Tongying Zhu

INSULIN RESISTANCE AS A PREDICTOR OF CARDIOVASCULAR DISEASE IN PATIENTS ON PERITONEAL DIALYSIS

♦ Background: Insulin resistance is associated with multiple risk factors for cardiovascular (CV) disease in the general population. Patients on peritoneal dialysis (PD) are more likely to develop insulin resistance. However, no evaluation of the impact of insulin resistance on CV disease morbidity or mortality in patients on PD has been performed. ♦ Methods: Our prospective cohort study included all non-diabetic patients on PD at our center (n = 66). Insulin resistance was evaluated at baseline by the homeostasis model assessment method (HOMA-IR) using fasting glucose and insulin levels. The cohort was followed for up to 58 months (median: 41.3 months; interquartile range: 34.3 months). A multivariate Cox model was used to analyze the impact of insulin resistance on CV disease mortality. ♦ Results: Fourteen CV events occurred in the higher HOMA-IR group [IR-H (HOMA-IR values in the range 2.85 - 19.5), n = 33], but only one event occurred in the lower HOMA-IR group (IR-L (HOMA-IR values in the range 0.83 - 2.71), n = 33) during the follow-up period. Level of HOMA-IR was a significant predictor of CV events [risk ratio: 17.7; 95% confidence interval (CI): 2.10 to 149.5; p = 0.008]. In the IR-H group, 10 patients died (8 CV events), but in the IR-L group, only 4 patients died (1 CV event). Patients in the IR-H group experienced significantly higher CV mortality (hazard ratio: 9.02; 95% CI: 1.13 to 72.2; p = 0.04). Even after adjustments for age, systolic blood pressure, body mass index, C-reactive protein, triglycerides, resistin, and leptin, HOMA-IR remained an independent predictor of CV mortality (hazard ratio: 14.8; 95% CI: 1.22 to 179.1; p = 0.03). ♦ Conclusions: Insulin resistance assessed using HOMA-IR was an independent predictor of CV morbidity and mortality in a cohort of nondiabetic patients on PD. Insulin resistance is a modifiable risk factor; the reduction of insulin resistance may reduce CV risk and improve survival in this group of patients.

Twelve weeks of pioglitazone therapy significantly attenuates dysmetabolism and reduces inflammation in continuous ambulatory peritoneal dialysis patients--a randomized crossover trial.

♦ Background: The aim of the present study was to investigate the effect of oral pioglitazone (PIO) on lipid metabolism, insulin resistance, inflammation, and adipokine metabolism in continuous ambulatory peritoneal dialysis (CAPD) patients. ♦ Methods: In this randomized crossover trial, 36 CAPD patients with serum triglyceride levels above 1.8 mmol/L were randomly assigned to receive either oral PIO 15 mg once daily or no PIO for 12 weeks. Then, after a 4-week washout, the patients were switched to the alternative regimen. The primary endpoint was change in serum triglycerides during the PIO regimen compared with no PIO. Secondary endpoints included changes in other lipid levels, homeostatic model assessment of insulin resistance (HOMA-IR), adipocytokines, and C-reactive protein (CRP). ♦ Results: All 36 CAPD patients (age: 64 ± 11 years; 33% men; 27.8% with diabetes mellitus) completed the study. Comparing patients after PIO and no PIO therapy, we found no significant differences in mean serum triglycerides (3.83 ± 1.49 mmol/L vs 3.51 ± 1.98 mmol/L, p = 0.2). However, mean high-density lipoprotein (0.94 ± 0.22 mmol/L vs 1.00 ± 0.21 mmol/L, p = 0.004) and median total adiponectin [10.34 μg/mL (range: 2.59 - 34.48 μg/mL) vs 30.44 μg/mL (3.47 - 93.41 μg/mL), p < 0.001] increased significantly. Median HOMA-IR [7.51 (1.39 - 45.23) vs 5.38 (0.97 - 14.95), p = 0.006], mean fasting blood glucose (7.31 ± 2.57 mmol/L vs 6.60 ± 2.45 mmol/L, p = 0.01), median CRP [8.78 mg/L (0.18 - 53 mg/L) vs 3.50 mg/L (0.17 - 26.30 mg/L), p = 0.005], and mean resistin (32.70 ± 17.17 ng/mL vs 28.79 ± 11.83 ng/mL, p = 0.02) all declined. The PIO was well tolerated, with only one adverse event: lower-extremity edema in a patient with low residual renal function. ♦ Conclusions: Blood triglycerides were not altered after 12 weeks of PIO 15 mg once daily in CAPD patients, but parameters of dysmetabolism were markedly improved, including insulin resistance, inflammation, and adipokine balance, suggesting that PIO could be of value for this high-risk patient group. Larger, more definitive studies are needed to confirm these findings.

