Although chronic obstructive pulmonary disease is a known cause of secondary polycythemia with elevated erythropoietic demands in response to hypoxemia, anemia is relatively common in patients with chronic obstructive pulmonary disease and is related to increased mortality. However, little is currently known about the relationship between various iron parameters and disease severity in chronic obstructive pulmonary disease patients.
Data from the fifth Korean National Health and Nutrition Examination Survey, a population-based epidemiologic survey conducted in 2010–2012, were used. A total of 1,129 patients with chronic obstructive pulmonary disease were examined to reveal the associations between the forced expiratory volume in 1 second (FEV1) and hemoglobin and iron parameters, including serum iron, ferritin, total iron binding capacity, and transferrin saturation, using Spearman correlations and multiple linear regression analyses.
The FEV1 was positively correlated with serum hemoglobin (γ=0.37, P<0.001), iron (γ=0.20, P<0.001), transferrin saturation (γ=0.19, P<0.001), and ferritin (γ=0.22, P<0.001), and negatively correlated with age (γ=−0.40, P<0.001) and lower in female patients (γ=−0.56, P<0.001) in the Spearman correlation. The FEV1 was independently associated with serum iron (β=0.049, P=0.035) and transferrin saturation (β=0.049, P=0.035) after adjusting for age, sex, and body mass index in the multiple linear regression analyses.
The serum iron and transferrin saturation levels were independently associated with FEV1 as a marker of chronic obstructive pulmonary disease severity.
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Metabolic syndrome is associated with cardiovascular diseases and is characterized by insulin resistance. Recent studies suggest that the triglyceride/high-density lipoprotein cholesterol (TG/HDLC) ratio predicts insulin resistance better than individual lipid levels, including TG, total cholesterol, low-density lipoprotein cholesterol (LDLC), or HDLC. We aimed to elucidate the relationship between the TG/HDLC ratio and metabolic syndrome in the general Korean population.
We evaluated the data of adults ≥20 years old who were enrolled in the Korean National Health and Nutrition Examination Survey in 2013 and 2014. Subjects with angina pectoris, myocardial infarction, stroke, or cancer were excluded. Metabolic syndrome was defined by the harmonized definition. We examined the odds ratios (ORs) of metabolic syndrome according to TG/HDLC ratio quartiles using logistic regression analysis (SAS ver. 9.4; SAS Institute Inc., Cary, NC, USA). Weighted complex sample analysis was also conducted.
We found a significant association between the TG/HDLC ratio and metabolic syndrome. The cutoff value of the TG/HDLC ratio for the fourth quartile was ≥3.52. After adjustment, the OR for metabolic syndrome in the fourth quartile compared with that of the first quartile was 29.65 in men and 20.60 in women (P<0.001).
The TG/HDLC ratio is significantly associated with metabolic syndrome.
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