Kenjiro Yamakawa

Osaka City University, Ōsaka, Ōsaka, Japan

Are you Kenjiro Yamakawa?

Claim your profile

Publications (8)21.17 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Background/Aims: Bone-specific alkaline phosphatase (BAP) hydrolyzes pyrophosphate, which inhibits vascular calcification. We examined association between serum BAP and vascular calcification of male hemodialysis patients. Methods: Hand roentgenography of 167 male maintenance hemodialysis patients was conducted, and visible vascular calcification of the hand arteries was evaluated. Serum levels of 3 bone formation markers (BAP, osteocalcin, and N-terminal propeptide of type I collagen) and 2 bone resorption markers (C-terminal telopeptide of type I collagen, and cross-linked N-telopeptide of type I collagen) were measured, along with serum intact parathyroid hormone (PTH). Results: Of 167 patients, visible vascular calcification was seen in 37 patients. Among the bone formation and resorption markers, serum BAP was significantly higher in patients with vascular calcification than in those without (p<0.05); although the other 5 serum bone markers were not significantly different between them. Multivariate logistic regression analyses revealed that log [BAP] was significantly associated with vascular calcification after adjustment for age, hemodialysis duration, presence of diabetes, log [intact PTH] and each of the other 5 bone markers (p<0.0001). Conclusions: Higher serum BAP, but not other bone markers, is significantly associated with the presence of vascular calcification in male hemodialysis patients. © 2014 S. Karger AG, Basel.
    Kidney and Blood Pressure Research 09/2014; 39(4):299-307. · 1.60 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background/Aims: Serum magnesium (Mg) levels have been associated with muscle performance in the general population. We hypothesized that serum Mg would be associated with muscle quality in hemodialysis patients. Methods: A total of 310 patients were examined (age: 58 ± 12 years, hemodialysis duration: 6.4 ± 6.0 years, 60.6% men, and 36.1% diabetics). Arm lean mass was measured by dual energy X-ray absorptiometry (DXA) on the dominant side. Arm muscle quality was defined as the ratio of the handgrip strength to the arm lean mass of the same side (kg/kg). Results: Serum Mg was 1.15 ± 0.16 mmol/L (2.8 ± 0.4 mg/dL), being higher than the reference range of normal subjects. There was a significant negative correlation between muscle quality and age (r = -0.326, p<0.0001) and duration of hemodialysis (r = -0.253, p<0.0001). The muscle quality of the diabetics was significantly lower than that of the non-diabetics (p<0.001). There was a significant, positive correlation between muscle quality and serum Mg (r = 0.118, p<0.05), but not serum calcium or phosphate. In multiple regression analysis, age, gender, hemodialysis duration, diabetes, and serum Mg (β = 0.129, p<0.05) were significantly and independently associated with muscle quality (R(2) = 0.298, p<0.0001). Conclusion: These results demonstrated that a lower serum Mg concentration was significantly associated with poor muscle quality in hemodialysis patients. Further studies are needed to explore the mechanism by which lower serum Mg affects muscle quality.
    Magnesium research: official organ of the International Society for the Development of Research on Magnesium 02/2014; · 1.38 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background:It has been reported that there is a significant positive relationship between PTH and body weight or body mass index in the general population. However, little is known about this relationship in dialysis patients in whom PTH levels are higher. It is also not known whether fat mass or lean mass is associated with serum PTH among these patients. In the present study, we examined the association of intact PTH with fat mass and lean mass in hemodialysis patients.Methods:Serum intact PTH, calcium, and phosphate were measured in 590 hemodialysis patients (age, 60.2 ± 12.2 y; median hemodialysis duration, 59.6 mo; 343 males and 247 females; diabetics, 27.7%). Fat mass and lean mass were measured by dual-energy x-ray absorptiometry.Results:Intact PTH correlated significantly and positively with body weight and body