The influence of interleukin-6 and tumor necrosis factor α gene polymorphisms on bone mineral density in postmenopausal women

Summary Proinflammatory cytokines, interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α), involved into osteoclastogenesis and responsible for bone resorption process, participate in the pathogenesis of the osteoporosis. In vitro studies have shown that single nucleotide polymorphisms of IL-6 and TNF-α genes could influence the transcription process of the genes and the cytokines level. Aim: Assessment of the influence of IL-6 and TNF-α gene polymorphisms on bone mineral density (BMD) and evaluation of their connection with osteoporosis prevalence in women from Wielkopolska region. Material and methods: In the group of 267 postmenopausal women (average age 58,5+/-5,9 years, average age of last period 49,8+/-3,9 years) bone mineral density in lumbar spine (L2-L4) was performed using dual energy X-ray absorptiometry (DXA). Genotypes frequencies were determined by polymerase chain reaction with restriction fragment length polymorphism (PCR/RFLP) using restriction enzymes Lwe I and Faq I, respectively. The connection between the polymorphisms of investigated genes and body mass index, age of menarche and menopause and length of reproductive age had been analyzed as well. Results: No statistically significant association was found between examined genetic factors and the value of bone mineral density in the investigated group of postmenopausal women. The frequencies of investigated genotypes were in compliance with Hardy-Weinberg equilibrium. The correspondence between evaluated clinical parameters and IL-6 i TNF-α genotypes frequencies has not been proven. Conclusions: The -174G/C polymorphism in the IL-6 and -308G/A polymorphism in TNF-α genes have no influence on bone mineral density value (BMD) in the investigated population of women from Wielkopolska region

Polymorphism in intron 23 of the endothelial nitric oxide synthase gene (NOS3) is not associated with hypertension.

Nitric oxide (NO) is synthesised in the vascular endothelium by nitric oxide synthase (NOS3) and is an important factor in the regulation of blood pressure. Impaired synthesis of NO due to mutations in the NOS3 gene is associated with hypertension. To date several allelic variants of the NOS3 gene have been identified and their possible linkage with hypertension investigated. We studied the distribution of genotypes and frequency of alleles of the G11T polymorphism in intron 23 of the NOS3 gene in patients with hypertension and in a control group of healthy individuals. The polymorphism was determined by PCR-RFLP analysis. The distribution of genotypes in the patients with hypertension and in the healthy individuals did not differ significantly from the values predicted from Hardy-Weinberg equilibrium for the general population. No major differences in the distribution of the G11T polymorphism in the patients and healthy individuals were found (P > 0.05)