Tsuyoshi Ohishi

Circadian Variation of Urinary Type I Collagen Crosslinked C-Telopeptide and Free and Peptide-Bound Forms of Pyridinium Crosslinks

This study was performed to investigate the circadian variation of urinary CrossLaps (CTx), which was the type I collagen peptide released during bone matrix degradation, and peptide-bound and free forms of urinary pyridinium crosslinks. Urine was obtained during the 24 h of the study in seven separate collections as follows: from 23:00 h to the first void (FV) followed by FV at 11:00, 11:00-14:00, 14:00-17:00, 17:00-20:00, 20:00-23:00, and 23:00 h to FV the next morning. Total, free, and peptide-bound pyridinoline (Pyr) and deoxypyridinoline (Dpyr) excretion measured by high-performance liquid chromatography (HPLC) and CTx measured by enzyme-linked immunosorbent assay in nine premenopausal women aged 22-40 years and nine osteoporotic women aged 65-83 years was analyzed. Among three parameters of Pyr measured by HPLC, a significant day and night difference was found only in total Pyr (21.9% higher at night than during the day in premenopausal women and 24.0% in osteoporotic women, whereas no significant day and night variation was found in free and peptide-bound Pyr in either group. In contrast, total and peptide-bound Dpyr were significantly (37.9% and 66.9%) higher at night than those during the day in premenopausal women (38.0%) and osteoporotic women (48.8%). For free Dpyr, there were no day and night differences in the two groups. The day and night variances were significantly greater in peptide-bound Dpyr than with total Dpyr in both groups. In urinary CTx, a significant circadian variation with a peak at night and a nadir at 17:00 h was found (p < 0.0001) (premenopausal was 54.0% higher at night than during the day; osteoporotic was 38.4%. In conclusion, urinary CTx represented remarkable circadian variation compared with urinary pyridinium crosslinks measured by HPLC. Furthermore, free pyridinium crosslinks did not undergo a circadian variation. Peptide-bound crosslinks might contribute mostly to the circadian variation of total excretion of pyridinium crosslinks.

Changes of biochemical markers during fracture healing.

The aim of this study was to evaluate the changes of biochemical markers during fracture healing in patients with osteoporosis. The study included 26 patients; 9 underwent hip hemiarthroplasty (mean age ± SD: 71.0 ± 10.2 years, group EN) for femoral neck fractures, 7 underwent osteosynthesis (75.3 ± 8.2 years, group OS) for trochanteric fractures, and 10 subjects had spinal compression fractures (68.2 ± 12.0 years, group CO). No operative procedures were performed in group CO. Urinary pyridinoline (Pyr), deoxypyridinoline (Dpyr) by high performance liquid chromatography (HPLC), Crosslaps by both enzyme-linked immunosorbent assay (ELISA) and radioimmunoassay (RIA) (CTx-ELISA and CTx-RIA) and serum N-terminal mid-fragment osteocalcin (OCN-Mid) by ELISA were analyzed at the time of admission and at weeks 1, 2, 4, 8 and 24 after operation or, in the case of group CO, after admission. As a whole, bone resorption markers started to increase from week 1, with various peak values between weeks 4 and 8 depending upon the particular marker, but returned to the initial vales at week 24. OCN-Mid started to increase from week 8 and remained at elevated levels at week 24. In groups EN and OS, bone resorption markers changed in the same manner as they did as a whole group. OCN-Mid did not change in group EN, although it increased significantly from week 8 in group OS. No biochemical markers changed significantly in group CO. In conclusion, bone resorption was accelerated at an early stage due to acute osteonecrosis or bed rest, followed by bone formation due to callus or mechanical stress later on. As far as bone resorption markers are concerned, 24 weeks are enough to eliminate the effect of fracture.

Bone mineral density and bone turnover in patients with knee osteoarthritis compared with generalized osteoarthritis.

Abstract The aim of this study was to investigate bone mineral density (BMD) and bone turnover in patients with primary knee osteoarthritis (KOA) and to compare them with generalized OA (GOA) and nonGOA patients. A total of 88 postmenopausal primary KOA patients were studied. OA was graded by using knee radiographs. BMD of the lumber spine, femur, and radius, and biochemical markers of bone turnover, pyridinoline (Pyr), deoxypyridinoline (Dpyr), CTx, and osteocalcin were compared among each grade. BMD was also compared with 88 normal controls who were age and weight-matched. In 88 KOA patients, 56 were divided into 28 GOA and 28 non-GOA groups by grading hand radiographs. BMD and biochemical markers were compared between GOA and non-GOA. KOA patients had higher BMD at several skeletal sites compared with age- and weight-matched normals. A significant difference of BMD between each grade was observed between grades 0–1 and 3 (0.774 ± 0.143 versus 0.940 ± 0.185 g/cm2, P < 0.001), grades 2 and 3 (0.781 ± 0.125 versus 0.940 ± 0.185 g/cm2, P < 0.01) in the spine, and between grades 0–1 and 3 (0.505 ± 0.100 versus 0.564 ± 0.127 g/cm2, P < 0.05) in the trochanter. A significant difference of biochemical bone markers was observed between grades 0–1 and 3 (P < 0.05) and between grades 2 and 3 (P < 0.05) in Pyr and grades 0–1 and 3 (P < 0.05) and between grades 1 and 4 (P < 0.05) in Dpyr, but not in osteocalcin and CTx. GOA patients had higher BMD of the spine (0.902 ± 0.175 versus 0.747 ± 0.138 g/cm2, P < 0.01), trochanter (0.535 ± 0.107 versus 0.480 ± 0.107 g/cm2, P < 0.05), and one-third of the radius (0.526 ± 0.068 versus 0.472 ± 0.089 g/cm2, P < 0.05) and had significantly higher biochemical markers in Pyr and Dpyr than non-GOA patients. It is concluded that KOA patients had higher BMD at several skeletal sites. Biochemical bone markers were influenced by some degree of cartilage damage in OA patients. This tendency was stronger in GOA patients than in non-GOA patients.

