更好的情景记忆表现。神经精神症状的严重程度与双侧额颞叶区域的体积/厚度以及MMSE评分呈负相关，主要在MSR组中。
在我们的研究中，MSR参与者的认知状况比SSR参与者更差。MSR - CI参与者的左侧颞中叶体积显著更小，这是阿尔茨海默病的一种神经特征。神经精神症状在MSR中比在SSR组中更一致地预测了更小的额颞叶体积。这些发现可能是由于SM老年人中未被探索的认知能力下降保护因素。事实上，社会支持已被提出作为一个保护因素，值得未来进行研究。
