Prevalence of chronic kidney disease in hypertensive patients in Ghana

Chronic kidney disease (CKD) is common in tropical Africa although there are few data on the prevalence of this disorder. Therefore we initiated a multicenter screening study to identify the prevalence and staging of CKD in 712 patients with known hypertension in four polyclinics in Accra, Ghana. We measured estimated glomerular filtration rate by the six-variable modification of diet in renal disease equation and proteinuria by the protein/creatinine ratio. All the subjects studied were Ghanaian. Of the 712 patients studied, the median age was 59 years (range 19-90 years) and 560 (78.7%) of the patients were female. The mean duration of hypertension was 4 years (range 0.1-50). The overall prevalence of CKD was 46.9% (95% CI: 43.2-50.7%); 19.1% had CKD stages 1-2 and 27.8% had CKD stages 3-5. There was no difference in age between patients with or without CKD (p?=?0.12). The overall prevalence of proteinuria was 28.9% (95% CI: 25.6-32.4%); 14.7% of subjects had preexisting diabetes mellitus and their prevalence of CKD (55%; 95% CI: 42.4-62.2) did not differ from those without diabetes (46%; 95% CI: 41.9-50.0, p?=?0.133). CKD is common in hypertensive patients in Ghana, with a prevalence of 46.9%. This provides justification for the inclusion of this group in CKD screening programs in Ghana.     

Development of chronic kidney disease and cardiovascular prognosis in essential hypertensive patients

The existence of a significant percentage of treated hypertensive patients presenting a diminished renal function has been recently described. Mild renal function abnormalities are recognized as powerful predictors of cardiovascular morbidity and mortality. However, longitudinal data demonstrating this association are lacking. The objectives of this study have been analysis of the evolution of GFR, assessed as creatinine clearance (CrCl), during long-term follow-up of hypertensive patients and evaluation of the impact of the development of chronic kidney disease (CKD) on cardiovascular prognosis. A historical cohort of 281 patients attending our Hypertension Unit was selected according to the following criteria: essential hypertension, more than 5 yr of follow-up, and normal GFR at baseline (CrCl > 90 ml/min per 1.73 m(2)). Patients had an average follow-up of 13.2 +/- 4.8 yr. Forty-one patients (14.6%) developed CKD (CrCl < 60 ml/min per 1.73 m(2)) attributed to hypertensive nephrosclerosis. Initial serum creatinine, age, systolic BP at baseline, and average total cholesterol during follow-up were independent predictors of CKD development. Forty-nine (17.4%) of 281 patients presented a cardiovascular event during follow-up: 17 patients (40.6%) who developed CKD and 32 patients (13.3%) with preserved renal function (log rank test P < 0.001). After adjustment in a Cox multivariate analysis, age, development of CKD during follow-up, and male gender were independent predictors of the appearance of cardiovascular events. In essential hypertensive patients with normal renal function at baseline, the development of CKD during the follow-up is strongly and independently related with poor cardiovascular prognosis.     

慢性肾脏病并发高血压危象临床分析

目的探讨慢性肾脏病（CKD）合并高血压危象患者的发病诱因、诊治时间与肾功能改善的相关性。方法回顾性分析我院10年来发生高血压危象的38例CKD患者的临床资料,对表现为慢性肾衰竭急性加重的患者进行随访。结果38例中,15例发生高血压危象时有明确诱因,主要为情绪激动、过度劳累和大量饮酒。高血压危象发病季节以秋冬季为主,就诊时间在起病24h之后居多。在18例表现为慢性肾衰竭急性加重的CKD患者中,24h内就诊者出院时肾功能明显改善,平均随访1年,坚持降压治疗者进入替代治疗的比率显著低于未规律服药者（P=0．020）。结论高血压危象使CKD患者的肾功能急剧恶化,及时就诊和有效的降压治疗可以延缓肾功能恶化。     

Blood pressure measures and risk of chronic kidney disease in men.

