Serum Zinc-α2-Glycoprotein Levels Were Decreased in Patients With Premature Coronary Artery Disease

Abstract

Objectives: To explore serum zinc-α2-glycoprotein (ZAG) changes in patients with or without premature coronary artery disease (PCAD) and its association with several cardiovascular risk factors. Methods: A total of 3,364 patients who were undergone coronary angiography in Peking Union Medical College Hospital were screened. According to the degree of coronary artery stenosis, the number of 364 patients with PCAD (age <55 years in males and <65 years in females) and 126 age and gender matched patients without premature coronary artery disease (NPCAD) were recruited in our present study. In addition, 182 age and gender matched healthy controls were also enrolled. Serum ZAG levels were determined by enzyme-linked immunosorbent assay (ELISA) method. Results: Serum ZAG were significantly lower in the PCAD (8.03 ± 1.01 vs. 8.78 ± 1.89 μg/mL, p < 0.05) and NPCAD groups (8.28 ± 1.61 vs. 8.78 ± 1.89 μg/mL, p < 0.05), respectively, when compared with the controls. Multiple regression analysis showed that PCAD was independently associated with serum ZAG levels ( B = −0.289, p = 0.002). The probability of PCAD in subjects with low tertile ZAG levels was 2.48-fold higher than those with high tertile levels after adjusting for other confounders [OR = 3.476, 95% CI 1.387–8.711, p = 0.008]. This phenomenon was more likely to be observed in male subjects with BMI <24 kg/m 2 . The receiver operating curve (ROC) analysis showed a weak diagnostic performance of serum ZAG for PCAD (AUC = 0.659, 95% CI 0.612–0.705, p < 0.05). At the cutoff value of 7.955 μg/mL serum ZAG, the sensitivity and specificity for differentiating patients with PCAD from controls were 50.5 and 78.0%, respectively. The combination of ZAG with other clinical variables including age, gender, BMI, SBP, FBG, TC, HDL-C, Cr, and Urea had significantly improved the diagnosis accuracy with a sensitivity of 82.6%, a specificity of 95.0%, and AUC of 0.957 (95% CI, 0.940–0.975, p < 0.05). Conclusion: Serum ZAG levels were firstly found to be decreased in Chinese PCAD patients. Subjects with lower ZAG levels were more likely to have PCAD, especially for male subjects with BMI <24 kg/m 2 . ZAG might be the potential diagnostic biomarkers for PCAD patients, and the combination of ZAG and clinical variables had higher discriminative performance.

Serum Zinc-α2-Glycoprotein Levels in Patients with or without Coronary Artery Disease in Chinese North Population

“…Recent clinical studies also found that serum ZAG levels were significantly lower in overweight/obese patients and were negatively correlated with BMI, waist circumstance, hip circumference, and fat mass [21,22]. Beyond these observations, accumulating evidence revealed the close relationship between serum ZAG levels and various cardiometabolic risk factors, including cigarette smoking [26], dyslipidemia [27], hypertension [25], T2DM [23,24], and metabolic syndrome [14] and our recently published paper in Chinese population [30] found the significant lower serum ZAG levels in PCAD patients (males <55y, females <65y) in comparison to the controls. Our present study further extended the available data in an elderly population and firstly found that serum ZAG levels were significantly lower in elderly CAD/NCAD patients from Chinese population.…”

“…Interestingly, our recently published paper in PCAD patients also demonstrated that subjects with low tertile ZAG levels have higher probability of PCAD/NPCAD than those with high ZAG tertile levels [30]. Even after adjusting for other confounders, this phenomenon still existed [30]. In this respect, ZAG was indicated International Journal of Endocrinology as a protective factor for CAD/NCAD, not only in the middleaged population, but also in an elderly population, and ZAG may be a candidate biomarker of the diagnosis of CAD/NCAD.…”

“…As we knew, NCAD refers to individuals who cannot be diagnosed as CAD due to all coronary artery stenosis <50%, but already have abnormalities in glycolipid and cardiovascular metabolism. Interestingly, our recently published paper in PCAD patients also demonstrated that subjects with low tertile ZAG levels have higher probability of PCAD/NPCAD than those with high ZAG tertile levels [30]. Even after adjusting for other confounders, this phenomenon still existed [30].…”

“…PCAD refers to the diagnosis with CAD in males before the age of 55 or females before the age of 65 [29]. Our recently published data in Chinese population also demonstrated the significantly decreased serum ZAG levels in PCAD patients [30]. In studies to date, the relationship between serum ZAG levels and CAD was performed in middle-aged populations.…”

“…e required sample size was calculated by using the MedSci Sample Size tools (MSST). Based on our previous studies that were conducted on the PCAD patients, the mean values of serum ZAG levels in the PCAD, nonpremature CAD (NPCAD), and control groups were 8.03, 8.28, and 8.78, respectively; the standard deviation (SD) in the PCAD, NPCAD, and control groups were 1.01, 1.61, and 1.89, respectively [30]. Assuming a twosided type I error (a) of 0.05 and a power of 0.80, and equal sample sizes in the two groups, 70 patients were required.…”