Claudine Mathieu

Prevalence and Diagnostic Approach to Sleep Apnea in Hemodialysis Patients: A Population Study

Background. Previous observations found a high prevalence of obstructive sleep apnea (OSA) in the hemodialysis population, but the best diagnostic approach remains undefined. We assessed OSA prevalence and performance of available screening tools to propose a specific diagnostic algorithm. Methods. 104 patients from 6 Swiss hemodialysis centers underwent polygraphy and completed 3 OSA screening scores: STOP-BANG, Berlins Questionnaire, and Adjusted Neck Circumference. The OSA predictors were identified on a derivation population and used to develop the diagnostic algorithm, which was validated on an independent population. Results. We found 56% OSA prevalence (AHI ≥ 15/h), which was largely underdiagnosed. Screening scores showed poor performance for OSA screening (ROC areas 0.538 [SE 0.093] to 0.655 [SE 0.083]). Age, neck circumference, and time on renal replacement therapy were the best predictors of OSA and were used to develop a screening algorithm, with higher discriminatory performance than classical screening tools (ROC area 0.831 [0.066]). Conclusions. Our study confirms the high OSA prevalence and highlights the low diagnosis rate of this treatable cardiovascular risk factor in the hemodialysis population. Considering the poor performance of OSA screening tools, we propose and validate a specific algorithm to identify hemodialysis patients at risk for OSA for whom further sleep investigations should be considered.

Pioglitazone Improves Fat Distribution, the Adipokine Profile and Hepatic Insulin Sensitivity in Non-Diabetic End-Stage Renal Disease Subjects on Maintenance Dialysis: A Randomized Cross-Over Pilot Study

Background Fat redistribution, increased inflammation and insulin resistance are prevalent in non-diabetic subjects treated with maintenance dialysis. The aim of this study was to test whether pioglitazone, a powerful insulin sensitizer, alters body fat distribution and adipokine secretion in these subjects and whether it is associated with improved insulin sensitivity. Trial Design This was a double blind cross-over study with 16 weeks of pioglitazone 45 mg vs placebo involving 12 subjects. Methods At the end of each phase, body composition (anthropometric measurements, dual energy X-ray absorptometry (DEXA), abdominal CT), hepatic and muscle insulin sensitivity (2-step hyperinsulinemic euglycemic clamp with 2H2-glucose) were measured and fasting blood adipokines and cardiometabolic risk markers were monitored. Results Four months treatment with pioglitazone had no effect on total body weight or total fat but decreased the visceral/sub-cutaneous adipose tissue ratio by 16% and decreased the leptin/adiponectin (L/A) ratio from 3.63×10−3 to 0.76×10−3. This was associated with a 20% increase in hepatic insulin sensitivity without changes in muscle insulin sensitivity, a 12% increase in HDL cholesterol and a 50% decrease in CRP. Conclusions/Limitations Pioglitazone significantly changes the visceral-subcutaneous fat distribution and plasma L/A ratio in non diabetic subjects on maintenance dialysis. This was associated with improved hepatic insulin sensitivity and a reduction of cardio-metabolic risk markers. Whether these effects may improve the outcome of non diabetic end-stage renal disease subjects on maintenance dialysis still needs further evaluation. Trial Registration ClinicalTrial.gov NCT01253928

Optimal and continuous anaemia control in a cohort of dialysis patients in Switzerland

BackgroundGuidelines for the management of anaemia in patients with chronic kidney disease (CKD) recommend a minimal haemoglobin (Hb) target of 11 g/dL. Recent surveys indicate that this requirement is not met in many patients in Europe. In most studies, Hb is only assessed over a short-term period. The aim of this study was to examine the control of anaemia over a continuous long-term period in Switzerland.MethodsA prospective multi-centre observational study was conducted in dialysed patients treated with recombinant human epoetin (EPO) beta, over a one-year follow-up period, with monthly assessments of anaemia parameters.ResultsThree hundred and fifty patients from 27 centres, representing 14% of the dialysis population in Switzerland, were included. Mean Hb was 11.9 ± 1.0 g/dL, and remained stable over time. Eighty-five % of the patients achieved mean Hb ≥ 11 g/dL. Mean EPO dose was 155 ± 118 IU/kg/week, being delivered mostly by subcutaneous route (64–71%). Mean serum ferritin and transferrin saturation were 435 ± 253 μg/L and 30 ± 11%, respectively. At month 12, adequate iron stores were found in 72.5% of patients, whereas absolute and functional iron deficiencies were observed in only 5.1% and 17.8%, respectively. Multivariate analysis showed that diabetes unexpectedly influenced Hb towards higher levels (12.1 ± 0.9 g/dL; p = 0.02). One year survival was significantly higher in patients with Hb ≥ 11 g/dL than in those with Hb <11 g/dL (19.7% vs 7.3%, p = 0.006).ConclusionIn comparison to European studies of reference, this survey shows a remarkable and continuous control of anaemia in Swiss dialysis centres. These results were reached through moderately high EPO doses, mostly given subcutaneously, and careful iron therapy management.

Changing trends in end-stage renal disease patients with diabetes

BACKGROUND Worldwide, diabetes has become the most common cause of end-stage renal disease (ESRD), yet Swiss data are largely lacking. METHODS This observational study examined ESRD patients with diabetes mellitus (ESRD-DM) at end of 2009 and 2014. The prevalence and characteristics of ESRD-DM patients were collected in all dialysis facilities in the Canton of Vaud of Switzerland in 2009 and in 2014, and the 5-year mortality rate was assessed. RESULTS A total of 107 and 140 ESRD-DM patients underwent dialysis at end of 2009 and 2014, respectively. Within the 5-year period a total of 167 incidental ESRD-DM patients required dialysis, corresponding to an estimated incidental rate of 0.84/1000 person-years in the diabetic population. In 2009, all patients with ESRD-DM underwent haemodialysis, decreasing to 96.2% in 2014, with 3.8% on peritoneal dialysis. Age, sex, body mass index, type of diabetes, duration of diabetes, cause of ESRD, dialysis duration, dialysis frequency, vascular access, and glycosylated haemoglobin levels did not differ between 2009 and 2014. In 2014, macrovascular comorbidity was reported more often than in 2009, but not amputations. Haemoglobin level decreased significantly from 117.9 g/l to 112.3 g/l. Calcium-containing phosphate binder and angiotensin-converting enzyme inhibitor use significantly decreased, whereas iron therapy significantly increased with time. The 5-year mortality rate was 61.7%. Five-year survivors were significantly younger and had a higher body mass index. CONCLUSIONS The growing prevalence of ESRD-DM emphasises that prevention of chronic kidney disease and its progression should be a public health priority in Switzerland.