Vitamin D and osteoporosis in chronic kidney disease

Microbiota and Resveratrol: How Are They Linked to Osteoporosis?

Osteoporosis (OP), which is characterized by a decrease in bone density and increased susceptibility to fractures, is closely linked to the gut microbiota (GM). It is increasingly realized that the GM plays a key role in the maintenance of the functioning of multiple organs, including bone, by producing bioactive metabolites such as short-chain fatty acids (SCFA). Consequently, imbalances in the GM, referred to as dysbiosis, have been identified with a significant reduction in beneficial metabolites, such as decreased SCFA associated with increased chronic inflammatory processes, including the activation of NF-κB at the epigenetic level, which is recognized as the main cause of many chronic diseases, including OP. Furthermore, regular or long-term medications such as antibiotics and many non-antibiotics such as proton pump inhibitors, chemotherapy, and NSAIDs, have been found to contribute to the development of dysbiosis, highlighting an urgent need for new treatment approaches. A promising preventive and adjuvant approach is to combat dysbiosis with natural polyphenols such as resveratrol, which have prebiotic functions and ensure an optimal microenvironment for beneficial GM. Resveratrol offers a range of benefits, including anti-inflammatory, anti-oxidant, analgesic, and prebiotic effects. In particular, the GM has been shown to convert resveratrol, into highly metabolically active molecules with even more potent beneficial properties, supporting a synergistic polyphenol-GM axis. This review addresses the question of how the GM can enhance the effects of resveratrol and how resveratrol, as an epigenetic modulator, can promote the growth and diversity of beneficial GM, thus providing important insights for the prevention and co-treatment of OP.

Current therapeutic approach of chronic kidney disease-mineral and bone disorder

Chronic kidney disease (CKD) has emerged as one of the leading noncommunicable diseases affecting >10% of the population worldwide. Bone and mineral disorders are a common complication among patients with CKD resulting in a poor life quality, high fracture risk, increased morbidity and cardiovascular mortality. According to Kidney Disease: Improving Global Outcomes, renal osteodystrophy refers to changes in bone morphology found in bone biopsy, whereas CKD-mineral and bone disorder (CKD-MBD) defines a complex of disturbances including biochemical and hormonal alterations, disorders of bone and mineral metabolism and extraskeletal calcification. As a result, the management of CKD-MBD should focus on the aforementioned parameters, including the treatment of hyperphosphatemia, hypocalcemia, abnormal PTH and vitamin D levels. Regarding the bone fragility fractures, osteoporosis and renal osteodystrophy, which constitute the bone component of CKD-MBD, anti-osteoporotic agents constitute the mainstay of treatment. However, a thorough elucidation of the CKD-MBD pathogenesis is crucial for the ideal personalized treatment approach. In this paper, we review the pathology and management of CKD-MBD based on the current literature with special attention to recent advances.

Bone mineral density and related clinical and laboratory factors in peritoneal dialysis patients: Implications for bone health management

BACKGROUND

End-stage renal disease (ESRD) patients often experience accelerated bone turnover, leading to osteoporosis and osteopenia. This study aimed to determine the prevalence of osteoporosis in Peritoneal Dialysis (PD) patients using bone mineral density (BMD) measurements obtained through dual-energy X-ray absorptiometry (DEXA) scan and to explore any possible associations with clinical and biochemical factors.

METHODS

In this cross-sectional study, we enrolled 76 peritoneal dialysis patients from the dialysis center at An-Najah National University Hospital in Nablus, Palestine. We used the DEXA scan to measure BMD at the lumbar spine and hip, with values expressed as T-scores. We conducted a multivariate analysis to explore the relationship between BMD and clinical and biochemical parameters.

RESULTS

Over half (52.6%) of the PD patients had osteoporosis, with a higher prevalence observed among patients with lower BMI (p<0.001). Higher alkaline phosphatase levels were found among osteoporotic patients compared to non-osteoporotic patients (p = 0.045). Vitamin D deficiency was also prevalent in this population, affecting 86.6% of patients. No significant correlation was found between 25 vitamin D levels and BMD. No significant correlation was found between Parathyroid hormone (PTH) levels and BMD.

CONCLUSION

A notable proportion of PD patients experience reduced BMD. Our study found no correlation between vitamin D levels and BMD, but it highlighted the significant vitamin D deficiency in this population. Furthermore, our analysis indicated a positive correlation between BMI and BMD, especially in the femoral neck area. This underscores the significance of addressing bone health in PD patients to mitigate the risk of fractures and improve their overall well-being.

