Bryan M Curtis

University of Minnesota Duluth, Duluth, Minnesota, United States

Are you Bryan M Curtis?

Claim your profile

Publications (16)40.47 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Abstract Purpose: The primary objective of this cross-sectional study was to test factors associated with sleep apnea in patients with chronic kidney disease (CKD). The prevalence of sleep apnea was also assessed. Methods: We recruited patients with CKD Stage 3-5 who lived in the St. John's area from September 2012 to December 2012. The Berlin Questionnaire and Short Form 36 Quality of Life Health Survey Questions (SF-36) were administered to all participants. Results: We recruited 303 patients (41% female). A total of 157 (51.8%) patients had a high risk for sleep apnea. Higher body mass index and young age were correlated with sleep apnea. Physical component score of SF-36 (PCS) tested as a continuous variable indicated a significant association with the risk for sleep apnea (OR: 0.97, 95% CI: 0.94-0.99, p = 0.03). The association implies 3% change per one point increase in PCS. We categorized mental component score of SF-36 (MCS) into four quartiles, as the linearity assumption was violated. There was a 61% risk increase for poor sleep in those with an MCS score less than the 75th percentile, when compared to those above the 75th percentile (OR: 0.39, 95% CI: 0.21-0.71, p = 0.002). Conclusions: Sleep apnea is common in kidney patients. People who have low PCS and MCS scores are more prone to sleep apnea or vice versa. Our results also indicate that high BMI and young age are associated with sleep apnea.
    Renal Failure 09/2014; · 0.94 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Although left ventricular hypertrophy (LVH) is a characteristic finding in hemodialysis (HD) populations, few risk factors for progressive LVH have been identified. As part of a multinational, blinded, randomized, controlled trial that demonstrated no effect of hemoglobin targets on LV size, 596 incident HD patients, without symptomatic cardiac disease or cardiac dilation, had baseline echocardiograms within 18 months of starting dialysis and subsequently at 24, 48, and 96 weeks later. A wide array of baseline risk factors were assessed, as were BP and hemoglobin levels during the trial. The median age and duration of dialysis were 51.5 years and 9 months, respectively. LV mass index (LVMI) rose substantially during follow-up (114.2 g/m(2) at baseline, 121 at week 48, 123.4 at week 48, and 128.3 at week 96), as did fractional shortening, whereas LV volume (68.7, 70.1, 68.7, and 68.1 ml/m(2)) and E/A ratio remained unchanged. At baseline, the only multivariate associations of LVMI were gender and N terminal pro-B type natriuretic peptide. Comparing first and last echocardiograms in those without LVH at baseline, independent predictors of increase in LVMI were higher time-integrated systolic BP and cause of ESRD. An unadjusted association between baseline LVMI and subsequent cardiovascular events or death was eliminated by adjusting for age, diabetes, systolic BP, and N terminal pro-B type natriuretic peptide. Progressive concentric LVH and hyperkinesis occur in HD patients, which is partly explained by hypertension but not by a wide array of potential risk factors, including anemia.
    Clinical Journal of the American Society of Nephrology 04/2010; 5(5):805-13. · 5.07 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The effects of different hemoglobin targets when using erythropoiesis-stimulating agents on quality of life are somewhat controversial, and predictors of change in quality of life in endstage renal disease have not been well characterized. Five hundred ninety-six incident hemodialysis patients without symptomatic cardiac disease were randomly assigned to hemoglobin targets of 9.5 to 11.5 g/dl or 13.5 to 14.5 g/dl for 96 weeks, using epoetin_alfa as primary therapy. Patients and attending physicians were masked to treatment assignment. Quality of life, a secondary outcome, was prospectively recorded using the Kidney Disease Quality of Life (KDQoL) questionnaire at weeks 0, 24, 36, 48, 60, 72, 84, and 96, with prespecified outcomes being fatigue and quality of social interaction. The mean age and prior duration of dialysis therapy of the study population were 50.8 and 0.8 yr. Mortality was low, reflecting the relatively healthy group enrolled. Of 20 domains within the KDQoL only the prespecified domain of fatigue showed significant change over time between the two groups. Improvement in fatigue scores in the high-target group ranged from 3.2 to 7.9 over time (P = 0.007) compared with change in the low-target group. Higher body mass index and lower erythropoietin dose at baseline were independent predictors of improvement in multiple KDQoL domains. In relatively healthy hemodialysis patients, normal hemoglobin targets may have beneficial effects on fatigue. Improvement in multiple domains of quality of life is associated with higher body mass index and lower erythropoietin requirements.
