Different effect of hypercholesterolemia on mortality in hemodialysis patients based on coronary artery disease or myocardial infarction

Relationship of serum total cholesterol and triglyceride with risk of mortality in maintenance hemodialysis patients: a multicenter prospective cohort study

OBJECTIVE

The relationship between serum total cholesterol (TC) and triglyceride (TG) levels and mortality in maintenance hemodialysis (MHD) patients remains inconsistent. We aimed to explore the individual and combined association of TC and TG levels with the risk of mortality in Chinese MHD patients.

METHODS

1036 MHD patients were enrolled in this multicenter, prospective cohort study. The serum levels of total cholesterol and triglycerides were measured at baseline. The primary outcome was all-cause mortality and secondary outcome was cardiovascular disease (CVD) mortality.

RESULTS

During a median follow-up duration of 4.4 years (IQR= 2.0-7.9 years), 549 (53.0%) patients died, and 297 (28.7%) deaths were attributed to CVD. Compared with patients with TC levels in the first three quartiles (<182.5 mg/dL), a significantly higher risk of all-cause mortality was found in participants with TC in the fourth quartile (hazard ratio [HR], 1.43; 95% confidence interval [CI], 1.17-1.76). However, a significantly lower risk of all-cause mortality was observed in participants with TG in the fourth quartile (≥193.9 mg/dL) (HR, 0.78; 95%CI: 0.63-0.98), compared with participants with TG in the first three quartiles. Similar trends were observed in CVD mortality. When analyzed jointly, patients with lower TC (<182.5 mg/dL) and higher TG (≥193.9 mg/dL) levels had the lowest risk of all-cause mortality and CVD mortality.Conclusions: In MHD patients in southern China, higher TC levels were associated with higher risk of mortality, while higher TG levels were related to lower risk of mortality. Patients with lower TC and higher TG levels had the best survival prognosis.

Serum Cholesterol and Impact of Age on Coronary Heart Disease Death in More Than 4 Million Veterans

Background The lipid hypothesis postulates that lower blood cholesterol is associated with reduced coronary heart disease (CHD) risk, which has been challenged by reports of a U-shaped relation between cholesterol and death in recent studies. We sought to examine whether the U-shaped relationship is true and to assess the impact of age on this association. Method and Results We conducted a prospective cohort study of 4 467 942 veterans aged >18 years, with baseline outpatient visits from 2002 to 2007 and follow-up to December 30, 2018, in the Veterans Health Administration electronic health record system. We observed a J-shaped relation between total cholesterol (TC) and CHD mortality after a comprehensive adjustment of confounding factors: flat for TC <180 mg/dL, and greater risk was present at higher cholesterol levels. Compared with veterans with TC between 180 and 199 mg/dL, the multiadjusted hazard ratios (HRs) for CHD death were 1.03 (95% CI, 1.02-1.04), 1.07 (95% CI, 1.06-1.09), 1.15 (95% CI, 1.13-1.18), 1.25 (95% CI, 1.22-1.28), and 1.45 (95% CI, 1.42-1.49) times greater among veterans with TC (mg/dL) of 200 to 219, 220 to 239, 140 to 259, 260 to 279 and ≥280, respectively. Similar J-shaped TC-CHD mortality patterns were observed among veterans with and without statin use at or before baseline. Conclusions The cholesterol paradox, for example, higher CHD death in patients with a low cholesterol level, was a reflection of reverse causality, especially among older participants. Our results support the lipid hypothesis that lower blood cholesterol is associated with reduced CHD. Furthermore, the hypothesis remained true when TC was low due to use of statins or other lipid-lowering medication.

A nonlinear association of total cholesterol with all-cause and cause-specific mortality

Background

The link between total cholesterol (TC) and all-cause and specific mortality has not been elucidated. Herein, we aimed to evaluate the effect of TC levels on all-cause, cardiovascular disease (CVD), and cancer mortality.

Methods

All data analyzed were obtained from the National Health and Nutrition Examination Survey 1999–2014. The relationship between levels of TC and mortality was determined through Cox proportional hazard regression analysis coupled with multivariable adjustments. Two-piecewise linear regression models and Cox models with penalized splines were applied to explore nonlinear and irregular shape relationships. Kaplan–Meier survival curve and subgroup analyses were conducted.

