Aim To test whether renal biochemical markers were associated with physical performance and frail... more Aim To test whether renal biochemical markers were associated with physical performance and frailty in older people with advanced chronic kidney disease. Findings Biochemical markers associated with chronic kidney disease did not consistently associate with baseline physical performance or the rate of change of physical performance measures. Message Targeting improvements in renal biochemistry may not be a fruitful way to improve physical function and frailty in older people with advanced chronic kidney disease.
Summary This study assessed whether vitamin K, given with oral bisphosphonate, calcium and/or vit... more Summary This study assessed whether vitamin K, given with oral bisphosphonate, calcium and/or vitamin D has an additive effect on fracture risk in post-menopausal women with osteoporosis. No difference in bone density or bone turnover was observed although vitamin K1 supplementation led to a modest effect on parameters of hip geometry. Purpose Some clinical studies have suggested that vitamin K prevents bone loss and may improve fracture risk. The aim was to assess whether vitamin K supplementation has an additive effect on bone mineral density (BMD), hip geometry and bone turnover markers (BTMs) in post-menopausal women with osteoporosis (PMO) and sub-optimum vitamin K status receiving bisphosphonate, calcium and/or vitamin D treatment. Methods We conducted a trial in 105 women aged 68.7[12.3] years with PMO and serum vitamin K1 ≤ 0.4 µg/L. They were randomised to 3 treatment arms; vitamin K1 (1 mg/day) arm, vitamin K2 arm (MK-4; 45 mg/day) or placebo for 18 months. They were on or...
Introduction and Aims: Vitamin D deficiency is common in patients with chronic kidney disease (CK... more Introduction and Aims: Vitamin D deficiency is common in patients with chronic kidney disease (CKD) and can result in complications such as mineral and bone disorders. Vitamin D deficiency is also associated with extrarenal and extraskeletal complications. The purpose of this study is to determine the clinical and demographic risk factors for vitamin D deficiency in multiethnic CKD patients in Singapore, a sun-rich country, so that patients at risk for vitamin D deficiency can be identified early, and replacement with vitamin D supplements can be started before further worsening of their kidney function. Methods: Pre-dialysis CKD patients from the National University Hospital (NUH), Singapore, Outpatient Renal Clinic who had their serum 25-hydroxyvitamin D [25 (OH)D] levels measured between January 2008 and October 2010 were included in the study. The patients' clinical and demographic parameters were collected from hospital databases and medical charts. Data mining methodology was used to identify potential predictors for vitamin D deficiency in these CKD patients. Two models, Mt30 and Mt16, were built using threshold serum 25(OH)D levels of £30 and <16 ng/mL, respectively. Results: A total of 219 patients were included in the study. Approximately 83% of the patients had serum 25(OH)D levels £30 ng/mL, while 25.6% had serum 25(OH) D levels <16 ng/mL. Four predictors of vitamin D deficiency were identified. Patients not taking vitamin D supplements (ergocalciferol/cholecalciferol), those with type 2 diabetes mellitus or younger in age were more likely to be vitamin D deficient. Malay and Indian race was also associated with vitamin D deficiency. The area under the receiver-operating curve for the validation sets were 0.708 and 0.752 for the Mt30 and Mt16 models, respectively. Conclusions: Vitamin D deficiency is common among multiethnic CKD patients in Singapore. Risk factors for vitamin D deficiency identified in this study include absence of vitamin D supplementation, presence of diabetes mellitus, younger age, and Malay and Indian race. The knowledge of these risk factors is useful for predicting vitamin D deficiency in CKD patients in Singapore. This can guide healthcare professionals on their decisions to prescribe vitamin D supplements to CKD patients at risk for vitamin D deficiency.
