BackgroundThe relation of serum uric acid (SUA) with systemic inflammation has been
little explored in humans and results have been inconsistent. We analyzed
the association between SUA and circulating levels of interleukin-6 (IL-6),
interleukin-1β (IL-1β), tumor necrosis factor- α (TNF-α) and
C-reactive protein (CRP).Methods and FindingsThis cross-sectional population-based study conducted in Lausanne,
Switzerland, included 6085 participants aged 35 to 75 years. SUA was
measured using uricase-PAP method. Plasma TNF-α, IL-1β and IL-6 were
measured by a multiplexed particle-based flow cytometric assay and hs-CRP by
an immunometric assay. The median levels of SUA, IL-6, TNF-α, CRP and
IL-1β were 355 µmol/L, 1.46 pg/mL, 3.04 pg/mL, 1.2 mg/L and 0.34
pg/mL in men and 262 µmol/L, 1.21 pg/mL, 2.74 pg/mL, 1.3 mg/L and 0.45
pg/mL in women, respectively. SUA correlated positively with IL-6, TNF-α
and CRP and negatively with IL-1β (Spearman r: 0.04, 0.07, 0.20 and 0.05
in men, and 0.09, 0.13, 0.30 and 0.07 in women, respectively, P<0.05). In
multivariable analyses, SUA was associated positively with CRP (β
coefficient ± SE = 0.35±0.02,
P<0.001), TNF-α (0.08±0.02, P<0.001) and IL-6
(0.10±0.03, P<0.001), and negatively with IL-1β
(−0.07±0.03, P = 0.027). Upon further
adjustment for body mass index, these associations were substantially
attenuated.ConclusionsSUA was associated positively with IL-6, CRP and TNF-α and negatively
with IL-1β, particularly in women. These results suggest that uric acid
contributes to systemic inflammation in humans and are in line with
experimental data showing that uric acid triggers sterile inflammation.