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Baatjes K, Peeters A, McCaul M, Conradie MM, Apffelstaedt J, Conradie M, Kotze MJ. CYP19A1 rs10046 Pharmacogenetics in Postmenopausal Breast Cancer Patients Treated with Aromatase Inhibitors: One-year Follow-up. Curr Pharm Des 2021; 26:6007-6012. [PMID: 32900345 DOI: 10.2174/1381612826666200908141858] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 08/07/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND Significant individual variation in bone loss associated with aromatase inhibitors (AIs) emphasizes the importance of identifying postmenopausal breast cancer patients at high risk for this adverse effect. The study explores the clinical relevance of genetic variation in the Cytochrome P450 19A1 (CYP19A1) gene in a subset of South African patients during the first year of taking AIs for estrogen receptor (ER)-positive breast cancer. METHODS The study population consisted of ER-positive breast cancer patients on AIs, followed in real-life clinical practice. Body mass index was measured and bone mineral density (BMD) was determined at baseline and at month 12. CYP19A1 genotyping was performed using real-time polymerase chain reaction analysis of rs10046, extended to Sanger sequencing and whole exome sequencing in 10 patients with more than 5% bone loss at month 12 at the lumbar spine. RESULTS After 12 months of AI treatment, 72 patients had completed BMD and were successfully genotyped. Ten patients (14%) experienced more than 5% bone loss at the lumbar spine over the study period. Genotyping for CYP19A1 rs10046 revealed that patients with two copies of the A-allele were 10.79 times more likely to have an ordinal category change of having an increased percentage of bone loss or no increase at the lumbar spine, compared to patients with the GA or GG genotypes (CI of 1.771- 65.830, p=0.01). None of the 34 patients without lumbar spine bone loss at month 12 were homozygous for the functional CYP19A1 polymorphism. At the total hip region, patients with the AA genotype were 7. 37 times more likely to have an ordinal category change of having an increased percentage of bone loss or no increase (CI of 1.101- 49.336, p=0.04). CONCLUSION Homozygosity for the CYP19A1 rs10046 A-allele may provide information, in addition to clinical and biochemical factors that may be considered in risk stratification to optimize bone health in postmenopausal breast cancer women on AIs. Further investigation is required to place the clinical effect observed for a single CYP19A1 gene variant in a genomic context.
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Affiliation(s)
- Karin Baatjes
- Department Surgical Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, South Africa
| | - Armand Peeters
- Division of Chemical Pathology, Department of Pathology Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, South Africa
| | - Micheal McCaul
- Division of Epidemiology and Biostatistics, Department of Global Health, Stellenbosch University, South Africa
| | - Maria M Conradie
- Division of Endocrinology, Department of Medicine, Faculty of Medicine and Health Sciences Stellenbosch University, Tygerberg, South Africa
| | - Justus Apffelstaedt
- Department Surgical Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, South Africa
| | - Magda Conradie
- Division of Chemical Pathology, Department of Pathology Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, South Africa
| | - Maritha J Kotze
- Division of Chemical Pathology, Department of Pathology Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, South Africa
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Laubscher CV, Burger MC, Conradie MM, Conradie M, Jordaan JD. Prevalence of Sarcopenia in Older South African Patients Following Surgery for Fragility Fractures of the Hip. Geriatr Orthop Surg Rehabil 2020; 11:2151459320971560. [PMID: 33294251 PMCID: PMC7705786 DOI: 10.1177/2151459320971560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Accepted: 10/15/2020] [Indexed: 11/19/2022] Open
Abstract
Introduction: Geriatric patients with a fragility fracture of the hip (FFH) are especially
prone to sarcopenia with poor functional outcomes and quality of life. We
assessed the prevalence of sarcopenia in older South African patients with
FFH. Risk factors for sarcopenia were also investigated. Materials and Methods: From August 1 to November 30, 2018, all older patients with FFH were invited
to participate. Sarcopenia was diagnosed based on the revised criteria of
the European Working Group on Sarcopenia in Older People (EWGSOP2). Handgrip
strength (HGS) and muscle strength were assessed. Muscle quantity was
determined by dual-energy X-ray absorptiometry. Demographic information was
collected, and 25-hydroxyvitamin D (25[OH]D) status was determined. Results: Of the 100 hip fracture cases, 65 were enrolled, and 52% (34/65) were
sarcopenic (women: 62%; men: 38%). HGS accurately identified sarcopenia
(sensitivity and specificity: 100%). Patients >80 years of age had a
prevalence of sarcopenia twice (18/21 [83%]) that of younger patients (18/44
[36%]). Women with sarcopenia were smaller than those without (weight: p
< 0.001; height: p < 0.001; body mass index: p = 0.018). Low 25(OH)D
was almost universally present, with median 25(OH)D levels significantly
lower in the patients with sarcopenia (27 nmol/L [interquartile range {IQR}:
20–39] vs. 40 nmol/L [IQR: 29–53]). Several risk factors, including advanced
age; female sex; a smaller body size, especially among women; limited
physical activity; and low 25(OH)D levels, were identified. Discussion: The accuracy of HGS testing in this cohort underscores EWGSOP2’s
recommendation that muscle strength is key to sarcopenia. Further study and
follow-up are required to determine the clinical relevance of sarcopenia
among FFH patients. Conclusion: The prevalence of sarcopenia in our FFH population is high. Sarcopenia is
associated with poor patient outcomes following surgical intervention.
