Background: Systemic inflammation and endothelial activation are implicated in the development of hypertension. However, epidemiologic studies have yet to compare multiple corresponding biomarkers in relation to risk of hypertension, particularly in multiethnic populations.
Methods: We identified 800 individuals with incident hypertension and 800 matched controls, each group with equal numbers of white and black women, in a nested case-control study within the Women's Health Initiative Observational Study. We measured markers of inflammation [high-sensitivity C-reactive protein (hsCRP), interleukin (IL)-6, IL-1β, tumor necrosis factor receptor 2 (TNF-r2)] and endothelial activation [soluble intercellular adhesion molecule-1 (sICAM-1)] in baseline blood samples.
Results: Before adjustment for measures of adiposity, higher hsCRP and IL-6 concentrations were associated with increased risk of hypertension in both white and black women, higher TNF-r2 was associated with increased risk of hypertension in black women only, and IL-1β and sICAM-1 were not associated with risk of hypertension. All the positive associations were attenuated after adjustment for body mass index. The resulting multivariable-adjusted relative risks (95% CI) of hypertension comparing the highest vs lowest quartile were 1.52 (0.94-2.48) and 1.23 (0.76-1.97) for hsCRP and IL-6 in white women and 1.30 (0.81-2.07), 1.58 (0.96-2.59), and 1.49 (0.94-2.36) for hsCRP, IL-6, and TNF-r2 in black women. The results after adjustment for waist circumference were similar.
Conclusions: After adjustment for measures of adiposity, there was no significant association of hsCRP, IL-6, IL-1β, TNF-r2, or sICAM-1 with incident hypertension in either white or black women. The interrelationships between inflammation and adiposity in development of hypertension need further investigation.