    Clinical Journal of the American Society of Nephrology 04/2009; 4(4):726-33. · 5.07 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Today's clinical practice relies on the application of well-designed clinical research, the gold standard test of an intervention being the randomized controlled trial. Principles of the randomized controlled trial include emphasis on the principal research question, randomization, and blinding; definitions of outcome measures, inclusion and exclusion criteria, and comorbid and confounding factors; enrolling an adequate sample size; planning data management and analysis; preventing challenges to trial integrity, such as dropout, drop-in, and bias. The application of pretrial planning is stressed to ensure the proper application of epidemiological principles, resulting in clinical studies that are feasible and generalizable. In addition, funding strategies and trial team composition are discussed.
    Methods in molecular biology (Clifton, N.J.) 02/2009; 473:95-111. · 1.29 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Optimal hemoglobin targets for chronic kidney disease patients receiving erythropoiesis-stimulating agents remain controversial. The effects of different hemoglobin targets on blood transfusion requirements have not been well characterized, despite their relevance to clinical decision-making. Five hundred ninety-six incident hemodialysis patients without symptomatic cardiac disease were randomly assigned to hemoglobin targets of 9.5 to 11.5 g/dl or 13.5 to 14.5 g/dl for 96 wk using epoetin alfa as primary therapy and changes in left ventricular structure as the primary outcome (previously reported). Patients were masked to treatment assignment. Blood transfusion data were prospectively collected at 4-wk intervals. The mean age and prior duration of dialysis therapy of the study population were 50.8 and 0.8 yr, respectively. Previously reported mortality was similar in low and high-target subjects, at 4.7 (95% confidence interval 3.0, 7.3) and 3.1 (1.8, 5.4) per hundred patient years, respectively. Transfusion rates were 0.66 (0.59, 0.74) units of blood per year in low and 0.26 (0.22, 0.32) in high-target subjects (P < 0.0001). Hemoglobin level at transfusion (7.7 [7.5, 7.9]) versus 8.1 [7.6, 8.5] g/dl) were similar with both groups. High hemoglobin target was a significant predictor of time to first transfusion independent of baseline associations (hazard ratio = 0.42; 95% confidence interval = 0.26-0.67). In hemodialysis patients with comparatively low mortality risks, normal hemoglobin targets may reduce the need for transfusions.
    Clinical Journal of the American Society of Nephrology 11/2008; 3(6):1669-75. · 5.07 Impact Factor
  • Source
    Nephrology Dialysis Transplantation 01/2008; 22(12):3681-90. · 3.37 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Much of the comorbidity associated with chronic kidney disease (CKD) begins in the early stages. Interventions with proven efficacy exist to decrease progression, morbidity, and mortality. This study examines their use in patients with CKD before and at their first nephrologist encounter in Canada. Prospective multicenter cohort study. 482 patients at their first nephrologist encounter enrolled from 13 Canadian centers. Inclusion criteria were measured or estimated glomerular filtration rate less than 50 mL/min/1.73 m(2). Exclusion criteria were patients with acute kidney failure or those likely to require dialysis therapy within 3 months of referral. Describe: (1) characteristics of patients at their first nephrology encounter in Canada; (2) the evaluation for cardiac risk factors, cardiac diseases and CKD complications and their management before the encounter; (3) changes in management initiated by nephrologists at the first encounter; and (4) the availability and use of allied health professional services for CKD care. Patients had a mean age of 69.7 years, estimated glomerular filtration rate of 29 mL/min/1.73 m(2) (0.48 mL/s/1.73 m(2), hemoglobin level of 12.1 g/dL (121 g/L), albumin level of 3.6 g/dL (36 g/L), and blood pressure of 147/76 mm Hg. Transmission of results from prior evaluation was variable. At the encounter, nephrologists had available or ordered albumin and calcium/phosphate tests in greater than 70% of patients. Nephrologists did not evaluate parathyroid hormone in 83% of patients, lipids in greater than 50%, iron studies (in those with anemia) in 57%, and urine studies in 30%. Despite a high prevalence of diabetes and coronary artery disease, only 46% were administered medications to interrupt the renin-angiotensin system, 37% were administered acetylsalicylic acid, and 32% were administered lipid medication after the encounter. Availability and use of allied health professional resources varied and was low in an unstructured setting. External validity, referral bias, and inability to make causal inferences. In Canada, patients with CKD continue to be encountered late by nephrologists (stage IV CKD). Information for prior evaluation is incompletely transmitted. Finally, there appears to be room for improvement in evaluation and treatment at the first nephrologist encounter.
