Plasma procalcitonin is associated with obesity, insulin resistance, and the metabolic syndrome.

CONTEXT Procalcitonin, a well-known biomarker of sepsis and bacterial infections, is produced by adipose tissue and has potential as a marker for chronic low-grade inflammation. OBJECTIVES The objective of this study was to investigate whether plasma procalcitonin levels in the normal range are associated with obesity, insulin resistance, and metabolic syndrome (MS) in the general population. METHODS Plasma procalcitonin (0.006-0.1 ng/ml) was measured in 3197 men and 3638 women (aged 28-75 yr) of the Prevention of Renal and Vascular End-Stage Disease (PREVEND) study using an ultrasensitive immunoluminometric assay. MS was defined according to Adult Treatment Panel III criteria. RESULTS Median (interquartile range) plasma procalcitonin was 0.018 (0.015-0.022) ng/ml in men and 0.014 (0.012-0.017) ng/ml in women (P < 0.001). Plasma procalcitonin was positively associated with body mass index and waist circumference. In both sexes, cross-sectional associations of plasma procalcitonin with insulin resistance and components of the MS remained significant after adjustment for age, body mass index, waist circumference, and other covariates. The age-adjusted odds ratio (OR) for MS was 3.2 [95% confidence interval (CI) = 2.5-4.2) in men and 4.1 (95% CI = 3.0-5.5) in women, when comparing the highest with the lowest quartile of plasma procalcitonin. The multivariate-adjusted OR for MS was 1.9 (95% CI = 1.4-2.6) in men and 2.3 (95% CI = 1.6-3.3) in women. The multivariate-adjusted OR for insulin resistance was 3.3 (95% CI = 2.4-4.3) in men and 2.5 (95% CI = 1.9-3.4) in women. CONCLUSIONS Elevated plasma procalcitonin levels in the normal range are associated with measures of obesity, insulin resistance, and MS in the general population.