Association of plasma chromium with metabolic syndrome among Chinese adults: a case-control study

Chromium has been suggested playing a role in alleviating diabetes, insulin resistance and lipid anomalies, but the effect on metabolic syndrome (MetS) in humans remains controversial. We conducted a matched case-control study in a Chinese population, involving 2141 MetS cases and 2141 healthy controls, which were 1:1 matched by age (±2 years) and sex. Plasma chromium was measured by inductively coupled plasma mass spectrometry. Plasma chromium levels were lower in MetS group than in control group (mean: 4.36 μg/L and 4.66 μg/L, respectively, P < 0.001), and progressively decreased with the number of MetS components (P for trend < 0.001). After adjustment for potential confounding factors, the odds ratios (95% confidence intervals) for MetS across increasing quartiles of plasma chromium levels were 1 (reference), 0.84 (0.67–1.05), 0.76 (0.61–0.95), and 0.62 (0.49–0.78), respectively (P for trend < 0.001). For the components of MetS (high waist circumference, high triglycerides and high blood glucose), the odds ratios (95% confidence intervals) of the highest quartiles were 0.77 (0.61–0.95), 0.67 (0.55–0.80), and 0.53 (0.44–0.64), respectively (P for trend < 0.05). Our results indicated that plasma chromium levels were inversely associated with MetS in Chinese adults. The association may be explained by the relations between plasma chromium levels and high waist circumference, and the triglycerides and blood glucose levels.