Background. Vitamin D is important for bone health, although high loading doses have been associa... more Background. Vitamin D is important for bone health, although high loading doses have been associated with an increase in fracture risk. The mechanisms remain uncertain. Aim. We hypothesize that supraphysiological concentrations of 1,25 (OH) 2 vitamin D may inhibit formation by increasing the production of Wnt inhibitors: sclerostin and DKK1. Subjects and Methods. We measured serum sclerostin and DKK1 in 34 patients (21 F, 13 M) aged mean (SD) 61.3 (15.6) years with vitamin D deficiency/insufficiency treated with a loading dose of vitamin D 2 (300,000 IU) intramuscularly. Blood samples were taken at baseline and serially up to 3 months. Results. Serum 1,25 (OH) 2 vitamin D increased markedly at 3 months (mean (SD) baseline 116 (63), 3 months : 229 (142) pmol/L, < 0.001). There was a significant correlation between sclerostin and DKK1 at baseline (= 0.504, = 0.002) and at 3 months (= 0.42, = 0.013). A significant inverse correlation was observed between sclerostin and eGFR at 3 months (= −0.494, = 0.007). Sclerostin increased significantly at 3 months (= 0.033). In a multilinear regression analysis with % change in sclerostin and DKK1 as dependent variable, a positive significant association was observed with % change in 1,25 (OH) 2 vitamin D (= 0.038), independent of changes in PTH and following correction for confounders such as age, gender, BMI, BMD and eGFR. Conclusions. Supraphysiological concentration in 1,25 (OH) 2 vitamin D achieved following a loading dose of vitamin D increases sclerostin and may inhibit Wnt signalling. This may have detrimental effects on bone.
End stage renal disease Chronic kidney disease Bone turnover Bone mineral density Objectives: Abn... more End stage renal disease Chronic kidney disease Bone turnover Bone mineral density Objectives: Abnormalities in PTH are implicated in the pathogenesis of bone abnormalities in chronic kidney disease (CKD)-mineral bone disorder (CKD-MBD). PTH concentrations are important in clinical decision and management. This emphasises the importance of providing an assay which measures biologically active PTH. We compared concentrations of intact PTH with biointact PTH (1-84) in CKD and end stage renal disease (ESRD) and investigated the relationship between the 2 PTH assays with bone and mineral laboratory parameters and bone mineral density (BMD) in CKD. Design and methods: We assessed 140 patients (61 in ESRD and 79 with CKD stages 1-4) in this crosssectional study. We measured biointact PTH (1-84) as well as routine biochemical parameters on all subjects. In the CKD cohort, bone turnover markers; bone alkaline phosphatase (BAP) and tartrate resistant acid phosphatase (TRACP)-5b and bone mineral density (BMD) were also determined. Results: In ESRD, intact PTH concentration was significantly higher compared to biointact PTH (1-84) (422 [443] v/s 266 [251] pg/mL, (p b 0.001) with an average bias of 60%. In CKD, intact PTH concentration was also higher compared to biointact PTH (1-84) (79[55] v/s 68[49] pg/mL p b 0.001) with an average bias of 18%. Only the biointact PTH (1-84) assay showed any significant correlation with serum calcium concentrations (r = −0.26, p b 0.05) and phosphate (r = 0.25, p b 0.05) in CKD. Following multilinear regression analysis and adjustment for all significant co-variables, only eGFR, BAP and 25 (OH)vitamin remained significantly associated with intact PTH and biointact PTH (1-84). The strength of association was stronger between BAP and biointact PTH (1-84) (biointact PTH (1-84): p = 0.007, intact PTH: p = 0.01). In adjusted analyses, only biointact PTH (1-84) was significantly associated with BMD at the forearm (FARM) (p = 0.049). Conclusions: The study confirms the differences between intact PTH and biointact PTH (1-84) in ESRD. Whilst there may be similarities in the diagnostic ability of both intact and biointact PTH (1-84), our data suggest that biointact PTH (1-84) assay may better reflect bone metabolism and BMD in CKD. Further longitudinal studies are needed.
