Maternal Arsenic Exposure and Gestational Diabetes: A Systematic Review and Meta-Analysis

Abstract

Gestational diabetes mellitus (GDM) is a metabolic complication associated with adverse outcomes for mother and fetus. Arsenic (As) exposure has been suggested as a possible risk factor for its development. The aim of this meta-analysis was to provide a comprehensive overview of published evidence on the association between As and GDM. The systematic search from PubMed, MEDLINE, and Scopus was limited to full-length manuscripts published in peer-reviewed journals up to April 2020, identifying fifty articles. Ten studies met the inclusion criteria, nine for quantitative synthesis with a total of n = 1984 GDM cases. The overall pooled risk was 1.56 (95% Confidence Interval - CI = 1.23, 1.99) with moderate heterogeneity (χ² = 21.95; I²% = 64). Several differences among the included studies that may account for heterogeneity were investigated. Stratification for exposure indicator confirmed a positive association for studies assessing urine As. A slightly higher risk was detected pooling studies based in Asia rather than in North America. Stratification for GDM diagnostic criteria showed higher risks when diagnosis was made according to the Canadian Diabetes Association (CDA-SOGC) or World Health Organization (WHO) criteria, whereas a lower risk was observed when adopting the American Diabetes Association (ADA) criteria. These results provide additional evidence for a possible association between As exposure and GDM, although the data need to be interpreted with caution due to heterogeneity.

Keywords: arsenic; arsenic exposure; arsenic toxicity; gestational diabetes mellitus; pregnancy.

Figure 1

Flow diagram of the search strategy, screening, eligibility and inclusion criteria. Abbreviations: GDM, Gestational diabetes mellitus; IGT, impaired glucose tolerance.

Figure 2

Forest plot of all studies included in the quantitative-synthesis (n = 9). The point estimate for each study is represented by a red square where the size of the square is proportional to the weight of the study in the meta-analysis and the 95% CI is symbolized by an horizontal line. The total effect with 95% CI is represented by a black diamond. The results of the pooled analysis demonstrate that As exposure increased the risk of developing GDM (OR = 1.59; 95% CI = 1.23, 1.99). Abbreviations: CI, confidence interval; df, degrees of freedom; IV, inverse variance; SE, standard error.

Figure 3

Funnel plot of all studies included in the quantitative-synthesis (n = 9). Visual inspection demonstrates slightly high publication bias, as confirmed by Egger’s test (t =3.00; p = 0.02). Abbreviations: CI, confidence interval; OR, odds ratio.