Orthopaedic surgeons should therefore be cognizant of the presentation and
associated risk of sarcopenia as our patient populations age.
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Affiliation(s)
- Cornelius V Laubscher
- Division of Orthopaedic Surgery, Department of Surgical Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Marilize C Burger
- Division of Orthopaedic Surgery, Department of Surgical Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Maria M Conradie
- Division of Endocrinology, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Magda Conradie
- Division of Endocrinology, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Jacobus D Jordaan
- Division of Orthopaedic Surgery, Department of Surgical Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
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Seboko AM, Conradie MM, Kruger MJ, Ferris WF, Conradie M, van de Vyver M. Systemic Factors During Metabolic Disease Progression Contribute to the Functional Decline of Adipose Tissue-Derived Mesenchymal Stem Cells in Reproductive Aged Females. Front Physiol 2018; 9:1812. [PMID: 30631282 PMCID: PMC6315119 DOI: 10.3389/fphys.2018.01812] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 12/04/2018] [Indexed: 12/28/2022] Open
Abstract
It is known that advanced metabolic disorders such as type 2 diabetes compromise the functional and regenerative capacity of endogenous adipose-tissue resident stem cells (ADSCs). It is, however, still unclear at which stage of disease progression ADSCs become compromised and whether systemic factors contribute to their functional decline. It was therefore hypothesized that inflammatory changes in the systemic microenvironment during distinct stages of disease progression negatively affect the functional capacity of ADSCs. A total of forty-seven (n = 47) black African reproductive aged females (32 ± 8 years; mean ± SD) were included in this study and subdivided into: (a) healthy lean (C; body mass index, BMI ≤ 25 kg/m2), (b) healthy overweight/obese (OB; BMI ≥ 25 kg/m2), (c) obese metabolic syndrome (MetS; BMI ≥ 30 kg/m2), and (d) type 2 diabetes mellitus (T2DM; previously diagnosed and on treatment) groups. Participants underwent anthropometric assessments and a DXA scan to determine their body composition and adipose indices. Each persons’ systemic metabolic- (cholesterol, HDL, LDL, triglycerides, and blood glucose) and inflammatory profiles (CRP, SDF1α, TNFα, IL6, IL8, IL10, and IFNy) were also evaluated. Participant-derived serum was then used to treat an ADSC cell line in vitro and its effect on viability (MTT-based assay), proliferation (BrdU), migration (wound healing assay), and osteogenic differentiation assessed. When exposed to serum derived from overweight/obese individuals (with or without metabolic syndrome), both the proliferative and migratory responses of ADSCs were less pronounced than when exposed to healthy control serum. Serum IL6 concentrations were identified as a factor influencing the proliferation of ADSCs, suggesting that long-term disruption to the systemic cytokine balance can potentially disrupt the proliferative responses of ADSCs. Obese participant-derived serum (with and without metabolic syndrome) furthermore resulted in lipid accumulation during osteogenic differentiation. This study, therefore demonstrated that systemic factors in obese individuals, regardless of the presence of metabolic syndrome, can be detrimental to the multifunctional properties of ADSCs.