Background: Metabolic acidosis is more common with advancing chronic kidney disease, and has been... more Background: Metabolic acidosis is more common with advancing chronic kidney disease, and has been associated with impaired physical function, impaired bone health, accelerated decline in kidney function and increased vascular risk. Although oral sodium bicarbonate is widely used to correct metabolic acidosis, there exist potential risks of therapy including worsening hypertension and fluid overload. Little trial evidence exists to decide whether oral bicarbonate therapy is of net benefit in advanced chronic kidney disease, particularly in older people who are most commonly affected, and in whom physical function, quality of life and vascular health are at least as important outcomes as decline in renal function. Methods/Design: BiCARB is a multi-centre, double-blind, placebo controlled, randomised trial evaluating the clinical and cost-effectiveness of oral sodium bicarbonate in the management of older people with chronic kidney disease and severely reduced glomerular filtration rate (GFR) who have a mild degree of metabolic acidosis. The trial will recruit 380 patients from renal, Medicine for the Elderly, and primary care services across centres in the United Kingdom. Male and female patients aged 60 years and older with an estimated glomerular filtration rate of <30 mL/min/1.73 m 2 , not on dialysis, and with serum bicarbonate concentrations <22 mmol/L will be eligible for participation. The primary clinical outcome for the trial is the between-group difference in the Short Physical Performance Battery score at 12 months. Secondary outcomes include muscle strength, quality of life measured using the EQ-5D score and KDQoL tools, cost effectiveness, renal function, presence of albuminuria and blood pressure. Markers of bone turnover (25-hydroxyvitamin D, 1,25-hydroxyvitamin D, tartrate-resistant acid phosphatase-5b and bone-specific alkaline phosphatase) and vascular health (B-type natriuretic peptide) will be measured. Participants will receive a total of 24 months of either bicarbonate or placebo. The results will provide the first robust test of the overall clinical and cost-effectiveness of this commonly used therapy in older patients with severely reduced kidney function.
Lean mass (LM) and fat mass (FM) are closely related to bone mass (BM) in post-menopausal women, ... more Lean mass (LM) and fat mass (FM) are closely related to bone mass (BM) in post-menopausal women, although their relative importance is unclear. Angiogenic factors which control angiogenesis may influence BM, LM and FM. The aim of the study was to compare the contribution of LM and FM to bone mineral density (BMD) and the association between these tissues and circulating angiogenic factors. The study population comprised of 392 post-menopausal women aged mean [SD] 61.8 [6.4] years. BMD was measured at the lumbar spine (LS), neck of femur and total hip (TH) by dual-energy X-ray absorptiometry (DXA). DXA scan was also used to determine LM and FM. Angiopoietin-1 and 2 (ANG-1, ANG-2) were measured by sandwich enzyme-linked immunosorbent assay. Following adjustment for confounders, significant positive independent associations were seen between LM with BMD at all skeletal sites (TH: p \ 0.0001) and FM with BMD at the hip sites (TH: p = 0.004). When BMD and LM were regressed against the angiogenic factors, positive associations were seen between ANG-2 with LM (p = 0.002) and LS BMD (p = 0.05). Negative associations were observed between the ratio of ANG-1/ANG-2 with LS BMD (p = 0.014), TH BMD (p = 0.049) and LM (p = 0.029). FM and fat distribution (android/gynoid fat ratio) were negatively associated with ANG-1 (p = 0.006) and ANG-2 (p = 0.004), respectively. ANG-1 and ANG-2 may be involved in the maintenance of bone, muscle and fat mass.
