Association of Arterial Stiffness and Osteoporosis in Healthy Men Undergoing Screening Medical Examination

BACKGROUND: Association of arterial stiffness and osteoporosis has been previously reported in women. However, this association is still controversial for men. Therefore, we investigated correlation of arterial stiffness and osteoporosis by measuring brachial-ankle (ba) pulse wave velocity (PWV) and bone mineral density (BMD). METHODS: We reviewed medical charts of 239 people (women: 128, men: 111) who visited the Health Promotion Center, retrospectively. ba-PWV was measured by automatic wave analyzer. Lumbar spine (L1-L4) BMD and femur BMD were measured by dual energy X-ray absorptiometry. Metabolic syndrome was based on the National Cholesterol Education Program (NCEP)-Adult Treatment Panel (ATPIII) definition. Body mass index (BMI)>25 kg/m2 was used instead of waist circumference. RESULTS: In Pearson's correlation analysis, PWV and femur BMD (Neck, total) had a significant inverse relationship in men (r=-0.254, P=0.007; r=-0.202, P=0.034). In women, PWV and the L-spine, femur (Neck, total) had a significant inverse relationship. (r=-0.321, P<0.001; r=-0.189, P=0.032; r=-0.177, P=0.046) Age and PWV showed the greatest association in both men and women (r=0.46 P<0.001; r=0.525, P<0.001) In multiple regression analysis, the L-spine BMD and PWV had an independent relationship in women after adjusting for age, metabolic syndrome, BMI, smoking, drinking and exercise. (r=-0.229, P=0.015). No independent association was found between PWV and BMD in men. CONCLUSIONS: The association between arterial stiffness and BMD was confirmed in women. However, this association was not statistically significant for men.

The Effect of Synovial Fluid from Degenerated Facet on Hypertrophy and Ossification of the Ligamentum Flavum / 대한척추외과학회지

STUDY DESIGN: In vitro experimental study OBJECTIVES: To examine the effect of a synovial supernatant on the cell viability, osteogenic phenotype, mRNA expression of the types collagen and various transcriptional factors on osteogenesis in ligamentum flavum (LF) cells stimulated with synovial fluid from a degenerated facet joint. LITERATURE REVIEW: In degenerative lumbar spinal stenosis, hypertrophied LF or osteoarthritic hypertrophy of a facet joint often causes neurogenic claudication. The facet joint is a synovial joint with hyaline cartilage on each side. Therefore, osteoarthritis of a facet joint eventually occurs with aging and other degenerative conditions of the spine. In lumbar spinal degeneration, inflammatory mediators or cytokines are released from the facet joint tissue, which consequently affects the adjacent LF because the LF covers posterolateral aspect of the spinal canal near facet joints. However, there are no reports on the relationship between a degenerated facet joint fluid and the LF in the lumbar spine. MATERIALS AND METHODS: LF surgical specimens were obtained from patients with a lumbar spine stenosis, and the cells were isolated by enzymatic digestion. Each of the synovium tissues were weighed and recorded. Each tissue was cut into small pieces with a pair of scissors and then washed 3 times with PBS. The washed tissue pieces were then cultured for 96 hr at 37degrees C, 5% CO2 in DMEM/F-12-0.1% FBS with a density of 200 mg/ml medium. The supernatant was collected after 96 hr. In order to measure quantitatively the proliferation of cells, the AlamarBlue assay was used. The total cellular RNA was extracted from the cells and amplification reactions specific to the following types of cDNA were performed: the osteogenic master transcription factors, Dlx5, Runx2, osterix, and types collagen and osteocalcin. Alkaline phosphatase staining for the biochemical assay and western blotting for osteocalcin protein expression were performed. RESULTS: Human LF cells cultured with the supernatant from the facet synovium showed a slightly stronger AlamarBlue staining than the intensity of the control culture. RT-PCR revealed the upregulation of the osteogenic master transcription factors, Dlx5, Runx2, and osterix in the synovium supernatant group from one hour to 72 hours, and an increase in osteocalcin, types collagen I, III, V, XI levels from one hour to one week. LF cells cultured with the supernatant from the facet synovium showed positive staining for alkaline phosphatase. The level of the osteocalcin protein in the LF cells cultured with the supernatant from the facet synovium was higher than the control group. Conclusions: The supernatant of the facet joint from patients with degenerative spinal stenosis affects LF cells by increasing the level of cellular proliferation, upregulating the mRNA expression of osteocalcin, types of collagen, osteogenic transcription factors, positive alkaline phosphatase staining, and osteocalcin protein expression. Therefore, degenerated synovial fluid from the facet joint is an important mechanism of LF hypertrophy and ossification.