    American Journal of Kidney Diseases 11/2007; 50(5):733-42. · 5.29 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To critically evaluate the quality of hospital medical care at the beginning, during and shortly after regionalization of health boards in Newfoundland and Labrador, and aggregation of hospitals in the St John's region. Retrospective chart audits for the years 1995/96, 1998/99 and 2000/01 (at the beginning, during and after restructuring) focused on outcomes in cardiology, respiratory medicine, neurology, nephrology, psychiatry, surgery and women's health programmes. Where possible, quality of care was judged on measurable outcomes in relation to published statements of likely optimal care. Comparisons were made over time within the St John's region, and separately for hospitals in the rest of the province. There was improvement in the use of thrombolytics and secondary measures post-myocardial infarction in both regions. Mortality and appropriateness of initial antibiotic choice for community-acquired pneumonia remained stable in both regions, with an improvement in admission appropriateness based on the severity in St John's. Aspects of stroke management (referral and time to see allied health professionals, imaging and discharge home) improved in both regions, while mortality remained stable. There was improvement in fistula rate, quality of dialysis and anaemia management in haemodialysis patients, and improvement in the peritoneal dialysis patient peritonitis rate. Readmission rate for schizophrenia remained unchanged. Stable mortality rates were observed for frequently performed surgical procedures. The post-coronary artery bypass grafting (CABG) morbid event rate improved, although access to CABG was not optimal. Aggregation of acute care hospitals was feasible without attendant deterioration in patient care, and in some areas care improved. However, access to services continued to be a major problem in all regions.
    Journal of Health Services Research & Policy 11/2005; 10 Suppl 2:S2:38-47. · 1.73 Impact Factor
  • Source
    Bryan M Curtis, Patrick S Parfrey
    [Show abstract] [Hide abstract]
    ABSTRACT: There is a high burden of cardiac disease in the CKD population. Severe LVH, dilated cardiomyopathy, and coronary artery disease occur frequently and result in the manifestations of CHF,which is probably more important with respect to prognosis than symptomatic. Multiple risk factors for CVD include traditional risk factors and those unique to the CKD population. Furthermore, the distinctive aspects of CKD patients sometimes warrant special consideration in making management decisions. Nonetheless, interventions such as controlling hypertension, specific pharmacologic options, lifestyle modification, anemia management, and early nephrology referral are recommended when appropriate.
    Cardiology Clinics 09/2005; 23(3):275-84. · 1.32 Impact Factor
  • Source
    Bryan M Curtis, Adeera Levin, Patrick S Parfrey
    [Show abstract] [Hide abstract]
    ABSTRACT: This article describes the relationship between CVD and CKD, the current state of knowledge regarding medical interventions, and underscores the importance of attending to both CVD and kidney disease aspects in each individual. The burden of cardiac disease in CKD patients is high with severe LVH, dilated cardiomyopathy and coronary artery disease occurring frequently. This predisposes to congestive heart failure, angina, myocardial infarction, and death. Multiple risk factors for cardiac disease exist and include hypertension, diabetes, smoking, anemia, abnormal calcium and phosphate metabolism, inflammation, and LVH. The efficacy of risk factor intervention has not been established in these populations, although there is good evidence for good blood pressure control, partial correction of anemia, treatment of dyslipidemia, cessation of tobacco use, correction of divalent abnormalities, and aspirin us. Appropriate use of ACE inhibitors, beta-blockers, and statins should be encouraged.
    Medical Clinics of North America 06/2005; 89(3):511-23. · 2.61 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This two country case control study of incident dialysis patients evaluates the outcomes of patients exposed to formalized multi-disciplinary clinic (MDC) programmes vs standard nephrologist care. Patients commencing dialysis in two centres (Vancouver, Canada and Cremona, Italy) were evaluated at and after dialysis start, as a function of MDC exposure vs nephrologist care alone. Only chronic kidney disease patients, with longer than 3 months of exposure to nephrology care, who had not previously received kidney replacement therapy were included. Study outcomes included laboratory parameters and survival. The MDC was similar in both countries and average exposure was 6-8 h per patient-year, as compared to 2-4 h for standard care. All patients had equal access to resources prior to dialysis and with respect to dialysis start, as all had been referred to the same local nephrology practices. During the evaluation period 288 patients commenced dialysis after receiving more than 3 months nephrology care prior to dialysis. There were no major demographic differences between the cohorts. Mean duration of nephrology care prior to dialysis was 42 months, and dialysis was initiated at similar low glomerular filtration rate (GFR), though statistically significantly different (7.0 and 8.4 ml/min/m2, P = 0.001). The MDC patients had higher haemoglobin (102 vs 90 g/l, P<0.0001), albumin (37.0 vs 34.8 g/l, P = 0.002) and calcium levels (2.29 vs 2.16 mmol/l, P<0.0001) at dialysis start. Survival was significantly better in the MDC group demonstrated by Kaplan-Meier analysis (P = 0.01). Cox proportional hazards analysis demonstrated standard nephrology clinic vs MDC attendance was a statistically significant independent predictor of death (hazards ratio = 2.17, 95% confidence interval 1.11-4.28) after adjusting for other variables known to impact outcomes. This analysis of outcomes in two different countries suggests that despite equal and long exposure to nephrology care prior to dialysis, there appears to be an association of survival advantage for those patients exposed to formalized clinic care in addition to standard nephrologist follow-up. While other known predictors of survival such as adequacy of dialysis and severity of illness measures were not included in the model, those parameters require time on dialysis to be accumulated. Thus, the data do suggest that knowledge of patient status at the time of dialysis start is important. Further research is needed to determine which specific components of care both prior to dialysis and after its commencement are most important with respect to outcomes.