Silicon deficiency in animals leads to bone defects. This element may therefore play an important... more Silicon deficiency in animals leads to bone defects. This element may therefore play an important role in bone metabolism. Silicon is absorbed from the diet as orthosilicic acid and concentrations in plasma are 5-20 microM. The in vitro effects of orthosilicic acid (0-50 microM) on collagen type 1 synthesis was investigated using the human osteosarcoma cell line (MG-63), primary osteoblast-like cells derived from human bone marrow stromal cells, and an immortalized human early osteoblastic cell line (HCC1). Collagen type 1 mRNA expression and prolyl hydroxylase activity were also determined in the MG-63 cells. Alkaline phosphatase and osteocalcin (osteoblastic differentiation) were assessed both at the protein and the mRNA level in MG-63 cells treated with orthosilicic acid. Collagen type 1 synthesis increased in all treated cells at orthosilicic acid concentrations of 10 and 20 microM, although the effects were more marked in the clonal cell lines (MG-63, HCCl 1.75- and 1.8-fold, respectively, P &lt; 0.001, compared to 1.45-fold in the primary cell lines). Treatment at 50 microM resulted in a smaller increase in collagen type 1 synthesis (MG-63 1.45-fold, P = 0.004). The effect of orthosilicic acid was abolished in the presence of prolyl hydroxylase inhibitors. No change in collagen type 1 mRNA level was seen in treated MG-63 cells. Alkaline phosphatase activity and osteocalcin were significantly increased (1.5, 1.2-fold at concentrations of 10 and 20 microM, respectively, P &lt; 0.05). Gene expression of alkaline phosphatase and osteocalcin also increased significantly following treatment. In conclusion, orthosilicic acid at physiological concentrations stimulates collagen type 1 synthesis in human osteoblast-like cells and enhances osteoblastic differentiation.
This article aims to review the methods used for the assessment of fracture risk and the use of o... more This article aims to review the methods used for the assessment of fracture risk and the use of osteoporosis medications for fracture prevention in the population with CKD, and highlights the difficulties faced by clinicians in the management of these patients and the latest recommendations and guidelines. Chronic kidney disease (CKD) and osteoporosis often co-exist in older adults, and they present a major healthcare challenge. CKD mineral and bone disorder (CKD-MBD) occurs as renal function declines and this syndrome affects most patients in CKD stages 4 and 5. The biochemical abnormalities of CKD-MBD, renal bone disease and risk factors associated with age-related bone loss and osteoporosis lead to a cumulative effect on fracture risk and mortality. There is a need for routine evaluation of fracture risk and fracture prevention in this population. Measurement of bone mineral density (BMD) and the use of the FRAX tool have predictive value for incident fractures in the general pop...
<b>Copyright information:</b>Taken from "The impact of vitamin D status on chang... more <b>Copyright information:</b>Taken from "The impact of vitamin D status on changes in bone mineral density during treatment with bisphosphonates and after discontinuation following long-term use in post-menopausal osteoporosis"BMC Musculoskeletal Disorders 2007;8():3-3.Published online 10 Jan 2007PMCID:PMC1781939.
<b>Copyright information:</b>Taken from "The impact of vitamin D status on chang... more <b>Copyright information:</b>Taken from "The impact of vitamin D status on changes in bone mineral density during treatment with bisphosphonates and after discontinuation following long-term use in post-menopausal osteoporosis"BMC Musculoskeletal Disorders 2007;8():3-3.Published online 10 Jan 2007PMCID:PMC1781939.
<b>Copyright information:</b>Taken from "The impact of vitamin D status on chang... more <b>Copyright information:</b>Taken from "The impact of vitamin D status on changes in bone mineral density during treatment with bisphosphonates and after discontinuation following long-term use in post-menopausal osteoporosis"BMC Musculoskeletal Disorders 2007;8():3-3.Published online 10 Jan 2007PMCID:PMC1781939.
<b>Copyright information:</b>Taken from "The impact of vitamin D status on chang... more <b>Copyright information:</b>Taken from "The impact of vitamin D status on changes in bone mineral density during treatment with bisphosphonates and after discontinuation following long-term use in post-menopausal osteoporosis"BMC Musculoskeletal Disorders 2007;8():3-3.Published online 10 Jan 2007PMCID:PMC1781939. A significant difference in % change in BMD at the hip was observed between the 2 groups. Values are shown as the mean [SEM], * p &lt; 0.05.
