Hb

"This study investigated the relationship between first-trimester hemoglobin (Hb) levels, the Haptoglobin (Hp) genotype, and the risk of gestational diabetes mellitus (GDM) in a cohort of 358 women with GDM and 1324 with normal glucose tolerance (NGT). Women who developed GDM had significantly higher Hb levels throughout pregnancy. A first-trimester Hb concentration exceeding 122 g/L was associated with a linear increase in GDM risk, glucose levels, HOMA-IR values, cesarean delivery rates, and adverse neonatal outcomes. Elevated first-trimester Hb was identified as an independent risk factor for GDM, even after adjusting for confounders.

The Hp2-2 genotype was more prevalent in GDM cases when Hb levels exceeded 122 g/L, and significant interactions were observed between Hb levels and the Hp genotype for GDM risk. Stratified analysis revealed an incremental increase in GDM risk when both high Hb levels and the Hp2-2 genotype were present. Mediation analysis further showed that first-trimester Hb partially mediated the association between the Hp genotype and GDM.

The study concludes that increased first-trimester Hb levels are strongly associated with GDM and adverse outcomes, and this relationship is moderated by the Hp2-2 genotype, highlighting the potential for integrating Hb levels and Hp genotype into GDM risk prediction."