Department of Family Medicine, Nowon Eulji Medical Center, Eulji University School of Medicine, Seoul, 01830, Republic of Korea.
Biostatistics Collaboration Unit, Department of Research Affairs, Yonsei University College of Medicine, Seoul, 06273, Republic of Korea.
Clin Nutr. 2021 Oct;40(10):5252-5260. doi: 10.1016/j.clnu.2021.08.012. Epub 2021 Aug 25.
BACKGROUND & AIMS: Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease and is closely related to metabolic dysfunction, including insulin resistance, obesity, and metabolic syndrome. Dairy protein, rich in casein and whey protein, could help to reduce metabolic diseases. Therefore, we investigated the relationship between dairy protein intake and incident NAFLD.
We analyzed data for 5171 adults aged 40-69 years from the Korean Genome and Epidemiology Study.(KoGES) Participants were separated as men, women aged ≥50 years, and women aged <50 years and then divided into tertiles based on dairy protein intake. NAFLD was defined as NAFLD liver fat score >-0.640. Scores were calculated as 1.18 × metabolic syndrome (Yes: 1, No: 0) + 0.45 × diabetes mellitus (Yes: 2, No: 0) + 0.15 × serum insulin +0.04 × AST - 0.94 × (AST/ALT) - 2.89. Cox proportional hazards spline curves were drawn to visualize dose-response relationships between dairy protein intake and incident NAFLD. Multiple Cox hazard regression analysis was conducted to examine associations between dairy protein intake and incident NAFLD.
The Cox proportional hazards spline curves revealed a negative linear relationship between dairy protein intake and incident NAFLD. The cumulative incidence of NAFLD significantly decreased with increasing tertiles of dairy protein intake in men and women aged ≥50 years. After adjusting for confounding factors, the hazard ratios and 95% confidence intervals for NAFLD in the middle and highest tertiles, compared to the lowest tertile, were 0.80 (0.67-0.96) and 0.71 (0.57-0.88) in men, 0.89 (0.72-1.09) and 0.72 (0.56-0.92) in women aged ≥50 years, and 1.01 (0.80-1.27) and 0.91 (0.67-1.24) in women aged <50 years, respectively.
We found that higher dairy protein intake was significantly and inversely associated with the risk of incident NAFLD in men and women aged ≥50 years. Consumption of milk and other dairy products could help prevent the development of NAFLD.
非酒精性脂肪性肝病（NAFLD）是最常见的慢性肝病，与代谢功能障碍密切相关，包括胰岛素抵抗、肥胖和代谢综合征。富含酪蛋白和乳清蛋白的乳制品可能有助于预防代谢疾病。因此，我们研究了乳制品蛋白摄入与新发非酒精性脂肪性肝病（NAFLD）之间的关系。
我们分析了韩国基因与流行病学研究（KoGES）中 5171 名年龄在 40-69 岁的成年人的数据。根据乳制品蛋白摄入量，将参与者分为男性、≥50 岁女性和<50 岁女性，然后分为三分位组。NAFLD 定义为 NAFLD 肝脂肪评分>-0.640。评分计算方法为：1.18×代谢综合征（是：1，否：0）+0.45×糖尿病（是：2，否：0）+0.15×血清胰岛素+0.04×AST-0.94×（AST/ALT）-2.89。绘制 Cox 比例风险样条曲线以直观地显示乳制品蛋白摄入量与新发 NAFLD 之间的剂量-反应关系。进行多 Cox 风险回归分析以检验乳制品蛋白摄入与新发 NAFLD 之间的关联。
Cox 比例风险样条曲线显示乳制品蛋白摄入与新发 NAFLD 之间呈负线性关系。在≥50 岁的男性和女性中，随着乳制品蛋白摄入量三分位的增加，NAFLD 的累积发病率显著降低。在调整混杂因素后，与最低三分位相比，中间和最高三分位的 NAFLD 的风险比和 95%置信区间分别为男性 0.80（0.67-0.96）和 0.71（0.57-0.88），≥50 岁女性 0.89（0.72-1.09）和 0.72（0.56-0.92），<50 岁女性 1.01（0.80-1.27）和 0.91（0.67-1.24）。
我们发现，较高的乳制品蛋白摄入与男性和≥50 岁女性新发 NAFLD 的风险呈显著负相关。摄入牛奶和其他乳制品可能有助于预防 NAFLD 的发生。