The Maillard protein cross-link pentosidine in urine from diabetic patients

SummaryThe Maillard protein cross-link pentosidine is a fluorescent condensation product of lysine, arginine and ribose. It accumulates in human tissues with age, and the accumulation process is accelerated in the tissues of diabetic patients. Using SP-Sephadex C-25 in the pretreatment for HPLC, we examined levels of pentosidine in urine without hydrolysis (free form) and levels of pentosidine in urine after hydrolysis (total forms), from 23 diabetic patients and 21 control subjects. The mean percentages of the values of free form per total forms (±SD) were 89±15% in diabetic patients, 88±16% in control subjects and 89±15% in total populations of diabetic patients and control subjects. There was a significant correlation between the values of free form and total forms in diabetic patients (r=0.938, p=0.0001), in control subjects (r=0.820, p<0.02) and in total populations of diabetic patients and control subjects (r=0.951, p=0.0001). The mean level of pentosidine per mol creatinine (±SD) was significantly elevated in urine from diabetic patients as compared to the level in control subjects (8.8±4.3 μmol/mol creatinine vs 4.2±1.4 μmol/mol creatinine, p=0.0001 in free form; 10.1±5.3 μmol/mol creatinine vs 4.7±1.4 μmol/mol creatinine, p=0.0001 in total forms). These results demonstrate that urinary pentosidine, especially in free form, could be a useful marker for the assessment of diabetes and diabetic complications.

Effect of vitamin K and/or D on undercarboxylated and intact osteocalcin in osteoporotic patients with vertebral or hip fractures.

To examine serum undercarboxylated osteocalcin (OC) with application of an ELISA in normal women and in osteoporotic patients with vertebral fractures or hip fractures, and to investigate the effects of vitamin K and/or D treatment on undercarboxylated OC and intact OC in vertebral fractures.

The effect of menopause on biochemical markers and ultrasound densitometry in healthy females.

Urinary pyridinoline (pyr) and deoxypyridinoline (dpyr) are new markers for bone resorption, and serum osteocalcin reportedly indicates osteoblastic activity. Recently, a new ultrasound bone densitometer instrument has been developed that measures ultrasonic properties of the os calcis, namely, the speed of sound (SOS), broadband ultrasound attenuation (BUA), and stiffness index. The effects of menopause on biochemical markers and ultrasound densitometry were investigated in 40 healthy females, 36–39 years, with regular menstruation, and in 117 healthy perimenopausal females, 47–57 years, who were divided into a premenopausal group and a postmenopausal group. Significantly elevated values of pyr, dpyr, and serum osteocalcin were found for the postmenopausal group as a whole compared with the premenopausal group. We examined postmenopausal groups 48–57 years of age stratified into 2-year intervals (within 2 years of the menopause, 2–4 years postmenopause and 4–6 years postmenopause). Elevated values of urinary pyr, dpyr, and serum osteocalcin were evident even in the first 2 years postmenopause compared with the premenopausal group, and these higher values were exhibited until 6 years after menopause. We found a significant decrease in SOS, BUA, and stiffness index of the postmenopausal group as a whole, compared with those of the premenopausal group. SOS, BUA, and stiffness index of the group within 2 years of menopause significantly decreased compared with those of the premenopausal group. The Z-scores of the increase in biochemical markers and the decrease in stiffness index in the postmenopausal group were approximately 0.7–1.3 compared with the premenopausal group. The results suggest that these biochemical markers and ultrasound densitometry are potentially sensitive parameters of postmenopausal bone change.

Urinary bone resorption markers in patients with metabolic bone disorders.

