Dose-response association between animal protein sources and risk of gestational diabetes mellitus: a systematic review and meta-analysis

CONTEXT: There are contradictory findings about the relationship between various animal protein sources and the risk of gestational diabetes mellitus (GDM).

OBJECTIVE: The purpose of our study was to understand better the associations between total protein, animal protein, and animal protein sources and the risk of developing GDM.

DATA SOURCES: A systematic literature search was conducted in PubMed, Scopus, and Web of Science encompassing the literature up until August 2022. A random-effects model was used to combine the data. For estimating the dose-response curves, a one-stage linear mixed-effects meta-analysis was conducted.

DATA EXTRACTION: Data related to the association between animal protein consumption and the risk of GDM in the general population was extracted from prospective cohort studies.

DATA ANALYSIS: It was determined that 17 prospective cohort studies with a total of 49 120 participants met the eligibility criteria. It was concluded with high certainty of evidence that there was a significant association between dietary animal protein intake and GDM risk (1.94, 95% CI 1.42 to 2.65, n = 6). Moreover, a higher intake of total protein, total meat, and red meat was positively and significantly associated with an increased risk of GDM. The pooled relative risks of GDM were 1.50 (95% CI: 1.16, 1.94; n = 3) for a 30 g/d increment in processed meat, 1.68 (95% CI: 1.25, 2.24; n = 2) and 1.94 (95% CI: 1.41, 2.67; n = 4) for a 100 g/d increment in total and red meat, and 1.21 (95% CI: 1.10, 1.33; n = 4) and 1.32 (95% CI: 1.15, 1.52; n = 3) for a 5% increment in total protein and animal protein, respectively. GDM had a positive linear association with total protein, animal protein, total meat consumption, and red meat consumption, based on non-linear dose-response analysis.

CONCLUSION: Overall, consuming more animal protein-rich foods can increase the risk of GDM. The results from the current study need to be validated by other, well-designed prospective studies.

SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration no. CRD42022352303.