Cholesterol-rich diet, variants of metabolism genes predict GDM development

A diet rich in cholesterol during early pregnancy and genetic variations of cholesterol metabolism genes both contribute to the risk of gestational diabetes mellitus (GDM), suggests a study.

A total of 1,116 pregnant women from the Tongji Birth Cohort were assessed in this study. GDM was diagnosed using a 75-g 2-h oral glucose tolerance test at 24‒28 weeks of gestation. A validated food frequency questionnaire was used to collect dietary data.

The authors identified dietary patterns using the reduced-rank regression method, with dietary cholesterol as the response variable. They also carried out genotyping using time-of-flight mass spectrometry and assessed the odds ratio (OR) for GDM using conditional logistic regression models.

Using genetic variants in 28 cholesterol metabolism-related single nucleotide polymorphisms (SNPs), the authors constructed the genetic risk score (GRS) for GDM.

The cholesterol-rich dietary pattern primarily consisted of livestock and poultry meat and eggs, with a lower proportion of cereals. Multivariable-adjusted analysis revealed a higher likelihood of GDM per SD increase in cholesterol-rich pattern scores (OR, 1.24, 95 percent confidence interval [CI], 1.06‒1.44) and per tertile GRS (OR, 1.28, 95 percent CI, 1.09‒1.49).

Likewise, GDM significantly correlated with the variants of the CYP7A1 rs3808607 G→T/rs8192871 G→A/rs7833904 A→T, as well as AGGG and TTGA haplotypes of 4 CYP7A1-spanning SNPs.

The joint effect of these genetic variations and a cholesterol-rich diet showed an OR of 3.53 (95 percent CI, 1.71‒7.31) in the highest categories of both dietary pattern scores and GRS relative to individuals in the lowest strata without significant interaction (p=0.101 for interaction).

“Adherence to a cholesterol-rich dietary pattern during early pregnancy promotes the chance of GDM, especially in women with higher GRS,” the authors said.