The Molecular Mechanisms Underlying the Systemic Effects Mediated by Parathormone in the Context of Chronic Kidney Disease

Chronic kidney disease (CKD) stands as a prominent non-communicable ailment, significantly impacting life expectancy. Physiopathology stands mainly upon the triangle represented by parathormone-Vitamin D-Fibroblast Growth Factor-23. Parathormone (PTH), the key hormone in mineral homeostasis, is one of the less easily modifiable parameters in CKD; however, it stands as a significant marker for assessing the risk of complications. The updated "trade-off hypothesis" reveals that levels of PTH spike out of the normal range as early as stage G2 CKD, advancing it as a possible determinant of systemic damage. The present review aims to review the effects exhibited by PTH on several organs while linking the molecular mechanisms to the observed actions in the context of CKD. From a diagnostic perspective, PTH is the most reliable and accessible biochemical marker in CKD, but its trend bears a higher significance on a patient's prognosis rather than the absolute value. Classically, PTH acts in a dichotomous manner on bone tissue, maintaining a balance between formation and resorption. Under the uremic conditions of advanced CKD, the altered intestinal microbiota majorly tips the balance towards bone lysis. Probiotic treatment has proven reliable in animal models, but in humans, data are limited. Regarding bone status, persistently high levels of PTH determine a reduction in mineral density and a concurrent increase in fracture risk. Pharmacological manipulation of serum PTH requires appropriate patient selection and monitoring since dangerously low levels of PTH may completely inhibit bone turnover. Moreover, the altered mineral balance extends to the cardiovascular system, promoting vascular calcifications. Lastly, the involvement of PTH in the Renin-Angiotensin-Aldosterone axis highlights the importance of opting for the appropriate pharmacological agent should hypertension develop.

Trend of using cementless total knee arthroplasty: a nationwide analysis from 2015 to 2021

BACKGROUND

Modern cementless total knee arthroplasty (TKA) fixation has shown comparable long-term outcomes to cemented TKA, but the trend of using cementless TKA remains unclear. This study aimed to investigate the trend of using cementless TKA based on a national database.

METHODS

The patients undergoing cementless TKA between 2015 and 2021 were retrospectively extracted from the PearlDiver (Mariner dataset) Database. The annual percentage of cementless TKA was calculated using the following formula: annual number of cementless TKA/annual number of TKA. The trend of the number of patients undergoing cementless TKA was created according to a compounded annual growth rate (CAGR) calculation of annual percentages. Patient age, comorbidity, region, insurance type, etc., were also investigated. Differences were considered statistically significant at P < 0.05.

RESULTS

Of the 574,848 patients who received TKA, 546,731 (95%) underwent cemented fixation and 28,117 (5%) underwent cementless fixation. From 2015 to 2021, the use of cementless TKA significantly increased by 242% from 3 to 9% (compounded annual growth rate (CAGR): + 20%; P < 0.05). From 2015 to 2021, we observed a CAGR greater than 15% for all age groups (< 50, 50-59, 60-69, 70-74, 75 +), insurance types (cash, commercial, government, Medicare, Medicaid), regions (Midwest, Northeast, South, West), sex (male and female), and certain comorbidities (osteoporosis, diabetes mellitus, tobacco use, underweight (BMI < 18.5), rheumatoid arthritis) (P < 0.05 for all). Patients undergoing TKA with chronic kidney disease, prior fragility fractures, and dementia demonstrated a CAGR of + 9%-13% from 2015 to 2021 (P < 0.05).

CONCLUSION

From 2015 to 2021, the use of cementless TKA saw a dramatic increase in all patient populations. However, there is still no consensus on when to cement and in whom. Clinical practice guidelines are needed to ensure safe and effective use of cementless fixation.

Osteoporosis in Renal Disease

Introduction

Osteoporosis is a disorder characterized by decreased bone mass and skeletal fragility with increased fracture risk. Chronic kidney disease presents with wide range of bone metabolic disorders, including osteoporosis. Osteoporosis prevalence is high in early stages of CKD; whereas in late stages, it coexists with renal osteodystrophy.

Risk factors

Risk factors for osteoporosis include advancing age, low bone mineral density (BMD), glucocorticoid therapy, smoking, alcohol intake, etc.

