High ferritin linked to gestational diabetes mellitus

There appears to be a direct correlation between ferritin concentrations and the risk of gestational diabetes mellitus (GDM), reports a new meta-analysis.

Accessing the databases of PubMed, the Cochrane Library, Embase and Web of Science, researchers retrieved 10 observational studies corresponding to 4,690 participants. Most of the participants (n=3,650) were euglycaemic; the remaining 1,040 had GDM. Seven of the included studies scored at least 6 on the Newcastle-Ottawa Scale.

Women in the topmost category of ferritin concentrations were significantly more likely to develop GDM than their counterparts in the lowest category (summarized relative risk [SRR], 1.87, 95 percent confidence interval [CI], 1.50–2.34). Heterogeneity of evidence was null (p=0.26).

Four studies were eligible for the analysis of a dose-response relationship. Meta-analysis revealed that an increase in ferritin of 10 µg/L led to a corresponding 8-percent jump in the likelihood of developing GDM (SRR, 1.08, 95 percent CI, 1.05–1.13; p<0.01). Heterogeneity was high and of borderline significance (p=0.08).

Stratifying according to whether ferritin was measured from the plasma or serum, meta-analysis found that plasma ferritin (SRR, 2.51, 95 percent CI, 1.64–3.86) appeared to play a bigger role in GDM risk than serum ferritin (SRR, 1.63, 95 percent CI, 1.33–2.15).

The risk elevation likewise remained significant even when measurements were made during the first (SRR, 2.05, 95 percent CI, 1.39–3.02) or second (SRR, 1.79, 95 percent CI, 1.36–2.36) trimesters.