Aim To test whether renal biochemical markers were associated with physical performance and frail... more Aim To test whether renal biochemical markers were associated with physical performance and frailty in older people with advanced chronic kidney disease. Findings Biochemical markers associated with chronic kidney disease did not consistently associate with baseline physical performance or the rate of change of physical performance measures. Message Targeting improvements in renal biochemistry may not be a fruitful way to improve physical function and frailty in older people with advanced chronic kidney disease.
Summary This study assessed whether vitamin K, given with oral bisphosphonate, calcium and/or vit... more Summary This study assessed whether vitamin K, given with oral bisphosphonate, calcium and/or vitamin D has an additive effect on fracture risk in post-menopausal women with osteoporosis. No difference in bone density or bone turnover was observed although vitamin K1 supplementation led to a modest effect on parameters of hip geometry. Purpose Some clinical studies have suggested that vitamin K prevents bone loss and may improve fracture risk. The aim was to assess whether vitamin K supplementation has an additive effect on bone mineral density (BMD), hip geometry and bone turnover markers (BTMs) in post-menopausal women with osteoporosis (PMO) and sub-optimum vitamin K status receiving bisphosphonate, calcium and/or vitamin D treatment. Methods We conducted a trial in 105 women aged 68.7[12.3] years with PMO and serum vitamin K1 ≤ 0.4 µg/L. They were randomised to 3 treatment arms; vitamin K1 (1 mg/day) arm, vitamin K2 arm (MK-4; 45 mg/day) or placebo for 18 months. They were on or...
Introduction and Aims: Vitamin D deficiency is common in patients with chronic kidney disease (CK... more Introduction and Aims: Vitamin D deficiency is common in patients with chronic kidney disease (CKD) and can result in complications such as mineral and bone disorders. Vitamin D deficiency is also associated with extrarenal and extraskeletal complications. The purpose of this study is to determine the clinical and demographic risk factors for vitamin D deficiency in multiethnic CKD patients in Singapore, a sun-rich country, so that patients at risk for vitamin D deficiency can be identified early, and replacement with vitamin D supplements can be started before further worsening of their kidney function. Methods: Pre-dialysis CKD patients from the National University Hospital (NUH), Singapore, Outpatient Renal Clinic who had their serum 25-hydroxyvitamin D [25 (OH)D] levels measured between January 2008 and October 2010 were included in the study. The patients' clinical and demographic parameters were collected from hospital databases and medical charts. Data mining methodology was used to identify potential predictors for vitamin D deficiency in these CKD patients. Two models, Mt30 and Mt16, were built using threshold serum 25(OH)D levels of £30 and <16 ng/mL, respectively. Results: A total of 219 patients were included in the study. Approximately 83% of the patients had serum 25(OH)D levels £30 ng/mL, while 25.6% had serum 25(OH) D levels <16 ng/mL. Four predictors of vitamin D deficiency were identified. Patients not taking vitamin D supplements (ergocalciferol/cholecalciferol), those with type 2 diabetes mellitus or younger in age were more likely to be vitamin D deficient. Malay and Indian race was also associated with vitamin D deficiency. The area under the receiver-operating curve for the validation sets were 0.708 and 0.752 for the Mt30 and Mt16 models, respectively. Conclusions: Vitamin D deficiency is common among multiethnic CKD patients in Singapore. Risk factors for vitamin D deficiency identified in this study include absence of vitamin D supplementation, presence of diabetes mellitus, younger age, and Malay and Indian race. The knowledge of these risk factors is useful for predicting vitamin D deficiency in CKD patients in Singapore. This can guide healthcare professionals on their decisions to prescribe vitamin D supplements to CKD patients at risk for vitamin D deficiency.