mass index in all patients. Intact PTH correlated significantly and positively with fat mass and lean mass in males (P < .01), and tended to correlate positively with fat mass and lean mass in females (P < .1). In multiple regression analyses after adjustment for age, gender, hemodialysis duration, calcium, phosphate, vitamin D use, and phosphate binder use, intact PTH was associated significantly with body weight (β = .190; P < .0001), body mass index (β = .177; P < .0001), fat mass (β = .142; P < .0005), and lean mass (β = .192; P < .01). Furthermore, intact PTH was associated significantly and independently with both fat mass and lean mass after adjustment (R(2) = .206; P < .0001).Conclusion:Serum intact PTH in chronic hemodialysis patients is associated significantly and positively with body composition of fat mass and lean mass.
    The Journal of Clinical Endocrinology and Metabolism 02/2013; · 6.31 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) was originally isolated as an inducer of apoptosis in transformed cells. In addition to tumor surveillance, recent findings suggest that TRAIL and its receptor system have a protective role against infection and cardiovascular disease (CVD). Patients undergoing hemodialysis have a high mortality rate with a unique risk factor profile. Considering that the leading causes of death in these patients are infection and CVD, TRAIL represents an attractive candidate for predicting mortality in this population. We therefore investigated whether TRAIL predicted mortality in hemodialysis patients. METHODS: The study was a retrospective observational cohort design of 45-month duration in 149 male hemodialysis patients. The subjects were divided into two groups according to their baseline TRAIL level measured by ELISA (low or high TRAIL group). The main outcome was all-cause mortality. RESULTS: During the follow-up period, 33 patients died, mostly because of CVD (n=11) or infection (n=9). Crude survival analyses showed that a low TRAIL level was a powerful predictor of all-cause (p=0.011) and infectious mortality (p=0.048). The predictive power of TRAIL remained after adjustment for various confounding factors. CONCLUSIONS: The serum TRAIL level may be a novel biomarker for predicting prognosis in hemodialysis patients.
    Cytokine 02/2013; · 2.52 Impact Factor
  • Nihon Naika Gakkai Zasshi 12/2012; 101(12):3516-8.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Increased levels of serum undercarboxylated osteocalcin, which were associated with bone metabolism markers, correlated inversely with indices of glucose metabolism (plasma glucose, hemoglobin A1C, and glycated albumin) in hemodialysis patients with abnormalities of bone metabolism. INTRODUCTION: Undercarboxylated osteocalcin (ucOC), a possible marker of bone metabolism and one of the osteoblast-specific secreted proteins, has recently been reported to be associated with glucose metabolism. We tested the hypothesis that ucOC levels are associated with indices of glucose metabolism in chronic hemodialysis patients with abnormalities of bone metabolism. METHODS: Serum ucOC, bone alkaline phosphatase (BAP, a bone formation marker), and tartrate-resistant acid phosphatase-5b (TRACP-5b, a bone resorption marker) were measured in 189 maintenance hemodialysis patients (96 diabetics and 93 non-diabetics), and their relationships with glucose metabolism were examined. RESULTS: ucOC correlated positively with BAP (ρ = 0.489, p < 0.0001), TRACP-5b (ρ = 0.585, p < 0.0001) and intact parathyroid hormone (iPTH; ρ = 0.621, p < 0.0001). Serum ucOC levels in the diabetic patients were lower than those of non-diabetic patients (p < 0.001), although there were no significant differences in serum BAP or TRACP-5b between diabetic and non-diabetic patients. Serum ucOC correlated negatively with plasma glucose (ρ = -0.303, p < 0.0001), hemoglobin A1C (ρ = -0.214, p < 0.01), and glycated albumin (ρ = -0.271, p < 0.001), although serum BAP or TRACP-5b did not. In multiple linear regression analysis, log [plasma glucose], log [hemoglobin A1C], and log [glycated albumin] were associated significantly with log [ucOC] after adjustment for age, gender, hemodialysis duration, and body mass index but were not associated with log [BAP], log [TRACP-5b], or log [intact PTH]. CONCLUSION: Increased levels of serum ucOC, which were associated with bone metabolism markers, were inversely associated with indices of glucose metabolism in hemodialysis patients.
