Effect of resistance training during hemodialysis on circulating cytokines: a randomized controlled trial.

The purpose of this study was to evaluate the effect of a 12-week intradialytic progressive resistance training (PRT) regimen on circulating pro- and anti-inflammatory cytokines. Forty-nine patients (62.6 ± 14.2 years) were recruited from the outpatient hemodialysis unit of the St. George Public Hospital, Sydney, Australia. Patients were randomized to: PRT + usual care (n = 24) or usual care control (n = 25). The PRT group performed two sets of 10 exercises at high intensity using free-weights, 3 times per week for 12 weeks during dialysis, while the control group did not exercise. Tumor necrosis factor-alpha, interleukin-1b, interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-10, and interleukin-12 were measured in serum before and after the intervention period. Muscle cross-sectional area (CSA), intramuscular lipid, intermuscular adipose tissue, and subcutaneous and total thigh fat, evaluated via computed tomography of the non-dominant mid-thigh, were also collected at both time points. All cytokines were significantly elevated in the total cohort at baseline compared with normative data. There were no cytokine changes over time or between groups (p > 0.05). In secondary analyses pooling the groups, changes in logIL-6 and IL-8 were inversely related to changes subcutaneous thigh fat (p < 0.05) while changes in logIL-6 were also inversely related to changes in thigh muscle CSA, and total thigh fat (p < 0.03). These data suggest that 12 weeks of intradialytic progressive resistance training does not improve circulating pro- and anti-inflammatory markers. Further research is required to elucidate the implications and mechanisms of the relationships between IL-6 and IL-8 and body composition in ESRD.

Screening tests for renal artery stenosis: a case-series from an Australian tertiary referral centre.

BACKGROUND: Renal artery stenosis is a common, correctable cause of hypertension and renal impairment, with multiple screening tests available to aid diagnosis. Data assessing the accuracy of screening tests are mostly derived from tight 'experimental' protocols and the application of these tests to large-scale clinical practice is not clear. Our aim was to investigate physician preferences and diagnostic accuracy of screening tests for renal artery stenosis when applied to clinical practice in a large, Australian tertiary referral centre. METHODS: We investigated all renal angiograms performed at our institution between September 2002 and September 2004, as referred by renal physicians. We accessed hospital and physician records of all patients to document demographics, clinical history, screening investigations, source of screening and angiogram results. The series involved 75 consecutive patients who had 79 screening investigations (four patients had two screening tests). RESULTS: The case series showed that 19 (24%) patients did not have any screening investigations prior to angiography. Duplex ultrasonography was the most utilised screening test, being used in 20 (33%) of the remaining 60 screening tests. Computed tomographic angiography (CTA) was used in 19 (32%), magnetic resonance imaging in 13 (22%) and renal scintigraphy was used in four (7%) screening procedures. Magnetic resonance angiography was the most accurate screening test with a positive predictive value of 92%, followed by duplex ultrasonography with 88% and CTA was relatively inaccurate, with a positive predictive value (PPV) of 58% (P = 0.036). Clinical suspicion alone was inaccurate with a PPV of 40%, except in previously treated renal artery stenosis (PPV 89%). CONCLUSION: Duplex ultrasonography was the most utilised screening investigation amongst the physicians of our referral base. Magnetic resonance angiography and duplex ultrasonography had good positive predictive values, while CTA may not be as reliable as previously reported when applied to a large, non-selective clinical practice.