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Affiliation(s)
- Ascentia M Seboko
- Division of Endocrinology, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - M M Conradie
- Division of Endocrinology, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - M J Kruger
- Division of Endocrinology, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - William Frank Ferris
- Division of Endocrinology, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Magda Conradie
- Division of Endocrinology, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Mari van de Vyver
- Division of Endocrinology, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
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Conradie J, Conradie MM, Mtshali Z, Potgieter JH. DFT and CV data of 4-phenyl-substituted dichloro(bis{2-[1-(phenyl)-1H-1,2,3-triazol-4-yl-κN 3]pyridine-κN})iron(II) coordination compounds. Data Brief 2018; 21:1458-1471. [PMID: 30456271 PMCID: PMC6234228 DOI: 10.1016/j.dib.2018.10.085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 10/22/2018] [Accepted: 10/23/2018] [Indexed: 11/30/2022] Open
Abstract
The data presented in this paper are related to the research article entitled “Synthesis, characterisation and electrochemistry of eight Fe coordination compounds containing substituted 2-(1-(4-R-phenyl-1H-1,2,3-triazol-4-yl)pyridine ligands, R=CH3, OCH3, COOH, F, Cl, CN, H and CF3.” (Conradie et al., 2019) [1]. This paper presents electrochemical and density functional theory data of 4-phenyl-substituted dichloro(bis{2-[1-(4-R-phenyl)-1H-1,2,3-triazol-4-yl-κN3]pyridine-κN})iron(II) compounds, containing differently substituted 2-(1-(4-R-phenyl)-1H-1,2,3-triazol-1-yl)pyridine ligands (L2 – L9) (Tawfiq et al., 2014) [2]. Density functional theory calculated data of five different structural isomers for each compound, consistently show that the title compounds are octahedral and that the isomer with the chloride atoms, the pyridine nitrogens and the triazol nitrogens trans to each other, has the lowest energy. Natural bonding orbital (NBO) data and quantum theory of atoms in molecules (QTAIM) data of dichloro(bis{2-[1-(phenyl)-1H-1,2,3-triazol-4-yl-κN3]pyridine-κN})iron(II) show origin for the preference of the trans isomer.
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Affiliation(s)
- J Conradie
- Department of Chemistry, University of the Free State, P.O. Box 339, Bloemfontein 9300, South Africa
| | - M M Conradie
- Department of Chemistry, University of the Free State, P.O. Box 339, Bloemfontein 9300, South Africa
| | - Z Mtshali
- Department of Chemistry, University of the Free State, P.O. Box 339, Bloemfontein 9300, South Africa
| | - J H Potgieter
- Division of Chemistry and Environmental Science, Manchester Metropolitan University, Manchester M1 5GD, UK.,School of Chemical and Metallurgical Engineering, University of the Witwatersrand, Private Bag X3, Wits 2050, South Africa
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Conradie J, Conradie MM, Tawfiq KM, Al-Jeboori MJ, D'Silva C, Coles SJ, Wilson C, Potgieter JH. Chemical and structural data of (1,2,3-triazol-4-yl)pyridine-containing coordination compounds. Data Brief 2018; 20:1397-1408. [PMID: 30255118 PMCID: PMC6148730 DOI: 10.1016/j.dib.2018.08.125] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Accepted: 08/24/2018] [Indexed: 12/01/2022] Open
Abstract
The data presented in this paper are related to the research article entitled “Novel dichloro(bis{2-[1-(4-methylphenyl)-1H-1,2,3-triazol-4-yl-κN3]pyridine-κN})metal(II) coordination compounds of seven transition metals (Mn, Fe, Co, Ni, Cu, Zn and Cd)” (Conradie et al., 2018) [1]. This paper presents characterization and structural data of the 2-(1-(4-methyl-phenyl)-1H-1,2,3-triazol-1-yl)pyridine ligand (L2) (Tawfiq et al., 2014) [2] as well as seven dichloro(bis{2-[1-(4-methylphenyl)-1H-1,2,3-triazol-4-yl-κN3]pyridine-κN})metal(II) coordination compounds, [M(L2)2Cl2], all containing the same ligand but coordinated to different metal ions. The data illustrate the shift in IR, UV/VIS, and NMR (for diamagnetic complexes) peaks when L is coordinated to the metals, as well as the influence of the different metals on the peak positions. Solid state structural data is presented for M = Ni and Zn, while density functional theory calculated energies, structures and optimized coordinates are provided for the lowest energy cis and trans conformations for L2 as well as [M(L2)2Cl2] with M = Mn, Fe, Co, Ni, Cu, Zn and Cd.
