Serum carotenoids and markers of inflammation in nonsmokers.
One explanation for discrepant results between epidemiologic studies and randomized trials of beta-carotene and cardiovascular disease may be a failure to consider inflammation as a confounder. To evaluate the potential for such confounding, the authors relate the serum concentrations of five carotenoids (alpha-carotene, beta-carotene, beta-cryptoxanthin, lycopene, and lutein/zeaxanthin) to levels of three inflammatory markers (C-reactive protein, fibrinogen, and white blood cell count) measured during the Third National Health and Nutrition Survey, 1988-1994. The analysis included 4,557 nonsmoking participants aged 25-55 years. Adjusted concentrations of all five carotenoids were significantly lower in those with C-reactive protein levels above 0.88 mg/dl (p = 0.001). There was a trend toward lower adjusted beta-cryptoxanthin concentrations with increasing level of fibrinogen (p value test for trend = 0.01), but other carotenoids were not related. Many of the carotenoid concentrations were lower among participants with high white blood cell counts. After log transformation, only adjusted mean beta-carotene levels were significantly lower in those with white blood cell counts above 7.85 x 10(9)/liter (p < 0.01). These cross-sectional data do not clarify the biologic relation between carotenoids and C-reactive protein but, to the extent that the carotenoids are associated with C-reactive protein levels, a carotenoid-heart disease association may be, in part, an inflammation-heart disease association.
Kritchevsky
S B
SB
Department of Preventive Medicine, University of Tennessee, Memphis 38105, USA. skritchevsky@utmem.edu
Bush
A J
AJ
Pahor
M
M
Gross
M D
MD
D000209:Acute-Phase Proteins / Q000378:metabolism; D000328:Adult; D015415:Biomarkers; D002097:C-Reactive Protein / Q000378:metabolism; D002318:Cardiovascular Diseases / Q000453:epidemiology*; D002338:Carotenoids / Q000097:blood*; D003430:Cross-Sectional Studies; D015987:Effect Modifier, Epidemiologic; D005260:Female; D005340:Fibrinogen / Q000378:metabolism; D006801:Humans; D007249:Inflammation / Q000097:blood*; D007958:Leukocyte Count; D008297:Male; D012306:Risk; D019207:beta Carotene / Q000378:metabolism
D000209:Acute-Phase Proteins; D015415:Biomarkers; D019207:beta Carotene; D002338:Carotenoids; D005340:Fibrinogen; D002097:C-Reactive Protein