ACEI/ARB underused in patients with type 2 diabetes in Chinese population (CCMR-3B study).

Objective In patients with diabetic kidney disease, it is well documented that RAS blockade is associated with an improved outcome. This observational, multicenter study examined the “real-world” use of ACEI/ARB in patients with type 2 diabetes (T2DM) in China. Method Data from the China Cardiometabolic Registries on blood pressure, blood lipid and blood glucose in Chinese T2DM patients (CCMR-3B) were used for the present study. Consecutive outpatients with T2DM for more than 6 months were recruited to this non-interventional, observational, cross-sectional study. Albuminuria was defined as urine albumin creatinine ratio (ACR) ≥ 30mg/g. Results A total of 25,454 outpatients with T2DM from 6 regions in China were enrolled, 47.0% were male, and 59.8% had hypertension. ACR was measured in 6,383 of these patients and 3,231 of them ≥ 30mg/L. Among patients with hypertension, 73.0% were on antihypertensives, and 39.7% used ACEI/ARB. Of the 2,157 patients with hypertension and albuminuria, only 48.3% used ACEI/ARB. Among the non-hypertensive patients with albuminuria, ACEI/ARB usage was < 1%. Multivariate analysis revealed that comorbidities, region, hospital tier, physician specialty and patient’s educational level were associated with ACEI/ARB use. Conclusion In T2DM with hypertension and albuminuria in China, more than half of them were not treated with ACEI/ARB. This real world evidence suggests that the current treatment for patients with diabetes coexisting with hypertension and albuminuria in China is sub-optimal.

Coronary Artery Calcification Score as A Predictor of All-Cause Mortality and Cardiovascular Outcome in Peritoneal Dialysis Patients

♦ Background: This study aimed to examine whether the coronary artery calcification score (CaCS) was associated with the prognosis of peritoneal dialysis (PD) patients. ♦ Methods: Adult PD patients who were clinically stable for at least 2 months were recruited for this prospective, observational cohort study. Coronary artery calcification was assessed using multislice spiral computed tomography and was recorded according to the Agatston score. The endpoints including all-cause mortality, cardiovascular events, and cardiovascular mortality were assessed. Multivariate Cox regression was used to identify independent predictors of all-cause mortality, cardiovascular events (CVEs), and cardiovascular mortality. ♦ Results: A total of 179 PD patients (86 men) with a mean age of 63.5 ± 14.8 years were recruited for this study. Coronary artery calcification scores ranging from 0 to 5,257 were stratified as follows: no (CaCS = 0, n = 54), low (0 < CaCS < 400, n = 72), and high (CaCS ≥ 400, n = 53) calcification. The follow-up duration was 30.6 ± 16.2 (24 – 63) months. Compared with the no calcification group, patients with a higher CaCS were older and had lower diastolic blood pressure, residual renal function, and serum albumin, and higher HbA1C and serum insulin. Multivariate Cox regression revealed that the CaCS was an independent predictor for all the 3 endpoints after adjustment in PD patients. ♦ Conclusions: CaCS was an independent predictor of all-cause mortality, cardiovascular events, and cardiovascular mortality in patients receiving peritoneal dialysis.

Associations Between Serum-Intact Parathyroid Hormone, Serum 25-Hydroxyvitamin D, Oral Vitamin D Analogs and Metabolic Syndrome in Peritoneal Dialysis Patients: A Multi-Center Cross-Sectional Study

