Cardiac and Noncardiac Determinants of Exercise Capacity in CKD.

BACKGROUND: Impaired exercise capacity is a significant symptom of CKD and is associated with poor survival. Furthermore, there is a growing interest in applying exercise as a diagnostic tool or as therapy in CKD. However, an in-depth understanding of exercise physiology in CKD is still lacking. METHODS: To evaluate the role of cardiac (central) and noncardiac (peripheral) determinants of exercise capacity in CKD, we conducted a cross-sectional study of 70 male patients with CKD (stages 2-5) without diabetes or cardiac disease, 35 healthy controls, and 25 patients with heart failure. An integrated cardiopulmonary exercise test using a CO2 rebreathing technique was used to measure peak O2 consumption (VO2peak) and peak cardiac output simultaneously, and to calculate peak peripheral O2 extraction (C[a-v]O2), the peripheral determinant (the ability of exercising skeletal muscles to extract oxygen). We performed multiple regression analysis and used Bayesian information criteria (BIC) changes to quantitatively assess the individual contribution of central and peripheral factors. RESULTS: Compared with healthy controls, in patients with CKD, the VO2peak was impaired proportionate to its severity. Peak cardiac output was the predominant determinant of VO2peak in healthy controls and patients with heart failure, whereas C(a-v)O2 played a more significant role in determining VO2peak in CKD (ß=0.68, P<0.001) compared with cardiac output (ß=0.63, P<0.001). In addition, the magnitude of BIC reduction was greater for C(a-v)O2 compared with cardiac output (BIC, 298.72 versus 287.68) in CKD. CONCLUSIONS: In CKD, both peak cardiac output and peak C(a-v)O2 are independent predictors of VO2peak, and the more significant roleplayed by peak C(a-v)O2 highlights the importance of noncardiac factors in determining exercise capacity in CKD.

Early and asymptomatic cardiac dysfunction in chronic kidney disease.

Background: Heart failure (HF) is highly prevalent and associated with high mortality in chronic kidney disease (CKD). However, the pathophysiology of cardiac dysfunction in CKD, especially in the early asymptomatic stage, is not well understood. We studied subclinical cardiac dysfunction in asymptomatic CKD patients without comorbid cardiac disease or diabetes mellitus by evaluating peak cardiac performance. Methods: In a cross-sectional study (n = 130) we investigated 70 male non-diabetic CKD patients (21 CKD stage 2-3a, 27 CKD stage 3b-4 and 22 CKD stage 5) employing specialized cardiopulmonary exercise testing to measure peak cardiac output and cardiac power output non-invasively. Data from 35 age-matched healthy male volunteers were obtained for comparison. In addition, as a positive control, data from 25 age-matched male HF patients in New York Heart Association class II and III were also obtained. Results: The study subjects showed a graded reduction in peak cardiac power, with 6.13 ± 1.11 W in controls, 5.02 ± 0.78 W in CKD 2-3a, 4.59 ± 0.53 W in CKD 3b-4 and 4.02 ± 0.73 W in CKD 5, although not as impaired as in HF, with 2.34 ± 0.63 W (all P < 0.005 versus control). The central haemodynamic characteristics of the cardiac impairment in CKD mirrored that of HF, with reduced flow and pressure-generating capacities, reduced chronotropic reserve and impaired contractility. Conclusions: The study demonstrates for the first time impaired peak cardiac performance and cardiac functional reserve in asymptomatic CKD patients. The evidence of myocardial dysfunction in the absence of comorbid cardiac disease and diabetes warrants further evaluation of current pathophysiological concepts of cardiovascular disease in CKD.

Use of prophylactic antibiotics for intra-vesicle Botox® injection.

AIM: Botox injection in bladder wall is increasingly used in urology for over active bladder and neurogenic bladder. Aim of this audit is to assess the incidence of UTI after procedure and need for routine use of pre and post procedure antibiotics. METHOD: It was case notes and lab results based retrospective study of all the patients attended for intra-vesicle Botox injection. RESULTS: Rate of UTI's were lower in the group who received antibiotics pre and post operatively as compared to those who did not. CONCLUSION: Routine antibiotics use lowers the risk of UTI's in patients receiving intra-vesicle botox. Neurourol. Urodynam. 36:828-828, 2017. © 2016 Wiley Periodicals, Inc.

Differences in side-effect duration and related bother levels between phosphodiesterase type 5 inhibitors.

OBJECTIVE: To assess whether the longer half-life of tadalafil is associated with longer lasting or more severe side-effects than the other phosphodiesterase type 5 inhibitors (PDE-5Is), as clinical trials have shown that the efficacy and safety of the three available are similar, but tadalafil has a half-life four times longer than the other two drugs. PATIENTS AND METHODS: Treatment-naive men beginning PDE5-I therapy were recruited from a specialist clinic. Data on the type and duration of drug-associated side-effects were collected prospectively. Levels of bother were assessed with a visual analogue scale (VAS). Differences in type, duration and bother of side-effect were compared between drugs. RESULTS: In all, 409 men provided data; there were no differences between drugs in the proportion of men responding, or the overall prevalence of side-effects. The mean duration of side-effects with tadalafil was 14.9 h, compared to 3.9 and 7.7 h for sildenafil and vardenafil. Of men taking tadalafil, 30% had side-effects lasting >12 h. There were no differences in mean VAS scores between the drugs. Individual side-effects caused similar levels of bother, except for facial flushing, which was less bothersome. CONCLUSIONS: Men taking tadalafil are at risk of prolonged side-effects, although levels of bother associated with these side-effects are not significantly greater than those seen with short-acting PDE5-Is.

The prevalence of newly diagnosed hyperlipidaemia in men with erectile dysfunction.

OBJECTIVE: To determine the prevalence of newly diagnosed hypercholesterolaemia and hypertriglyceridaemia in patients presenting to an andrology clinic with erectile dysfunction (ED), and to assess the relationship between serum lipid levels and the severity of ED. PATIENTS AND METHODS: In all, 199 consecutive men attending an ED clinic were assessed for risk factors for ED; patients completed the International Index of Erectile Function (IIEF)-15 questionnaire and provided venous blood samples for assaying fasting total cholesterol and total triglyceride levels. The proportion of newly diagnosed hyperlipidaemia in patients presenting with ED was calculated and related to patient age, total IIEF score and severity of ED. RESULTS: Using a threshold of 5.0 mmol/L, there was newly diagnosed hypercholesterolaemia in 40% of the men, while there was undiagnosed hypertriglyceridaemia (>2 mmol/L) in 29% of the population. There was no clear correlation between patient age and the fasting lipid levels, and no association between total IIEF-15 score or severity of ED and serum cholesterol and triglyceride levels. CONCLUSION: This study shows the high prevalence of undiagnosed hypercholesterolaemia and hypertriglyceridaemia in men presenting with ED. The opportunity to screen for and treat these risk factors has long-term benefits in preventing cardiovascular disease in this group of patients.