A comprehensive review of nearly 130 studies provides the strongest evidence to date that ‘forever chemicals’ are associated with gestational diabetes, but highlights uncertainty about other diabetes outcomes and the need for more prospective research.
study: Associations of perfluoroalkyl and polyfluoroalkyl substances with markers of glycemic control, insulin secretion and sensitivity, and diabetes risk: a systematic review and meta-analysis. Image credit: Reshetnikov_art/Shutterstock.com
In a recent study published in e-clinical medicineresearchers evaluated the association between exposure to perfluoroalkyl and polyfluoroalkyl substances (PFAS) and diabetes outcomes.
Exposure to PFAS emerges as a potential diabetes risk factor
Diabetes (DM) is a chronic disease in which the body cannot use insulin efficiently or the pancreas does not produce enough insulin. Its prevalence has increased since the 1990s and is now estimated to affect more than 828 million people worldwide. Beyond lifestyle and genetic factors, exposure to environmental chemicals may contribute to disease pathogenesis. DM.
PFAS A persistent and ubiquitous chemical that can interfere with the endocrine system and increase the risk of: DM. These are called eternal chemicals because of their permeability and long half-life. PFAS Associated with metabolic syndrome and its components, promotes insulin resistance, induces cellular stress, inflammationor alter pancreatic function and homeostasis.
Investigating the relationship between PFAS and diabetes
In this study, researchers characterized the following associations: PFAS Exposure and markers of glycemic control, pancreatic β-cell function, insulin resistance, and diabetes risk. First, we conducted a systematic literature search to identify human studies from the Medline and Embase databases. Eligible studies were population-based observational studies that analyzed the association between diabetes and diabetes. PFAS.
Screening of titles, abstracts, and full texts of eligible studies was performed to extract relevant information. For each outcome of interest, the number of studies reporting at least one significant positive or negative association with individuals. PFAS I have summarized. Qualitative synthesis was conducted as an exploratory analysis of studies examining multiple contaminants or mixtures. PFAS Association.
Additionally, a random effects meta-analysis was performed between: PFAS and pregnant DM (GDM), type 2 diabetes (T2D), homeostasis model evaluation of β-cell function (HOMA-β) and insulin resistance (homer il), fasting insulin, glycated hemoglobin (HbA1c), fasting blood sugar level. The risk of bias and quality and strength of evidence of the studies were assessed using a navigation guide.
Strongest evidence linking PFAS exposure and gestational diabetes
Of the 738 records identified in the database search, 129 records were included after screening. Most studies us (54) and China (30), which was a cross-sectional design (70). Across the studies, 45 different PFAS The most common were perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorohexane sulfonic acid (PFHxS), perfluorodecanoic acid (PFDA), and perfluorononanoic acid (PFNA).
Most studies investigated PFAS Exposure during adulthood (75), pregnancy or prenatal period (42), adolescence (22), and childhood (16), highlighting potential differences due to timing of exposure. The most common diabetes outcomes are: T2D, GDMfasting blood glucose, and homer il. The research subjects were mainly the general public. Almost one-third of the studies investigated outcomes in pregnant individuals.
Only three studies investigated type 1 diabetes, and the results were inconsistent. Meta-analysis including 79 studies assessing 18 different items PFASshowed some things PFAS It was associated with higher odds of gestational diabetes. Specifically, each doubling of PFOS and perfluorobutane sulfonic acid (PFBS) levels was associated with an increase in concentration. GDM Risks in prospective studies.
Nested case, control studies have reported positive associations with several long and emerging chains. PFASPFOA, PFNA, PFDA, PFBS, perfluoroheptane sulfonic acid (PFHpS), and 6:2 chlorinated polyfluoroalkyl ether sulfonate (6:2 Cl-PFESA).In cross-sectional or case-control studies, a positive association was found for perfluorododecanoic acid (PFDoDA) and PFOA, and a negative association was found for perfluoroheptanoic acid. (PFHPA).
for T2DPFNA, PFOA, and PFOS showed an overall positive direction in prospective studies, but the associations were not significant. Several important associations were observed in the homeostasis model evaluation. The idea is that for every doubling of beta-cell function, beta-cell function and insulin resistance increase. PFAS level. in particular, homer il Prospective studies showed positive correlations with PFOS and PFNA.
HOMA-β It was associated with PFOA, PFOS, and PFNA in cross-sectional studies, and with PFNA in prospective studies. For fasting insulin measurements, positive associations with PFOS and PFNA were observed in prospective studies. In general, there were no significant associations with: HbA1c In the main analysis. However, a sensitivity analysis restricted to studies with low risk of bias identified a positive association between PFOS and PFOS. HbA1c In a cross-sectional study.
Associations with fasting blood glucose were limited and inconsistent across. PFAS Study designs with mixed or largely invalid findings, especially in pregnancy-specific analyses. Most studies were classified as having low or probable low risk of bias with respect to outcome and exposure measures, study populations, baseline differences, and confounding.
60 studies conducted multiple surveys PFAS Or use with other chemicals. 35 of them include PFAS Six also considered other chemicals as part of the exposure mixture. PFAS. Evaluation of most mixture studies GDM or T2D reported a positive association, whereas studies using total PFAS Measurements often reported inconsistent or invalid results.
Finally, we found moderate quality evidence for some long chains or legacies. PFAS Selected results, but poor quality if short chain or emerging PFAS And for results like: T2Dfasting blood glucose, and HbA1cwere limited or insufficient to reliably determine the association between them. PFAS Exposure and diabetes outcomes in humans.
Effects on metabolism are gradual, but uncertainty remains
The most consistent finding is that PFAS Exposure and greater odds GDM. evidence PFAS, T2D Although the relationship has not yet been elucidated, the association with type 1 diabetes remains weak. Meta-analysis revealed a positive association between: PFAS and homer illimited association with fasting blood glucose; HOMA-βand fasting insulin.
Effect sizes for continuous metabolic markers are generally small and many findings come from cross-sectional studies, which limits causal inferences and increases the possibility of reverse causation. Overall, the evidence suggests exposure to several substances. PFAS is associated with an increase in GDM Risk and mild changes in insulin sensitivity and secretion in the general population.