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Phytosterols are natural sterols widely found in plants that have a variety of physiological functions, and their role in reducing cholesterol absorption has garnered much attention. Although the bioavailability of phytosterols is only 0.5–2%, they can still promote cholesterol balance in the body. A mechanism of phytosterols for lowering cholesterol has now been proposed. They not only reduce the uptake of cholesterol in the intestinal lumen and affect its transport, but also regulate the metabolism of cholesterol in the liver. In addition, phytosterols can significantly reduce the plasma concentration of total cholesterol, triglycerides, and low-density lipoprotein cholesterol (LDL-C), with a dose-response relationship. Ingestion of 3 g of phytosterols per day can reach the platform period, and this dose can reduce LDL-C by about 10.7%. On the other hand, phytosterols can also activate the liver X receptor α-CPY7A1 mediated bile acids excretion pathway and accelerate the transformation and metabolism of cholesterol. This article reviews the research progress of phytosterols as a molecular regulator of cholesterol and the mechanism of action for this pharmacological effect. Full article

Vitamin D plays an important role in bone metabolism and is important for the prevention of multifactorial pathologies, including osteoporosis (OP). The biological action of vitamin is realized through its receptor, which is coded by the VDR gene. VDR gene polymorphism can influence individual predisposition to OP and response to vitamin D supplementation. The aim of this work was to reveal the effects of VDR gene ApaI rs7975232, BsmI rs1544410, TaqI rs731236, FokI rs2228570, and Cdx2 rs11568820 variants on bone mineral density (BMD), 25-hydroxyvitamin D level, and OP risk in Belarusian women. Methods. The case group included 355 women with postmenopausal OP, and the control group comprised 247 women who met the inclusion criteria. TaqMan genotyping assay was used to determine VDR gene variants. Results. Rs7975232 A/A, rs1544410 T/T, and rs731236 G/G single variants and their A-T-G haplotype showed a significant association with increased OP risk (for A-T-G, OR = 1.8, p = 0.0001) and decreased BMD (A-T-G, −0.09 g/cm², p = 0.0001). The rs11568820 A-allele showed a protective effect on BMD (+0.22 g/cm², p = 0.027). A significant dose effect with 25(OH)D was found for rs1544410, rs731236, and rs11568820 genotypes. Rs731236 A/A was associated with the 25(OH)D deficiency state. Conclusion. Our novel data on the relationship between VDR gene variants and BMD, 25(OH)D level, and OP risk highlights the importance of genetic markers for personalized medicine strategy. Full article

Background and Objective. Variation of osteoporosis in the population is the result of an interaction between the genotype and the environment, and the genetic causes of osteoporosis are being widely investigated. The aim of this study was to analyze the association between the polymorphisms of the vitamin D receptor (VDR), type I collagen (COL1A1), and lactase (LCT) genes and severe postmenopausal osteoporosis as well as bone mineral density (BMD).
Material and Methods. A total of 54 women with severe postmenopausal osteoporosis and 77 controls (mean age, 58.3 years [SD, 6.2] and 56.7 years [SD, 7.42], respectively) were included into the study. The subjects were recruited at the City Center for Osteoporosis Prevention (Minsk, Belarus). Dual-energy x-ray absorptiometry was used to measure bone mineral density at the lumbar spine and the femoral neck. Severe osteoporosis was diagnosed in the women with the clinical diagnosis of postmenopausal osteoporosis and at least 1 fragility fracture. The control group included women without osteoporosis. Polymorphic sites in osteoporosis predisposition genes (ApaI, BsmI, TaqI, and Cdx2 of the VDR gene, G2046T of the COL1A1 gene, and T-13910C of the LCT gene) were determined using the polymerase chain reaction on the deoxyribonucleic acid isolated from dried bloodspots.
Results. The data showed that the ApaI and BsmI polymorphisms of the VDR gene and T- 13910C of the LCT gene were associated with severe postmenopausal osteoporosis in the analyzed Belarusian women (P<0.01). A statistically significant positive correlation between the VDR risk genotypes ApaI and TaqI and bone mineral density was found (P<0.05).
Conclusions. The findings of this study suggest that at least the ApaI and BsmI polymorphisms of the VDR gene and T-13910C of the LCT gene are associated with the risk of postmenopausal osteoporosis in our sample of the Belarusian women. Full article