Risk factor paradox in CKD and ESRD: does a healthy lifestyle matter?

Relationships of Weight Change from 20 Years of Age with the Risks of All-Cause and Cardiovascular Mortality in Patients with Chronic Kidney Disease

AIMS

Weight changes from a young age are known to be associated with poor life outcomes in the general population. However, little is known about the association between weight change from a young age and life expectancy in patients with chronic kidney disease (CKD).

METHODS

Data of 2,806 nondialysis CKD patients who participated in the Fukuoka Kidney Disease Registry (FKR) Study, a multicenter observational study, were analyzed. The primary outcome was all-cause death, whereas the secondary outcome was cardiovascular mortality. The covariate of interest was weight change, defined as the difference between body weight at study enrollment and at 20 years old. Cox proportional-hazards models were used to estimate the risks of mortality for participants with weight changes of ≥ 5 or ＜5 kg compared with those with stable weights.

RESULTS

During the 5-year observation period, 243 participants died from all causes and 62 from cardiovascular disease. The risk of all-cause mortality in the weight-loss group was significantly higher than that in the stable-weight group (multivariable-adjusted hazard ratio, 2.11; 95% confidence interval [CI], 1.52-2.93). Conversely, the risk of cardiovascular mortality in the weight-loss group was significantly higher than that in the stable-weight group (multivariable-adjusted hazard ratio, 2.48; 95% CI, 1.32-4.64). However, no significant association was observed between weight gain and the risks of all-cause and cardiovascular mortalities.

CONCLUSION

Weight loss from 20 years of age was found to be associated with higher risks of all-cause and cardiovascular mortalities in patients with CKD.

Dyslipidemia in Chronic Kidney Disease: Contemporary Concepts and Future Therapeutic Perspectives

BACKGROUND

Chronic kidney disease (CKD) is an increasingly prevalent disease state met with great morbidity and mortality primarily resulting from the high incidence of adverse cardiovascular outcomes. Therapeutic strategies in this patient population aim at controlling modifiable cardiovascular risk factors, including dyslipidemia.

SUMMARY

In this review article, we first provide the latest pathophysiologic evidence regarding the altered dyslipidemia pattern in CKD, followed by its contemporary management according to the latest guidelines. Moreover, we present the current progress regarding the emerging therapeutic strategies. Key Messages: The presence of renal impairment leads to alterations in cholesterol structure, metabolism, and reverse transport paired with increased oxidative stress. Statins remain the cornerstone of dyslipidemia management in patients with kidney dysfunction who are at risk for cardiovascular events. However, their efficacy is debatable in end-stage renal disease under renal replacement therapy. Therefore, novel treatment approaches aiming at hypertriglyceridemia, proprotein convertase subtilisin/kexin type 9, and lipoprotein(a) are under rigorous investigation while the research of gut microbiome might provide additional mechanistic and therapeutic insight.

End-Stage Renal Disease Patients on Chronic Hemodialysis Fare Better With COVID-19: A Retrospective Cohort Study From the New York Metropolitan Region

Introduction

Several comorbid conditions have been identified as risk factors in patients with coronavirus disease 2019 (COVID-19). However, there is a dearth of data describing the impact of COVID-19 infection in patients with end-stage renal disease on hemodialysis (ESRD-HD).

Methods

This retrospective case series analyzed 362 adult patients consecutively hospitalized with confirmed COVID-19 illness between March 12, 2020, and May 13, 2020, at a teaching hospital in the New York City metropolitan area. The primary outcome was severe pneumonia as defined by the World Health Organization. Secondary outcomes were the (1) the Combined Outcome of Acute respiratory distress syndrome or in-hospital Death (COAD), and (2) need for high levels of oxygen supplementation (HiO₂).

Results

Patients with ESRD-HD had lower odds for poor outcomes including severe pneumonia [odds ratio (OR) 0.4, confidence interval (CI) 0.2-0.9, p=.04], HiO₂ [OR 0.3, CI (0.1-0.8), p=.02] and COAD [OR 0.4, CI (0.2-1.05), p=.06], when compared to patients without ESRD. In contrast, higher odds for severe pneumonia, COAD and HiO₂ were seen with advancing age. African Americans were over-represented in the hospitalized patient cohort, when compared to their representation in the community (35% vs 18%). Hispanics had higher odds for severe illness and HiO₂ when compared to Caucasians.

