The investigators planned to research the association between plasma melatonin and coronary artery calcification in a Chinese population.

Coronary artery calcification (CAC) is prevalent in coronary artery disease (CHD), and the extent of CAC predicts cardiovascular risk. The causes of CAC include dysregulated matrix metabolism, epitaxial mineral deposition, inflammation, oxidative stress, and apoptosis. Melatonin is the main indoleamine produced by the pineal gland; it is known recently to have anti-inflammatory, anti-cancer and antioxidant activities. Several studies have shown that melatonin protects against inflammation and apoptosis in vascular calcification. Melatonin also inhibits oxidative stress-induced apoptosis and calcification in endplate chondrocytes. However, no study has evaluated whether melatonin is associated with CAC in patients with coronary atherosclerosis. The investigators planned to research the association between plasma melatonin and coronary artery calcification.

Inclusion Criteria:

Patients with angina-like chest pain, were included in this study. All subjects had blood samples collected and all underwent a coronary CTA scan.

Exclusion Criteria:

1. melatonin treatment
2. coronary revascularization (percutaneous coronary intervention or coronary artery bypass graft surgery)
3. heart failure or cardiomyopathies
4. hepatic failure
5. renal dysfunction
6. haemolytic disorders
7. thyroid disease
8. neoplastic diseases
9. acute infectious or inflammatory conditions.

PLA general hospital (PLAGH) is a large national tertiary-care center in the Beijing, China. The investigators enrolled patients consecutively in PLAGH.