Haptoglobin Phenotype, Preeclampsia and Response to Supplementation with Vitamins C and E in Pregnant Women with Type 1 Diabetes.

Objective The phenotype of the antioxidant and pro-angiogenicprotein haptoglobin (Hp) predicts cardiovascular disease risk andtreatment response to antioxidant vitamins in individuals withdiabetes. Our objective was to determine whether Hp phenotypeinfluences pre-eclampsia risk, or the efficacy of vitamins C and Ein preventing pre-eclampsia, in women with type-1 diabetes.<br/>Design This is a secondary analysis of a randomised controlledtrial in which women with diabetes received daily vitamins C andE, or placebo, from 8 to 22 weeks of gestation until delivery.<br/>Setting Twenty-five antenatal metabolic clinics across the UK (innorth-west England, Scotland, and Northern Ireland).<br/>Population Pregnant women with type-1 diabetes.<br/>Methods Hp phenotype was determined in white women whocompleted the study and had plasma samples available (n = 685).<br/>Main outcome measure Pre-eclampsia.<br/>Results Compared with Hp 2-1, Hp 1-1 (OR 0.59, 95% CI 0.30–1.16) and Hp 2-2 (OR 0.93, 95% CI 0.60–1.45) were notassociated with significantly decreased pre-eclampsia risk afteradjusting for treatment group and HbA1c at randomisation. Ourstudy was not powered to detect an interaction between Hpphenotype and treatment response; however, our preliminaryanalysis sugge sts that vitamins C and E did not prevent pre-eclampsia in women of any Hp phenotype (Hp 1-1, OR 0.77, 95%CI 0.22–2.71; Hp 2-1, OR 0.81, 95% CI 0.46–1.43; Hp 2-2, 0.67,95% CI 0.34–1.33), after adjusting for HbA1c at randomisation.<br/>Conclusions The Hp phenotype did not significantly affect pre-eclampsia risk in women with type-1 diabetes.<br/><br/><br/>