    Nephrology Dialysis Transplantation 02/2005; 20(1):147-54. · 3.37 Impact Factor
  • Methods in molecular medicine 02/2003; 86:475-89.
  • [Show abstract] [Hide abstract]
    ABSTRACT: The current growth in end-stage kidney disease populations has led to increased efforts to understand the impact of status at dialysis initiation on long-term outcomes. Our main objective was to improve the understanding of current Canadian nephrology practice between October 1998 and December 1999. Fifteen nephrology centers in 7 provinces participated in a prospective data collection survey. The main outcome of interest was the clinical status at dialysis initiation determined by: residual kidney function, preparedness for chronic dialysis as measured by presence or absence of permanent peritoneal or hemodialysis access, hemoglobin and serum albumin. Uremic symptoms at dialysis initiation were also recorded, however, in some cases these symptom data were obtained retrospectively. Data on 251 patients during 1-month periods were collected. Patients commenced dialysis at mean calculated creatinine clearance levels of approximately 10 ml/min, with an average of 3 symptoms. 35% of patients starting dialysis had been known to nephrologists for less than 3 months. These patients are more likely to commence without permanent access and with lower hemoglobin and albumin levels. Even of those known to nephrologists, only 66% had permanent access in place. Patients commencing dialysis in Canada appear to be doing so in relative concordance with published guidelines with respect to timing of initiation. Despite an increased awareness of kidney disease, a substantial number of patients continues to commence dialysis without previous care by a nephrologist. Of those who are seen by nephrologists, clinical and laboratory parameters are suboptimal according to current guidelines. This survey serves as an important baseline for future comparisons after the implementation of educational strategies for referring physicians and nephrologists.
    Clinical nephrology 11/2002; 58(4):282-8. · 1.29 Impact Factor
  • Bryan M Curtis, Patrick S Parfrey
    Seminars in Dialysis 01/2002; 15(1):22-4. · 2.25 Impact Factor
  • Source
    B Curtis, B J Barrett, A Levin
    [Show abstract] [Hide abstract]
    ABSTRACT: To help inform primary care physicians about how to identify and slow progressive chronic renal failure. The National Library of Medicine (1996 to 2000) was searched using PubMed with search terms pertinent to studies on identification, course, and management of chronic renal failure. References in retrieved papers and older literature known to the authors supplemented the searches. In general, sufficient high-quality studies, systematic reviews, or guidelines based on such evidence were available to support our main points. End-stage renal disease (ESRD) poses a large and growing morbidity, mortality, and financial burden. Almost all patients reach ESRD as a result of chronic progressive conditions, particularly diabetic nephropathy, hypertensive-vascular renal disease, and glomerular disorders. Patients at risk merit regular renal assessment with serum creatinine tests and urinalysis. Persistent high blood pressure and heavy proteinuria are the strongest predictors of progression of chronic renal failure. Patients with renal disease should be examined and treated for vascular disease and vice versa. Blood pressure lowering, ACE inhibition, and avoidance of further renal insults (such as use of nephrotoxins) can slow the decline of renal function. Restricting dietary protein has a weak effect on slowing renal failure and is not easy to apply in primary care. Timely involvement of specialized nephrology teams is important. Family physicians play an important role in recognizing patients with potential for renal failure, in demonstrating progressive chronic renal failure, and in initiating therapy early to improve outcomes.
    Canadian family physician Médecin de famille canadien 01/2002; 47:2512-8. · 1.81 Impact Factor
  • Source