Background. Vitamin D is important for bone health, although high loading doses have been associa... more Background. Vitamin D is important for bone health, although high loading doses have been associated with an increase in fracture risk. The mechanisms remain uncertain. Aim. We hypothesize that supraphysiological concentrations of 1,25 (OH) 2 vitamin D may inhibit formation by increasing the production of Wnt inhibitors: sclerostin and DKK1. Subjects and Methods. We measured serum sclerostin and DKK1 in 34 patients (21 F, 13 M) aged mean (SD) 61.3 (15.6) years with vitamin D deficiency/insufficiency treated with a loading dose of vitamin D 2 (300,000 IU) intramuscularly. Blood samples were taken at baseline and serially up to 3 months. Results. Serum 1,25 (OH) 2 vitamin D increased markedly at 3 months (mean (SD) baseline 116 (63), 3 months : 229 (142) pmol/L, < 0.001). There was a significant correlation between sclerostin and DKK1 at baseline (= 0.504, = 0.002) and at 3 months (= 0.42, = 0.013). A significant inverse correlation was observed between sclerostin and eGFR at 3 months (= −0.494, = 0.007). Sclerostin increased significantly at 3 months (= 0.033). In a multilinear regression analysis with % change in sclerostin and DKK1 as dependent variable, a positive significant association was observed with % change in 1,25 (OH) 2 vitamin D (= 0.038), independent of changes in PTH and following correction for confounders such as age, gender, BMI, BMD and eGFR. Conclusions. Supraphysiological concentration in 1,25 (OH) 2 vitamin D achieved following a loading dose of vitamin D increases sclerostin and may inhibit Wnt signalling. This may have detrimental effects on bone.
End stage renal disease Chronic kidney disease Bone turnover Bone mineral density Objectives: Abn... more End stage renal disease Chronic kidney disease Bone turnover Bone mineral density Objectives: Abnormalities in PTH are implicated in the pathogenesis of bone abnormalities in chronic kidney disease (CKD)-mineral bone disorder (CKD-MBD). PTH concentrations are important in clinical decision and management. This emphasises the importance of providing an assay which measures biologically active PTH. We compared concentrations of intact PTH with biointact PTH (1-84) in CKD and end stage renal disease (ESRD) and investigated the relationship between the 2 PTH assays with bone and mineral laboratory parameters and bone mineral density (BMD) in CKD. Design and methods: We assessed 140 patients (61 in ESRD and 79 with CKD stages 1-4) in this crosssectional study. We measured biointact PTH (1-84) as well as routine biochemical parameters on all subjects. In the CKD cohort, bone turnover markers; bone alkaline phosphatase (BAP) and tartrate resistant acid phosphatase (TRACP)-5b and bone mineral density (BMD) were also determined. Results: In ESRD, intact PTH concentration was significantly higher compared to biointact PTH (1-84) (422 [443] v/s 266 [251] pg/mL, (p b 0.001) with an average bias of 60%. In CKD, intact PTH concentration was also higher compared to biointact PTH (1-84) (79[55] v/s 68[49] pg/mL p b 0.001) with an average bias of 18%. Only the biointact PTH (1-84) assay showed any significant correlation with serum calcium concentrations (r = −0.26, p b 0.05) and phosphate (r = 0.25, p b 0.05) in CKD. Following multilinear regression analysis and adjustment for all significant co-variables, only eGFR, BAP and 25 (OH)vitamin remained significantly associated with intact PTH and biointact PTH (1-84). The strength of association was stronger between BAP and biointact PTH (1-84) (biointact PTH (1-84): p = 0.007, intact PTH: p = 0.01). In adjusted analyses, only biointact PTH (1-84) was significantly associated with BMD at the forearm (FARM) (p = 0.049). Conclusions: The study confirms the differences between intact PTH and biointact PTH (1-84) in ESRD. Whilst there may be similarities in the diagnostic ability of both intact and biointact PTH (1-84), our data suggest that biointact PTH (1-84) assay may better reflect bone metabolism and BMD in CKD. Further longitudinal studies are needed.
