Joint effects of lipid abnormalities and infection burden on CRP among childbearing age Mexican American women

Growing evidence links childhood metabolic diseases to maternal inflammation.  Childbearing age Mexican American women (CAMAW) have one of the highest levels of C-reactive protein (CRP) in the U.S. but factors associated with increased inflammation in this population are not fully understood. Contribution of infectious burden (IB) to inflammation remains un-examined in this group, even though IB is an established pro-inflammatory factor and highly prevalent among young Mexican Americans.  Total cholesterol (TC) and high density lipoprotein (HDL) significantly modulate infection-associated inflammatory sequelae.  Since TC and HDL lipid abnormalities are highly prevalent among CAMAW, they may modify the effect of IB on CRP.

Purpose: (1) To examine the association of IB with CRP; (2) To investigate interactive effects of IB with TC and HDL on CRP.

Methods:  Non-pregnant MA women participants (age 18-49) in the National Health and Nutrition Examination Survey, 1999-2010 (N=1,428).  IB summates seropositive status for 3 viruses: Herpes Simplex virus-1 and -2 and Hepatitis B (range 0-3).  Categorized as “high” when positive for 2-3 viruses, “low” positive for one virus, and “seronegative”.  Lipid categories: TC - low (<160 mg/dL), normal  (160-199 mg/dL), borderline high (200-239mg/dL) and high (240 mg/dL and above); HDL - normal (50 mg/dL or greater) and low (< 50 md/dL).  CRP dichotomized as normal < 3.0 mg/L and elevated 3.0-10.0 mg/L. Associations were examined using binary logistic regression.

Results: The association between IB and CRP varied based on TC and HDL levels, after adjustment for age, education , waist circumference, diabetes status, and birth control pill use (both P for interaction =0.01). Seropositive women with high TC were 5.42 (95% CI 1.14-25.71) and seropositive women with borderline high TC were 2.82 (95% CI 1.07-7.44) times as likely to have elevated CRP, compared to seronegative women with high and borderline high TC levels, respectively.  Women with normal HDL levels had significantly decreased odds of elevated CRP if they were seronegative (OR=0.50, 95% CI 0.26-0.96) or had low IB (OR=0.71, 95% CI 0.54-0.93), compared to women with low HDL level and similar IB status.  In women with high IB, anti-inflammatory effect of HDL disappeared (OR=1.32, 95% CI 0.61-2.84).

Conclusion:  Lipid abnormalities significantly interact with IB to create heightened inflammation risk.  Increased attention to IB/lipid screening and lipid therapy may be needed among CAMAW.