Diagnosis

The diagnosis of osteoporosis in renal disease is made after assessment of BMD, in addition to exclusion of chronic kidney disease-mineral bone disorder (CKD-MBD), eliciting history of prior fragility fractures and relevant laboratory investigations.

Management

The treatment of osteoporosis varies with the different stages of CKD, with management in stages 1-3 being similar to the general population. Special emphasis must be laid on prevention of fractures as well.

Definition, Assessment, and Management of Vitamin D Inadequacy: Suggestions, Recommendations, and Warnings from the Italian Society for Osteoporosis, Mineral Metabolism and Bone Diseases (SIOMMMS)

In the recent years, both the prescriptions of serum 25(OH)D levels assay, and vitamin D supplementation are constantly increasing, as well as the costs to be incurred relating to these specific aspects. As in many other countries, the risk of vitamin D deficiency is particularly high in Italy, as recently confirmed by cohort studies in the general population as well as in patients with metabolic bone disorder. Results confirmed the North-South gradient of vitamin D levels described among European countries, despite the wide use of supplements. Although vitamin D supplementation is also recommended by the Italian Medicine Agency for patients at risk for fragility fracture or for initiating osteoporotic medication, the therapeutic gap for osteoporosis in Italy is very high. There is a consistent proportion of osteoporotic patients not receiving specific therapy for osteoporosis following a fragility fracture, with a poor adherence to the recommendations provided by national guidelines and position paper documents. The failure or inadequate supplementation with vitamin D in patients on antiresorptive or anabolic treatment for osteoporosis is thought to further amplify the problem and exposes patients to a high risk of re-fracture and mortality. Therefore, it is important that attention to its possible clinical consequences must be given. Thus, in light of new evidence from the literature, the SIOMMMS board felt the need to revise and update, by a GRADE/PICO system approach, its previous original recommendations about the definition, prevention, and treatment of vitamin D deficiency in adults, released in 2011. Several key points have been here addressed, such as the definition of the vitamin D status: normality values and optimal values; who are the subjects considered at risk of hypovitaminosis D; opportunity or not of performing the biochemical assessment of serum 25(OH)D levels in general population and in subjects at risk of hypovitaminosis D; the need or not to evaluate baseline serum 25(OH)D in candidate subjects for pharmacological treatment for osteoporosis; how and whether to supplement vitamin D subjects with hypovitaminosis D or candidates for pharmacological treatment with bone active agents, and the general population; how and whether to supplement vitamin D in chronic kidney disease and/or chronic liver diseases or under treatment with drugs interfering with hepatic metabolism; and finally, if vitamin D may have toxic effects in the subject in need of supplementation.

Associations between bone mineral density and chronic obstructive pulmonary disease

Objective

To assess the relationship between chronic obstructive pulmonary disease (COPD) severity and bone mineral density (BMD) in the whole body and different body areas.

Methods

This retrospective, cross-sectional study included patients with COPD. Demographic and lung function data, COPD severity scales, BMD, and T scores were collected. Patients were grouped by high (≥–1) and low (<–1) T scores, and stratified by body mass index, airway obstruction, dyspnoea, and exercise capacity (BODE) index. The relationship between whole-body BMD and BODE was evaluated by Kendall’s tau-b correlation coefficient. Risk factors associated with COPD severity were identified by univariate analyses. BMD as an independent predictor of severe COPD (BODE ≥5) was verified by multivariate logistic regression. BMD values in different body areas for predicting severe COPD were assessed by receiver operating characteristic curves.

Results

Of 88 patients with COPD, lung-function indicators and COPD severity were significantly different between those with high and low T scores. Whole-body BMD was inversely related to COPD severity scales, including BODE. Multivariate logistic regression revealed that BMD was independently associated with COPD severity. The area under the curve for pelvic BMD in predicting severe COPD was 0.728.

Conclusion

BMD may be a novel marker in predicting COPD severity, and pelvic BMD may have the strongest relative predictive power.

Vitamin D levels in patients with small and medium vessel vasculitis

OBJECTIVES

To determine the prevalence of vitamin D deficiency in patients with small and medium vessel systemic vasculitis.

