Maternal telomere dynamics and lipid profiles across pregnancy: a secondary analysis of a randomized controlled trial

Abstract Background Telomere length, a biomarker of biological aging, has been linked to lipid metabolism, yet evidence during pregnancy is limited. The aim of this study was to assess the associations of maternal relative telomere length (RTL) and its changes with lipid profiles across pregnancy. Methods This was a secondary analysis of a randomized controlled trial including 360 pregnant women. RTL was measured in the first, second, and third trimesters, with available measurements in 360, 161, and 96 participants, respectively. RTL changes were calculated as between-trimester differences. Lipid profiles, including total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), non-HDL cholesterol (nHDL-C), the atherogenic index of plasma (AIP), and the triglyceride-glucose index (TyG), were assessed longitudinally. Restricted cubic spline models were used to examine non-linear relationships, followed by stratified linear regression analyses. Results First-trimester RTL was associated with TG-related markers in the second and third trimesters (β range = − 0.273 to − 0.040, all P < 0.05) and with third-trimester HDL-C (β = 0.086, P = 0.0073); these associations were restricted to women with RTL ≥ 2.5. Second-trimester RTL showed non-linear relationships with concurrent lipid indices (all P values for nonlinearity < 0.05), including inverted U-shaped associations with TG-related markers and U-shaped associations with cholesterol-related measures. Among women with decreasing RTL, RTL change was positively associated with TG-related markers (β range = 0.102 to 0.622, all P < 0.05) and inversely associated with TC (β = − 0.740, P = 0.0011) and nHDL-C (β = − 0.686, P = 0.0013). Conclusions RTL and its dynamic changes across gestation were related to lipid metabolism, particularly TG-related indices. These findings may enhance understanding of cardiometabolic adaptations during pregnancy and inform future efforts to identify adverse lipid profiles and promote maternal cardiometabolic health. Trial registration ChiCTR2000032488.