Statistical analysis
As pre-defined in MAMPED, primary analysis compared DM+PE+ vs. DM+PE-. Secondary analyses compared ‘uncomplicated’ T1DM (DM+PE-) with non-diabetic women (DM-). Results were expressed as means ± SD (Tables 1 & 2) or SEM (Figures 1-2). Groups were compared using unpaired Student’s t tests for continuous measures and \(\chi^{2}\) test for categorical measures; unpaired tests were used because of differential sample attrition. Analyses of repeated measures used Friedman’s test. Logistic regression, with and without covariate adjustments, was used to estimate the probability of women with T1DM developing PE based on clinical characteristics and biomarker values. The following covariates were selected based on differences at the time of visit, and/or their known associations with vitamin D metabolism: BMI, HbA1c, and total adiponectin.37 All tests were two-tailed, with p<0.05 considered significant. Statistical analyses were performed using SPSS software, version 22 (IBM Corp, Armonk, NY).