Center for Human Nutrition and Departments of Clinical Nutrition, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390, USA.
J Alzheimers Dis. 2013;36(3):571-5. doi: 10.3233/JAD-130443.
Centenarians with normal cognitive function have a "longevity phenotype" characterized by large low-density lipoproteins (LDL) and high-density lipoproteins (HDL) and low incidence of metabolic syndrome, hypertension, and cognitive impairment. Alzheimer's disease (AD) is associated with a number of cardiovascular risk factors, but it is not known if they have or lack the "longevity phenotype".
The study was designed to determine LDL size and body fat content and distribution in subjects with mild cognitive impairment (MCI) and AD.
Fifty-eight persons with MCI or AD (cases) and 42 control subjects of similar age had measurement of LDL size and lipoprotein lipids after a 12 h fast and analysis of body composition by dual x-ray absorptiometry. Cases had small LDL size more often than controls (73% versus 66%) associated with significantly higher triglycerides, lower HDL cholesterol, and higher triglyceride/HDL cholesterol ratio (p ≤ 0.02). Cases with large LDL had a better lipoprotein profile than those with small LDL. Cases and controls had similar percent body fat, fat index, and lean mass index. Forty-seven percent of cases and 39% of controls were obese.
The prevalence of small LDL phenotype in MCI and AD cases contrasts with the "longevity phenotype" reported for centenarians with preserved cognitive function. The small LDL phenotype is an atherogenic lipoprotein profile found in metabolic syndrome, type 2 diabetes, and insulin resistance. It is now also reported in persons with MCI and AD.
认知功能正常的百岁老人具有“长寿表型”，其特征是大密度脂蛋白（LDL）和高密度脂蛋白（HDL）低，代谢综合征、高血压和认知障碍发生率低。阿尔茨海默病（AD）与许多心血管危险因素有关，但尚不清楚其是否具有或缺乏“长寿表型”。
本研究旨在确定轻度认知障碍（MCI）和 AD 患者的 LDL 大小和体脂含量及分布。
58 名 MCI 或 AD 患者（病例）和 42 名年龄相似的对照者在禁食 12 小时后测量 LDL 大小和脂蛋白脂质，并通过双 X 线吸收法分析身体成分。病例的 LDL 大小比对照者小（73%比 66%），与甘油三酯显著升高、HDL 胆固醇降低以及甘油三酯/HDL 胆固醇比值升高有关（p ≤ 0.02）。具有大 LDL 的病例比具有小 LDL 的病例具有更好的脂蛋白谱。病例和对照者的体脂百分比、脂肪指数和瘦体重指数相似。47%的病例和 39%的对照者肥胖。
MCI 和 AD 病例中 LDL 小表型的患病率与认知功能正常的百岁老人所报告的“长寿表型”形成对比。小 LDL 表型是代谢综合征、2 型糖尿病和胰岛素抵抗中发现的动脉粥样硬化脂蛋白谱。现在也在 MCI 和 AD 患者中报告。
