A genome-wide association study had showed G-protein–coupled receptor kinase 5 (GRK5) rs10886471 was related to the risk of type 2 diabetes mellitus (T2DM) through upregulated GRK5 mRNA expression. Rs10886471 is located in the intron region of GRK5. However, the mechanism by which intronic SNP affects gene expression remains unclear, whether the effect on gene expression depends on the intronic short tandem repeat (STR) (CA)n splicing regulator or not. Here we investigated the STR (CA)n polymorphism in rs10886471 and further discussed its role in the T2DM risk of Chinese Hainan Island individuals. A total of 1164 subjects were recruited and classified into a normal fasting glucose (NFG) group, an impaired fasting glucose (IFG) group, an impaired glucose tolerance (IGT) group, and a T2DM group. STR (CA)n polymorphisms were detected through polymerase chain reaction and sequencing. Five intronic (CA)n alleles, (CA)15 to (CA)19, were identified in GRK5 rs10886471. Only the (CA)16 allele was significantly associated with increased prediabetes and T2DM risk [odds ratio (OR)>1, P<0.05]. Conversely, multiple alleles without any (CA)16 protected against prediabetes and T2DM (0

Abstract.To investigate the association between apolipoprotein E (APOE) polymorphisms and insulin resistance and Traditional Chinese Medicine (TCM) syndromes in type 2 diabetes mellitus (T2DM) with macroangiopathy, 60 patients with T2DM macroangiopathy were enrolled and divided into three groups: dryness-heat due to deficiency of yin, Qi-Yin deficiency, and Yin-Yang deficiency, according to the TCM syndromes, with a control group of 20 healthy individuals. APOE genotype analysis was performed with polymerase chain reaction amplification and restriction fragment length polymorphism, and the results showed that the proportion of the ε4/4 and ε3/4 genotypes and frequencies of the ε4 and ε3 alleles were higher in the Qi-Yin deficiency group (P<0.05). Among the T2DM macroangiopathy patients, the E4 group had the largest number of cases, as well as a significantly longer disease course compared to the E2 group (P<0.05). The insulin resistance index (IRI), insulin action index and body mass index (BMI) of patients in the Yin-Yang deficiency group were significantly different from those of patients with dryness-heat due to deficiency of yin and Qi-Yin deficiency. Furthermore, correlation analysis of the BMI and IRI of patients in the Yin-Yang deficiency group revealed a correlation coefficient r= 0.696 (P<0.01) and a typical correlation between them. In conclusion, the Qi-Yin deficiency in T2DM patients with macroangiopathy is associated with the APOE E4 and E3 genotypes. Thus, the APOE gene polymorphism can, to some degree, reflect the TCM syndrome types of T2DM patients with macroangiopathy. Insulin resistance plays an important role in the occurrence of T2DM macroangiopathy and is closely associated with the Yin-Yang deficiency according to the TCM differentiating types.