METHODS

In this cross-sectional study, 25-hydroxy (OH) vitamin D3 levels were measured in adult patients with systemic small and medium vessel vasculitis including antineutrophil cytoplasmic antibody-associated vasculitis (AAV), cryoglobulinaemic vasculitis (CryV), IgA vasculitis (IgAV) and polyarteritis nodosa (PAN), and age- and sex-matched healthy subjects (HS) and patients with rheumatoid arthritis (RA) as control groups. 25OH vitamin D3 levels<30ng/ml and <20ng/ml were regarded as insufficiency and deficiency, respectively.

RESULTS

Fifty-seven patients (42 AAV, 2 CryV, 8 IgA vasculitis, 5 PAN) with systemic vasculitis, 101 HS, and 111 RA patients were included. The mean 25OH vitamin D3 level was 21.8±14.2ng/mL in patients with vasculitis, 42.7±27.6ng/mL in HS (p<.001) and 20.1±18.47ng/mL in patients with RA (p=.54). Vitamin D insufficiency and deficiency were significantly higher in patients with systemic vasculitis compared to HS (75.4% vs 33.7%, p<.001; %50 vs 21.8%, p<.001, respectively). Vitamin D status was not different in patients with systemic vasculitis compared to RA. There was a negative correlation between vitamin D status and CRP levels (=-.364, p=.007). The multivariate logistic regression analysis showed that renal involvement was significantly associated with vitamin D deficiency/insufficiency in patients with vasculitis (OR 22.5 [95% CI 1.6-128.9].

CONCLUSION

Vitamin D deficiency and insufficiency are more frequent in patients with systemic small and medium vessel vasculitis and RA than HS. Renal involvement is one of the factors associated with vitamin D deficiency/insufficiency in patients with vasculitis.

Osteoporosis, an Inevitable Circumstance of Chronic Kidney Disease: A Systematic Review

Nowadays, chronic kidney disease (CKD) and osteoporosis have become crucial health-related issues globally. CKD-induced osteoporosis is a systemic disease characterized by the disruption of mineral, hormone, and vitamin homeostasis that elevates the likelihood of fracture. Here, we review recent studies on the association of CKD and osteoporosis. In particular, we focus on the pathogenesis of CKD-associated osteoporosis, including the homeostasis and pathways of several components such as parathyroid hormone, calcium, phosphate, vitamin D, fibroblast growth factor, and klotho, as well as abnormal bone mineralization, remodeling, and turnover. In addition, we explore the diagnostic tools and possible therapeutic approaches for the management and prevention of CKD-associated osteoporosis. Patients with CKD show higher osteoporosis prevalence, greater fracture rate, increased morbidity and mortality, and an elevated occurrence of hip fracture. We also rule out that increased severity of CKD is related to a more severe condition of osteoporosis. Furthermore, supplements such as calcium and vitamin D as well as lifestyle modifications such as exercise and cessation of smoking and alcohol help in fracture prevention. However, new approaches and advancements in treatment are needed to reduce the fracture risk in patients with CKD. Therefore, further collaborative multidisciplinary research is needed in this regard.

Chronic Kidney Disease: Role of Diet for a Reduction in the Severity of the Disease

Chronic kidney disease affects ~37 million adults in the US, and it is often undiagnosed due to a lack of apparent symptoms in early stages. Chronic kidney disease (CKD) interferes with the body's physiological and biological mechanisms, such as fluid electrolyte and pH balance, blood pressure regulation, excretion of toxins and waste, vitamin D metabolism, and hormonal regulation. Many CKD patients are at risk of hyperkalemia, hyperphosphatemia, chronic metabolic acidosis, bone deterioration, blood pressure abnormalities, and edema. These risks may be minimized, and the disease's progression may be slowed through careful monitoring of protein, phosphorus, potassium, sodium, and calcium, relieving symptoms experienced by CKD patients. In this review, the current Kidney Disease Outcomes Quality Initiative (KDOQI) recommendations are highlighted, reflecting the 2020 update, including explanations for the pathophysiology behind the recommendations. The Dietary Approaches to Stop Hypertension, the Mediterranean diet, and the whole foods plant-based diet are currently being examined for their potential role in delaying CKD progression. Biological explanations for why the whole foods plant-based diet may benefit CKD patients compared to diets that include animal products are examined. Strong evidence continues to support the importance of diet meeting the daily requirement in the prevention and progression of kidney disease, and medical nutrition therapy with a registered dietitian is a critical aspect in medical intervention for CKD.

