Yutaka Furumitsu

Positive correlation between levels of IL-1 or IL-2 and 1,25(OH)2D/25-OH-D ratio in synovial fluid of patients with rheumatoid arthritis

The present study determined the levels in synovial fluid (SF) of vitamin D metabolites (1,25-dihydroxyvitamin D (1,25(OH)2D), 24,25-dihydroxyvitamin D (24,25(OH)2D) and 25-hydroxyvitamin D (25-OH-D)), and of the cytokines. We evaluated SF from 21 patients with rheumatoid arthritis (RA) and 6 patients with osteoarthritis (OA). The levels of vitamin D metabolites in SF, as determined by two different extraction methods, were significantly correlated (p < 0.05, n=7). The levels of 3 vitamin D metabolites were significantly higher in the RA SF than in OA SF (p < 0.05). The ratio of 1,25(OH)2D/25-OH-D in RA SF, which is presumed to reflect the activity of 25-OH-D-1-hydroxylase (1-OH-ase), was positively correlated with the levels of interleukin-1alpha (IL-1alpha), IL-1beta, and IL-2 in such SF, and was significantly higher than that in sera from RA patients. This suggests an important role for these cytokines in the activation of 1-OH-ase in RA synovium. The ratio of 24,25(OH)2D/25-OH-D, which is presumed to reflect 25-OH-D-24-hydroxylase (24-OH-ase) activity, was significantly correlated with 1,25(OH)2D levels only in RA SF, but not in sera from RA patients, suggesting a local regulation of vitamin D metabolism that 1,25-(OH)2D induces 24-OH-ase as in other target cells. Our observations suggested that 1,25(OH)2D and 24,25(OH)2D are produced locally from 25-OH-D in RA synovium, and that the syntheses of 1,25(OH)2D and 24,25(OH)2D may be affected by IL-1/IL-2 and 1,25(OH)2D in RA SF, respectively.

Effects of Pravastatin on Serum Osteoprotegerin Levels in Patients With Hypercholesterolemia and Type 2 Diabetes

Osteoprotegerin is a secretory glycoprotein. Recent experimental findings have suggested that osteoprotegerin may protect against vascular calcification and/or atherosclerosis. In humans, osteoprotegerin levels are positively correlated with the presence and severity of coronary artery disease and the progression of atherosclerosis. However, it is unclear how osteoprotegerin levels are regulated. Statins are known to have beneficial pleiotropic effects against atherosclerosis beyond their lipid-lowering effects. In this study, we examined whether treatment with pravastatin can alter osteoprotegerin levels in patients with hypercholesterolemia and type 2 diabetes. Osteoprotegerin levels were significantly increased from 6.64 ± 2.18 pmol/L at baseline to 7.08 ± 2.29 pmol/L (P = .024) after 3-month treatment with pravastatin. These increases in osteoprotegerin levels remained after 6 months of treatment (7.05 ± 2.22 pmol/L, P = .026). These findings suggest that pravastatin may exert its pleiotropic effects in part through alteration of osteoprotegerin levels.

Measurement of composition changes using dual-photon absorptiometry in obese patients undergoing semistarvation

The changes in total fat mass (TFM) and lean body mass (LBM) under semistarvation treatment were measured by dual-photon absorptiometry (DPA) in this study. Three females with massive obesity were followed over two periods consuming a very-low-calorie diet (VLCD). Although LBM changes attributed to water shifts related to sodium balance were observed, DPA proved sensitive enough to measure LBM and TFM changes in semistarvation treatment. LBM measured by DPA did not change significantly following 4 weeks of VLCD. However, TFM decreased significantly (70.9 +/0 24.1 kg to 62.4 +/- 21.7 kg) and paralleled body weight.

Beneficial effect of risedronate on arterial thickening and stiffening with a reciprocal relationship to its effect on bone mass in female osteoporosis patients: A longitudinal study

AIMS A longitudinal study was performed to examine the effect of risedronate on arterial thickening and stiffening in postmenopausal female osteoporosis patients. MAIN METHODS Patients treated with risedronate (2.5mg/day) (n=33) and those that did not receive risedronate (n=30, control group) were monitored over a 1-year period. Bone metabolic markers, bone mineral density (BMD) of the femur neck (FN), brachial-ankle pulse wave velocity (baPWV), and intima-media thickness at the carotid artery (CA-IMT) were measured. KEY FINDINGS At baseline, there was no significant difference in blood pressure, serum lipid profiles, FN BMD, baPWV and CA-IMT between the risedronate-treated patients and the controls. Baseline levels of FN BMD were significantly negatively correlated with those of CA-IMT and baPWV. During the study, FN BMD increased significantly in the risedronate group (p=0.0097), but decreased significantly in the control group (p=0.0013). BaPWV and CA-IMT did not change significantly in the risedronate group, but both increased significantly in the control group. The percentage change in FN BMD over the study period showed a significant negative correlation with those for baPWV (r=-0.294, p=0.0262) and CA-IMT (r=-0.305, p=0.0234) in all subjects (risedronate-treated patients and controls). SIGNIFICANCE In addition to increasing BMD, risedronate significantly suppressed the progression of arterial thickening and stiffening in postmenopausal osteoporotic patients over one year. These changes may indirectly be due to the effect of risedronate on bone.

Inhibitory Effect of Heparin and/or Antithrombin III on Intraperitoneal Fibrin Formation in Continuous Ambulatory Peritoneal Dialysis

The intraperitoneal fibrin formation and its inhibition by intraperitoneal heparin and/or antithrombin III (AT III) were examined in 8 patients on continuous ambulatory peritoneal dialysis (CAPD). With 1,000 and 2,000 U/L of heparin added to inflow dialysate, the concentration of fibrinopeptide A (FPA) in plasma decreased from 39.43 +/- 5.30 (mean +/- SEM) to 8.00 +/- 2.20 and to 0.74 +/- 0.12 ng/ml, respectively. The FPA concentration in outflow dialysate decreased from 34.20 +/- 5.75 to 12.94 +/- 2.10 ng/ml (1,000 U/l of heparin) and to 4.54 +/- 0.79 ng/mg (2,000 U/l of heparin). The AT III concentration was 0.47 +/- 0.07 mg/dl in dialysate and that in plasma was 24.20 +/- 2.76 mg/dl. With 100 U/bag of AT III added to inflow dialysate, the AT III concentration increased from 0.47 +/- 0.07 to 3.36 +/- 0.17 mg/dl in outflow dialysate but did not increase in plasma. The inhibition of fibrin formation of intraperitoneal heparin was increased by addition of AT III without a systemic inhibitory effect on fibrin formation. These data suggest that intraperitoneal administration of heparin without AT III would be sufficient for the purpose of preventing fibrin formation in CAPD patients without any trouble, and additional AT III might increase inhibitory effect of heparin.