Background: Metabolic acidosis is more common with advancing chronic kidney disease, and has been... more Background: Metabolic acidosis is more common with advancing chronic kidney disease, and has been associated with impaired physical function, impaired bone health, accelerated decline in kidney function and increased vascular risk. Although oral sodium bicarbonate is widely used to correct metabolic acidosis, there exist potential risks of therapy including worsening hypertension and fluid overload. Little trial evidence exists to decide whether oral bicarbonate therapy is of net benefit in advanced chronic kidney disease, particularly in older people who are most commonly affected, and in whom physical function, quality of life and vascular health are at least as important outcomes as decline in renal function. Methods/Design: BiCARB is a multi-centre, double-blind, placebo controlled, randomised trial evaluating the clinical and cost-effectiveness of oral sodium bicarbonate in the management of older people with chronic kidney disease and severely reduced glomerular filtration rate (GFR) who have a mild degree of metabolic acidosis. The trial will recruit 380 patients from renal, Medicine for the Elderly, and primary care services across centres in the United Kingdom. Male and female patients aged 60 years and older with an estimated glomerular filtration rate of <30 mL/min/1.73 m 2 , not on dialysis, and with serum bicarbonate concentrations <22 mmol/L will be eligible for participation. The primary clinical outcome for the trial is the between-group difference in the Short Physical Performance Battery score at 12 months. Secondary outcomes include muscle strength, quality of life measured using the EQ-5D score and KDQoL tools, cost effectiveness, renal function, presence of albuminuria and blood pressure. Markers of bone turnover (25-hydroxyvitamin D, 1,25-hydroxyvitamin D, tartrate-resistant acid phosphatase-5b and bone-specific alkaline phosphatase) and vascular health (B-type natriuretic peptide) will be measured. Participants will receive a total of 24 months of either bicarbonate or placebo. The results will provide the first robust test of the overall clinical and cost-effectiveness of this commonly used therapy in older patients with severely reduced kidney function.
Lean mass (LM) and fat mass (FM) are closely related to bone mass (BM) in post-menopausal women, ... more Lean mass (LM) and fat mass (FM) are closely related to bone mass (BM) in post-menopausal women, although their relative importance is unclear. Angiogenic factors which control angiogenesis may influence BM, LM and FM. The aim of the study was to compare the contribution of LM and FM to bone mineral density (BMD) and the association between these tissues and circulating angiogenic factors. The study population comprised of 392 post-menopausal women aged mean [SD] 61.8 [6.4] years. BMD was measured at the lumbar spine (LS), neck of femur and total hip (TH) by dual-energy X-ray absorptiometry (DXA). DXA scan was also used to determine LM and FM. Angiopoietin-1 and 2 (ANG-1, ANG-2) were measured by sandwich enzyme-linked immunosorbent assay. Following adjustment for confounders, significant positive independent associations were seen between LM with BMD at all skeletal sites (TH: p \ 0.0001) and FM with BMD at the hip sites (TH: p = 0.004). When BMD and LM were regressed against the angiogenic factors, positive associations were seen between ANG-2 with LM (p = 0.002) and LS BMD (p = 0.05). Negative associations were observed between the ratio of ANG-1/ANG-2 with LS BMD (p = 0.014), TH BMD (p = 0.049) and LM (p = 0.029). FM and fat distribution (android/gynoid fat ratio) were negatively associated with ANG-1 (p = 0.006) and ANG-2 (p = 0.004), respectively. ANG-1 and ANG-2 may be involved in the maintenance of bone, muscle and fat mass.