Prevalence and predictors of vitamin D deficiency in a nationally representative sample of Australian Aboriginal and Torres Strait Islander adults

Vitamin D deficiency (serum 25-hydroxyvitamin D (25(OH)D) concentration <50 nmol/l) is recognised as a public health problem globally. The present study details the prevalence and predictors of vitamin D deficiency in a nationally representative sample (n 3250) of Australian Aboriginal and Torres Strait Islander adults aged ≥18 years. We used data from the 2012-2013 Australian Aboriginal and Torres Strait Islander Health Survey (AATSIHS). Serum 25(OH)D concentrations were measured by liquid chromatography-tandem MS. Survey-weighted logistic regression models were used to determine the independent predictors of vitamin D deficiency. Approximately 27 % of adult AATSIHS participants were vitamin D deficient. Vitamin D deficiency was more prevalent in remote areas (39 %) than in non-remote areas (23 %). Independent predictors of vitamin D deficiency included assessment during winter (men, adjusted OR (aOR) 5·7; 95 % CI 2·2, 14·6; women, aOR 2·2; 95 % CI 1·3, 3·8) and spring (men, aOR 3·3; 95 % CI 1·4, 7·5; women, aOR 2·6; 95 % CI 1·5, 4·5) compared with summer, and obesity (men, aOR 2·6; 95 % CI 1·2, 5·4; women, aOR 4·3; 95 % CI 2·8, 6·8) compared with healthy weight. Statistically significant associations were evident for current smokers (men only, aOR 2·0; 95 % CI 1·2, 3·4), remote-dwelling women (aOR 2·0; 95 % CI 1·4, 2·9) and university-educated women (aOR 2·4; 95 % CI 1·2, 4·8). Given the high prevalence of vitamin D deficiency in this population, strategies to maintain adequate vitamin D status through safe sun exposure and dietary approaches are needed.

FRAX scores are increased in patients with ANCA-associated vasculitis

PURPOSE

Prognosis in ANCA-associated vasculitis (AAV) has greatly improved with immunosuppressive use whereas incidence of treatment-related comorbidities such as osteoporosis has increased. However, studies investigating bone disease in AAV are limited. Fracture Risk Assesment Tool (FRAX) was developed to estimate 10-year hip and major osteoporotic fracture risks. Aim of this study was to estimate FRAX scores in AAV patients and compare them to healthy controls.

METHODS

30 AAV patients and 20 healthy controls were included. Demographic, disease, and medication history were recorded from patient files. Femoral neck, lumbar spine and forearm bone mineral densitometry, and thoracolumbar radiographs were performed. FRAX fracture risk scoring was assessed for all participants.

RESULTS

There were 18 male and 12 female patients. Mean age was 58.5 ± 11.7 years. Osteoporosis and osteopenia were present in 23.3% and 50% of patients, respectively. There were fractures in eight patients (26.7%). FRAX major fracture (9.4 ± 7.3% vs 5.9 ± 3.2%, p = 0.02) and hip fracture (2.2 ± 3.2% vs 0.9 ± 0.8%, p = 0.03) scores were higher in patients than controls. In seven (23.3%) patients, the 10-year probability of hip fracture was  ≥ 3% and in five (16%) patients the 10-year risk of a major osteoporosis-related fracture was  ≥ 20%. None of the controls exceeded these thresholds.

CONCLUSION

AAV patients are at high risk for future fractures as calculated with FRAX. Life-long monitoring for bone disease and fractures are essential. Large studies with longer follow-up are needed to determine the accuracy of FRAX risk scoring in predicting fractures.

Vitamin D Levels in Patients With Small and Medium Vessel Vasculitis

OBJECTIVES

To determine the prevalence of vitamin D deficiency in patients with small and medium vessel systemic vasculitis.

METHODS

In this cross-sectional study, 25-hydroxy (OH) vitamin D3 levels were measured in adult patients with systemic small and medium vessel vasculitis including antineutrophil cytoplasmic antibody-associated vasculitis (AAV), cryoglobulinaemic vasculitis (CryV), IgA vasculitis (IgAV) and polyarteritis nodosa (PAN), and age- and sex-matched healthy subjects (HS) and patients with rheumatoid arthritis (RA) as control groups. 25OH vitamin D3 levels<30ng/ml and <20ng/ml were regarded as insufficiency and deficiency, respectively.

