脂肪酸作为肌细胞内脂质(IMCL)储存在肌肉内。一些,但不是全部,研究表明,在高脂肪饮食(HFD)之后,IMCL可能会累积并影响胰岛素敏感性。本系统综述和荟萃分析旨在量化HFD对IMCL的影响。它还探讨了HFD脂肪含量和持续时间的潜在调节作用,IMCL测量技术,身体活动状况,IMCL与胰岛素敏感性的关系。系统地搜索了五个数据库,以研究≥3d的HFD(>35%的每日能量摄入来自脂肪)对健康个体IMCL含量的影响。元回归用于调查HFD总脂肪含量的相关性,持续时间,身体活动状况,IMCL测量技术,胰岛素敏感性与IMCL反应。使用具有95%置信区间(95%CIs)的随机效应模型,将IMCL含量和胰岛素敏感性的变化(通过高胰岛素-正常血糖钳夹评估)表示为标准化平均差(SMD)。19项研究纳入系统评价,16项纳入荟萃分析。HFD后IMCL含量增加(SMD=0.63;95%CI:0.31,0.94,P=0.001)。IMCL积累不受HFD总脂肪含量(P=0.832)或持续时间(P=0.844)的影响,身体活动状态(P=0.192),或通过IMCL测量技术(P>0.05)。HFD后胰岛素敏感性下降(SMD=-0.34;95%CI:-0.52,-0.16;P=0.003),但这与HFD后IMCL含量的增加无关(P=0.233).无论HFD总脂肪含量和体力活动状态的持续时间如何,在健康个体中消耗HFD(>35%的每日能量从脂肪中摄取)≥3d显著增加IMCL含量。所有IMCL测量技术都检测到HFD后IMCL含量的增加。IMCL变化和胰岛素敏感性之间的分离表明,其他因素可能会导致健康个体中HFD诱导的胰岛素敏感性受损。该试验在PROSPERO注册为CRD42021257984。
Fatty acids are stored within the muscle as intramyocellular lipids (IMCL). Some, but not all, studies indicate that following a high-fat diet (HFD), IMCL may accumulate and affect insulin sensitivity. This systematic
review and meta-analysis aimed to quantify the effects of an HFD on IMCL. It also explored the potential modifying effects of HFD fat content and duration, IMCL measurement technique, physical activity status, and the associations of IMCL with insulin sensitivity. Five databases were systematically searched for studies that examined the effect of ≥3 d of HFD (>35% daily energy intake from fat) on IMCL content in healthy individuals. Meta-regressions were used to investigate associations of the HFD total fat content, duration, physical activity status, IMCL measurement technique, and insulin sensitivity with IMCL responses. Changes in IMCL content and insulin sensitivity (assessed by hyperinsulinemic-euglycemic clamp) are presented as standardized mean difference (SMD) using a random effects model with 95% confidence intervals (95% CIs). Nineteen studies were included in the systematic
review and 16 in the meta-analysis. IMCL content increased following HFD (SMD = 0.63; 95% CI: 0.31, 0.94, P = 0.001). IMCL accumulation was not influenced by total fat content (P = 0.832) or duration (P = 0.844) of HFD, physical activity status (P = 0.192), or by the IMCL measurement technique (P > 0.05). Insulin sensitivity decreased following HFD (SMD = -0.34; 95% CI: -0.52, -0.16; P = 0.003), but this was not related to the increase in IMCL content following HFD (P = 0.233). Consumption of an HFD (>35% daily energy intake from fat) for ≥3 d significantly increases IMCL content in healthy individuals regardless of HFD total fat content and duration of physical activity status. All IMCL measurement techniques detected the increased IMCL content following HFD. The dissociation between changes in IMCL and insulin sensitivity suggests that other factors may drive HFD-induced impairments in insulin sensitivity in healthy individuals. This trial was registered at PROSPERO as CRD42021257984.