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Affiliation(s)
- J Conradie
- Department of Chemistry, University of the Free State, P.O. Box 339, Bloemfontein 9300, South Africa
| | - M M Conradie
- Department of Chemistry, University of the Free State, P.O. Box 339, Bloemfontein 9300, South Africa
| | - K M Tawfiq
- Division of Chemistry and Environmental Science, Manchester Metropolitan University, Manchester M1 5GD, UK.,Department of Chemistry, College of Education for Pure Science (Ibn Al-Haitham), University of Baghdad, Baghdad, Iraq
| | - M J Al-Jeboori
- Department of Chemistry, College of Education for Pure Science (Ibn Al-Haitham), University of Baghdad, Baghdad, Iraq
| | - C D'Silva
- Manipal University Jaipur, Department of Chemistry, VPO Dehmi Kalan, Jaipur 303007, Rajasthan, India
| | - S J Coles
- EPSRC National Crystallography Service, School of Chemistry, University of Southampton, Southampton SO17 1BJ, England, UK
| | - C Wilson
- School of Chemistry, University of Glasgow, Joseph Black Building, University Avenue, Glasgow G12 8QQ, Scotland, UK
| | - J H Potgieter
- Division of Chemistry and Environmental Science, Manchester Metropolitan University, Manchester M1 5GD, UK.,School of Chemical and Metallurgical Engineering, University of the Witwatersrand, Private Bag X3, Wits 2050, South Africa
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Conradie MM, van de Vyver M, Andrag E, Conradie M, Ferris WF. A Direct Comparison of the Effects of the Antiretroviral Drugs Stavudine, Tenofovir and the Combination Lopinavir/Ritonavir on Bone Metabolism in a Rat Model. Calcif Tissue Int 2017; 101:422-432. [PMID: 28528404 DOI: 10.1007/s00223-017-0290-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 05/11/2017] [Indexed: 01/27/2023]
Abstract
Antiretroviral (ARV) treatment may induce metabolic complications in HIV patients on long-term therapy that can affect bone health. In this study, the effects of the ARVs Stavudine (d4T), Tenofovir (TDF) and Lopinavir/ritonavir (LPV/r) on bone metabolism and lipodystrophy were directly compared in rats to negate the consequences of HIV-associated confounding factors. Healthy 12-14-week-old male Wistar rats (n = 40) were divided into four treatment groups and received an oral animal equivalent dose of either Stavudine (6.2 mg/kg/day), TDF (26.6 mg/kg/day), LPV/r (70.8 mg/kg/day) or water (Control 1.5 mL water/day) for a period of 9 weeks. Whole-body DXA measurements, a biomechanical three-point breaking test and histomorphometric analysis were performed on the femurs and tibias at the end of the treatment period. Stavudine monotherapy was found to be associated with decreased femoral bone mineral density that translated into reduced bone strength, whereas histomorphometric analysis demonstrated that Stavudine induces an imbalance in bone metabolism at tissue level, evident in higher resorption (eroded surfaces, osteoclast surfaces and osteoclast number) and lower formation parameters (osteoblast surfaces and osteoid surfaces). This was less clear in the rats treated with either TDF or LPV/r. Furthermore, both Stavudine and TDF treatment resulted in significant bone marrow adiposity, although no significant redistribution of body fat was noted in the treated rats compared to controls. The data from this study suggest that in the absence of HIV-associated factors, LPV/r is less detrimental to bone metabolism compared to Stavudine and TDF.
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Affiliation(s)
- M M Conradie
- Division of Endocrinology, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University, PO Box 241, Cape Town, 8000, South Africa
| | - M van de Vyver
- Division of Endocrinology, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University, PO Box 241, Cape Town, 8000, South Africa
| | - E Andrag
- Division of Endocrinology, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University, PO Box 241, Cape Town, 8000, South Africa
| | - M Conradie
- Division of Endocrinology, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University, PO Box 241, Cape Town, 8000, South Africa
| | - W F Ferris
- Division of Endocrinology, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University, PO Box 241, Cape Town, 8000, South Africa.
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Conradie M, Conradie MM, Scher AT, Kidd M, Hough S. Vertebral fracture prevalence in black and white South African women. Arch Osteoporos 2015; 10:203. [PMID: 25675880 DOI: 10.1007/s11657-015-0203-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Accepted: 01/12/2015] [Indexed: 02/03/2023]
Abstract
UNLABELLED Black women are generally regarded as being less prone to the development of osteoporosis. This study reports a similar prevalence of morphometric vertebral fractures in black (9.1 %) and white (5.0 %) South African women. Clinical risk factors and bone strength parameters contributed differently to fracture risk in the two ethnic cohorts. PURPOSE Vertebral fracture represents one of the most common osteoporotic fractures and is a significant cause of morbidity and mortality. Little is known regarding the prevalence of vertebral fractures on the African continent. We therefore prospectively examined the prevalence of vertebral fracture on radiographs of the thoraco-lumbar spine in otherwise healthy community-dwelling older black and white South African women. METHODS Radiographs of the spine (T4-L5) were obtained randomly in 189 women (47 % black), aged 40 years or older, for the analysis of vertebral fracture. Radiographs were evaluated by a single radiologist, blinded to clinical data, using Genant's semi-quantitative method. Clinical risk factors for osteoporosis, risk factors for falls (fall history, quadriceps strength, lateral sway and reaction time), areal and volumetric bone mineral density of the spine and hip, calcaneal ultrasonography (QUS) and vertebral macro-geometry were assessed in the two ethnic groups and the association with prevalent vertebral fractures examined. RESULTS Vertebral fracture prevalence in older South African black and white women was similar (9.1 % in black and 5.0 % in white women). In black women, lower body weight and lower areal and volumetric bone mineral density (BMD) at all sites could serve as markers of increased fracture risk. Older age, physical inactivity, lower muscle strength and lower femoral BMD were associated with vertebral fracture risk in whites. CONCLUSION Our findings are noteworthy and the first attempt to compare vertebral fracture risk in women of different ethnicities on the African continent. A similar vertebral fracture risk between black and white women in South Africa must be considered at present to ensure appropriate evaluation in all subjects who present with clinical risk factors for osteoporosis, regardless of ethnicity.