RESULTS

Fifty-seven patients (42 AAV, 2 CryV, 8 IgA vasculitis, 5 PAN) with systemic vasculitis, 101 HS, and 111 RA patients were included. The mean 25OH vitamin D3 level was 21.8±14.2ng/mL in patients with vasculitis, 42.7±27.6ng/mL in HS (p<.001) and 20.1±18.47ng/mL in patients with RA (p=.54). Vitamin D insufficiency and deficiency were significantly higher in patients with systemic vasculitis compared to HS (75.4% vs 33.7%, p<.001; %50 vs 21.8%, p<.001, respectively). Vitamin D status was not different in patients with systemic vasculitis compared to RA. There was a negative correlation between vitamin D status and CRP levels (=-.364, p=.007). The multivariate logistic regression analysis showed that renal involvement was significantly associated with vitamin D deficiency/insufficiency in patients with vasculitis (OR 22.5 [95% CI 1.6-128.9].

CONCLUSION

Vitamin D deficiency and insufficiency are more frequent in patients with systemic small and medium vessel vasculitis and RA than HS. Renal involvement is one of the factors associated with vitamin D deficiency/insufficiency in patients with vasculitis.

Osteoporosis in Patients with Chronic Kidney Diseases: A Systemic Review

Chronic kidney disease (CKD) is associated with the development of mineral bone disorder (MBD), osteoporosis, and fragility fractures. Among CKD patients, adynamic bone disease or low bone turnover is the most common type of renal osteodystrophy. The consequences of CKD-MBD include increased fracture risk, greater morbidity, and mortality. Thus, the goal is to prevent the occurrences of fractures by means of alleviating CKD-induced MBD and treating subsequent osteoporosis. Changes in mineral and humoral metabolism as well as bone structure develop early in the course of CKD. CKD-MBD includes abnormalities of calcium, phosphorus, PTH, and/or vitamin D; abnormalities in bone turnover, mineralization, volume, linear growth, or strength; and/or vascular or other soft tissue calcification. In patients with CKD-MBD, using either DXA or FRAX to screen fracture risk should be considered. Biomarkers such as bALP and iPTH may assist to assess bone turnover. Before initiating an antiresorptive or anabolic agent to treat osteoporosis in CKD patients, lifestyle modifications, such as exercise, calcium, and vitamin D supplementation, smoking cessation, and avoidance of excessive alcohol intake are important. Managing hyperphosphatemia and SHPT are also crucial. Understanding the complex pathogenesis of CKD-MBD is crucial in improving one’s short- and long-term outcomes. Treatment strategies for CKD-associated osteoporosis should be patient-centered to determine the type of renal osteodystrophy. This review focuses on the mechanism, evaluation and management of patients with CKD-MBD. However, further studies are needed to explore more details regarding the underlying pathophysiology and to assess the safety and efficacy of agents for treating CKD-MBD.

The Association of Vitamin D Status with Lipid Profile and Inflammation Biomarkers in Healthy Adolescents

Background: The association between vitamin D status and inflammatory biomarkers and lipid profile is not well known, especially in adolescents. Therefore, the aim of the current study is to investigate the association of vitamin D status with serum lipids and inflammatory biomarkers, including IL-10, IL-6, hsCRP, and TNFR-2, in male adolescents. Methods and materials: A sample of seventy-one high school male students, aged 17 years old, from a high school in Tehran were enrolled in the study. They were divided into four groups including group with serum vitamin D below 25 (ng/mL) (SVD < 25; n = 36), 25 and above (ng/mL) (SVD ≥ 25; n = 35), negative-hsCRP (n = 48), and positive-hsCRP (n = 23). Weight, height, body mass index, dietary intake, serum lipids, and inflammatory biomarkers, including IL-10, IL-6, hsCRP, and TNFR-2, were measured. Results: In the (SVD < 25) group, the serum level of TNFR-2 was significantly higher compared to that in the (SVD ≥ 25) group. There was a significant negative association between serum TNFR-2 and vitamin D levels in the whole sample. We found significant lower levels of IL-10 in positive-hsCRP group compared to the negative-hsCRP group. In addition, there was a significant negative correlation between the serum vitamin D level and hsCRP in both hsCRP groups. The HDL level was lower in the (SVD < 25) group compared to that in the (SVD ≥ 25) group. Finally, there was a negative correlation between the serum HDL and hsCRP levels in the positive-hsCRP subjects. Conclusion: Based on the findings it can be concluded that serum vitamin D affects HDL and inflammation status. Although serum levels of HDL and inflammation status are both predictors of metabolic syndrome and cardiovascular disease, further studies are needed to prove it, especially in adolescents.

