Impact of extracorporeal blood flow rate on blood pressure, pulse rate and cardiac output during haemodialysis.

BACKGROUND: If blood pressure (BP) falls during haemodialysis (HD) [intradialytic hypotension (IDH)] a common clinical practice is to reduce the extracorporeal blood flow rate (EBFR). Consequently the efficacy of the HD (Kt/V) is reduced. However, only very limited knowledge on the effect of reducing EBFR on BP exists and data are conflicting. The aim of this study was to evaluate the effect and the potential mechanism(s) involved by investigating the impact of changes in EBFR on BP, pulse rate (PR) and cardiac output (CO) in HD patients with arteriovenous-fistulas (AV-fistulas). METHODS: We performed a randomized, crossover trial in 22 haemodynamically stable HD patients with AV-fistula. After a conventional HD session each patient was examined during EBFR of 200, 300 and 400 mL/min in random order. After 15 min when steady state was achieved CO, BP and PR were measured at each EFBR, respectively. RESULTS: Mean (SD) age was 71 (11) years. Systolic BP was significantly higher at an EBFR of 200 mL/min as compared with 300 mL/min [133 (23) versus 128 (24) mmHg; P < 0.05], but not as compared with 400 mL/min [133 (23) versus 130 (19) mmHg; P = 0.20]. At EBFR of 200, 300 and 400 mL/min diastolic BP, mean arterial pressure, PR and CO remained unchanged. CONCLUSION: Our study does not show any consistent trend in BP changes by a reduction in EBFR. Reduction in EBFR if BP falls during IDH is thus not supported. However, none of the patients experienced IDH. Further studies are required to evaluate the impact of changes in EBFR on BP during IDH.

Stable incidence and survival of arteriovenous fistulas over 39 years: A long-term national cohort study.

INTRODUCTION: The age and number of comorbidities in the hemodialysis population has increased over time. This may influence the construction and survival of the arteriovenous fistula (AVF). The present study explored the incidence and survival of AVFs over a period of 39 years. METHODS: A retrospective cohort study was conducted based on Danish registries. Incident hemodialysis patients between 1977 and 2015 were included. The incidence of AVF and factors associated with the construction of an AVF were described. Risk factors for AVF survival and repair were explored by Kaplan Meier and Cox proportional hazard analysis. RESULTS: The total number of arteriovenous accesses (AVF and arteriovenous grafts) were 10,187 and there were 4201 central venous catheters (CVC). No significant difference in the proportion of AVFs during the 39 years was seen. Age and renal diagnosis did not influence the proportion of AVFs. Patients with CVCs were found to have a significantly higher prevalence of comorbidities (p < 0.01). AVF survival remained stable during the 39 years. The first constructed AVF had the best survival, 35% still functioning after 15 years. Factors such as brachiocephalic AVF, female sex, and diabetic nephropathy increased the risk of AVF failure (Odds Ratio (OR): 2.46, 95% Confidence Interval (CI) (2.29-2.65), 1.17 (1.10-1.25), and 1.21 (1.12-1.3)), respectively. CONCLUSION: Despite an older dialysis population, the proportion and survival of the AVF in the Danish dialysis population has not changed, probably because of increased awareness of AVF as the first choice of vascular access and improved surveillance, surgery, and repair.

Urinary neutrophil gelatinase-associated lipocalin and progression of diabetic nephropathy in type 1 diabetic patients in a four-year follow-up study.

