[Association of small dense low-density lipoprotein cholesterol with H-type hypertension and MTHFR gene polymorphism]

To investigate the expression of small dense low-density lipoprotein cholesterol (sdLDL-C) in patients with H-type hypertension and its association with H-type hypertension and methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms. The retrospective study method was used,and a total of 207 hospitalized hypertensive patients (76 males and 131 females, aged 40-82 years, median age 66 years) admitted to the Zibo First Hospital from March 2021 to March 2022 were enrolled in this study. The levels of homocysteine (Hcy), sdLDL-C, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), total cholesterol (TC), triglyceride (TG) and lipoprotein (a) [Lp(a)] were measured. The patients were divided into H-type hypertensive group (n=105, 40 males and 65 females) and non-H-type hypertensive group (n=102, 36 males and 66 females) according to Hcy levels. The C677T polymorphism of methylenetetrahydrofolate reductase (MTHFR) gene was detected in each group. Logistic regression analysis was performed for the related factors of H-type hypertension. The serum sdLDL-C levels were (0.92±0.31) and (0.65±0.28) mmol/L in H-type hypertension group and non-H-type hypertension group, respectively. The sdLDL-C levels in H-type hypertension group were significantly higher than those in non-H-type hypertension group (t=6.500, P<0.01). There was no significant difference in the serum sdLDL-C levels between males and females in H-type hypertension group (t=-1.543, P=0.129). The CC, CT, TT genotypes and C and T allele frequencies of MTHFR C677T in H-type hypertension group were significantly different from those in non-H-type hypertension group (P<0.05). The Hcy and sdLDL-C levels in different genotypes of MTHFR in H-type hypertension group were significantly different (H=12.742, P=0.002; F=3.345, P=0.042). Among them, Hcy levels were higher in TT genotype than in CT and CC genotypes, respectively (Z=-28.099, P=0.003; Z=-16.112, P=0.040), and sdLDL-C levels were higher in TT genotype than in CC genotype (t=-2.587, P=0.012). Logistic regression analysis showed that age, sdLDL-C, and MTHFRC677T TT genotypes were associated with the development for H-type hypertension. In conclusion, the level of sdLDL-C is associated with MTHFR gene polymorphisms and may be associated with the development of H-type hypertension.