Gavin Dreyer

The effect of ethnicity on the prevalence of diabetes and associated chronic kidney disease

BACKGROUND The effect of ethnicity on the prevalence of diabetes mellitus (DM) and associated chronic kidney disease (CKD) is unknown. AIM To establish the impact of ethnicity on the prevalence and severity of diabetes mellitus and associated CKD. DESIGN Cross-sectional study of 34 359 adult diabetic patients in three primary care trusts in the UK. METHODS Read coded data from general practice computers was used to analyse the relationship between ethnicity, DM and CKD. RESULTS The prevalence of DM was 3.5% for Whites, 11% for South Asians and 8% for Black groups. The prevalence of CKD (stages 3-5) among diabetics was 18%. CKD stage 3 was more prevalent in Whites compared to South Asians--OR 0.79 (95% CI: 0.71-0.87) and Blacks--OR 0.49 (95% CI: 0.43-0.57). Among all CKD patients severity (CKD stages 4, 5) was associated with Black (OR 1.39, 95% CI: 1.06-1.81) and South Asian (OR 1.54, 95% CI: 1.26-1.88) ethnicity compared to Whites. Less than 50% of diabetics with CKD met the target blood pressure (BP) of 130/80 mmHg. The prevalence of a blood pressure > 150/90 mmHg in diabetics with CKD was South Asian 15.6%, White 13.9%, Black 21.8% (P < 0.001). Proteinuria was present in 8.6% of all diabetic patients. However, this increased to 18.6% in patients with CKD, and was more frequent in Black (22.6%) and South Asian (21%) patients compared to White patients (14.1%) (P < 0.001). CONCLUSION Significant disparities exist between the major ethnic groups in both disease prevalence and management. Future studies examining the management of CKD need to take variation by ethnicity into account.

Ergocalciferol and microcirculatory function in chronic kidney disease and concomitant vitamin d deficiency: an exploratory, double blind, randomised controlled trial.

Background and Objectives Vitamin D deficiency and endothelial dysfunction are non-traditional risk factors for cardiovascular events in chronic kidney disease. Previous studies in chronic kidney disease have failed to demonstrate a beneficial effect of vitamin D on arterial stiffness, left ventricular mass and inflammation but none have assessed the effect of vitamin D on microcirculatory endothelial function. Study Design We conducted a randomised controlled trial of 38 patients with non diabetic chronic kidney disease stage 3–4 and concomitant vitamin D deficiency (<16 ng/dl) who received oral ergocalciferol (50,000 IU weekly for one month followed by 50,000 IU monthly) or placebo over 6 months. The primary outcome was change in microcirculatory function measured by laser Doppler flowmetry after iontophoresis of acetylcholine. Secondary endpoints were tissue advanced glycation end products, sublingual functional capillary density and flow index as well as macrovascular parameters. Parallel in vitro experiments were conducted to determine the effect of ergocalciferol on cultured human endothelial cells. Results Twenty patients received ergocalciferol and 18 patients received placebo. After 6 months, there was a significant improvement in the ergocalciferol group in both endothelium dependent microcirculatory vasodilatation after iontophoresis of acetylcholine (p = 0.03) and a reduction in tissue advanced glycation end products (p = 0.03). There were no changes in sublingual microcirculatory parameters. Pulse pressure (p = 0.01) but not aortic pulse wave velocity was reduced. There were no significant changes in bone mineral parameters, blood pressure or left ventricular mass index suggesting that ergocalciferol improved endothelial function independently of these parameters. In parallel experiments, expression of endothelial nitric oxide synthase and activity were increased in human endothelial cells in a dose dependent manner. Conclusions Ergocalciferol improved microcirculatory endothelial function in patients with chronic kidney disease and concomitant vitamin D deficiency. This process may be mediated through enhanced expression and activity of endothelial nitric oxide synthase. Trial Registration Clinical trials.gov NCT00882401

The relationship of ethnicity to the prevalence and management of hypertension and associated chronic kidney disease.