Silicon deficiency in animals leads to bone defects. This element may therefore play an important... more Silicon deficiency in animals leads to bone defects. This element may therefore play an important role in bone metabolism. Silicon is absorbed from the diet as orthosilicic acid and concentrations in plasma are 5-20 microM. The in vitro effects of orthosilicic acid (0-50 microM) on collagen type 1 synthesis was investigated using the human osteosarcoma cell line (MG-63), primary osteoblast-like cells derived from human bone marrow stromal cells, and an immortalized human early osteoblastic cell line (HCC1). Collagen type 1 mRNA expression and prolyl hydroxylase activity were also determined in the MG-63 cells. Alkaline phosphatase and osteocalcin (osteoblastic differentiation) were assessed both at the protein and the mRNA level in MG-63 cells treated with orthosilicic acid. Collagen type 1 synthesis increased in all treated cells at orthosilicic acid concentrations of 10 and 20 microM, although the effects were more marked in the clonal cell lines (MG-63, HCCl 1.75- and 1.8-fold, respectively, P &lt; 0.001, compared to 1.45-fold in the primary cell lines). Treatment at 50 microM resulted in a smaller increase in collagen type 1 synthesis (MG-63 1.45-fold, P = 0.004). The effect of orthosilicic acid was abolished in the presence of prolyl hydroxylase inhibitors. No change in collagen type 1 mRNA level was seen in treated MG-63 cells. Alkaline phosphatase activity and osteocalcin were significantly increased (1.5, 1.2-fold at concentrations of 10 and 20 microM, respectively, P &lt; 0.05). Gene expression of alkaline phosphatase and osteocalcin also increased significantly following treatment. In conclusion, orthosilicic acid at physiological concentrations stimulates collagen type 1 synthesis in human osteoblast-like cells and enhances osteoblastic differentiation.
This article aims to review the methods used for the assessment of fracture risk and the use of o... more This article aims to review the methods used for the assessment of fracture risk and the use of osteoporosis medications for fracture prevention in the population with CKD, and highlights the difficulties faced by clinicians in the management of these patients and the latest recommendations and guidelines. Chronic kidney disease (CKD) and osteoporosis often co-exist in older adults, and they present a major healthcare challenge. CKD mineral and bone disorder (CKD-MBD) occurs as renal function declines and this syndrome affects most patients in CKD stages 4 and 5. The biochemical abnormalities of CKD-MBD, renal bone disease and risk factors associated with age-related bone loss and osteoporosis lead to a cumulative effect on fracture risk and mortality. There is a need for routine evaluation of fracture risk and fracture prevention in this population. Measurement of bone mineral density (BMD) and the use of the FRAX tool have predictive value for incident fractures in the general pop...
<b>Copyright information:</b>Taken from "The impact of vitamin D status on chang... more <b>Copyright information:</b>Taken from "The impact of vitamin D status on changes in bone mineral density during treatment with bisphosphonates and after discontinuation following long-term use in post-menopausal osteoporosis"BMC Musculoskeletal Disorders 2007;8():3-3.Published online 10 Jan 2007PMCID:PMC1781939.
<b>Copyright information:</b>Taken from "The impact of vitamin D status on chang... more <b>Copyright information:</b>Taken from "The impact of vitamin D status on changes in bone mineral density during treatment with bisphosphonates and after discontinuation following long-term use in post-menopausal osteoporosis"BMC Musculoskeletal Disorders 2007;8():3-3.Published online 10 Jan 2007PMCID:PMC1781939.
<b>Copyright information:</b>Taken from "The impact of vitamin D status on chang... more <b>Copyright information:</b>Taken from "The impact of vitamin D status on changes in bone mineral density during treatment with bisphosphonates and after discontinuation following long-term use in post-menopausal osteoporosis"BMC Musculoskeletal Disorders 2007;8():3-3.Published online 10 Jan 2007PMCID:PMC1781939.
<b>Copyright information:</b>Taken from "The impact of vitamin D status on chang... more <b>Copyright information:</b>Taken from "The impact of vitamin D status on changes in bone mineral density during treatment with bisphosphonates and after discontinuation following long-term use in post-menopausal osteoporosis"BMC Musculoskeletal Disorders 2007;8():3-3.Published online 10 Jan 2007PMCID:PMC1781939. A significant difference in % change in BMD at the hip was observed between the 2 groups. Values are shown as the mean [SEM], * p &lt; 0.05.
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