Nakhaee Samaneh, Azadi Rasul, Salehinia Hamid, Moodi Mitra, Zarban Asghar, Sharifi Farshad, Khorashadizadeh Masoumeh, Farrokhfall Khadijeh
Medical Toxicology and Drug Abuse Research Center (MTDRC), Birjand University of Medical Sciences, Birjand, Iran.
Geriatric Health Research Center, Birjand University of Medical Sciences, Birjand, Iran.
Sci Rep. 2024 Dec 3;14(1):30020. doi: 10.1038/s41598-024-81551-3.
Aging is accompanied by possible cognitive impairment, as well as a reduction in nitric oxide (NO) bioavailability, insulin resistance, and vitamin D deficiency. Among these Nitric oxide exhibits a dual role in brain biology, where both low and high levels can have detrimental effects on memory and neurotoxicity. In this study we aimed to investigate the role of nitric oxide, insulin resistance, and vitamin D in cognitive function of elderly individuals. This case-control study involved participants aged ≥ 60 years who were under observation in the Birjand Longitudinal Aging Study. A total of 40 participants were selected as controls, while 64 participants with cognitive impairment were identified as cases. The cases were further subdivided according to their Mini-Mental State Examination (MMSE) scores into two groups: mild and moderate cognitive impairment. Cognitive function in both cases and controls was assessed using the MMSE. The levels of total NOx, vitamin D, insulin, and blood glucose were measured using ELISA and spectrophotometric immunoassays. Insulin resistance indices, such as homeostasis model assessment of insulin resistance (HOMA-IR) and quantitative insulin sensitivity check index (QUICKI) were calculated. Serum NOx levels were significantly lower in participants with cognitive impairment compared to the control group (p < 0.01). However, the mean (SD) levels of serum vitamin D, insulin, and glucose, as well as the insulin resistance markers, showed no significant differences between the groups. A positive correlation was observed between serum NOx levels and MMSE scores. NO may be an essential factor for normal brain function, as serum NOx levels were significantly higher in controls compared to those with cognitive impairment, and there was a positive correlation with MMSE scores. Other metabolic and nutritional markers, including vitamin D and insulin resistance, did not demonstrate a significant effect.
衰老伴随着认知功能障碍的可能性，以及一氧化氮（NO）生物利用度的降低、胰岛素抵抗和维生素D缺乏。在这些因素中，一氧化氮在大脑生物学中具有双重作用，低水平和高水平的一氧化氮都可能对记忆和神经毒性产生有害影响。在本研究中，我们旨在探讨一氧化氮、胰岛素抵抗和维生素D在老年人认知功能中的作用。这项病例对照研究涉及在比尔詹德纵向衰老研究中接受观察的60岁及以上的参与者。总共选择了40名参与者作为对照组，而64名有认知障碍的参与者被确定为病例组。病例组根据其简易精神状态检查表（MMSE）得分进一步细分为两组：轻度和中度认知障碍。使用MMSE评估病例组和对照组的认知功能。使用酶联免疫吸附测定法（ELISA）和分光光度免疫测定法测量总氮氧化物、维生素D、胰岛素和血糖的水平。计算胰岛素抵抗指数，如胰岛素抵抗稳态模型评估（HOMA-IR）和定量胰岛素敏感性检查指数（QUICKI）。与对照组相比，认知障碍参与者的血清氮氧化物水平显著降低（p<0.01）。然而，血清维生素D、胰岛素和葡萄糖的平均（标准差）水平以及胰岛素抵抗标志物在两组之间没有显著差异。血清氮氧化物水平与MMSE得分之间存在正相关。NO可能是正常脑功能的一个重要因素，因为与认知障碍者相比，对照组的血清氮氧化物水平显著更高，并且与MMSE得分呈正相关。其他代谢和营养标志物，包括维生素D和胰岛素抵抗，没有显示出显著影响。