BackgroundThe effect of ethnicity on the prevalence and management of hypertension and associated chronic kidney (CKD) disease in the UK is unknown.MethodsWe performed a cross sectional study of 49,203 adults with hypertension to establish the prevalence and management of hypertension and associated CKD by ethnicity. Routinely collected data from general practice hypertension registers in 148 practices in London between 1/1/07 and 31/3/08 were analysed.ResultsThe crude prevalence of hypertension was 9.5%, and by ethnicity was 8.2% for White, 11.3% for South Asian and 11.1% for Black groups. The prevalence of CKD stages 3-5 among those with hypertension was 22%. Stage 3 CKD was less prevalent in South Asian groups (OR 0.77, 95% CI 0.67 - 0.88) compared to Whites (reference population) with Black groups having similar rates to Whites. The prevalence of severe CKD (stages 4-5) was higher in the South Asian group (OR 1.53, 95% CI 1.17 - 2.0) compared to Whites, but did not differ between Black and White groups. In the whole hypertension cohort, achievement of target blood pressure (< 140/90 mmHg) was better in South Asian (OR 1.43, 95% CI 1.28 - 1.60) and worse in Black groups (OR 0.79, 95% CI 0.74 - 0.84) compared to White patients. Hypertensive medication was prescribed unequally among ethnic groups for any degree of blood pressure control.ConclusionsSignificant variations exist in the prevalence of hypertension and associated CKD and its management between the major ethnic groups. Among those with CKD less than 50% were treated to a target BP of ≤ 130/80 mmHg. Rates of ACE-I/ARB prescribing for those with CKD were less than optimal, with the lowest rates (58.5%) among Black groups.

Progression of chronic kidney disease in a multi-ethnic community cohort of patients with diabetes mellitus.

Ethnicity is a risk factor for the prevalence of severe chronic kidney disease among patients with diabetes. We studied the effect of ethnicity on progression of chronic kidney disease in people with diabetes managed in community settings.

A cohort study on the rate of progression of diabetic chronic kidney disease in different ethnic groups.

Objective To compare the rate of progression of diabetic chronic kidney disease in different ethnic groups. Design Prospective longitudinal observational study. Participants All new patients attending a tertiary renal unit in east London with diabetic chronic kidney disease between 2000 and 2007 and followed up till 2009 were included. Patients presenting with acute end-stage kidney failure were excluded. Main outcome measures The primary outcome was annual decline in the estimated glomerular filtration rate (eGFR) in different ethnic groups. Secondary end points were the number of patients developing end-stage kidney failure and total mortality during the study period. Results 329 patients (age 60±11.9 years, 208 men) were studied comprising 149 south Asian, 105 White and 75 Black patients. Mean follow-up was 6.0±2.3, 5.0±2.7 and 5.6±2.4 years for White, Black and south Asian patients, respectively. South Asian patients were younger and had a higher baseline eGFR, but both systolic and diastolic blood pressures were higher in Black patients (p<0.05). Baseline proteinuria was highest for the south Asian group followed by the White and Black groups. Adjusted linear regression analysis showed that an annual decline in eGFR was not significantly different between the three groups. The numbers of patients developing end-stage kidney failure and total mortality were also not significantly different between the three groups. ACE or angiotensin receptor blockers use, and glycated haemoglobin were similar at baseline and throughout the study period. Conclusions We conclude that ethnicity is not an independent factor in the rate of progression renal failure in patients with diabetic chronic kidney disease.

Collection of data on race and ethnic group by physician practices.