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Affiliation(s)
- Magda Conradie
- Division of Endocrinology and Metabolism, Department of Medicine, Faculty of Health Sciences, University of Stellenbosch, P.O. Box 241, Cape Town, 8000, South Africa,
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Conradie M, Conradie MM, Kidd M, Hough S. Bone density in black and white South African women: contribution of ethnicity, body weight and lifestyle. Arch Osteoporos 2014; 9:193. [PMID: 25190256 DOI: 10.1007/s11657-014-0193-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Accepted: 08/07/2014] [Indexed: 02/03/2023]
Abstract
UNLABELLED Ethnic differences in bone mineral density (BMD) between healthy adult black and white South African women were studied. Higher BMD was only noted at the femoral sites in black women. Body weight significantly impacted these findings. A lower fracture risk at all skeletal sites cannot be assumed in black South African (SA) women. PURPOSE Bone mineral density (BMD) varies amongst women of different ethnicities. African-Americans have higher BMD at all skeletal sites compared with whites. On the African continent, bone density studies suggest site-specific ethnic differences in BMD. To examine the contribution of body weight and lifestyle characteristics to ethnic differences in BMD between adult black and white South African women, we assessed lumbar spine (SBMD), femoral neck (FNBMD) and total femoral BMD (FTBMD) by dual-energy X-ray absorptiometry (DXA) in 184 black and 143 white women aged between 23 and 82 years. METHODS BMDs were compared amongst pre- and postmenopausal blacks and whites before and after adjustment for covariates with significant univariate association with BMD. Volumetric bone mineral apparent density (BMAD) of the spine and femoral neck was also calculated to account for ethnic differences in bone size. RESULTS Before adjustment, SBMD was lower (p < 0.05), FTBMD similar and FNBMD (p < 0.01) higher in premenopausal black women. Similar SBMD, but significantly higher BMD at the femoral sites (p < 0.01), was noted in postmenopausal blacks compared with whites. Amongst anthropometric measures and lifestyle factors, only adjustment for weight significantly altered these observed ethnic differences in bone density. After adjustment for weight, SBMD remained lower in premenopausal blacks and became lower in young postmenopausal blacks. Weight adjustment eliminated all ethnic differences in proximal femoral BMD measurements, with the exception of FNBMD that remained higher in younger postmenopausal blacks. Before adjustment, calculated SBMAD was similar and FNBMAD consistently higher in blacks in all the menstrual groups. Adjustment for weight did not alter these findings. CONCLUSION Most of the observed ethnic difference in BMD was explained by differences in body weight between black and white SA women. The higher femoral BMD in older blacks may explain, the lower hip fracture prevalence in black South African women. The lower SBMD in pre- and postmenopausal black women in this study suggests that factors other than BMD should be considered to explain a lower vertebral fracture prevalence in blacks, if a lower fracture prevalence does indeed exist.