Effect of Resistance Exercise Plus Cholecalciferol on Nutritional Status Indicators in Adults With Stage 4 Chronic Kidney Disease

OBJECTIVE

Decreased serum concentrations of 25-hydroxyvitamin D (25(OH)D) affect people with chronic kidney disease (CKD); lower concentrations of 25(OH)D have been associated with decrease in nutritional status indicators. On the other hand, muscle resistance exercise has improved the nutritional status of patients with CKD.The aim of this study was to evaluate the effect of resistance exercise and dietary supplementation with cholecalciferol on nutritional status indicators in adults with stage 4 CKD.

METHODS

Patients with an estimated glomerular filtration rate between 15 and 29 mL/min/1.73 m² in an open-label clinical trial were followed for 12 weeks. The intervention group received exercise resistance training sessions three times per week with oral cholecalciferol supplementation each day. The control group only received standard medical care. The outcomes were anthropometric measurements, handgrip strength, and bioelectrical impedance analysis.

RESULTS

Thirty-nine patients of a median age of 48 (36-52) years had an estimated glomerular filtration rate of 21.8 ± 6.5 mL/min/1.73 m². A total of 57.5% of the patients were women. In 41% of the patients, the etiology of CKD was diabetes. After 12 weeks, in the intervention group, the adherence to the resistance training was 77%, and the adherence to the supplementation with cholecalciferol was 96.2%. Significant improvements in 25(OH)D serum concentrations and in handgrip strength were detected in the intervention group (P < .05). In the control group, a decrease in 25(OH)D serum concentrations and a loss in handgrip strength were observed, although the difference was not statistically significant. Anthropometrics and biochemical and dietary indicators, but not bioelectrical impedance data, exhibited changes.

CONCLUSION

Supplementation with cholecalciferol improves serum concentrations of 25(OH)D and, when combined with resistance exercise, improved muscle function as measured by handgrip strength in a study of patients with CKD not on dialysis.

Native Hypovitaminosis D in CKD Patients: From Experimental Evidence to Clinical Practice

Native hypovitaminosis D (n-hVITD) is frequently found from the early stages of chronic kidney disease (CKD) and its prevalence increases with CKD progression. Even if the implications of n-hVITD in chronic kidney disease-mineral bone disorder (CKD-MBD) have been extensively characterized in the literature, there is a lot of debate nowadays about the so called “unconventional effects” of native vitamin D (25(OH)VitD) supplementation in CKD patients. In this review, highlights of the dimension of the problem of n-hVITD in CKD stages 2–5 ND patients will be presented. In addition, it will focus on the “unconventional effects” of 25(OH)VitD supplementation, the clinical impact of n-hVITD and the most significant interventional studies regarding 25(OH)VitD supplementation in CKD stages 2–5 ND.

Health Benefits of Resveratrol in Kidney Disease: Evidence from In Vitro and In Vivo Studies

Different diseases and disorders that affect the kidneys include, but are not limited to, glomerulonephritis, diabetic nephropathy, polycystic kidney disease, kidney stones, renal fibrosis, sepsis, and renal cell carcinoma. Kidney disease tends to develop over many years, making it difficult to identify until much later when kidney function is severely impaired and undergoing kidney failure. Although conservative care, symptom management, medication, dialysis, transplantation, and aggressive renal cancer therapy are some of the current strategies/approaches to kidney disease treatment, new preventative targeted therapies are needed. Epidemiological studies have suggested that a diet rich in fruits and vegetables is associated with health benefits including protection against kidney disease and renal cancer. Resveratrol, a polyphenol found in grapes and berries, has been reported to have antioxidant, anti-inflammatory, antidiabetic, hepatoprotective, neuroprotective, and anti-cancer properties. The current review summarizes the existing in vitro and in vivo animal and human studies examining the nephroprotective effects of resveratrol.

Aortic pulse wave velocity is greater in peritoneal dialysis patients with lower dual energy X-ray absorptiometry (DXA) femoral neck bone mineral density

BACKGROUND

Increased vascular stiffness is associated with low bone mineral density (BMD) in the general population, and both are risk factors for mortality. We wished to determine whether vascular stiffness is associated with BMD in peritoneal dialysis (PD) patients.