To the Editor: We support the principle that Wynia et al. (March 4 issue)1 outline on the collection of data on patients’ race and ethnic group. It is critical, however, to link that information to the delivery of care. Comparative feedback and public reporting of outcomes according to race and ethnic group are necessary to lessen the gap in results between these groups. These efforts also will increase awareness about the unique health challenges faced by specific populations.2 HealthPartners Medical Group reports key clinical outcomes of more than 400,000 patients. These outcomes are classified according to socioeconomic status and race and ethnic group. Since 2004, more than 90% of patients have willingly shared their race and ethnic group, country of origin, and preferred language. We are using the information to improve care. Where we have identified gaps in the care of minority patients, we have implemented targeted interventions. We established a structured approach to improve rates of mammographic screening among minority women (Fig. 1). We also changed our metrics, and we now report rates of colonoscopic screening among blacks starting at 45 years of age.3 Our work remains focused on developing additional usable quality measurements. Our future goal is even more customized, individualized information resulting in better outcomes for our patients.4 Tom von Sternberg, M.D. Beth Averbeck, M.D. Nancy McClure, J.D.

Therapeutic Implications of Coexisting Severe Pulmonary Hemorrhage and Pulmonary Emboli in a Case of Wegener Granulomatosis

Wegener granulomatosis classically involves the renal, respiratory, and ear, nose, and throat systems. Pulmonary hemorrhage is recognized as a severe respiratory complication. Untreated, the mortality rate approaches 90% at 2 years. We describe a case of Wegener granulomatosis with coexistent severe lung hemorrhage and pulmonary and deep vein thromboses. A 31-year-old man presented with features of vasculitis, including epistaxis, fever, and acute kidney injury with an increased serum creatinine level (3.27 mg/dL). Kidney biopsy confirmed pauci-immune crescentic glomerulonephritis, and antineutrophil cytoplasmic antibody showing a cytoplasmic staining pattern was strongly positive. Standard immunosuppression therapy (prednisolone and cyclophosphamide) was started. Eleven days later, the patient developed sudden dyspnea. A computed tomographic pulmonary angiogram showed pulmonary emboli, and ultrasound of the limbs showed ileofemoral thrombi bilaterally. Subcutaneous enoxaparin and warfarin therapy was started, but 8 days later, the patient had a massive pulmonary hemorrhage. Anticoagulation therapy was stopped, and plasma exchange was started to prevent further life-threatening hemorrhage. An inferior vena cava filter was inserted to prevent further pulmonary emboli during the period when anticoagulation was withheld. Kidney function improved, and pulmonary hemorrhage resolved after 5 plasma exchanges. Reintroduction of intravenous heparin and subsequently warfarin caused no further bleeding. We discuss the difficult management dilemma this combination of disease manifestations presents and review the current literature.

Evaluating ethnic differences in the prescription of NSAIDs for chronic kidney disease: a cross-sectional survey of patients in general practice.

BACKGROUND The public health burden of chronic kidney disease (CKD) and end-stage kidney disease is a national priority and is the subject of recent guidelines. In the UK, ethnic minority groups are over-represented in the renal replacement population (17.8%) compared with the white population (11%). AIM Non-steroidal anti-inflammatory drugs (NSAIDs) are a preventable cause of renal damage. Previous studies suggest a prescribing prevalence between 9% and 36% among those with CKD, but have not examined differences by ethnic group. DESIGN AND SETTING Cross-sectional survey of 12 011 patients with identified CKD (stages 3-5) in the three PCTs of Tower Hamlets, Hackney, and Newham. METHOD Assessment of NSAID prescribing rates in a multi-ethnic, socially-deprived population, using descriptive and multivariate analysis. RESULTS NSAIDs were prescribed for 11.1% of patients with CKD in the year prior to November 2012. Prescribing rates decreased stepwise by stage of renal impairment. Using daily defined dosages this study shows that in comparison with white groups both South Asian and black groups are much less likely to be in the top decile of NSAID prescribing, hence the overall prescribing load will be less: (odds ratio [OR] for South Asians = 0.34, 95% confidence interval [CI] = 0.22 to 0.54, OR for black groups = 0.34, 95% CI = 0.19 to 0.63). CONCLUSION National rates of NSAID prescribing continue to rise, and over-the-counter sales remain unmonitored, despite longstanding concerns about renal outcomes. Prescribing patterns indicate that GPs reduce prescribing as CKD progresses. Differential use of NSAIDs by ethnic group is unlikely to contribute to the high rates of end-stage kidney disease in ethnic minority groups.