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Affiliation(s)
- Magda Conradie
- Division of Endocrinology and Metabolism, Department of Medicine, Faculty of Health Sciences, University of Stellenbosch, P.O. Box 19063, Tygerberg, Cape Town, 7505, South Africa,
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Innes S, Cotton MF, Haubrich R, Conradie MM, van Niekerk M, Edson C, Rabie H, Jain S, Sun X, Zöllner EW, Hough S, Browne SH. High prevalence of lipoatrophy in pre-pubertal South African children on antiretroviral therapy: a cross-sectional study. BMC Pediatr 2012; 12:183. [PMID: 23176441 PMCID: PMC3584923 DOI: 10.1186/1471-2431-12-183] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Accepted: 10/31/2012] [Indexed: 11/10/2022] Open
Abstract
Abstract Background Despite changes in WHO guidelines, stavudine is still used extensively for treatment of pediatric HIV in the developing world. Lipoatrophy in sub-Saharan African children can be stigmatizing and have far-reaching consequences. The severity and extent of lipoatrophy in pre-pubertal children living in sub-Saharan Africa is unknown. Methods In this cross-sectional study, children who were 3-12 years old, on antiretroviral therapy and pre-pubertal were recruited from a Family HIV Clinic in South Africa. Lipoatrophy was identified and graded by consensus between two HIV pediatricians using a standardized grading scale. A professional dietician performed formal dietary assessment and anthropometric measurements of trunk and limb fat. Previous antiretroviral exposures were recorded. In a Dual-Energy X-ray Absorbtiometry (DXA) substudy body composition was determined in 42 participants. Results Among 100 recruits, the prevalence of visually obvious lipoatrophy was 36% (95% CI: 27%–45%). Anthropometry and DXA measurements corroborated the clinical diagnosis of lipoatrophy: Both confirmed significant, substantial extremity fat loss in children with visually obvious lipoatrophy, when adjusted for age and sex. Adjusted odds ratio for developing lipoatrophy was 1.9 (95% CI: 1.3 - 2.9) for each additional year of accumulated exposure to standard dose stavudine. Cumulative time on standard dose stavudine was significantly associated with reductions in biceps and triceps skin-fold thickness (p=0.008). Conclusions The prevalence of visually obvious lipoatrophy in pre-pubertal South African children on antiretroviral therapy is high. The amount of stavudine that children are exposed to needs review. Resources are needed to enable low-and-middle-income countries to provide suitable pediatric-formulated alternatives to stavudine-based pediatric regimens. The standard stavudine dose for children may need to be reduced. Diagnosis of lipoatrophy at an early stage is important to allow timeous antiretroviral switching to arrest progression and avoid stigmatization. Diagnosis using visual grading requires training and experience, and DXA and comprehensive anthropometry are not commonly available. A simple objective screening tool is needed to identify early lipoatrophy in resource-limited settings where specialized skills and equipment are not available.
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Affiliation(s)
- Steve Innes
- Department of Paediatrics, Children's Infectious Diseases Clinical Research Unit (KID CRU), Tygerberg Children's Hospital, Stellenbosch University, Cape Town, South Africa.
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Conradie MM, Cato ACB, Ferris WF, de Wet H, Horsch K, Hough S. MKP-1 knockout does not prevent glucocorticoid-induced bone disease in mice. Calcif Tissue Int 2011; 89:221-7. [PMID: 21698455 DOI: 10.1007/s00223-011-9509-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Accepted: 05/06/2011] [Indexed: 11/25/2022]
Abstract
Glucocorticoid-induced osteoporosis (GCOP) is predominantly caused by inhibition of bone formation, resulting from a decrease in osteoblast numbers. Employing mouse (MBA-15.4) and human (MG-63) osteoblast cell lines, we previously found that the glucocorticoid (GC) dexamethasone (Dex) inhibits cellular proliferation as well as activation of the MAPK/ERK signaling pathway, essential for mitogenesis in these cells, and that both these effects could be reversed by the protein tyrosine phosphatase (PTP) inhibitor vanadate. In a rat model of GCOP, the GC-induced changes in bone formation, mass, and strength could be prevented by vanadate cotreatment, suggesting that the GC effects on bone were mediated by one or more PTPs. Employing phosphatase inhibitors, qRT-PCR, Western blotting, and overexpression/knockdown experiments, we concluded that MKP-1 was upregulated by Dex, that this correlated with the dephosphorylation of ERK, and that it largely mediated the in vitro effects of GCs on bone. To confirm the pivotal role of MKP-1 in vivo, we investigated the effects of the GC methylprednisolone on the quantitative bone histology of wild-type (WT) and MKP-1 homozygous knockout (MKP-1(-/-)) mice. In WT mice, static bone histology revealed that GC administration for 28 days decreased osteoid surfaces, volumes, and osteoblast numbers. Dynamic histology, following time-spaced tetracycline labeling, confirmed a significant GC-induced reduction in osteoblast appositional rate and bone formation rate. However, identical results were obtained in MKP-1 knockout mice, suggesting that in these animals upregulation of MKP-1 by GCs cannot be regarded as the sole mediator of the GC effects on bone.
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Affiliation(s)
- Maria M Conradie
- Division of Endocrinology, Department of Medicine, Stellenbosch University, Tygerberg, Cape Town, South Africa.