Conclusions

Patients with ESRD-HD had a milder course of illness with a lower likelihood of severe pneumonia and a lesser need for aggressive oxygen supplementation when compared to patients not on chronic dialysis. The lower odds of severe illness in ESRD-HD patients might have a pathophysiologic basis and need to be further explored.

Cholesterol Disturbances and the Role of Proper Nutrition in CKD Patients

Chronic kidney disease (CKD) is a widespread disease with increasing prevalence in the modern society. Lipid disturbances are common in this group of patients. In most patients with CKD atherogenic dyslipidemia is observed. Dyslipidemia in patients with renal diseases increases the risk of cardiovascular diseases and it accelerates the progression of chronic kidney disease to its end stage. The amelioration of dyslipidemia and the lowering of oxidative stress, inflammatory processes, insulin sensitivity and remnant lipoproteins levels may lead to the reduction in cardiovascular burden. Nutritional interventions can strengthen the beneficial effect of treatment and they play an important role in the preservation of overall well-being of the patients with CKD since the aim of appropriate diet is to reduce the risk of cardiovascular events, prevent malnutrition, and hamper the progression of kidney disease. The management of dyslipidemia, regardless of the presence of chronic kidney disease, should be initiated by the introduction of therapeutic lifestyle changes. The introduction of diet change was shown to exert beneficial effect on the lipid level lowering that reaches beyond pharmacological therapy. Currently available evidence give the impression that data on dietary interventions in CKD patients is not sufficient to make any clinical practice guidelines and is of low quality.

BMI and its association with death and the initiation of renal replacement therapy (RRT) in a cohort of patients with chronic kidney disease (CKD)

Background

A survival advantage associated with obesity has often been described in dialysis patients. The association of higher body mass index (BMI) with mortality and renal replacement therapy (RRT) in preterminal chronic kidney disease (CKD) patients has not been established.

Methods

Subjects were patients with pre-terminal CKD who were recruited to the CKD.QLD registry. BMI at time of consent was grouped as normal (BMI 18.5–24.9 kg/m²), overweight (BMI 25–29.9 kg/m²), mild obesity (BMI 30–34.9 kg/m²) and moderate obesity+ (BMI ≥ 35 kg/m²) as defined by WHO criteria. The associations of BMI categories with mortality and starting RRT were analysed.

Results

The cohort consisted of 3344 CKD patients, of whom 1777 were males (53.1%). The percentages who had normal BMI, or were overweight, mildly obese and moderately obese+ were 18.9, 29.9, 25.1 and 26.1%, respectively. Using people with normal BMI as the reference group, and after adjusting for age, socio-economic status, CKD stage, primary renal diagnoses, comorbidities including cancer, diabetes, peripheral vascular disease (PVD), chronic lung disease, coronary artery disease (CAD), and all other cardiovascular disease (CVD), the hazard ratios (HRs, 95% CI) of males for death without RRT were 0.65 (0.45–0.92, p = 0.016), 0.60 (0.40–0.90, p = 0.013), and 0.77 (0.50–1.19, p = 0.239) for the overweight, mildly obese and moderately obese+. With the same adjustments the hazard ratios for death without RRT in females were 0.96 (0.62–1.50, p = 0.864), 0.94 (0.59–1.49, p = 0.792) and 0.96 (0.60–1.53, p = 0.865) respectively.

In males, with normal BMI as the reference group, the adjusted HRs of starting RRT were 1.15 (0.71–1.86, p = 0.579), 0.99 (0.59–1.66, p = 0.970), and 0.95 (0.56–1.61, p = 0.858) for the overweight, mildly obese and moderately obese+ groups, respectively, and in females they were 0.88 (0.44–1.76, p = 0.727), 0.94 (0.47–1.88, p = 0.862) and 0.65 (0.33–1.29, p = 0.219) respectively.

Conclusions

More than 80% of these CKD patients were overweight or obese. Higher BMI seemed to be a significant “protective” factor against death without RRT in males but there was not a significant relationship in females. Higher BMI was not a risk factor for predicting RRT in either male or female patients with CKD.

Truncal Adiposity Influences High-Density Lipoprotein Cholesterol Levels and Cardiovascular Events in Hemodialysis Patients

OBJECTIVE

Adiposity influences lipid metabolism and atherosclerotic cardiovascular disease (CVD) in the general population. The aim of the present study was to assess the association between fat mass (FM) and lipid metabolism and CVD events among patients on hemodialysis (HD).

