Table 2. Adjusted HRsa and ratesb (95% CI) of hypertension and CVD according to weight change from prepregnancy to 18 months postpartum (n = 47,966).
| Hypertension | CVD | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cases (n) | Rate | 95% CI | HR | 95% CI | P value | Cases (n) | Rate | 95% CI | HR | 95% CI | P value | |
| All | ||||||||||||
| <−1 | 498 | 16.6 | (14.3, 19.3) | 0.98 | (0.88, 1.10) | 0.79 | 325 | 12.4 | (10.3, 15.0) | 1.14 | (0.99, 1.32) | 0.06 |
| −1 to 1 | 964 | 16.8 | (14.8, 19.2) | Ref | 656 | 10.9 | (9.2, 12.8) | Ref | ||||
| >1 to 2 | 319 | 21.0 | (17.9, 24.6) | 1.25 | (1.10, 1.42) | 0.001 | 174 | 11.1 | (9.0, 13.7) | 1.02 | (0.87, 1.21) | 0.79 |
| >2 | 230 | 22.1 | (18.5, 26.3) | 1.31 | (1.14, 1.52) | <0.001 | 134 | 13.4 | (10.7, 16.8) | 1.24 | (1.02, 1.49) | 0.03 |
| Prepregnancy BMI <25 kg/m2 | ||||||||||||
| <−1 | 141 | 12.3 | (9.7, 15.5) | 0.99 | (0.83, 1.19) | 0.95 | 138 | 11.1 | (8.6, 14.4) | 1.28c | (1.06, 1.55) | 0.01 |
| −1 to 1 | 610 | 12.6 | (10.6, 15.1) | Ref | 464 | 8.8 | (7.2, 10.8) | Ref | ||||
| >1 to 2 | 189 | 15.8 | (12.8, 19.5) | 1.26 | (1.07, 1.48) | 0.006 | 122 | 9.6 | (7.4, 12.4) | 1.09 | (0.89, 1.33) | 0.39 |
| >2 | 112 | 18.5 | (14.4, 23.6) | 1.49 | (1.22, 1.82) | <0.001 | 85 | 12.9 | (9.7, 17.2) | 1.48d | (1.17, 1.87) | 0.001 |
| Prepregnancy BMI ≥25 kg/m2 | ||||||||||||
| <−1 | 357 | 30.4 | (34.9, 37.2) | 0.93 | (0.80, 1.08) | 0.37 | 187 | 16.9 | (12.8, 22.4) | 0.95c | (0.77, 1.16) | 0.60 |
| −1 to 1 | 354 | 32.4 | (26.5, 39.6) | Ref | 192 | 17.8 | (13.5, 23.6) | Ref | ||||
| >1 to 2 | 130 | 39.0 | (30.6, 49.7) | 1.21 | (0.99, 1.47) | 0.07 | 52 | 15.4 | (10.7, 22.1) | 0.86 | (0.63, 1.17) | 0.34 |
| >2 | 118 | 36.6 | (28.5, 47.0) | 1.13 | (0.92, 1.39) | 0.25 | 49 | 15.8 | (10.9, 22.9) | 0.88d | (0.65, 1.21) | 0.44 |
CI, confidence interval; CVD, cardiovascular disease (ischemic heart disease and stroke); HR, hazard ratio.
a Cox regression models were used to estimate HRs and 95% CIs adjusted for prepregnancy BMI, parity, and alcohol intake before the index pregnancy, maternal age at conception, socio-occupational status, dietary intake, leisure-time exercise, diabetes, preeclampsia, and preterm birth during index pregnancy, smoking status during index pregnancy and the first 6 months postpartum, and total duration of breastfeeding.
b Poisson regression models were used to estimate rates and 95% CIs per 10,000 person-years for a reference woman: primiparous, 29.8 years of age at conception, prepregnancy BMI of 23.5 kg/m2 (for BMI <25 kg/m2, this was 21.5 kg/m2 and for BMI ≥25 kg/m2, this was 29.0 kg/m2), high in socio-occupational status, no preeclampsia, no diabetes, delivered at term, and during pregnancy was nonsmoker, had an intermediate dietary pattern, did no exercise, and breastfed total 4 to 10 months.
c P value for interaction by prepregnancy BMI = 0.03. The p value refers to the difference between the two associations.
d P value for interaction by prepregnancy BMI = 0.01. The p value refers to the difference between the two associations.