Insulin beneficial to pregnant women with triglyceride-rich lipoproteins

Women with high levels of very low-density lipoprotein (VLDL) cholesterol or high apolipoprotein B to A-1 ratio (apoB/apoA-1) may fare better with insulin than metformin, with a recent study showing that treatment with the latter leads to higher serum concentrations of triglyceride-rich lipoproteins in the last trimester of pregnancy.

In addition, offspring birth weight tends to increase with higher triglyceride and cholesterol content in VLDL particles.

Researchers conducted a secondary analysis of a randomized trial evaluating the effect of metformin (n=110) vs insulin (n=107) in the treatment of women with gestational diabetes mellitus (GDM) to analyse the associations between individual lipids and offspring birth weight.

Age, prepregnancy body mass index, fasting glucose, HbA1c, and gestational weight gain, among others, were similar in the two treatment groups. Likewise, there were no significant between-group differences seen in absolute mean and adjusted birth weight in children. The incidence of small or large for gestational age was likewise not significantly different.

At 36 gestational weeks, total and VLDL triglycerides and VLDL cholesterol rose from baseline. However, the increase in triglycerides was greater in the metformin-treated group (p<0.01).

Baseline total and VLDL triglycerides, VLDL cholesterol, and apoB/apoA-1 showed a positive association with birth weight, and these relationships were more pronounced in the metformin group.

Among patients in the highest baseline VLDL cholesterol or apoB/apoA-1 quartile, those treated with insulin gave birth to infants with smaller birth weight than those treated with metformin (p<0.03).

Larger studies are needed to confirm the results of the study.