The association between high sensitivity C-reactive protein and micronutrient levels: A cross-sectional analysis...

Low-grade chronic inflammation is a condition underlying many serious diseases but there is no good single biomarker which can estimate and monitor the severity of the inflammation. C-reactive protein (CRP) is the best validated and most extensively used marker. The aims of the study were to investigate the extent to which CRP levels associate with levels of micronutrients.

We retrieved the levels of S-hsCRP and nutritional variables fB-β-carotenes, fS-Q10 (Ubiquinon), fS-Fe, E-Cu, fS-A vitamin, B-Se, B-Zn, and fB-B12 vitamin from the database of clinical laboratory Mila Oy from the years 1988-2018, a total of nearly 18 800 samples from outpatient clinics, Helsinki and Oulu, Finland. Sample sizes for nutritional variables measured concurrently with S-hsCRP varied between 4356 and 8621. S-hsCRP levels were categorized into five ordered categories. The levels of each micronutrient in those categories were compared using analysis of variance (ANOVA). Males and females were analyzed separately.

It was observed that an increase of S-hsCRP associated with the decrease of fS-Fe (p < 0.001 for both genders); fS-A vitamin (p < 0.001 for both genders), and fS-β-carotenes (p < 0.001 for both genders); these are considered negative acute phase reactants. For both genders there was no significant association between the levels of fS-B12 vitamin (p = 0.14 for males; p = 0.03 for females), fS-Q10 (p < 0.001 for males; p = 0.06 for females) and fB-Se (p < 0.001 for males; p = 0.01 for females) and the categorized S-hsCRP. In contrast, fB-Zn (p < 0.001 for both genders) behaved like a positive acute phase reactant whereas copper measured from washed blood cells (E-Cu) did not display any significant associations with S-hsCRP (p = 0.001 for males; p = 0.05 for females).

A linear association was observed for some micronutrients - the higher the degree of low-grade inflammation (S-hsCRP), the more disturbed were the levels of some micronutrients. For clinicians, this finding means that inflammation needs to be acknowledged when assessing micronutrient deficiency. Substitution therapy should be implemented only after the inflammation has been rectified.