Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, MA, USA; Division of Medical Oncology, Department of Internal Medicine, The Ohio State University College of Medicine and Comprehensive Cancer Center - James Cancer Hospital and Solove Research Institute, Columbus, OH, USA.
Clin Nutr. 2022 Jun;41(6):1272-1280. doi: 10.1016/j.clnu.2022.04.003. Epub 2022 Apr 14.
BACKGROUND & AIMS: Insulin and insulin-like growth factor (IGF)-1 signaling is a proposed mechanism linking dietary protein and major chronic diseases. However, it is unclear whether animal and plant proteins are associated with biomarkers of insulin and IGF axis.
We analyzed a total of 14,709 participants from Nurses' Health Study and Health Professionals Follow-up Study who had provided a blood sample. Detailed dietary information was assessed using validated food frequency questionnaires. We assessed C-peptide, insulin, IGF-1, and IGF binding proteins (BP). Multivariable-adjusted linear regressions were used to examine associations of animal and plant protein intake with biomarkers after adjusting for confounders.
The medians (5th-95th percentiles) of animal and plant protein intake (% of total energy) were 13% (8-19%) and 5% (4-7%), respectively. Compared to participants in the lowest quintile, those in the highest quintile of animal protein had 4.8% (95% CI: 1.9, 7.9; P-trend<0.001) higher concentration of IGF-1 and -7.2% (95% CI: -14.8, 1.1; P for trend = 0.03) and -11.8% (95% CI: -20.6, -1.9; P-trend<0.001) lower concentration of IGFBP-1 and IGFBP-2, respectively, after adjustment for major lifestyle factors and diet quality. In contrast, no association was observed between animal protein intake and C-peptide, insulin and IGFBP-3. The associations were restricted to participants with at least one unhealthy lifestyle risk factor (i.e., overweight/obese, physical inactivity, smoking, and heavy alcohol intake). Plant protein tended to be strongly associated with numerous biomarkers in age-adjusted analyses but these became largely attenuated or non-significant in multivariable adjustment. Plant protein intake remained positively associated with IGF-1 (P-trend = 0.002) and possibly IGFBP-1 (P-trend = 0.02) after multivariable adjustment. Substitution of plant protein with animal protein sources was associated with lower IGFBP-1. In additional analysis, IGF-1 and IGFBPs were estimated to mediate approximately 5-20% of the association between animal protein and type 2 diabetes.
Higher animal protein intake was associated with higher IGF-1 and lower IGFBP-1 and IGFBP-2, whereas higher plant protein intake was associated with higher IGF-1 and IGFBP-1.
胰岛素和胰岛素样生长因子（IGF）-1 信号转导是一种将膳食蛋白质与主要慢性疾病联系起来的假说机制。然而，动物蛋白和植物蛋白是否与胰岛素和 IGF 轴的生物标志物有关尚不清楚。
我们分析了共有 14709 名来自护士健康研究和健康专业人员随访研究的参与者提供了血液样本。详细的饮食信息使用经过验证的食物频率问卷进行评估。我们评估了 C 肽、胰岛素、IGF-1 和 IGF 结合蛋白（BP）。多变量调整线性回归用于在调整混杂因素后，检查动物蛋白和植物蛋白摄入与生物标志物之间的关联。
动物蛋白和植物蛋白摄入（占总能量的百分比）的中位数（5 百分位数-95 百分位数）分别为 13%（8%-19%）和 5%（4%-7%）。与最低五分位数组的参与者相比，动物蛋白摄入量最高五分位数组的 IGF-1 浓度高 4.8%（95%CI：1.9，7.9；P 趋势<0.001），IGFBP-1 浓度低-7.2%（95%CI：-14.8，1.1；P 趋势=0.03），IGFBP-2 浓度低-11.8%（95%CI：-20.6，-1.9；P 趋势<0.001），经主要生活方式因素和饮食质量调整后。相比之下，动物蛋白摄入与 C 肽、胰岛素和 IGFBP-3 之间无关联。这些关联仅限于至少有一个不健康的生活方式危险因素的参与者（即超重/肥胖、身体活动不足、吸烟和大量饮酒）。在年龄调整分析中，植物蛋白与许多生物标志物呈强烈关联，但在多变量调整后，这些关联大多减弱或变得无统计学意义。植物蛋白摄入与 IGF-1（P 趋势=0.002）和可能的 IGFBP-1（P 趋势=0.02）呈正相关，在多变量调整后仍有统计学意义。用动物蛋白替代植物蛋白来源与 IGFBP-1 降低有关。在额外的分析中，IGF-1 和 IGFBPs 估计占动物蛋白与 2 型糖尿病之间关联的 5-20%。
较高的动物蛋白摄入与 IGF-1 升高和 IGFBP-1、IGFBP-2 降低有关，而较高的植物蛋白摄入与 IGF-1 和 IGFBP-1 升高有关。
