Previous studies suggest that cholesterol metabolic dysregulation, characterized by abnormally low or high serum total cholesterol (TC) values, constitutes a risk for pronounced cognitive decline in old age. We tested this prediction using a population-based representative Swedish sample (N = 382), born in 1901-1902, and subsequently assessed on TC and 3 cognitive outcomes (verbal ability, spatial ability, and perceptual-motor-speed) at ages 70, 75, 79, 85, 88, and 90. None of the participants were on lipid-lowering medication, as prescription availability for these medications were not initiated in Sweden until the mid-1990s. We used a 3-level hierarchical model, with cognitive tests nested within time, nested within individuals. Estimates from this model revealed a nonlinear between-person association between TC and cognition, indicating that low, and to some degree high, TC values were associated with poorer cognition. This association was stronger among nondementia-cases (n = 255). Among subsequent dementia cases (n = 127), the data suggested a linear trend, indicating that lower TC values were associated with poorer cognition. TC levels declined over time in the vast majority (96%), and the steepness of this decline was associated with the rate of cognitive decline. This within-person association was particularly strong among incident dementia cases with low TC values. Our findings indicate an optimal range of TC values associated with better cognition in old age and that the within-person association between TC and cognition is related to dementia pathologies. Further, our findings demonstrate the need to separate between-person from within-person associations when evaluating the relation between TC and cognition in old age. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

中文翻译：

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胆固醇和认知老化：基于人群的代表性样本中的人际关系和人际关系，不涉及降脂药物。

先前的研究表明，以血清总胆固醇（TC）值异常低或高为特征的胆固醇代谢失调构成了老年认知功能明显下降的风险。我们使用以人口为基础的代表性瑞典样本（N = 382）出生于1901-1902年，并在70岁时对TC和3种认知结果（语言能力，空间能力和感知运动速度）进行了评估，检验了这一预测分别是75、79、85、88和90。没有参与者使用降脂药，因为这些药物的处方供应直到1990年代中期才在瑞典启动。我们使用了一个三级分层模型，其中认知测试嵌套在时间之内，嵌套在个体之内。根据该模型的估算，TC和认知之间存在非线性的人际关联，表明TC值较低（在某种程度上较高）与较差的认知能力有关。在非痴呆病例中这种关联更强（n = 255）。在随后的痴呆病例（n = 127）中，数据表明呈线性趋势，表明较低的TC值与较差的认知能力有关。绝大多数（96％）的TC水平随时间下降，这种下降的陡峭程度与认知能力下降的速度有关。这种人际关联在TC值较低的痴呆事件中尤为突出。我们的研究结果表明与老年人的更好认知相关的TC值的最佳范围，并且TC和认知之间的人际关联与痴呆症病理相关。进一步，我们的研究结果表明，在评估老年人的TC和认知之间的关系时，有必要将人际关联与人际关联分开。（PsycINFO数据库记录（c）2020 APA，保留所有权利）。