Open Access Research article

Cardiovascular inflammation in healthy women: multilevel associations with state-level prosperity, productivity and income inequality

Cheryl R Clark12, Paul M Ridker345, Mark J Ommerborn2, Carrie E Huisingh2, Brent Coull6, Julie E Buring3 and Lisa F Berkman78*

Author Affiliations

1 Division of General Medicine and Primary Care, Brigham and Women's-Faulkner Hospitalist Program, Harvard Medical School, Boston, Massachusetts, USA

2 Center for Community Health and Health Equity, Brigham and Women's Hospital, Boston, Massachusetts, USA

3 Division of Preventive Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA

4 Center for Cardiovascular Disease Prevention, Brigham and Women's Hospital, Boston, Massachusetts, USA

5 Division of Cardiovascular Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA

6 Department of Biostatistics, Harvard School of Public Health, Boston, Massachusetts, USA

7 Harvard Center for Population and Development Studies, Harvard School of Public Health, Cambridge, Massachusetts, USA

8 Department of Society, Human Development and Health, Harvard School of Public Health, Boston, Massachusetts, USA

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BMC Public Health 2012, 12:211  doi:10.1186/1471-2458-12-211

Published: 20 March 2012

Abstract

Background

Cardiovascular inflammation is a key contributor to the development of atherosclerosis and the prediction of cardiovascular events among healthy women. An emerging literature suggests biomarkers of inflammation vary by geography of residence at the state-level, and are associated with individual-level socioeconomic status. Associations between cardiovascular inflammation and state-level socioeconomic conditions have not been evaluated. The study objective is to estimate whether there are independent associations between state-level socioeconomic conditions and individual-level biomarkers of inflammation, in excess of individual-level income and clinical covariates among healthy women.

Methods

The authors examined cross-sectional multilevel associations among state-level socioeconomic conditions, individual-level income, and biomarkers of inflammation among women (n = 26,029) in the Women's Health Study, a nation-wide cohort of healthy women free of cardiovascular diseases at enrollment. High sensitivity C-reactive protein (hsCRP), soluble intercellular adhesion molecule-1 (sICAM-1) and fibrinogen were measured between 1993 and 1996. Biomarker levels were examined among women within quartiles of state-level socioeconomic conditions and within categories of individual-level income.

Results

The authors found that favorable state-level socioeconomic conditions were correlated with lower hsCRP, in excess of individual-level income (e.g. state-level real per capital gross domestic product fixed effect standardized Βeta coefficient [Std B] -0.03, 95% CI -0.05, -0.004). Individual-level income was more closely associated with sICAM-1 (Std B -0.04, 95% CI -0.06, -0.03) and fibrinogen (Std B -0.05, 95% CI -0.06, -0.03) than state-level conditions.

Conclusions

We found associations between state-level socioeconomic conditions and hsCRP among healthy women. Personal household income was more closely associated with sICAM-1 and fibrinogen than state-level socioeconomic conditions. Additional research should examine these associations in other cohorts, and investigate what more-advantaged states do differently than less-advantaged states that may influence levels of cardiovascular inflammation among healthy women.

Keywords:
C-reactive protein; Geography; Income; Inflammation; Multilevel analysis; Poverty; Socioeconomic factors; Women's health