The prevalence of non-alcoholic fatty liver disease (NAFLD) tends to increase with age, but little is known regarding relations between the risk of NAFLD in older adults and serum vitamin D (25-hydroxyvitamin D) and physical fitness levels. The aim of this study was to investigate the relationship between NAFLD risk and serum vitamin D levels combined with physical fitness in elderly adults using a non-invasive diagnostic approach. We enrolled 533 Korean older adults (80.8 % women), aged 65 years or older in this cross-sectional study. NAFLD in absence of another cause of liver disease was defined according to the ZJU and NAFLD liver fat (LFS) score. Physical fitness was assessed using a senior fitness test protocol. Logistic regression analysis was used to estimate odds ratios (ORs) and 95 % confidence intervals (CIs) of NAFLD for different combinations of serum vitamin D and physical fitness levels. According to the ZJU (OR: 3.073, CI: 1.285-7.350, p = 0.012) and LFS (OR = 2.443, CI = 1.071-5.572, p = 0.034), individuals with serum vitamin D < 30 ng/ml and poor physical fitness had a significantly higher risk of NAFLD than individuals with serum vitamin D ≥ 30 ng/ml and high fitness (reference, OR = 1), even after adjustments for age, sex, smoking, alcohol consumption and physical inactivity. However, there was no significant association after adjustment for additional metabolic diseases. Our findings suggest that the maintenance of appropriate levels of serum vitamin D and/or high physical fitness and the monitoring metabolic diseases can help reduce the risk of NAFLD in older adults.

中文翻译：

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在韩国老年人中，非酒精性脂肪肝疾病与血清维生素D水平及身体素质相结合。

非酒精性脂肪肝疾病（NAFLD）的患病率随着年龄的增长而增加，但是对于老年人中NAFLD的风险与血清维生素D（25-羟基维生素D）和身体健康水平之间的关系知之甚少。这项研究的目的是使用非侵入性诊断方法来调查老年人的NAFLD风险与血清维生素D水平与身体健康状况之间的关系。在这项横断面研究中，我们纳入了533名年龄在65岁以上的韩国老年人（女性占80.8％）。根据ZJU和NAFLD肝脂肪（LFS）评分定义了没有其他肝病原因的NAFLD。使用高级体能测试方案评估身体适应性。使用Logistic回归分析来估计血清维生素D和体质水平不同组合的NAFLD的优势比（OR）和95％置信区间（CI）。根据ZJU（OR：3.073，CI：1.285-7.350，p = 0.012）和LFS（OR = 2.443，CI = 1.071-5.572，p = 0.034），血清维生素D <30 ng / ml且身体状况较差的个体即使在调整了年龄，性别，吸烟，饮酒和缺乏运动后，健康状况也比血清维生素D≥30 ng / ml且健康状况良好（参考值，OR = 1）的个体明显高。但是，调整其他代谢性疾病后，没有显着相关性。