BACKGROUND: High blood pressure (BP) has been associated with a decrease in kidney function. However, it remains unclear which BP measure best predicts impaired kidney function. METHODS: We compared systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse pressure (PP) and mean arterial pressure (MAP) in predicting risk of chronic kidney disease (CKD). We prospectively followed 8093 male participants in the Physicians' Health Study, without a known history of kidney disease at baseline, who provided BP values on the baseline and 24-month questionnaires, and for whom we had creatinine measures after 14 years of follow-up. Reported BP was averaged from both questionnaires. The main outcome was CKD, defined as an estimated glomerular filtration rate <60 mL/min/1.73 m(2). We used multivariable-adjusted logistic regression to evaluate the association between BP measures and CKD and compared models using the likelihood ratio test. RESULTS: After 14 years of follow-up, 1039 men (12.8%) had CKD. An increase of 10 mmHg had corresponding multivariable-adjusted odds ratios (95% confidence intervals) of 1.11 (1.03-1.19) for SBP, 1.11 (1.00-1.23) for MAP, 1.14 (1.05-1.25) for PP and 1.05 (0.93-1.17) for DBP. SBP and PP were the strongest predictors of chronic kidney function, with equal predictive abilities. Combining BP measures did not add significantly to the prediction. CONCLUSIONS: Increases in SBP, PP and MAP were significantly associated with CKD. SBP may be the most clinically useful predictor of CKD, since no further calculations are required.     

The association of serum inflammatory biomarkers with chronic kidney disease in hypertensive patients

A positive association between inflammation and chronic kidney disease (CKD) has been reported but the impact of hypertension on this relation remains unclear. The aim of this study is to investigate the association of various inflammation markers with risk of CKD in hypertensive patients. 387 hypertensive patients (mean age 55.5 years) were recruited. Serum matrix metalloproteinase-2 (MMP-2), matrix metalloproteinase-9 (MMP-9), tissue inhibitor of metalloproteinase-1(TIMP-1), high-sensitivity C-reactive protein (hsCRP) and osteopontin (OPN) were measured by ELISA. CKD was diagnosed either as evidence of kidney damage, including microalbuminuria, or by low glomerular filtration rate (GFR) (<60?mL/min/1.73?m²), which was estimated using the Modification of Diet in Renal Disease (MDRD) abbreviated equation. Compared with the reference groups (eGFR?≥?60?mL/min/1.73?m²), the serum levels of TIMP-1, OPN, hsCRP were significantly higher, and the MMP-9/TIMP-1 ratio was lower in the risk group (eGFR?2). Multiple logistic regression analysis showed that TIMP-1, MMP-9/TIMP-1 ratio, OPN and hsCRP were associated with low GFR separately after adjustment, whereas MMP-9/TIMP-1 ratio, OPN and hsCRP were associated with microalbuminuria. The significant association of MMP-9/TIMP-1 ratio and OPN with low GFR and microalbuminuria persisted after additional adjustment for other studied inflammatory biomarkers. Our data suggest that inflammation is strongly and independently associated with renal damage in hypertensive patients. MMP-9/TIMP-1 ratio and OPN may serve as novel risk factors and therapeutic targets for the treatment of CKD in hypertensive patients.     

Relationship of femoral artery ultrasound measures of atherosclerosis with chronic kidney disease

Background

Chronic kidney disease (CKD) is strongly associated with peripheral artery disease (PAD). Detection of subclinical PAD may allow early interventions for or prevention of PAD in persons with CKD. Whether the presence of atherosclerotic plaque and femoral intima-media thickness (IMT) are associated with kidney function is unknown.

慢性肾脏病患者降压药物的合理选用

高血压作为心血管疾病传统的危险因素,在慢性肾脏病(CKD)的发展中起到了重要作用。它既是导致CKD的主要病因,也是CKD最常见的并发症。控制CKD患者血压达标不仅有利于延缓CKD进展,还可降低心血管事件发生。但CKD患者病因复杂、疾病阶段不一,降压药物的合理选用极为重要。     

Assessment of dual-energy x-ray absorptiometry measures of bone health in pediatric chronic kidney disease

Background

Dual-energy X-ray absorptiometry (DXA) techniques are limited in childhood chronic kidney disease (CKD) by the confounding effect of short stature and opposing parathyroid hormone effects on trabecular and cortical bone. Peripheral quantitative computed tomography (pQCT) is not subject to these limitations.