Results

The sample studied comprised 14,662 men and 16,025 women, categorized as 25,429 adults aged 18–65 and 5,258 adults over 65 years old. A total of 2,570 deaths were recorded. All-cause, cardiovascular, and cancer mortality showed U-curve associations after adjusting for confounding variables in the restricted cubic spline analysis. Hazard ratios (HRs) of all-cause and cancer mortality were particularly negatively related to TC levels in the lower range < 200 mg/dL, especially in the range < 120 mg/dL (HR 1.97; 95% CI 1.38, 2.83, HR 2.39; 95% CI 1.21, 4.71, respectively). However, the HRs of cardiovascular disease mortality in the range < 120 mg/dL were the lowest (HR 0.60; 95% CI 0.15, 2.42). In the upper range, a TC range of ≥ 280 mg/dL was correlated with mortality as a result of CVD and cancer (HR 1.31; 95% CI 0.87, 1.97 and HR 1.22; 95% CI 0.82, 1.79). The lowest cumulative survival rate of all-cause mortality was recorded in the lowest TC-level group, while the lowest cumulative survival rate of CVD mortality was recorded in the highest TC-level group.

Conclusions

A nonlinear association of TC level with all-cause, cancer, and CVD mortality in the American population was observed, suggesting that too low or too high serum total cholesterol levels might correlate with adverse outcomes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12986-021-00548-1.

The modulating effect of dietary protein intake on mortality in long-term hemodialysis patients: A nationwide population-based study

AIMS OF THE STUDY

A high prevalence of protein-energy wasting and malnutrition among uremic patients is associated with an increase in morbidity and mortality. We aimed to investigate the modulating effect of daily dietary protein intake (DPI) evaluated by normalised protein catabolic rate (nPCR) on mortality in long-term haemodialysis (HD) patient from a nationwide population-based study.

METHODS USED TO CONDUCT THE STUDY

By Taiwan Renal Registry Data System between 2005 and 2012, we divided the long-term HD patients into average nPCR < 1.2 and nPCR ≥ 1.2 groups according to the current guideline. The relation of nPCR with three-year all-cause and cardiovascular (CV) mortality were evaluated. The cox regression method for predicted mortality by nPCR was used.

RESULTS OF THE STUDY

Among 88 330 HD patients, 58 122 (65.8%) patients were in average nPCR < 1.2 group and 30 208 (34.2%) in average nPCR ≥ 1.2 group. Both all-cause and cardiovascular (CV) mortality risks were increased in nPCR < 1.2 group after adjusting for demographics and laboratories cofactors in our multivariate cox regression model. Patients with nPCR < 1.2 and albumin ≥ 3.7 had a higher adjusted hazard ratio (aHR) for all-cause and CV mortality (1.16 [95% confidence interval (CI): 1.07-1.25, P < .001]; 1.15 [95% CI: 1.02-1.31, P = .03], respectively), compared with the reference group with nPCR ≥ 1.2 and albumin ≥ 3.7. Interestingly, there was no difference in mortality risk between low DPI subgroup (nPCR < 1.2 and Alb < 3.7) and the reference group (nPCR ≥ 1.2 and Alb < 3.7). Further stratification analysis revealed that low DPI subgroup (nPCR < 1.2, Alb ≥ 3.7 and TC ≥ 150) had an increased risk of both all-cause and CV mortality (aHR 1.14 [95% CI: 1.04-1.25, P = .005]; aHR 1.17 [95% CI: 1.02-1.35, P = .026], respectively).

CONCLUSIONS DRAWN FROM THE STUDY

Low DPI (as presented by nPCR) independently correlated with all-cause and CV mortality among HD patients. Mortality risks were higher in low DPI patients even with normoalbuminaemia and non-hypocholesterolaemia. Further investigations on the importance of increasing DPI in HD patients is warranted.

Effects of dialysis modality choice on the survival of end-stage renal disease patients in southern China: a retrospective cohort study

BACKGROUND

The optimal choice of treatment, with hemodialysis (HD) or peritoneal dialysis (PD), for end-stage renal disease (ESRD) patients, is still controversial. Only a few studies comparing HD and PD have been conducted in China, which has the largest number of dialysis patients in the world.

METHODS

A retrospective cohort study was conducted on ESRD patients who began renal replacement treatment from January 1, 2012 to December 31, 2017 in Guangdong Provincial Hospital of Chinese Medicine. Propensity scoring match was applied to balance the baseline conditions and multivariate Cox regression analysis to compare the mortality between HD and PD patients, and evaluated the correlation between mortality and various baseline characteristics.

