Haptoglobin Phenotype Modulates Lipoprotein-Associated Risk for Preeclampsia in Women with Type 1 Diabetes

Context: The incidence of preeclampsia (PE) is increased in women with diabetes (∼20% vs ∼5% in the general population), and first trimester lipoprotein profiles are predictive. Haptoglobin (Hp), a protein with functional genetic polymorphisms, has antioxidant, anti-inflammatory, and angiogenic effects. Among people with diabetes, the Hp 2-2 phenotype is associated with cardiorenal disease. 

Objective: To investigate whether Hp phenotype is associated with PE in type 1 diabetes mellitus (T1DM) and/or modulates lipoprotein-associated risks. 

Design and Setting: Multicenter prospective study of T1DM pregnancy. 

Patients: Pregnant women with T1DM (normal albuminuria, normotensive at enrolment, n = 47) studied at three visits, all preceding PE onset: 12.3 ± 1.9, 21.8 ± 1.5, and 31.5 ± 1.6 weeks' gestation (mean ± SD). 

Main Outcome Measures: Hp phenotype and lipoprotein profiles in women with (n = 23) vs without (n = 24) subsequent PE. 

Results: Hp phenotype did not predict PE, but lipoprotein associations with subsequent PE were confined to women with Hp 2-2, in whom the following associations with PE were observed: increased low-density lipoprotein (LDL) cholesterol, LDL particle concentration, apolipoprotein B (APOB), triacylglycerol/high-density lipoprotein (HDL) cholesterol ratio, and APOB/apolipoprotein AI (APOA1) ratio; decreased HDL cholesterol, APOA1, large HDL particle concentration, and peripheral lipoprotein lipolysis (all P < 0.05). In women with one or two Hp-1 alleles, no such associations were observed.

Conclusions: In women with T1DM, although Hp phenotype did not predict PE risk, lipoprotein-related risks for PE were limited to those with the Hp 2-2 phenotype. Hp phenotype may modulate PE risk in diabetes.