Obesity and preeclampsia: the potential role of inflammation.
OBJECTIVE
Systemic inflammation might contribute to the pathogenesis of preeclampsia. In addition, the association between obesity and inflammation in preeclampsia has not been examined in detail. We determined whether first-trimester elevation of serum C-reactive protein, an index of systemic inflammation, was associated with preeclampsia.


METHODS
We conducted a prospective, nested case-control study among women enrolled in the Massachusetts General Hospital Obstetrical Maternal Study cohort. High-resolution C-reactive protein assays were performed on first-trimester (11 +/- 2 weeks' gestation) serum samples in 40 women in whom preeclampsia developed (blood pressure [BP] greater than 140/90 mmHg, and proteinuria, either 2+ or more by dipstick or greater than 300 mg per 24 hours), and in 80 matched controls. This sample size had greater than 80% power to detect a difference in C-reactive protein levels between cases and controls. We used nonparametric tests to compare C-reactive protein levels and conditional logistic regression to control for confounding variables.


RESULTS
First-trimester C-reactive protein levels were significantly higher among women in whom preeclampsia subsequently developed compared with controls (4.6 compared with 2.3 mg/L, P =.04). When women were subdivided into C-reactive protein quartiles, the odds ratio (OR) of being in the highest quartile of C-reactive protein was 3.2 (95% confidence interval [CI] 1.1, 9.3, P =.02) among cases of preeclampsia compared with controls. When body mass index (BMI) was added to the multivariable model, the highest quartile of C-reactive protein was no longer associated with increased risk of preeclampsia (OR 1.1, 95% CI.3, 4.3, P =.94). In the same model without BMI, the highest quartile of C-reactive protein was associated with increased risk of preeclampsia (OR 3.5, 95% CI 1.3, 9.5, P =.01).


CONCLUSIONS
In women with preeclampsia, there was evidence of increased systemic inflammation in the first trimester. Inflammation might be part of a causal pathway through which obesity predisposes to preeclampsia.
Wolf
M
M
Renal Unit, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts 02114, USA. mswolf@partners.org
Kettyle
E
E
Sandler
L
L
Ecker
J L
JL
Roberts
J
J
Thadhani
R
R
D000328:Adult; D015992:Body Mass Index; D002097:C-Reactive Protein / Q000032:analysis*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D009765:Obesity / Q000097:blood / Q000453:epidemiology*; D010298:Parity; D011225:Pre-Eclampsia / Q000097:blood / Q000453:epidemiology* / Q000209:etiology; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors
D002097:C-Reactive Protein