Catherine M. Clase

Muscle weakness and falls in older adults: a systematic review and meta-analysis.

Objectives: To evaluate and summarize the evidence of muscle weakness as a risk factor for falls in older adults.

A Systematic Review and Meta-Analysis of Hypoglycemia and Cardiovascular Events: A comparison of glyburide with other secretagogues and with insulin

OBJECTIVE—Glyburide is the most widely used sulfonylurea but has unique pharmacodynamic properties that may increase harm. We hypothesized that glyburide causes more hypoglycemia and cardiovascular events than other secretagogues or insulin. RESEARCH DESIGN AND METHODS—Data sources were Medline, Embase, Cochrane, and three other web-based clinical trial registers (1966–2005). Parallel, randomized, controlled trials in people with type 2 diabetes comparing glyburide monotherapy with monotherapy using secretagogues or insulin were selected. Outcomes were hypoglycemia, glycemic control, cardiovascular events, body weight, and death. Titles and abstracts of 1,806 publications were reviewed in duplicate and 21 relevant articles identified. Data on patient characteristics, interventions, outcomes, and validity were extracted in duplicate using predefined criteria. RESULTS—Glyburide was associated with a 52% greater risk of experiencing at least one episode of hypoglycemia compared with other secretagogues (relative risk 1.52 [95% CI 1.21–1.92]) and with 83% greater risk compared with other sulfonylureas (1.83 [1.35–2.49]). Glyburide was not associated with an increased risk of cardiovascular events (0.84 [0.56–1.26]), death (0.87 [0.70–1.07]), or end-of-trial weight (weighted mean difference 1.69 kg [95% CI −0.41 to 3.80]) compared with other secretagogues. Limitations included suboptimal reporting of original trials. Loss to follow-up exceeded 20% in some studies, and major hypoglycemia was infrequently reported. CONCLUSIONS—Glyburide caused more hypoglycemia than other secretagogues and other sulfonylureas. Glyburide was not associated with an increased risk of cardiovascular events, death, or weight gain.

Prevalence of Low Glomerular Filtration Rate in Nondiabetic Americans: Third National Health and Nutrition Examination Survey (NHANES III)

End-stage renal disease is an important and costly health problem. Strategies for its prevention are urgently needed. Knowledge of the population-based prevalence of renal insufficiency in nondiabetic adults would inform such strategies. Black and white nondiabetic adult participants in the Third National Health and Nutrition Examination Survey were analyzed. The analysis was stratified by age, gender, and race, and four clinically applicable methods were used to assess renal function. There were 13,251 complete records for analysis. By the Modification of Diet in Renal Diseases (MDRD) GFR (GFR) prediction Equation 7, 58% (95% confidence interval [CI], 56 to 60%) of the total adult nondiabetic black and white US population had MDRD GFR below 80 ml/min per 1.73m(2), 13% (95% CI, 11 to 14%) below 60 ml/min per 1.73m(2), and 0.26% (95% CI, 0.19 to 0.33%) below 30 ml/min per 1.73m(2). By the Cockcroft-Gault formula, the equivalent figures were 39% (95% CI, 37 to 41%), 14% (95% CI, 12% - 16%), and 0.81% (95% CI, 0.46 to 1.2%), respectively. The findings of an unexpectedly high prevalence of low clearance and the increased prevalence of low clearance with age were consistent across the four clearance estimation methods used and for each race-sex stratum. The absolute magnitude of the prevalence of low clearance was, however, dependent on the clearance method used. Assessed by estimation from serum creatinine, low clearance may be very common, particularly with advancing age. The prognosis (in terms of risk for progression and end-stage renal disease) of low clearance in unreferred populations may differ from that in referred populations and requires further study.

Is routine ureteric stenting needed in kidney transplantation? A randomized trial.

Background. Whether routine ureteric stenting in low-urological-risk patients reduces the risk of urological complications in kidney transplantation is not established. Methods. Eligible patients were recipients of single-organ renal transplants with normal lower urinary tracts. Patients were randomized intraoperatively to receive either routine stenting or stenting only in the event of technical difficulties with the anastomosis. All patients underwent Lich-Gregoire ureteroneocystostomy. Results. Between June 1994 and December 1997, 331 kidney transplants were performed at a single center, 305 patients were eligible, and 280 patients were enrolled and randomized. Donor and recipient age, sex, donor source, whether first or subsequent grafts, ureteric length, native renal disease, and immunosuppression were similar in each group. In the no-routine-stenting group 6 of 137 patients (4.4%) received stents after randomization for intraoperative events that in the surgeon’s opinion required use of a stent. In an intention-to-treat analysis there was no difference between groups in the primary outcome cluster of obstruction or leak [routine stenting 5 of 143 (3.5%) vs. no routine stenting 9 of 137 (6.6%);P =0.23], or in either of these complications analyzed separately. All urological complications were successfully managed without major morbidity. Living donor organs and shorter ureteric length (after trimming) were univariate risk factors for leaks, although increasing donor age was associated with obstruction. Conclusions. Routine ureteric stenting is unnecessary in kidney transplantation in patients at low risk for urological complications. Careful surgical technique with selective stenting of problematic anastomoses yields similar results.

