Tumati Shankar, Burger Huibert, Martens Sander, van der Schouw Yvonne T, Aleman André
Department of Neuroscience, University Medical Center Groningen, University of Groningen, The Netherlands.
Department of General Practice, University Medical Center Groningen, Groningen, The Netherlands.
PLoS One. 2016 Apr 26;11(4):e0154450. doi: 10.1371/journal.pone.0154450. eCollection 2016.
Low levels of insulin-like growth factor-1 (IGF-1), an essential neurotrophic factor, have been associated with worse cognitive function in older adults. However, few studies have assessed the prospective association of serum IGF-1 with cognitive function. We aimed to determine the association between serum IGF-1 on concurrent and prospective cognitive function in a population sample of men aged 40-80 years. Blood samples were assessed for IGF-1 levels at baseline and neuropsychological assessments were performed at baseline (n = 400) and at follow-up after a mean duration of 8.3 years (n = 286). Linear regression analyses were carried out to determine the associations between quintiles of IGF-1 and cognitive function at the baseline and follow-up visits. Results showed that those in the top quintile of IGF-1 had lower processing capacity and global cognition scores at follow-up after controlling for cognitive function at baseline and other confounding factors. Additional analyses exploring associations with IGF-1 separately in middle-aged and older participants, and with quartiles of IGF-1 produced similar results. In those older than 60 years, high IGF-1 levels were also associated with lower baseline processing capacity. These results suggest that high IGF-1 levels are associated with worse long-term cognition in men. Together with past studies, we suggest that both, high and low levels of IGF-1 may be associated with poor cognitive function and that optimum levels of IGF-1 (quintile 2 and 3 in current study) may be associated with better cognitive function.
胰岛素样生长因子-1（IGF-1）水平较低，而IGF-1是一种重要的神经营养因子，这与老年人较差的认知功能有关。然而，很少有研究评估血清IGF-1与认知功能之间的前瞻性关联。我们旨在确定40至80岁男性人群样本中血清IGF-1与同时期及前瞻性认知功能之间的关联。在基线时评估血样中的IGF-1水平，并在基线时（n = 400）以及平均8.3年的随访后（n = 286）进行神经心理学评估。进行线性回归分析以确定IGF-1五分位数与基线和随访时认知功能之间的关联。结果显示，在控制了基线时的认知功能和其他混杂因素后，IGF-1最高五分位数的人群在随访时的处理能力和整体认知得分较低。在中年和老年参与者中分别探索与IGF-1的关联以及与IGF-1四分位数的额外分析产生了类似的结果。在60岁以上的人群中，高IGF-1水平也与较低的基线处理能力相关。这些结果表明，高IGF-1水平与男性较差的长期认知有关。与过去的研究一起，我们认为，IGF-1的高水平和低水平都可能与较差的认知功能有关，而IGF-1的最佳水平（本研究中的第二和第三五分位数）可能与较好的认知功能有关。
