Intake of animal and plant proteins and risk of all-cause mortality in patients with type 2 diabetes: results from NHANES.

Background/objective: There is little and inconsistent data on the relationship between protein intake and mortality in patients with type 2 diabetes. Our goal was to look at the relationship between consuming plant- and animal-based proteins and the risk of all-cause death in patients with type 2 diabetes.

Subjects/methods: We included 4646 patients with type 2 diabetes aged ≥20 years participating in continuous NHANES from 1999 to 2018. All-cause mortality was ascertained through linkage to National Death Index until December 31, 2019. Cox proportional hazard regression models were used to estimate multivariable-adjusted hazard ratios (HRs) and 95%CIs.

Results: Over an average follow-up of nine years, 969 deaths took place. The multivariable-adjusted HRs of all-cause mortality across quartiles of plant protein intake, were, respectively, 1.00 (reference), 0.77 (95%CI: 0.65, 0.93), 0.79 (95%CI: 0.64, 0.97), and 0.73 (95%CI: 0.58, 0.93) (P_trend = 0.022). Intake of animal protein was not linked to all-cause mortality. The HR was 0.94 (95%CI: 0.81, 1.08) for replacing 5% of energy from animal protein with plant protein. Intake of protein from individual animal- and plant-based foods was not related to the risk of all-cause mortality, nor was replacing 5% of energy intake from red meat protein with those from other foods.

Conclusions: Among individuals with type 2 diabetes, a higher intake of plant protein is linked to a lower risk of death from all causes. Nevertheless, the results should be interpreted with caution because some subgroups did not show an inverse relationship, and observational studies have limitations.