Research into practice: understanding ethnic differences in healthcare usage and outcomes in general practice

### Why is recording ethnicity important? Race Relations Act of 1968 required all public bodies to consider the race equality implications in all policies. Since then, the official collection of ethnic group statistics has been mandated as an essential first step towards identifying and addressing ethnic inequalities. Capturing ethnic group information in routine health records is recognised in the UK as a necessary prerequisite to addressing need and inequalities in health service usage and health-related outcomes. As recommended by the Commission for Racial Equality, ethnic identity must be chosen by the individual. As such, ethnicity refers to the individual’s self-perception, rather than how he or she appears to others, and recognises that an individual’s self-conceptualisation may change over time. The concept of ethnicity draws on a range of socially constructed characteristics, hence the meaning and interpretation of ethnic differences is entirely context dependent. Despite this temporal instability, ethnicity is currently the best marker we have for defining population subgroups that may have differing needs. This is because it can serve as a surrogate for shared exposures or risks for people with similar social, biological, and cultural characteristics. This article describes how the Clinical Effectiveness Group at Queen Mary University London has, over the past 20 years, worked alongside the east London primary care community to identify and describe ethnic differences in the local population, and their impact on disease management in primary care. ### Origins of GP research on differences by ethnicity in east London Since 1993, the Clinical Effectiveness Group has supported primary care service provision across the three east London boroughs of Tower Hamlets, Newham, and City and Hackney. This area has a highly diverse ethnic population, with over 50% of residents of non-white ethnicity, and includes some of the most socially-deprived communities in the UK. The Clinical Effectiveness Group has a longstanding commitment to improving equity of health services provision across the area. A central …

Effect of Vitamin D Supplementation on Markers of Vascular Function: A Systematic Review and Individual Participant Meta-Analysis

Background Low 25‐hydroxyvitamin D levels are associated with an increased risk of cardiovascular events, but the effect of vitamin D supplementation on markers of vascular function associated with major adverse cardiovascular events is unclear. Methods and Results We conducted a systematic review and individual participant meta‐analysis to examine the effect of vitamin D supplementation on flow‐mediated dilatation of the brachial artery, pulse wave velocity, augmentation index, central blood pressure, microvascular function, and reactive hyperemia index. MEDLINE, CINAHL, EMBASE, Cochrane Central Register of Controlled Trials, and http://www.ClinicalTrials.gov were searched until the end of 2016 without language restrictions. Placebo‐controlled randomized trials of at least 4 weeks duration were included. Individual participant data were sought from investigators on included trials. Trial‐level meta‐analysis was performed using random‐effects models; individual participant meta‐analyses used a 2‐stage analytic strategy, examining effects in prespecified subgroups. 31 trials (2751 participants) were included; 29 trials (2641 participants) contributed data to trial‐level meta‐analysis, and 24 trials (2051 participants) contributed to individual‐participant analyses. Vitamin D3 daily dose equivalents ranged from 900 to 5000 IU; duration was 4 weeks to 12 months. Trial‐level meta‐analysis showed no significant effect of supplementation on macrovascular measures (flow‐mediated dilatation, 0.37% [95% confidence interval, −0.23 to 0.97]; carotid‐femoral pulse wave velocity, 0.00 m/s [95% confidence interval, −0.36 to 0.37]); similar results were obtained from individual participant data. Microvascular function showed a modest improvement in trial‐level data only. No consistent benefit was observed in subgroup analyses or between different vitamin D analogues. Conclusions Vitamin D supplementation had no significant effect on most markers of vascular function in this analysis.