METHODS

We measured vascular stiffness by aortic pulse wave velocity (aPWV), BMD by dual electron absorptiometry (DXA) scanning, and body composition using bioimpedance.

RESULTS

We reviewed DXA scans in 125 PD patients, 56.8% male, mean age 64.4 ± 15.3 years, mean aPWV, 10.2 ± 2.6 m/s. We divided patients by aPWV (< 10 and > 10 m/s), and there were no statistical differences in patient demographics, body composition, PD adequacy, peritoneal and urinary calcium losses. On univariate analysis aPWV was negatively associated with total body T score (r = - 0.20, p = 0.037). On multivariable logistic regression patients with higher aPWV were prescribed fewer non-calcium containing phosphate binders, odds ratio (OR) 0.83, 95% confidence interval (CI) 0.70-0.99, p = 0.039, more had lower 25 hydroxy-vitamin D₃ concentrations < 50 ng/L (OR 0.34, CI 0.12-0.93, p = 0.035, and lower femoral BMD OR 0.03 (CI 0-0.3.4), p = 0.029, but there was no association with total or lumbar spine BMD.

CONCLUSION

Our study reinforces the hypothesis of a link between bone disease and vascular disease in dialysis patients. As patients with higher aPWV were prescribed fewer non-calcium containing phosphate binders and fewer had higher 25 hydroxy-vitamin D₃ concentrations, then this raises the possibility that differences in clinical practice and drug prescribing may help to reduce vascular stiffness, which will require testing in future trials.

Correlation of the severity of chronic kidney disease with serum inflammation, osteoporosis and vitamin D deficiency

Correlation of the severity of chronic kidney disease (CKD) with serum inflammation, osteoporosis and vitamin D deficiency was investigated. A total of 78 patients suffering from CKD who presented to the Union Hospital from December 2015 to December 2017 were selected randomly and divided into three groups based on the severity of the disease. Comparisons of interleukin-6 (IL-6), C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), indicators of osteoporosis [serum phosphate, serum calcium and bone mineral density (BMD)], content of 25(OH)D, serum sodium, serum potassium and BUN were conducted among groups. The correlation of in vivo creatinine (Cr) with C-reactive protein (CRP), TNF-α, BMD and vitamin D deficiency were analyzed. With the aggravation of illness, IL-6, CRP, TNF-α, serum phosphate, serum sodium, serum potassium and blood urea nitrogen (BUN) were increased gradually, while serum calcium, BMD and vitamin D were decreased significantly (P<0.05). The content of Cr in patients suffering from osteoporosis was significantly higher than that in normal group (P<0.05). The Cr of patients in the group with abnormal CRP was significantly higher than that with normal CRP (P<0.05). Analysis showed that there is positive correlation between Cr and CRP (r=0.6961, P<0.001), as well as between Cr and TNF-α (r=0.8969, P<0.001); and negative correlation between Cr and BMD (r=0.5472, P<0.001), and between Cr and 25(OH)D (r=0.4733, P<0.001). The severity of CKD is correlated with serum inflammation, osteoporosis and vitamin D deficiency. The higher the severity of the illness, the worse the condition of osteoporosis will be.

Klotho and Postmenopausal Hormone Replacement Therapy in Women with Chronic Kidney Disease

Kidney function is highly susceptible to age-related changes, with chronic kidney disease (CKD) serving as an important cause of morbidity and mortality in older patients. The prevalence of CKD in Korea is higher among the elderly, relative to the general population, with the most significant increases seen following the onset of menopause. Under normal conditions, estrogen attenuates renal superoxide production and protects the kidney from oxidative damage. As estrogen levels are known to decrease by as much as 80% during menopause, this represents a significant risk for older women. Postmenopausal hormone replacement therapy (HRT) modulates the renin-angiotensin system, thereby reducing the progressive deterioration of renal function. Use of estrogen-based HRT has been shown to ameliorate renal function in postmenopausal women, and delay CKD progression. Renal expression of klotho, an important suppressor of aging, is markedly decreased in CKD patients, making it a promising candidate for use as a prognostic biomarker in CKD. Here, we review the key links between renal function, sex, age, and estrogen levels during menopause, and discuss the use of postmenopausal HRT in CKD attenuation.