    Osteoporosis International 05/2012; · 4.04 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background/Aim: Cinacalcet, an allosteric modulator of the calcium sensing receptor, effectively reduces serum parathyroid hormone (PTH) in patients with secondary hyperparathyroidism. It is not well known whether bone mineral density (BMD) of hemodialysis patients with secondary hyperparathyroidism is altered after cinacalcet treatment. Methods: The BMD in the distal 1/3 of the radius and in the ultradistal radius, which are enriched with cortical and cancellous bone, respectively, was examined by dual X-ray absorptiometry, 1 year prior to, at the start, and 1 year after cinacalcet treatment, in 61 patients. Results: The BMD of both the distal 1/3 and ultradistal radius decreased significantly in the year prior to cinacalcet treatment (p < 0.01). However, the BMD at either site did not change significantly in the year after cinacalcet treatment. The annual changes in the BMD of the distal 1/3 radius increased significantly from -0.023 ± 0.029 g/cm2/year to -0.002 ± 0.033 g/cm2/year, prior to and after cinacalcet treatment, respectively; however, the annual changes in the BMD of the ultradistal radius did not change significantly prior to and after cinacalcet treatment. Conclusion: There was a significant association between cinacalcet treatment and reduction in BMD loss in patients with secondary hyperparathyroidism. Cortical bone, rather than cancellous bone, was particularly affected by cinacalcet treatment.
    Clinical nephrology 10/2011; 76(4):259-65. · 1.29 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Bone mineral density of the 1/3 distal radius, ultra-distal radius, and lumbar spine correlated significantly and negatively with serum adiponectin. There was a significant positive correlation between serum adiponectin and serum NTX. Thus, adiponectin may play a role in mineral and bone disorder in chronic kidney disease stage 5 dialysis (CKD 5D) patients. Serum adiponectin, an adipocyte-produced hormone, has been reported to correlate negatively with bone mineral density (BMD) in the general population. However, little is known about the association between adiponectin and BMD in patients with CKD. BMD of the 1/3 distal and ultra-distal radius, which are enriched with cortical and cancellous bone, respectively, and the lumbar spine was measured by dual X-ray absorptiometry in 114 Japanese male hemodialysis patients (age 61.0 ± 11.1 years; hemodialysis duration 6.6 ± 3.0 years; 43.9% diabetics). Serum total adiponectin, bone formation marker (bone alkaline phosphatase, BAP), and bone resorption marker (cross-linked N-telopeptide of type I collagen (NTX)) were measured. The BMD of the 1/3 distal radius, ultra-distal radius, and lumbar spine correlated significantly and negatively with serum adiponectin level (r = -0.229, p = 0.014; r = -0.286, p = 0.002; r = -0.227, p = 0.013, respectively). In multiple linear regression analyses, serum adiponectin was significantly and independently associated with the BMD of the 1/3 distal radius (R(2) = 0.173, p < 0.001) and ultra-distal radius (R(2) = 0.278, p < 0.001) after adjustment of age, hemodialysis duration, body weight, %fat mass, and log [intact PTH], although it was not with the BMD of the lumbar spine. There was a significant positive correlation between serum adiponectin and serum NTX (r = 0.321, p < 0.001), although there was no significant correlation between serum adiponectin and serum BAP. Increased levels of serum adiponectin were associated with decrease in BMD in male hemodialysis patients. Adiponectin may play a role in mineral and bone disorder, possibly in bone resorption, of patients with CKD 5D.
    Osteoporosis International 09/2011; 23(7):2027-35. · 4.04 Impact Factor

Publication Stats

15 Citations
21.17 Total Impact Points

Institutions

  • 2011–2013
    • Osaka City University
      • • Department of Metabolism, Endocrinology, and Molecular Medicine
      • • Department of Nephrology
      Ōsaka, Ōsaka, Japan
    • Shirasagi Hospital
      Ōsaka, Ōsaka, Japan