Methods

Lumbar spine (LS) and whole-body (WB) DXA and tibia pQCT scans were obtained in 88 stage 4–5 CKD and >650 healthy participants, ages 5–21?years. Sex- and race-specific Z-scores were generated for bone mineral density (BMD) and bone mineral content (BMC) by DXA, relative to age and adjusted for height Z-score (LS-BMD-Z and WB-BMC-Z), and compared to pQCT Z-scores for trabecular BMD (TrabBMD-Z) for age and cortical BMC (CortBMC-Z) for age and tibia length.

Results

LS-BMD-Z [0.50 (95% C.I. 0.28, 0.73), p? p? p? p? R?=?0.36) and cortical (WB-BMC-Z and CortBMC-Z: R?=?0.64) sites in CKD; similar to correlations in reference participants.

Conclusions

Lumbar spine and whole-body DXA suggested greater trabecular BMD and lower cortical BMC in CKD, consistent with pQCT results; however, correlations were modest. Studies are needed to identify methods that predict fracture in childhood CKD.     

Update on pregnancy in chronic kidney disease

The occurrence of pregnancy in patients with chronic kidney disease (CKD) has been considered a dangerous event both for the mother and for the fetus. However, increasing evidence shows that the stage of CKD is the leading factor that can predict possible acceleration in the declining of renal function and complications of pregnancy. This review summarizes recent data on pregnancy in patients with CKD, dialysis and kidney transplantation.     

Tuberculosis in chronic kidney disease

BACKGROUND: The incidence of tuberculosis is high in chronic kidney disease (CKD) which needs a high index of suspicion, early diagnosis and management for gratifying outcome. MATERIALS: The clinical, laboratory profile, management and outcome of tuberculosis in 36 patients with chronic kidney disease between 2000 and 2005 constitute the material of this study. RESULTS: During this study period, over 900 chronic renal failure patients were evaluated in our unit and 36 of them were found to have tuberculosis, the incidence being 4%. In majority (69.4%), tuberculosis was observed in association with CKD Stage V. Age range was 25 - 77 years, male : female ratio was 33 : 3. Fever, malaise and weight loss were the commonest symptoms observed at presentation. Extrapulmonary tuberculosis (23 patients, 63.8%) predominated over pulmonary tuberculosis (10 patients, 36.1%). Tuberculin skin test was negative in 23 patients (63.8%). The diagnosis of tuberculosis was confirmed by tissue or specimen examination in 17 patients (47.2%) and in the rest it was empirical basing on clinical picture, pleural fluid analysis and radiological tests. All the patients were planned for a minimum period of 9-month antituberculous therapy (ATT). Of them, 17 patients (47.2%) were cured from tuberculosis and did not relapse, 9 patients (25%) died during treatment and 10 patients were lost for follow-up. Two patients were managed for anti-tuberculous therapy-related side effects: hepatotoxicity and psychosis. CONCLUSIONS: We observed a 4% incidence of tuberculosis in CKD. Extrapulmonary form of tuberculosis predominated over pulmonary form. Fever and malaise were important clues for suspicion of tuberculosis. Tuberculin skin test was negative in the majority. Diagnostic confirmation was possible in 47.2% of patients and in the rest it was based on clinical suspicion, pleural fluid analysis and radiological findings. Cure from tuberculosis was observed in 47.2% of patients with antituberculous therapy.     

Growth in chronic kidney disease

Poor growth is a common sequela of CKD in childhood. It not only affects the psychosocial development of a child but also has significant effects even in the adult life. The multifactorial etiology and severe consequences of growth failure in CKD warrant evaluation of all the modifiable and nonmodifiable causes. Treatment strategies must be directed toward the specific factors for each child with CKD. Among the various metabolic, nutritional, and hormonal disturbances complicating CKD, disordered growth hormone (GH) and insulin-like growth factor-1 axis are important contributors toward poor growth in children with CKD. CKD is recognized as a state of GH resistance rather than GH deficiency, with multiple mechanisms contributing to this GH resistance. Recombinant GH (rGH) therapy can be used in this population to accelerate growth velocity. Although its use has been shown to be effective and safe in children with CKD, there continues to be some uncertainty and reluctance among practitioners and families regarding its usage, thereby resulting in a surprisingly low use in children with CKD. This review focuses on the pathogenesis of growth failure, its effect, and management strategies in children with CKD.     

