The study flow is depicted in Figure 1. The overall follow-up rate was 76.7% (n=56) and 61.6% (n=45) at 6 and 12 months, respectively. There was no difference in the follow-up loss rate at one year between the two groups (p=0.81). There were no clinical events in either group such as death, myocardial infarction, or hospitalization from heart failure or renal deterioration. Participants who dropped out of the study indicated that they did not have time to participate due to infant care. CAVI measurements were performed in 71 women (97.2%) at baseline, 50 women (68.5%) at 6 months, and 45 women (61.6%) at 12 months.
The baseline characteristics of the study participants are shown in Table 1. There was no significant difference in the baseline mean CAVI between the control and preeclampsia groups (6.92±1.69 vs 6.53±1.5, p=0.306). However, compared to those in the control group, the women in the preeclampsia group were significantly older (34.8±3.6 years vs 32.9±3.6 years, p=0.029), and had significantly higher systolic BP (142.4 mmHg vs 111.4 mmHg p<0.001) and diastolic BP (83.9 mmHg vs 63.2 mmHg, p<0.001). There were also significant differences between the two groups in the baseline levels of total cholesterol, triglyceride, creatinine, AST, and ALT. Furthermore, 62.2% (23/37) of the women with preeclampsia were treated with antihypertensive drugs. A calcium-channel blocker (n=23, 100%) was the most prescribed antihypertensive agent; however, two women were also prescribed beta-blockers. In patients with preeclampsia, 22 had early-onset preeclampsia (defined as preeclampsia that develops before 34 weeks of gestation), whereas 15 had late-onset preeclampsia.
Relationship between Preeclampsia and Longitudinal Change in the CAVI
Both between-subject (group) and within-subject (time) differences in the mean CAVI were analyzed. At 6 months, the mean CAVI was higher in the preeclampsia group than in the control group (6.64 vs 6.23, p=0.03). However, at 12 months, the group difference did not remain significant (Table 2A, Figure 2). For the preeclampsia group, the mean CAVI showed a decreasing trend over 1 year; however, the trend was not statistically significant. For both groups, the within-subject comparisons in the mean CAVI between time points did not reveal any significant differences (Table 2B, Figure 2).
Predictors of the Longitudinal Change in the CAVI
After adjusting for the time since delivery, age, BMI, and diabetes mellitus, there was no difference in the longitudinal change in the mean CAVI between the two groups (β=0.11, 95% confidence interval [C.I]: -0.31 – 0.54, p=0.60). No interaction between group and time was observed in this mixed-effects model (p=0.2488).
The mixed-effects model indicated that the time since delivery (β= -0.54, 95% C.I: -0.97 – - 0.11, p=0.015), presence of diabetes mellitus (β= 1.07, 95% C.I: 0.25 – 1.89, p=0.012), age (β= 0.08, 95% C.I: 0.02 – 0.14, p=0.013), and BMI (β= -0.07, 95% C.I: -0.12 – 0.03, p=0.003) were significant predictors of the longitudinal change in the CAVI. No interactions were observed among any of the covariates in the mixed-effects model (Table 3).
In addition, when R2 was considered as the proportion of explained variance, substantial differences between marginal R2 and conditional R2 in the mixed-effects models were observed. This indicates that a substantial amount of variability was in random effects.
Relationships between Preeclampsia and BP/Metabolic Indices
Compared to the control group, the preeclampsia group had significantly higher age- and time-adjusted levels of systolic BP (β=21.6, 95% C.I: 15.9 – 27.4, p<0.0001), diastolic BP (β=16.1, 95% C.I: 12.0 – 20.2, p<0.0001), total cholesterol (β=20.5, 95% C.I: 2.08 – 38.8, p=0.03), triglyceride (β=31.7, 95% C.I: 0.41 – 62.9, p=0.047), creatinine (β=0.115, 95% C.I: 0.032 – 0.197, p=0.007), AST (β=4.78, 95% C.I: 1.22 – 8.35, p=0.009), and ALT (β=7.23, 95% C.I: 1.53 – 12.9, p=0.014) during follow-up (Table 4). However, no group differences were observed in the waist/hip ratio, LDL cholesterol, and HDL cholesterol.