Recently, urinary pyridinoline and deoxypyridinoline have been commonly employed as bone resorption markers. We studied these markers in 17 patients with hyperthyroidism, 15 undergoing long-term anticonvulsant drug therapy, and 28 with postmenopausal osteoporosis. Both markers had significantly higher levels than those in age-matched control groups. Values of urinary pyridinoline and deoxypyridinoline correlated well with urinary hydroxyproline levels in patients with hyperthyroidism (r = 0.856, p < 0.001 for pyridinoline and hydroxyproline; r = 0.919, p < 0.001 for deoxypyridinoline and hydroxyproline); however, poor correlations were observed, especially between urinary deoxypyridinoline and urinary hydroxyproline (r = 0.357, NS) in patients with postmenopausal osteoporosis. To compare the discriminatory ability of urinary pyridinoline and deoxypyridinoline, receiver operating characteristic (ROC) curves were generated for each of these patient groups using data from age-matched healthy females as the control group. The areas under the curves for both markers were 100.0% in hyperthyroidism. The areas under the curves for pyridinoline in patients undergoing long-term anticonvulsant drug therapy (mean +/- SE; 98.1 +/- 2.8%) and postmenopausal osteoporosis (77.9 +/- 5.7%) were significantly higher than those for deoxypyridinoline in anticonvulsant drug therapy (92.4 +/- 3.3%) and in osteoporosis (64.9 +/- 4.3%). Using data from premenopausal healthy females as the control group, areas under ROC curves for urinary pyridinoline (100.0%) and deoxypyridinoline (94.8 +/- 5.9%) were significantly higher than those for urinary hydroxyproline (73.8 +/- 9.4%) in patients undergoing long-term anticonvulsant drug therapy. In patients with postmenopausal osteoporosis, those for urinary pyridinoline (97.0 +/- 2.8%) were also significantly higher than those for urinary hydroxyproline (74.0 +/- 6.4%).(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of bone turnover in postmenopause, vertebral fracture, and hip fracture using biochemical markers for bone formation and resorption

The purpose of this study is to evaluate bone turnover in postmenopausal status and established osteoporosis with vertebral fracture and hip fracture by assessing bone biochemical markers. Subjects were 50 healthy premenopausal subjects, 44 healthy postmenopausal subjects, 30 osteoporotic patients with vertebral fracture, and 31 osteoporotic patients with hip fracture. Alkaline phosphatase, osteocalcin, PICP, ICTP, NTx, free deoxypyridinoline, total pyridinoline and deoxypyridinoline were measured. In postmenopause, both Z-scores of bone formation markers and resorption markers were around 1–2. In osteoporosis, although Z-scores of bone formation markers were 0.4–2.8, resorption markers were 2.3–9.5. Moreover, Z-scores of resorption markers were higher in hip fracture than in vertebral fracture. These results indicate that bone formation and resorption increased and balanced in postmenopausal status. However, bone resorption increased more than bone formation and did not balance at all in osteoporosis. This imbalance is greater in hip fractures than in vertebral fractures.

Bone turnover and cortical bone mineral density in the distal radius in patients with hyperthyroidism being treated with antithyroid drugs for various periods of time

Whether patients, who have lost bone mass, can be restored to age‐matched control levels by some means is still controversial. We investigated how the thyroid status after antithyroid drug therapy for various periods of time affects bone metabolism in patients with hyperthyroidism by assessing currently used biochemical markers of bone turnover and distal radius bone mineral density (BMD).

The Relationships Between the Degree of β-Isomerization of Type I Collagen Degradation Products in the Urine and Aging, Menopause and Osteoporosis with Fractures

Abstract: We have evaluated the effect of aging, menopause and osteoporosis on the measurements of both nonisomerized type I collagen C-telopeptide breakdown products (α-CTx) by radioimmunoassay (RIA) and β-isomerized type I collagen C-telopeptide breakdown products (β-CTx) by enzyme-linked immunosorbent assay (ELISA). In 86 premenopausal healthy women (PRE), 144 postmenopausal healthy women (POST), 74 patients with vertebral fractures (VX) and 61 patients with hip fractures (HX), urinary CTx excretion was measured by both ELISA and RIA assays. Samples were collected more than 6 months after fracture in the VX group and within 48 h after fracture in the HX group. In all subjects a highly significant correlation was found between α-CTx and β-CTx (r= 0.85). The values of β-CTx in the POST group greatly increased compared with those in the PRE group (% mean increase: 82%), while the values of α-CTx in the POST group moderately increased compared with those in the PRE group (% mean increase: 47%). The values of both α-CTx and β-CTx in the HX group were significantly higher than those in the other groups, but particularly the increase in mean α-CTx (211% for HX versus POST) was very high compared with the increase in mean β-CTx (68% for HX versus POST). Moreover, the α-CTx/β-CTx ratio in the HX group was significantly higher than in the other groups. These results suggest that both assays well reflect the increase in bone resorption associated with high bone turnover, especially, in osteoporotic patients with hip fracture. However, there was a difference between the urinary excretion of α-CTx and β-CTx in patients with hip fracture, so the α-CTx/β-CTx radio might be a good indicator reflecting the characteristics of bone metabolism for osteoporosis with hip fracture.