Association between Copper–Zinc Ratio in Hair and Neutrophil–Lymphocyte Ratio within the Context of a Normal White Blood Cell Count among Overweight or Obese Korean Individuals: A Pilot Study

BACKGROUND: Obesity is considered a state of enhanced oxidative stress as well as chronic and low-grade inflammation. The copper–zinc ratio in obese individuals has been reported to reflect systemic oxidative stress and inflammatory status. We investigated whether the neutrophil–lymphocyte ratio is related to the copper–zinc ratio in hair, within the context of a normal white blood cell count among overweight or obese Korean individuals. METHODS: We included 56 participants aged older than 20 years who voluntarily sought weight reduction treatment and met the inclusion criterion of body mass index of 23 kg/m(2) or greater. Intra-abdominal visceral adipose tissue was measured by computed tomography imaging, while the copper and zinc levels were measured by hair mineral analysis. Using multiple linear regression analysis, we examined the associations between the neutrophil–lymphocyte ratio and the copper–zinc ratio. RESULTS: The mean age, body mass index, and visceral adipose tissue were 46.0±10.5 years, 29.0±4.1 kg/cm(2), and 142.9±68.8 cm(2), respectively. Pearson’s correlation analysis revealed the association of the neutrophil–lymphocyte ratio with copper level (r=0.475, P<0.001) and copper–zinc ratio (r=0.494, P<0.001). After adjusting for confounding variables, we found the neutrophil–lymphocyte ratio was significantly associated with the level of copper and the copper–zinc ratio in hair (regression coefficient: 0.055±0.015; P<0.001 and regression coefficient: 0.761±0.185; P<0.001, respectively). CONCLUSION: A higher copper–zinc ratio in hair is positively and independently associated with the neutrophil–lymphocyte ratio. Thus, a high hair copper–zinc ratio could be a useful parameter for oxidative burden of individuals predisposed to obesity-related comorbidity.