Depression in chronic kidney disease

Depression is the most frequent psychiatric problem in patients with chronic renal disease and may predict patient outcome and mortality. Depression is linked to stressful life characterized by many losses and by dependence, which even may lead to suicide. Despite the large number of patients with chronic kidney disease and the economic burden they represent, only a few of these patients receive adequate diagnosis and therapy. Diagnostic and Statistical Manual of Mental Disorders-IV criteria for major depression may help in differentiating symptoms of uremia and depression. Pharmacotherapy is available and antidepressants (tricyclic antidepressants and selective serotonin re-uptake inhibitors) have been used successfully in various studies. Finally, there is a need for further well-designed, longitudinal, survival studies to clarify the relationship better between depression and the different stages of renal dysfunction.     

Bisalbuminemia in chronic kidney disease

Hereditary and acquired bisalbuminemia, in which the serum contains an albumin variant differing from albumin A by single amino-acid substitutions, have been reported in different races or ethnic groups and in association with various pathologic states. The importance of this rare condition in the pathophysiology of established diseases is uncertain. We evaluated a 68-year-old woman with chronic kidney disease who presented with worsened serum creatinine concentration despite lack of dietary or medical changes. Serum protein electrophoresis was performed with an automated rapid electrophoresis system. Bisalbuminemia was noted as an incidental finding on serum protein electrophoresis. The serum creatinine level stabilized with dietary protein restriction and a -blocking agent/diuretic combination for blood pressure control. Although the possibility that some physiologic or pharmacologic substances may not bind to abnormal albumin variants as well as they bind to normal albumin should not be discounted, the finding of bisalbuminemia did not influence the diagnosis, management, course, or prognosis of chronic kidney disease. The role of persistent bisalbuminemia in renal disease is uncertain.     

Oxidants in chronic kidney disease

Chronic kidney disease is a worldwide public health problem that affects approximately 10% of the US adult population and is associated with a high prevalence of cardiovascular disease and high economic cost. Chronic renal insufficiency, once established, tends to progress to end-stage kidney disease, suggesting some common mechanisms for ultimately causing scarring and further nephron loss. This review defines the term reactive oxygen metabolites (ROM), or oxidants, and presents the available experimental evidence in support of the role of oxidants in diabetic and nondiabetic glomerular disease and their role in tubulointerstitial damage that accompanies progression. It concludes by reviewing the limited human data that provide some proof of concept that the observations in experimental models may be relevant to human disease.     

Polysomnographic measures of nocturnal sleep in patients on chronic, intermittent daytime haemodialysis vs those with chronic kidney disease.

BACKGROUND: Numerous factors probably contribute to the high prevalence of sleep problems in haemodialysis (HD) patients including metabolic changes and treatment-related factors. In contrast, the sleep problems of patients with chronic kidney disease (CKD) may be more related to psychological factors rather than the metabolic changes associated with renal disease. Thus, the objective of this study was to compare polysomnographic measures of nocturnal sleep in a group of stable patients on chronic, intermittent daytime HD and an age- and gender-matched, metabolically comparable group with CKD, and evaluate the role that quality of life (including psychological factors) and the effects of treatment may play in sleep outcomes. METHODS: The sample included 16 patients on HD and eight patients with CKD all of whom were free from other significant physical and psychological morbidity. To assess for psychological, functional, family and economic responses to the disease and treatment, all subjects took the Ferrans and Powers Quality of Life Index. HD subjects received treatment three times a week and were adequately dialysed [Kt/V >1.2, equivalent to a weekly glomerular filtration rate (GFR) of 10-15 ml/min]; CKD subjects had an estimated GFR of 14.5 (+/-7.2; range 5.4-28.8) ml/min. All subjects underwent one night of laboratory-based polysomnography. Appropriate statistical procedures were used to explore group differences in sleep variables and their relationship to quality of life dimensions and the effect of treatment. RESULTS: The CKD patients reported significantly poorer functional and psychological quality of life; both groups had reduced total sleep time and sleep efficiency in comparison with normative data. However, HD subjects had less rapid eye movement sleep (P = 0.032). They also had a higher brief arousal index (P = 0.000), an independent predictor of which was treatment with HD, and respiratory disturbance index (P = 0.061). Less total sleep time, increased wake after sleep onset, lower sleep efficiency, higher periodic limb movement index, and longer latencies to sleep onset and rapid eye movement sleep were also noted in the HD group. Quality of life scores did not predict sleep variables in this small sample. CONCLUSIONS: The results suggest that the sleep problems of patients with CKD and those receiving chronic, intermittent daytime HD may have different aetiologies; functional and psychological factors may play a more prominent role in the former group, while intrinsic sleep disruption (arousals, apnoeas and limb movements) secondary to the effects of chronic, intermittent daytime HD may play a more significant role in the latter. The findings suggest that further exploration is warranted and that population-specific sleep-promoting interventions may be indicated.     