Low-Intensity Warfarin Is Ineffective for the Prevention of PTFE Graft Failure in Patients on Hemodialysis: A Randomized Controlled Trial

Polytetrafluoroethylene (PTFE) dialysis grafts in patients with end-stage renal disease (ESRD) are prone to thrombotic failure. The objective of this multicenter, randomized, double-blind, placebo-controlled clinical trial was to determine if warfarin reduces the risk of failure of PTFE dialysis grafts. Patients with ESRD and newly placed PTFE grafts were studied at community and academic dialysis centers in Southwestern Ontario. Patients were allocated to receive warfarin or matching placebo, with the warfarin administered to achieve a target INR of 1.4 to 1.9. Time to graft failure was the main outcome measure. A total of 107 patients (56 allocated to warfarin) were randomized. The time-to-event analysis revealed no significant difference in the likelihood of graft survival between the two groups (odds ratio, 1.76 in favor of placebo; 95% confidence interval, 0.72 to 4.34). Six major bleeds occurred in five patients allocated to warfarin compared with none in the patients who received placebo (P = 0.03). In conclusion, low-dose warfarin was associated with an excess of clinically important major bleeding in patients with ESRD enrolled in this study. Furthermore, low-intensity, monitored-dose warfarin does not appear to prolong PTFE graft survival.

Endovascular repair of ruptured abdominal aortic aneurysms: A systematic review and meta-analysis

OBJECTIVES The perioperative mortality for people with ruptured abdominal aortic aneurysms (RAAA) has not changed for two decades. Of patients who survive long enough to undergo open repair for ruptured aneurysms, half die (48%; 95% confidence interval [CI] 46 to 50). Randomized trials have shown that endovascular aneurysm repair (EVAR) for nonruptured abdominal aortic aneurysms decreases perioperative mortality compared with open repair. EVAR may similarly benefit patients with RAAA. We aimed to summarize studies of patients undergoing EVAR for ruptured aneurysms. METHODS Two reviewers searched Medline and EMBASE databases from 1994 to July 2006, Cochrane Database of Systematic Reviews, the Database of Abstracts of Reviews of Effectiveness, the Cochrane Central Register of Controlled Trials, Best Evidence 1994 to 2006, reference lists, clinical trial registries, and conference proceedings; we also contacted authors. All published and unpublished studies in which a group of people with ruptured aneurysms, assessed objectively by imaging, was treated with EVAR (REVAR) were eligible. We used the generic inverse variance function of the REVMAN software to pool results for death in hospital. Sensitivity analyses, using prespecified subgroups, explored heterogeneity between studies. RESULTS Pooled mortality in 18 observational studies describing 436 people who underwent REVAR was 21% (95% CI 13 to 29); however, 90% of the heterogeneity between studies was not explained by chance alone. Surgical volume explained substantial heterogeneity. According to study-specific criteria, 47% (95% CI 39 to 55) of people with ruptured aneurysms were potentially eligible for REVAR. CONCLUSIONS Mortality in people who underwent REVAR is lower than that in historical reports of unselected people undergoing open repair. Further investigation is needed to determine whether the difference in mortality is attributable to patient selection alone or to this new approach to treatment.

Cumulative Risk for Developing End-Stage Renal Disease in the US Population

The individual risk of developing end-stage renal disease (ESRD) and its overall impact on life expectancy is not known. This studys objectives were to determine the effect of ESRD on life expectancy for a cohort of 20-yr-olds and to compare this impact to that of several cancers for which population-based screening programs exist. A computer simulation, stratified by race (white, black) and by gender was used to calculate cumulative lifetime risk of ESRD, life-years lost to ESRD, and cumulative Medicare payments for ESRD. Similar calculations were made for breast, prostate, and colorectal cancer. The cumulative lifetime risk of ESRD for a 20-yr-old black woman is 7.8%. Equivalent risks for black men are 7.3%, white men 2.5%, and white women 1.8%. Lost years of life attributable to ESRD are 1.09, 1.10, 0.40, and 0.32 yr for black women, black men, white men, and white women, respectively. In blacks, ESRD is responsible for nearly as much loss of life-years as breast cancer in women and more loss of life-years than colorectal or prostate cancer in men. In addition, treatment costs for ESRD in this population are many-fold more expensive than cumulative treatment costs of these cancers. Exploring new screening and treatment strategies may be warranted to prevent ESRD, particularly in the US black population.