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Abstract
Skeletal mass is maintained by a balance between formation and resorption, cell proliferation and apoptosis. In vitro, glucocorticoids (GCs) decrease extracellular signal-regulated kinases (ERK) activation by mitogens, thus inhibiting osteoblast proliferation. Both ERK activity and proliferation are restored by co-treatment with the protein tyrosine phosphatase inhibitor, vanadate. Since ERK signalling may also be anti-apoptotic, we explored the effects of vanadate on GC-induced apoptosis in vitro and in vivo. Apoptosis in MBA-15.4 pre-osteoblasts increased from 6 h and remained up to eightfold higher through 6 days of 10(- 6) M dexamethasone (Dex) treatment. Co-incubation with 10(- 7) M vanadate markedly reduced apoptosis at all time points. Vanadate also prevented GC-induced poly-ADP-ribose polymerase cleavage. We assessed the transcriptional profiles of seven anti-apoptotic proteins (Bcl-2, Bcl-X(L), inhibitors of apoptosis protein-1 (IAP-1), IAP-2, X-linked IAP (XIAP), Fas-associated death-domain-like IL-1beta-converting enzyme-inhibitory protein (FLIP(Long)) and FLIP(Short)) in osteoblasts subjected to various stimuli using real-time quantitative PCR. Although these anti-apoptotic genes responded to different mitogenic conditions, Dex failed to repress their expression, and in fact significantly up-regulated Bcl-X(L), IAP-2 and XIAP. Dex may therefore induce apoptosis by up-regulating pro-apoptotic gene expression. We have previously demonstrated that rats treated with GC develop low formation osteoporosis (bone histomorphometry and DEXA) and skeletal fragility (breaking strength) that were largely prevented by co-treatment with vanadate. We report here that vertebrae from rats treated with 3.5 mg/kg per day methylprednisolone for 9 weeks showed increased incidence of terminal deoxynucleotidyl transferase-mediated biotin-dUTP nick end-labelling-positive apoptotic osteocytes, which was reduced by vanadate co-treatment. We conclude that vanadate prevents GC-induced apoptosis of pre-osteoblasts in vitro and osteocytes in vivo, and this may contribute to its bone-sparing effects in vivo.
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Affiliation(s)
- M M Conradie
- Division of Endocrinology and Metabolism, Department of Medicine, Faculty of Health Sciences, University of StellenboschTygerbergSouth Africa
| | - H de Wet
- Division of Endocrinology and Metabolism, Department of Medicine, Faculty of Health Sciences, University of StellenboschTygerbergSouth Africa
| | - D D R Kotze
- Division of Endocrinology and Metabolism, Department of Medicine, Faculty of Health Sciences, University of StellenboschTygerbergSouth Africa
| | - J M Burrin
- Department of Endocrinology, St Bart's Hospital, University of LondonLondonUK
| | - F S Hough
- Division of Endocrinology and Metabolism, Department of Medicine, Faculty of Health Sciences, University of StellenboschTygerbergSouth Africa
| | - P A Hulley
- Division of Endocrinology and Metabolism, Department of Medicine, Faculty of Health Sciences, University of StellenboschTygerbergSouth Africa
- Institute of Musculoskeletal Sciences, Botnar Research Centre, Nuffield Orthopaedic Centre, University of OxfordHeadington, Oxford OX3 7LDUK
- (Correspondence should be addressed to P A Hulley; )
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van der Merwe SW, Conradie MM, Bond R, Olivier BJ, Fritz E, Nieuwoudt M, Delport R, Slavik T, Engelbrecht G, Kahn D, Shephard EG, Kotze MJ, de Villiers NP, Hough S. Effect of rapamycin on hepatic osteodystrophy in rats with portasystemic shunting. World J Gastroenterol 2006; 12:4504-10. [PMID: 16874862 PMCID: PMC4125637 DOI: 10.3748/wjg.v12.i28.4504] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To study if T-cell activation related to portasystemic shunting causes osteoclast-mediated bone loss through RANKL-dependent pathways. We also investigated if T-cell inhibition using rapamycin would protect against bone loss in rats.
METHODS: Portasystemic shunting was performed in male Sprague-Dawley rats and rapamycin 0.1 mg/kg was administered for 15 wk by gavage. Rats received powderized chow and supplemental feeds to prevent the effects of malnutrition on bone composition. Weight gain and growth was restored after surgery in shunted animals. At termination, biochemical parameters of bone turnover and quantitative bone histology were assessed. Markers of T-cell activation, inflammatory cytokine production, and RANKL-dependent pathways were measured. In addition, the roles of IGF-1 and hypogonadism were investigated.
RESULTS: Portasystemic shunting caused low turnover osteoporosis that was RANKL independent. Bone resorbing cytokine levels, including IL-1, IL-6 and TNFα, were not increased in serum and TNFα and RANKL expression were not upregulated in PBMC. Portasystemic shunting increased the circulating CD8+ T-cell population. Rapamycin decreased the circulating CD8+ T-cell population, increased CD8+ CD25+ T-regulatory cell population and improved all parameters of bone turnover.