BACKGROUND: Neutrophil gelatinase-associated lipocalin (NGAL), a marker of renal tubular damage, predicts progression in non-diabetic chronic kidney. We evaluated urinary (u)-NGAL as a predictor of progression in diabetic nephropathy in type 1 diabetic (T1D) patients. METHODS: As a substudy of a 4-year randomized, intervention study evaluating low-protein diet in T1D patients with diabetic nephropathy, 78 patients were studied with yearly measurements of u-NGAL (ELISA, BioPorto). OUTCOME: Decline in glomerular filtration rate (GFR) ((51)Cr-EDTA), and end-stage renal disease (ESRD) or death. RESULTS: Mean age 40.7 (8.2) years and 50 men. 13 patients developed ESRD or died. Baseline GFR (mean, SD): 68 (31) ml/min/1.73 m(2). Baseline u-NGAL [geometric mean (95% CI)] and GFR were 15.6 ng/24 h (11.8-20.7) and 68 (31) ml/min/1.73 m(2). During follow-up, an increase in u-NGAL [geometric mean (95% CI)] of 15%/year (4-27) and a decline in GFR of 3.7 (3.0) ml/min/year were observed. Baseline u-NGAL was not associated with the decline in GFR. Elevated u-NGAL at baseline (log-transformed) predicted death and ESRD (HR 3.8, 95% CI 1.04-14.0), however not after adjustment for known progression promoters (HR 2.0, p = 0.6). CONCLUSION: Elevated u-NGAL was not related to decline in GFR during a 4-year follow-up. Elevated u-NGAL was associated with the development of ESRD and death, but not after adjustment.

Comparative effects of Irbesartan on ambulatory and office blood pressure: a substudy of ambulatory blood pressure from the Irbesartan in Patients with Type 2 Diabetes and Microalbuminuria study.

OBJECTIVE: Irbesartan was renoprotective independently of its blood pressure-lowering effect in the Irbesartan in Patients With Type 2 Diabetes and Microalbuminuria (IRMA2) study. However, blood pressure was evaluated by trough office blood pressure (OBP), which may underestimate reductions in 24-h ambulatory blood pressure (ABP). In the present study, we evaluated 24-h blood pressure patterns in a subpopulation of the IRMA2 trial. RESEARCH DESIGN AND METHODS: Type 2 diabetic patients (n = 43) with persistent microalbuminuria (as determined by repeated overnight measurements of urinary albumin excretion [UAE]) and hypertension who were included in the IRMA2 study at the Steno Diabetes Center were subjected to 24-h ABP (Takeda, TM2420) measurements before and 2 years after randomization to placebo (n = 15), irbesartan 150 mg daily (Irb150; n = 13), or irbesartan 300 mg daily (Irb300; n = 15). RESULTS: At baseline, the placebo, Irb150, and Irb300 groups were comparable: OBP: 157 +/- 15/89 +/- 7, 156 +/-15/91 +/- 11, and 159 +/- 16/90 +/- 9 mmHg (NS); 24-h ABP: 148 +/- 13/83 +/- 11, 148 +/- 16/82 +/- 7 and 147 +/- 16/81 +/- 10 mmHg (NS); and UAE (geometric mean with 95% CI): 43 (32-57), 46 (30-70), and 59 (42-85) micro g/min (NS), respectively. We found that 2 years after randomization, OBP was significantly reduced in all three groups (by 11/7, 13/8, and 13/8 mmHg in the placebo, Irb150, and Irb300 groups, respectively), but that there were no significant differences among groups. Reductions in 24-h ABP were similar in the three groups (11/10, 5/7, and 7/8 mmHg, respectively; NS), as were reductions in day ABP (11/9, 7/7, and 8/9 mmHg, respectively; NS) and night ABP (4/11, 7/7, and 3/3 mmHg, respectively; NS). The reduction in UAE at the end of the study was 0% (-86 to 42), 38% (-14 to 66), and 73% (59 to 82), respectively (overall, P < 0.01). CONCLUSION: Irbesartan is renoprotective independently of its beneficial effect in lowering 24-h blood pressure in patients with type 2 diabetes and persistent microalbuminuria.

Long-term haemodialysis survival.

Haemodialysis (HD) treatment for end-stage renal disease bears a poor prognosis. We present a case of a patient who, apart from two transplant periods lasting 8 months in all, was treated with conventional in-centre HD three times a week and who survived for 41 years. Patients should be aware that there is no theoretical upper limit for patient survival on HD.

