Multitudinous gene polymorphisms in Chinese T2DM patients.
Many studies have shown that gene polymorphisms influence T2DM therapeutic effects[17-24]. SNPs in the HTR3B, HTR7 or ABCB1 genes were associated with myalgia or liver injury[17, 23]. APOE and HMGCR mutations were associated with LDL-C levels[18, 21]. CETP, KIF6, SLCO1B1, and CYP2C9*3 were related to the statin effect[19, 20, 22, 24]. To check genetic polymorphisms in Chinese T2DM patients, HTR3B (rs2276307, A>G), APOE (rs7412, c.526C>T), APOE (rs429358, c.388T>C), CYP2C9*3 (rs1057910, c.1075A>C), KIF6 (rs20455, c.2155T>C), HMGCR (rs17238540, T>G), HMGCR (rs17244841, A>T), ABCB1 (rs2032582, c.2677G > T/A), HTR7 (rs1935349, C>T), SLCO1B1 (rs4149056, c.521T>C), and CETP (rs708272, G>A) were detected by the MassARRAY system before patients underwent statin therapy (Fig. 1b and Table 2).
All 11 mutation loci were checked; and we found all 11 genes had heterozygous mutation, and 7 genes had homozygous mutation in 352 T2DM patients (Fig. 1b). KIF6 (rs20455, c.2155T>C) had the highest heterozygous mutation (47.44%, n=167), while ABCB1 (rs2032582, c.2677G > T/A) had the highest homozygous mutation (21.31%, n=75) in these patients (Fig. 1b). These results reflected that gene polymorphisms were common in Chinese T2DM patients, and that gene polymorphism detection before treatment had a certain significance for patients. For instance, SLCO1B1 was related to myopathy; this test result showed that SLCO1B1 (rs4149056, 521CC) was harbored by 9.09% (n=32) of patients, and patients with this genotype had a high risk of myopathy and rhabdomyolysis. SLCO1B1 (rs4149056, 521TC) was carried by 17.90% (n=63) of patients, and these patients had a medium risk of myopathy and rhabdomyolysis, with statins tolerated at a medium dose (Fig. 1b). 2019 ESC/EAS guidelines for the management of dyslipidemia indicates that CYP2C8, CYP2C9, CYP2C19, and CYP2D6 are frequently involved in the metabolism of statins. In this study, CYP2C9*3 (rs1057910, c.1075A>C) AA, AC, and CC genotypes were carried by 89.77%, 10.23%, and 0% of the patients, respectively, and the AC genotype was associated with a high risk of myopathy after fluvastatin was used. Therefore, genotype evaluation is strongly necessary evaluation for T2DM patients before treatment therapy.
sdLDL-C subfractions had superior property in T2DM screening.
Previous researches found that sdLDL-C levels were significantly higher in diabetes patients than in nondiabetic individuals[13, 14]. To determine the expression of LDL-C and sdLDL-C in T2DM patients and healthy people, the Quantimetrix Lipoprint system was used for plasma sample analysis following the protocol. In total, 400 subjects were analyzed, including 352 T2DM patients and 48 healthy people. The detection rates of the LDL-1, LDL-2, LDL-3, LDL-4, LDL-5, LDL-6, and LDL-7 subfractions in T2DM patients were 100%, 99.72%, 99.15%, 76.99%, 26.70%, 3.69%, and 1.14%, while those in healthy people were 100%, 100%, 97.92%, 54.17%, 0%, 0%, and 0%, respectively (Fig. 2a). The strong CVD risk factor LDL-5 to LDL-7 existed in T2DM patients, were not found in healthy people (Fig. 2a).
Then LDL-C expression were analyzed, the mean amounts of LDL1-C to LDL7-C in T2DM patients were 18.59 mg/dl, 21.54 mg/dl, 12.27 mg/dl, 6.53 mg/dl, 3.45 mg/dl, 0.79 mg/dl, and 0.20 mg/dl, while these subfractions in healthy people were 23.48 mg/dl, 20.69 mg/dl, 7.85 mg/dl, 1.81 mg/dl, 0 mg/dl, 0 mg/dl, and 0 mg/dl (Fig. 2a and Table 1). Further analysis revealed that Pattern A, which consisted by LDL-1 and LDL-2, had no obvious difference between T2DM patients and healthy people. Predictable, Pattern B, composited by LDL3-C to LDL7-C, which was known as sdLDL had higher expression in T2DM patients than healthy people and had obvious differences (p < 0.001) (Fig. 2c). This result further confirmed that sdLDL was the high-risk T2DM factor.
To determine screening effect for T2DM, sdLDL-C, LDL-C, plasma LDL-C and plasma HDL-C of the 352 T2DM patients and 48 healthy people were analyzed by receiver operating characteristic (ROC) curve analysis. The area under the curve (AUC) of these four biomarkers in 352 T2DM patients and 48 healthy people were 0.7322, 0.5699, 0.5444 and 0.6269 respectively (Fig. 2d), and sdLDL-C had the highest value compared to the other three biomarkers. Therefore, sdLDL-C was highly expressed in T2DM patients and had superduper screening effect
LDL-C and sdLDL-C had excellent monitoring performance on T2DM therapy.
To verify the clinical value of LDL-C and sdLDL-C on T2DM therapy monitoring, these two biomarkers were detected and analyzed for 352 T2DM patients (194 males and 158 females) on the condition of prior treatment and after treatment remission. Total 352 T2DM patients were suffered drug therapy, and the guidance and remission evaluation criteria were referencing Guidelines for the Prevention and Treatment of Type 2 Diabetes in China (2017 Edition). Before treatment and anesis after treatment LDL-C and sdLDL-C were analyzed, after 352 T2DM patients alleviating, coincidence rate of decreasing LDL-C accounted for 88.35% (311/352), while coincidence rate of decreasing sdLDL-C was 84.09% (296/352), and there was no significant difference between these two values (Fig. 3a).
Next, the expression levels of total 352 T2DM patients before and after treatment of LDL-C and sdLDL-C were analyzed, found the expression of posttreatment LDL-C and sdLDL-C were reduced compared with prior treatment, and had significant difference (p < 0.001) (Fig. 3b). The results showed that LDL-C and sdLDL-C were good indicators for T2DM treatment effect evaluation. In order to accurately reflect the expression changes of LDL-C and sdLDL-C in the process of disease remission, 10 T2DM patients (6 males and 4 females) were randomly selected. Both the expression levels of LDL-C and sdLDL-C were decreased after disease remission (Fig. 3c and 3d). Therefore, LDL-C and sdLDL-C may be used as excellent monitoring biomarkers for T2DM therapy.