CONCLUSION: Osteoporosis caused by portasystemic shunting may be partially ameliorated by rapamycin in the rat model of hepatic osteodystrophy.
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Affiliation(s)
- Schalk W van der Merwe
- Department of Internal Medicine and Gastroenterology, Hepatology and GI- Research laboratory, University of Pretoria, PO Box 1649, Faerie Glen, Pretoria 0043, South Africa.
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Abstract
Glucocorticoid-induced osteoporosis is characterized by decreased osteoblast numbers and a marked impairment of new bone formation. We found that, in vitro, dexamethasone inhibits both preosteoblast proliferation and mitogenic kinase activity in response to mitogens, and that inhibition of protein tyrosine phosphatases (PTPs) using sodium orthovanadate prevents this. Therefore, dexamethasone may act by either upregulating antiproliferative PTPs or downregulating promitogenic tyrosine-phosphorylated substrates. In this study, osteoporosis was induced in 3.5-month-old rats by subcutaneous injection with methylprednisolone 3.5 mg/kg per day for 9 weeks. Rats were treated with steroid alone or in combination with 0.5 mg/mL sodium orthovanadate, administered continuously in drinking water. Steroid-treated bones were significantly (p < 0.005) osteopenic (according to dual-energy X-ray absorptiometry) and physically weaker (p < 0.05) than controls. Quantitative bone histology confirmed a significant decrease in osteoid surfaces (p < 0.001), osteoblast numbers (p < 0.05), and rate of bone formation (p < 0.001). Concomitant treatment with vanadate largely prevented the densitometric, histologic, and physical abnormalities induced by prednisolone. This study supports our finding that PTPs are central to the negative regulation of osteoblast proliferation by glucocorticoids and, furthermore, suggests that PTP inhibitors such as sodium orthovanadate should be considered as novel anabolic agents for the treatment of steroid-induced osteoporosis.
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Affiliation(s)
- P A Hulley
- Department of Endocrinology and Metabolism, University of Stellenbosch Medical School, Tygerberg, Cape Town, South Africa.
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Maritz FJ, Conradie MM, Hulley PA, Gopal R, Hough S. Effect of statins on bone mineral density and bone histomorphometry in rodents. Arterioscler Thromb Vasc Biol 2001; 21:1636-41. [PMID: 11597938 DOI: 10.1161/hq1001.097781] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Statins have been postulated to affect bone metabolism. We investigated the effects of different doses of simvastatin (1, 5, 10, and 20 mg. kg(-1). d(-1)), atorvastatin (2.5 mg. kg(-1). d(-1)), and pravastatin (10 mg. kg(-1). d(-1)) administered orally for 12 weeks to intact female Sprague-Dawley rats and the effect of 20 mg. kg(-1). d(-1) simvastatin in sham-operated and ovariectomized rats on femoral bone mineral density (BMD) and quantitative bone histomorphometry (QBH) and compared them with controls. BMD was decreased by 1 mg. kg(-1). d(-1) simvastatin (P=0.042), atorvastatin (P=0.0002), and pravastatin (P=0.002). The effect on QBH parameters differed with different doses of simvastatin (ANOVA, P=0.00012). QBH parameters of both bone formation and resorption were equivalently and markedly increased by 20 mg. kg(-1). d(-1) simvastatin in 2 separate groups of intact rats and were reflected by a relatively unchanged BMD. At lower doses, 1 mg. kg(-1). d(-1) simvastatin decreased bone formation while increasing bone resorption, as reflected by a marked decrease in BMD. Ovariectomized animals receiving 20 mg. kg(-1). d(-1) simvastatin showed no change in BMD relative to the untreated, ovariectomized controls; their increase in bone formation was smaller than in sham-operated rats receiving simvastatin, and there was no change in bone resorption. Dose-response curves of simvastatin for bone formation and resorption differed. These studies indicate that (1) statins decrease BMD in rodents, (2) high-dose simvastatin increases bone formation and resorption, (3) low-dose simvastatin decreases bone formation and increases bone resorption, (4) the effects of simvastatin on QBH differ at different dosages, (5) the effects of simvastatin seen in intact rats are not observed in ovariectomized rats, and (6) simvastatin is unable to prevent bone loss caused by ovariectomy.
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Affiliation(s)
- F J Maritz
- Endocrinology and Metabolism Unit, Department of Internal Medicine, University of Stellenbosch and Tygerberg Hospital, Tygerberg, South Africa.
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