Progression in chronic kidney disease

The pathogenic mechanisms that lead to chronic kidney disease (CKD) converge on a common pathway that results in progressive interstitial fibrosis, peritubular capillary loss with hypoxia, and destruction of functioning nephrons because of tubular atrophy. Interstitial recruitment of inflammatory leukocytes and myofibroblasts occurs early in kidneys destined to develop fibrosis. Circulating monocytes are recruited by locally secreted chemoattractant molecules, facilitated by leukocyte adhesion molecules. Functionally heterogeneous macrophages secrete many fibrosis-promoting molecules, but under some circumstances they may also serve a protective scavenging role. Excessive extracellular matrix production occurs primarily within interstitial myofibroblasts, a population of cells that appears to have more than 1 origin, including the resident interstitial fibroblasts, trans-differentiated tubular epithelial cells, and bone marrow-derived cells. Impaired activity of the endogenous renal matrix-degrading proteases may enhance interstitial matrix accumulation, but the specific pathways that are involved remain unclear. Tubules, inflammatory cells, and myofibroblasts synthesize the molecules that activate the fibrogenic cascades, the most important of which is transforming growth factor beta (TGF-beta). TGF-beta may direct cells to assume a pro-fibrotic phenotype or it may do so indirectly after stimulating synthesis of other fibrogenic molecules such as connective tissue growth factor and plasminogen activator inhibitor-1. Reduced levels of antifibrotic factors that are normally produced in the kidney such as hepatocyte growth factor and bone morphogenic protein-7 may accelerate fibrosis and its destructive consequences. Development of new therapeutic agents for CKD looks promising, but several agents that target different components of the fibrogenic cascade will almost certainly be necessary.     

慢性肾脏病的流行病学研究

在人类的发展史中，疾病谱的变迁可以分为3个阶段：“瘟疫与饥荒的年代”，“传染性疾病时代”和“退行性疾病及人为疾病时代”。目前慢性非感染性疾病已经成为人类面临的主要健康问题，其中包括慢性肾脏病(CKD)。美国肾脏数据登记系统(USRDS)的数据显示，从1988年至2002年美国终末期肾病(ESRD)的年发病率由39．4／百万人口上升至98-3／百万人。据估计，未来10年该数据仍将以每年4．1％的百分比上升。在我国，1999年全国透析移植登记报告的数据显示当年新进入透析的患者占透析患者总数的41、7％，     

Metabolic bone disease in chronic kidney disease

Metabolic bone disease is a common complication of chronic kidney disease (CKD) and is part of a broad spectrum of disorders of mineral metabolism that occur in this clinical setting and result in both skeletal and extraskeletal consequences. Detailed research in that past 4 decades has uncovered many of the mechanisms that are involved in the initiation and maintenance of the disturbances of bone and mineral metabolism and has been translated successfully from "bench to bedside" so that efficient therapeutic strategies now are available to control the complications of disturbed mineral metabolism. Recent emphasis is on the need to begin therapy early in the course of CKD. Central to the assessment of disturbances in bone and mineral metabolism is the ability to make an accurate assessment of the bone disease by noninvasive means. This remains somewhat problematic, and although measurements of parathyroid hormone are essential, recently recognized difficulties with these assays make it difficult to provide precise clinical practice guidelines for the various stages of CKD at the present time. Further research and progress in this area continue to evaluate the appropriate interventions to integrate therapies for both the skeletal and extraskeletal consequences with a view toward improving patient outcomes.