Postpregnancy BMI in the Progression From Hypertensive Disorders of Pregnancy to Type 2 Diabetes
Article Figures & Tables
Figures
- Figure 1
The joint effect of BMI after pregnancy and history of HDP on the risk of type 2 diabetes in women without a history of gestational diabetes mellitus by BMI, presented as HRs partitioned into the relative excess risks due to BMI, HDP, and their interaction (RERI). For each category of BMI, we show the relative excess risk due to each risk factor (BMI or HDP) and their additive interaction (RERI); the latter is supported if RERI >0. For example, in women with BMI ≥35.0 kg/m2, RERI is calculated as follows: RERIBMI ≥35.0 = HRBMI ≥35.0, HDP − HRBMI ≥18.5–24.9, HDP − HRBMI ≥35.0, No HDP + 1. All HRs are adjusted for age, race/ethnicity, parity, diet, physical activity, BMI at age 18 years, menopausal status, alcohol, smoking, and parental history of diabetes.
Tables
- Table 1
Descriptive characteristics of the study sample at study entry by history of HDP
Variable No HDP (n = 49,596) HDP (n = 6,563) Age, years, mean (SD) 46.3 (1.1) 46.3 (1.2) History of preeclampsia in any pregnancy* n/a 4,325 (65.9) History of gestational hypertension in any pregnancy* n/a 3,736 (56.9) BMI at age 18 years, kg/m2, mean (SD)† 20.9 (2.8) 21.7 (3.3) Parental history of diabetes 14,709 (29.7) 2,112 (32.2) Current BMI, kg/m2, mean (SD) 25.9 (5.3) 28.7 (6.4) Current BMI, kg/m2 18.5–24.9 26,577 (53.6) 2,261 (34.5) 25.0–29.9 13,688 (27.6) 1,949 (29.7) 30.0–34.9 5,868 (11.8) 1,224 (18.7) 35.0–50.0 3,463 (7.0) 1,129 (17.2) Physical activity, METs/week Fourth quartile (high activity) 12,273 (24.7) 1,455 (22.2) Third quartile 12,411 (25.0) 1,547 (23.6) Second quartile 12,533 (25.3) 1,713 (26.1) First quartile (low activity) 12,379 (25.0) 1,848 (28.2) DASH diet score Fourth quartile (high adherence) 10,917 (22.0) 1,316 (20.1) Third quartile 13,380 (27.0) 1,786 (27.2) Second quartile 12,439 (25.1) 1,693 (25.8) First quartile (low adherence) 12,860 (25.9) 1,768 (26.9) Race/ethnicity White/Caucasian 46,232 (93.2) 6,157 (93.8) African American 547 (1.1) 83 (1.3) Latina 620 (1.3) 84 (1.3) Asian 656 (1.3) 52 (0.8) Other 806 (1.6) 93 (1.4) Missing 735 (1.5) 94 (1.4) Alcohol intake No intake 19,180 (38.7) 2,832 (43.2) 1–15 g/day 27,078 (54.6) 3,347 (51.0) >15 g/day 3,338 (6.7) 384 (5.9) Smoking status Never 32,832 (66.2) 4,308 (65.6) Past 12,627 (25.5) 1,716 (26.1) Current 4,137 (8.3) 539 (8.2) Parity 1 birth 8,250 (16.6) 1,223 (18.6) 2 births 24,293 (49.0) 3,137 (47.8) 3 or more births 17,053 (34.4) 2,203 (33.6) Menopausal status Premenopause 41,853 (84.4) 5,354 (81.6) Postmenopause 6,340 (12.8) 995 (15.2) Unknown 1,403 (2.8) 214 (3.3) - Table 2
Incidence rates and HRs for type 2 diabetes according to BMI by history of HDP in parous middle-aged women without history of gestational diabetes mellitus
Incidence rates Normal weight (18.5–24.9 kg/m2) Overweight (25.0–29.9 kg/m2) Obesity class I (30.0–34.9 kg/m2) Obesity class II–III (≥35.0 kg/m2) Total Crude incidence No HDP Events/person-years* 60/193,169 221/113,891 313/50,566 443/29,306 1,037/386,932 Incidence per 1,000 person-years 0.31 1.9 6.2 15.1 2.7 History of HDP Events/person-years* 10/15,573 40/15,360 96/9,934 158/8,534 304/49,401 Incidence per 1,000 person-years 0.64 2.6 9.7 18.5 6.2 HR (95% CI) Normal weight (18.5–24.9 kg/m2) Overweight (25.0–29.9 kg/m2) Obesity class I (30.0–34.9 kg/m2) Obesity class II–III (≥35.0 kg/m2) Ptrend† Basic Cox regression model No HDP‡ 1.00 (Ref) 6.18 (4.65, 8.23) 19.60 (14.85, 25.87) 46.94 (35.79, 61.56) <0.001 History of HDP‡ 1.00 (Ref)§ 3.96 (1.98, 7.92) 14.73 (7.67, 28.28) 29.60 (15.60, 56.17) <0.001 Main Cox regression model No HDP‡ 1.00 (Ref) 5.89 (4.42, 7.85) 18.20 (13.72, 24.13) 44.6 (33.56, 59.25) <0.001 History of HDP‡ 1.00 (Ref)§ 3.83 (1.91, 7.67) 14.44 (7.50, 27.80) 28.78 (15.06, 54.98) <0.001 Ref, reference group. Women categorized as underweight (BMI <18.5 kg/m2) or with BMI >50 kg/m2 are excluded. Basic models include adjustment for age, race/ethnicity (white, Latina, African American, Asian, or other), and parity (1, 2, or ≥3 births). Main models additionally include DASH diet score (quartiles), physical activity (quartiles), BMI at age 18 years, smoking (nonsmoker, current smoker, or former smoker), alcohol intake (none, 1–15 g/day, or >15 g/day), menopausal status (premenopausal, postmenopausal, or unknown), parental history of diabetes (yes/no), and interaction terms between HDP and BMI categories.
↵*Rounded to year.
↵†Continuous BMI included in the models instead of categorical BMI.
↵‡Separate Cox proportional hazards models by HDP history.
↵§The same model as for “no HDP” except that women with prior HDP and BMI 18.5–24.9 kg/m2 constitute the reference group.
- Table 3
Statistics for additive interaction between postpregnancy BMI and history of HDP in multivariable-adjusted models of incident type 2 diabetes in parous women without history of gestational diabetes mellitus
Additive interaction statistic BMI category (kg/m2) Normal weight (18.5–24.9) Overweight (25.0–29.9) Obesity class I (30.0–34.9) Obesity class II–III (≥35.0) RERI (95% CI), null = 0 Reference* 0.98 (−1.92, 3.87) 10.69 (3.67, 17.70) 14.02 (2.83, 25.22) Attributable proportion (95% CI), null = 0† Reference* 0.12 (−0.22, 0.46) 0.36 (0.13, 0.59) 0.24 (0.05, 0.42) Synergy index (95% CI), null = 1 Reference* 1.16 (0.72, 1.60) 1.59 (1.34, 1.83) 1.31 (1.12, 1.51)
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