Effect of dietary protein restriction on prognosis in patients with diabetic nephropathy.

BACKGROUND: Recent data suggest that dietary protein restriction improves survival and delays the progression to end-stage renal disease (ESRD) in non-diabetic nephropathies. The purpose of our study was to determine the effect of dietary protein restriction on survival and progression to ESRD in diabetic nephropathy. METHODS: A four-year prospective, controlled trial with concealed randomization was performed comparing the effects of a low-protein diet (0.6 g/kg/day) with a usual-protein diet. The study included 82 type 1 diabetic patients with progressive diabetic nephropathy [pre-study mean decline in glomerular filtration rate (GFR) 7.1 mL/min/year (95% CI, 5.8 to 8.5)]. The main outcome measures were decline in GFR and development of ESRD or death. RESULTS: During the follow-up period the usual-protein diet group consumed 1.02 g/kg/day (95% CI; 0.95 to 1.10) as compared with 0.89 (0.83 to 0.95) in the low-protein diet group (P = 0.005). The mean declines in GFR were 3.9 mL/min/year (2.7 to 5.2) in the usual-protein diet group and 3.8 (2.8 to 4.8) in the low-protein diet group. ESRD or death occurred in 27% of patients on a usual-protein diet as compared with 10% on a low-protein diet (log-rank test; P = 0.042). The relative risk of ESRD or death was 0.23 (0.07 to 0.72) for patients assigned to a low-protein diet, after an adjustment at baseline for the presence of cardiovascular disease (P = 0.01). Blood pressure and glycemic control were comparable in the two diet groups during the follow-up period. CONCLUSION: Moderate dietary protein restriction improves prognosis in type 1 diabetic patients with progressive diabetic nephropathy in addition to the beneficial effect of antihypertensive treatment.

Impact of low-dose acetylsalicylic acid on kidney function in type 2 diabetic patients with elevated urinary albumin excretion rate.

BACKGROUND: Low-dose treatment with acetylsalicylic acid (ASA) is widely recommended to type 2 diabetic patients as primary prevention against cardiovascular disease. High-dose treatment with cyclooxygenase inhibitors reduces urinary albumin excretion rate (AER) in type 1 diabetic patients with micro- or macroalbuminuria. Whether a similar effect on AER exists during low-dose ASA treatment, which may confound the diagnosis and monitoring of micro- and macroalbuminuria in type 2 diabetic patients, remains to be elucidated. METHODS: In a randomized, double-blind, crossover trial, 31 type 2 diabetic patients with elevated levels of AER (>30 mg/24 h) were, in random order, given ASA (150 mg/day) for 4 weeks followed by placebo for 4 weeks with a 2 week washout period or vice versa. At the end of each treatment period AER, glomerular filtration rate (GFR), blood pressure (BP), transcapillary escape rate (TER(alb)) of albumin and haemoglobin A(1c) (HbA(1c)) were measured. RESULTS: The following variables remained unchanged (mean (95% CI) unless otherwise noted) (ASA vs placebo, paired Student's t-test): AER (201 (119-341) vs 205 (124-340) mg/24 h (geometric mean, 95% CI); P=0.78), GFR (103 (94-111) vs 102 (93-110) ml/min; P=0.58), systolic BP (151 (146-158) vs 152 (146-158) mmHg; P=0.68), diastolic BP (87 (83-91) vs 87 (82-91) mmHg; P=0.88), TER(alb) (6.3 (5.7-6.9) vs 5.9 (5.1-6.7); P=0.45) and HbA(1c) (8.6 (8.1-9.0) vs 8.5 (8.1-9.0) %; P=0.60). CONCLUSIONS: Low-dose treatment with 150 mg ASA daily does not have any impact on AER or GFR in type 2 diabetic patients with micro- or macroalbuminuria. Consequently, the widely recommended prescription of low-dose ASA as a primary and secondary prevention strategy against cardiovascular disease in these patients does not confound the diagnosis or monitoring of micro- or macroalbuminuria.