Georges Halabi

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

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.

Multimodal imaging of retinal pigment epithelial detachments in patients with C3 glomerulopathy: case report and review of the literature

BackgroundTo describe the optical coherence tomography angiograhy (OCTA) of drusenoid pigment epithelial detachments (PEDs) in a woman affected by Complement 3 (C3) glomerulopathy, which represents a spectrum of glomerular diseases characterized on fluorescent microscopy by C3 accumulation with absent, or scanty, immunoglobulin deposits. It is due to acquired or genetically defective alternative pathway control and is generally associated with drusen-like deposits in Bruch’s membrane, as well as choriocapillaris. These retinal lesions can be associated with choroidal neovascularization and central serous chorioretinopathy (CSCR). OCTA is useful to detect neovascularization without injecting a contrast product, particularly in these patients who may have renal insufficiency.Case presentationA 28-year-old woman affected by C3 glomerulpathy was diagnosed with asymptomatic multiple bilateral PEDs during a routine ophthalmologic consultation. To better characterize the lesions, multimodal imaging was performed and included: optic coherence tomography (OCT), en-face OCT, OCTA, fluorescence and indocyanine angiography. The OCTA clearly identified vascular network rarefaction with decreased choriocapillary vascularization. It confirmed that PEDs associated with C3 glomerulonephritis are not vascularized, but rather of serous type.ConclusionsPatients affected by C3 glomerulopathy can develop neovascular membranes as retinal complications of pigment epithelial detachments. Optical coherence angiography may be indicated to identify this complication, without injecting any contrast product that could produce further kidney damage.