Adequate Early Cyclosporin Exposure is Critical to Prevent Renal Allograft Rejection: Patients Monitored by Absorption Profiling

This study used receiver operating characteristic analysis to investigate the properties of area under the concentration‐time curve during the first 4 h after cyclosporin‐microemulsion dosing (AUC0−4) and cyclosporin (CyA) levels immediately before and at 2 and 3 h after dosing (C0, C2 and C3) to predict the risk of biopsy‐proven acute rejection (AR) at 6 months. Ninety‐eight kidney transplant recipients treated with CyA‐microemulsion‐based triple therapy immunosuppression were studied on post‐transplant days 3, 5, and 7, and at increasing intervals thereafter.

Systematic review and meta-analysis of incidence, prevalence and outcomes of atrial fibrillation in patients on dialysis

BACKGROUND The reported incidence, prevalence and outcomes of atrial fibrillation (AF) in patients with end-stage renal disease (ESRD) are variable. The risks and benefits of warfarin anticoagulation need to be defined as the risk of bleeding in ESRD patients may overwhelm the benefits of embolic stroke prevention. We undertook a systematic literature review to clarify these issues. METHODS A literature search was undertaken using Medline and EMBASE from 1990 to September 2011. Studies that reported incidence, prevalence or selected outcomes in ESRD patients with AF were included. Cross-sectional, cohort and randomized controlled trials with >25 participants were included. The lists of authors and abstracts from the search were reviewed by two investigators to determine the manuscripts for full text review. Data were abstracted to a form designed specifically for this study. The quality of the studies was assessed using the Newcastle-Ottawa scale. Event rates were calculated using a random-effects model. RESULTS Twenty-five studies met our inclusion criteria. The prevalence of AF was 11.6% and the overall incidence was 2.7/100 patient-years. The risk of mortality and stroke was increased in ESRD patients with AF at 26.9 and 5.2/100 patient-years versus 13.4 and 1.9/100 patient-years compared with ESRD patients without AF. The majority of studies do not support a protective effect for warfarin in ESRD patients with AF. CONCLUSIONS The incidence and prevalence of AF in ESRD patients are higher than in the general population and are associated with an increased risk of stroke and mortality. An appropriately designed randomized controlled trial is required to determine whether anticoagulation is an appropriate therapeutic strategy in patients with end-stage renal disease and atrial fibrillation.

Prolonged sulfonylurea-induced hypoglycemia in diabetic patients with end-stage renal disease.

Renal impairment is a recognized risk factor for prolonged hypoglycemia, but predisposing characteristics in patients with advanced renal impairment have not been studied. We observed prolonged hypoglycemia in a number of patients with end-stage renal disease (ESRD) and conducted a case-control study at two Canadian centers to identify such risk factors. Through hospital, pharmacy, and dialysis program records, we retrospectively identified 7 case patients and 31 controls with ESRD and type 2 diabetes using oral hypoglycemic monotherapy. Control patients had no history of hospital admission for prolonged hypoglycemia. All case patients and 28 controls were receiving glyburide (glibenclamide in Europe); the remainder were treated with tolbutamide. Duration of intravenous treatment for hypoglycemia ranged from 28 to 256 hours, with 83 g to 2 kg of glucose administered per episode. Preceding treatment with glyburide varied from 2 days to 13 years. Univariate analyses showed a recent decline in oral intake (odds ratio [OR], 81; 95% confidence interval [CI], 3.6 to 1,840), previous hypoglycemic episodes (OR, 15; 95% CI, 0.77 to 297), longer duration of diabetes (22 versus 12 years; P = 0.008), and a history of cerebrovascular disease (OR, 7. 0; 95% CI, 1.0 to 47) to be associated with prolonged hypoglycemia. No association between prolonged hypoglycemia and age, sex, beta blockers, angiotensin-converting enzyme inhibitors, oral hypoglycemic dose, or duration of treatment was identified. This study describes the potentially devastating effect of sulfonylurea-based oral hypoglycemic therapy in ESRD. Patients at greatest risk appear to be those with reduced intake, previous hypoglycemic episodes, and longer duration of diabetes. We describe the mechanisms for observed hypoglycemia and suggest that alternative drugs may be considered in this patient group.