♦ Introduction: Although previous studies have suggested associations between serum intact parathyroid hormone (iPTH), 25-hydroxyvitamin D (25(OH)D) and metabolic syndrome (MS) in the general population, these associations are still uncharacterized in peritoneal dialysis (PD) patients. ♦ Methods: In total, 837 prevalent PD patients from 5 centers in China were enrolled between April 1, 2011 and November 1, 2011. The demographic data, biochemical parameters and medical records were collected, except for serum 25(OH)D which was measured in 347 of 837 patients. The definition of MS was modified from National Cholesterol Education Program Third Adult Treatment Panel (NCEP-ATPIII). ♦ Results: 55.4% of 837 patients were found to have MS. The median concentration of iPTH, 25(OH)D and doses of oral vitamin D analogs for participants with MS was significantly lower than those without MS. The iPTH, 25(OH)D values and doses of vitamin D analogs were all associated with one or more components of MS. After multivariate adjustment, low serum iPTH values and oral vitamin D analogs, rather than serum 25(OH)D, were significantly associated with the presence of MS, abnormal fasting blood glucose (FBG) and high-density lipoprotein cholesterol (HDL-C). Compared to iPTH < 130pg/mL, iPTH 130-585 pg/mL and > 585pg/mL were associated with a lower risk of MS with adjusted odds ratio (OR) of 0.59 and 0.33, respectively. Taking vitamin D analogs was also associated with a lower risk of MS with adjusted OR of 0.55. ♦ Conclusions: Serum iPTH and the use of active vitamin D supplements rather than serum 25(OH)D were independently associated with the presence of MS in patients on PD.

The Association of Individual and Regional Socioeconomic Status on Initial Peritonitis and Outcomes in Peritoneal Dialysis Patients: A Propensity Score-Matched Cohort Study

♦ Background: Research indicates that the socioeconomic status (SES) of individuals and the area where they live are related to initial peritonitis and outcomes in peritoneal dialysis (PD). We conducted a retrospective, multi-center cohort study in China to examine these associations. ♦ Methods: Data on 2,171 PD patients were collected from 7 centers, including baseline demographic, socioeconomic, and laboratory data. We explored the potential risk factors for initial peritonitis and outcomes using univariate Cox regression and unadjusted binary logistic regression. Then, we used propensity score matching to balance statistically significant risk factors for initial peritonitis and outcomes, and Kaplan-Meier survival analysis to compare differences in peritonitis-free rates between different groups of participants after matching. ♦ Results: A total of 563 (25.9%) initial episodes of peritonitis occurred during the study period. The Kaplan-Meier peritonitis-free rate curve showed high-income patients had a significantly lower risk than low-income patients (p = 0.007) after matching for age, hemoglobin, albumin, and regional SES and PD center. The risk of treatment failure was significantly lower in the high-income than the low-income group after matching for the organism causing peritonitis and PD center: odds ratio (OR) = 0.27 (0.09 – 0.80, p = 0.018). Regional SES and education were not associated with initial peritonitis and outcomes. ♦ Conclusions: Our study demonstrates low individual income is a risk factor for the initial onset of peritonitis and treatment failure after initial peritonitis.

ISOLATED LESSER SAC INFECTION: AN UNCOMMON CAUSE OF ABDOMINAL PAIN IN CAPD PATIENTS

Peritonitis in peritoneal dialysis (PD) patients is characterized by abdominal pain and dialysate leukocytosis. Abdominal abscesses have been reported in PD patients with relapsing peritonitis. We report here 3 cases of lesser sac infection in PD patients who had severe abdominal pain but not generalized or diffuse peritonitis.

Hyperphosphatemia and hs-CRP Initiate the Coronary Artery Calcification in Peritoneal Dialysis Patients

Background. Coronary artery calcification (CAC) contributes to high risk of cardiocerebrovascular diseases in dialysis patients. However, the risk factors for CAC initiation in peritoneal dialysis (PD) patients are not known clearly. Methods. Adult patients with baseline CaCS = 0 and who were followed up for at least 3 years or until the conversion from absent to any measurable CAC detected were included in this observational cohort study. Binary logistic regression was performed to identify the risk factors for CAC initiation in PD patients. Results. 70 patients recruited to our study were split into a noninitiation group (n = 37) and an initiation group (n = 33) according to the conversion of any measurable CAC during their follow-up or not. In univariate analysis, systolic blood pressure, serum phosphorus, fibrinogen, hs-CRP, serum creatinine, and triglycerides were positively associated with the initiation of CAC, while the high density lipoprotein and nPCR did the opposite function. Multivariate analysis revealed that hyperphosphatemia and hs-CRP were the independent risk factors for CAC initiation after adjustments. Conclusions. Hyperphosphatemia and hs-CRP were the independent risk factors for CAC initiation in PD patients. These results suggested potential clinical strategies to prevent the initiation of CAC in PD patients.