Adiponectin (APN) is a kind of endogenous protein hormone with unique biological activity secreted by adipocytes, with a molecular weight of 30 kDa [1]. APN is abundant in normal human blood circulation, and the concentration in physiological circulation can reach 0.5–30 μg/mL, accounting for more than 0.05 % of the total plasma protein [2]. APN in circulating blood is considered to play an extensive variety of anti-inflammatory, anti-myocardial injury and reducing lipid peroxidation, which has become one of the hotspots and difficulties in recent years [3], [4].

Genome-wide scanning shows that the APN gene is mainly located in the susceptible regions of metabolic syndrome and cardiovascular disease, and there is a high frequency of gene single nucleotide polymorphism (SNP) changes [5], [6]. Coronary heart disease (CHD) is a polygenic genetic disease determined by genetic and environmental factors. The heritability of CHD in the Chinese population is 75 % [7]. At present, there are more than 10 common APN gene SNPs, some of which are closely related to metabolic diseases and cardiovascular and cerebrovascular diseases with contradictory conclusions. Although the results of some in vitro studies in humans or animals suggest that APN has a protective effect in the development and progression of atherosclerosis [8], [9], [10], there is also a large amount of clinical data suggesting that circulating levels of APN and the development and progression of cardiovascular disease are contradictory to the results obtained from in vitro studies, ranging from the ability of APN to reduce cardiovascular risk events [11], [12], [13] to an increase in cardiovascular risk events [14], [15], all of which are associated with increased levels of APN, and there are also findings suggesting that APN does not correlate with cardiovascular disease [16]. Those inconsistent conclusions that need to be further analyzed and investigated. Most studies have shown that APN is a protective factor for cardiovascular disease, i.e., APN levels are negatively correlated with the occurrence and development of coronary heart disease, and hypolipocalcaemia is an independent risk factor for coronary heart disease. Therefore, according to the relevant literature and the selection of the key functional region of the APN gene, and the SNPs sites with allele frequency (AF) greater than 0.05, rs1501299 and rs266729 were selected [17], [18], [19]. In this study, we aimed to analyze the correlation of serum APN level and APN gene single nucleotide polymorphism with CHD.