METHODS

This prospective observational study examined 240 patients on prevalent HD. Blood samples were obtained before dialysis at baseline to measure lipids, high-sensitivity C-reactive protein (hs-CRP), interleukin-6, and adiponectin. Lipids and hs-CRP were measured every 3 months for 12 months. FM was estimated by dual energy x-ray absorptiometric scan at baseline and 12 months later. Patients were then prospectively followed up for 36 months after the 1-year measurement period, and composite CVD events were estimated.

RESULTS

Truncal FM was positively correlated with body mass index, hs-CRP, interleukin-6, total cholesterol, low-density lipoprotein-C, triglyceride, and negatively correlated with high-density lipoprotein (HDL)-C and adiponectin at baseline. HDL-C levels were repeatedly decreased, and triglyceride and non-HDL-C were serially increased in the patient group with truncal FM > 7,000 g at both baseline and 12 months (large truncal FM group) compared with the other groups. Cox proportional hazards models adjusted for confounders showed composite CVD events occurred significantly in patients with large truncal FM and continuous low HDL-C levels.

CONCLUSIONS

Truncal adiposity influences lipid metabolism in patients on HD, and the prevalence of CVD events may be increased in those patients with high fat and lipid abnormalities, especially continuously low HDL-C levels.

Cigarette smoking reduced renal function deterioration in hypertensive patients may be mediated by elevated homocysteine

Elevated homocysteine (HCY) and smoking are both important risk factors for hypertensive patients. However, whether they have crossing effect on renal function deterioration of hypertensive patients and what is the underlying mechanism are unclear. In the present study, 3033 participants diagnosed as essential hypertension with estimated glomerular filtration rate (eGFR)> 30 ml/min/1.73 m² from southern China were enrolled in this cross-sectional study. We collected the demographic and clinical data. In addition, the mediation effects were analyzed. The results showed that, comparing with non-smokers, smokers had significant higher levels of HCY (13.10 (11.20−16.87) vs. 11.00 (8.90−13.40) umol/L, P < 0.001) and lower eGFR (79.71 (66.83−91.05) vs. 82.89 (69.80−95.85) ml/min/1.73m², P < 0.001). HCY levels and smoking were independently associated with decreased eGFR. Meanwhile, eGFR levels were significantly negatively correlated with HCY (P < 0.001), and this correlation might be stronger in current smokers. Current smoker consuming over 20 cigarettes per day would accelerate early renal function deterioration (OR = 1.859, P = 0.019). The mediation effects analysis further showed that the association between smoking and renal function deterioration was mediated by HCY. And elevated HCY was accounted for 56.94% of the estimated causal effect of smoking on renal function deterioration in hypertensive patients. Our findings indicated that cigarette smoking was associated with renal function deterioration in hypertensive patients, and the association between cigarette smoking and renal function deterioration was probably mediated by elevated HCY. Therefore, HCY-lowering therapy may be beneficial for renal function deterioration in hypertensive smoking patients.

Body mass index and causes of death in chronic kidney disease

In chronic kidney disease (CKD), a higher body mass index (BMI) is associated with a lower risk for death, but cause-specific death details are unknown across the BMI range. To define this, we studied 54,506 patients with CKD (stage 3 CKD- [91.5%]) from an institutional electronic medical record based-registry. We examined the associations among various causes of death (cardiovascular-, malignancy- and noncardiovascular/nonmalignancy-related deaths) across the BMI range using Cox proportional hazards and competing risks regression models. During a median follow-up of 3.7 years, 14,518 patients died. In the multivariable model, an inverted J-shaped association was noted between BMI and cardiovascular-related, malignancy-related, and noncardiovascular/nonmalignancy-related deaths. Similar associations were noted for BMI 25-29.9, 30-34.9, and 35-39.9 kg/m(2) categories. A BMI >40 kg/m(2) was not associated with cardiovascular-related and noncardiovascular/nonmalignancy-related deaths in CKD. Sensitivity analyses yielded similar results even after adjusting for proteinuria and excluding diabetes and hypertension from the models. In CKD, compared with a BMI of 18.5-24.9 kg/m(2), those who are overweight, with class 1 and 2 obesity have a lower risk for cardiovascular-related, malignancy-related, and noncardiovascular/nonmalignancy-related deaths. Future studies should examine the associations of other measures of adiposity with outcomes in CKD.