RESULTS

A total of 436 HD patients and 501 PD patients were included in this study, and PD patients had better survival than HD patients, but the difference was not statistically significant. For younger ESRD patients (≤60-year-old), the overall survival of PD was better than that of HD, but HD was associated with a lower risk of death in older patients (> 70-year-old). This difference was still significant after adjustment for a variety of confounding factors. Female gender, age at dialysis initiation, cardiovascular disease, cholesterol, and HD were risk factors of all-cause mortality in the younger subgroup, while PD was risk factor in the older subgroup.

CONCLUSION

PD may be a better choice for younger ESRD patients, and HD for the older patients.

Total cholesterol and all-cause mortality by sex and age: a prospective cohort study among 12.8 million adults

It is unclear whether associations between total cholesterol (TC) levels and all-cause mortality and the optimal TC ranges for lowest mortality vary by sex and age. 12,815,006 Korean adults underwent routine health examinations during 2001–2004, and were followed until 2013. During follow-up, 694,423 individuals died. U-curve associations were found. In the TC ranges of 50–199 and 200–449 mg/dL, each 39 mg/dL (1 mmol/L) increase in TC was associated with 23% lower (95% CI:23%,24%) and 7% higher (6%,7%) mortality, respectively. In the age groups of 18–34, 35–44, 45–54, 55–64, 65–74, and 75–99 years, each 1 mmol/L higher TC increased mortality by 14%, 13%, 8%, 7%, 6%, and 3%, respectively (P < 0.001 for each age group), for TC ≥ 200 mg/dL, while the corresponding TC changes decreased mortality by 13%, 27%, 34%, 31%, 20%, and 13%, respectively, in the range < 200 mg/dL (P < 0.001 for each age group). TC had U-curve associations with mortality in each age-sex group. TC levels associated with lowest mortality were 210–249 mg/dL, except for men aged 18–34 years (180–219 mg/dL) and women aged 18–34 years (160–199 mg/dL) and 35–44 years (180–219 mg/dL). The inverse associations for TC < 200 mg/dL were stronger than the positive associations in the upper range.

Effects of Cholesterol Levels on Mortality in Patients with Long-Term Peritoneal Dialysis Based on Residual Renal Function

The effect of dyslipidemia on peritoneal dialysis (PD) patients based on the presence of residual renal function (RRF; renal creatinine clearance >2 mL/min/1.73 m²) is unknown. Data from the Taiwan Renal Registry Data System between 2005 and 2012 were analyzed to estimate the association between dyslipidemia and mortality in PD patients. Long-term PD patients (n = 8032) were divided into groups with (RRF; n = 2691, 33.5%) and without RRF (non-RRF; n = 5341, 66.5%). The primary outcome was three-year mortality, and multivariate Cox regression was used for survival analysis. After stratifying the total cholesterol (TC) level between the first and third years, the hazard ratio for mortality was estimated. In the non-RRF group, TC < 120 mg/dL was associated with independently increased risk of mortality. In the RRF group, low TC was not independently correlated with increased mortality, but TC > 285 mg/dL was associated with increased risk. PD patients with higher level of TC (>200 mg/dL) in both first and third years of dialysis had significantly lower risk of mortality. In this nationwide cohort study, PD patients without RRF who had low TC level had the highest mortality, in contrast to those with RRF. Malnutrition in long-term PD patients without RRF is an important issue to be monitored.

Total Bilirubin in Prognosis for Mortality in End-Stage Renal Disease Patients on Peritoneal Dialysis Therapy

Background

Evidence regarding bilirubin's antioxidant properties and predictive roles is growing. However, it is unclear whether serum bilirubin would have a prognostic impact on survival of patients with regular peritoneal dialysis.

Methods and Results

We used the Taiwan Renal Registry Data System utilizing its 2005‐2012 data set. Data from patients on regular peritoneal dialysis were retrieved. The primary end point of observation was 3‐year mortality. A total of 3704 patients (mean age 53.5 years, 44% male) were enrolled, and these patients were divided according to baseline serum total bilirubin levels (<0.3, 0.3‐0.4, 0.4‐0.5, 0.5‐0.6, >0.6 mg/dL). Serum total bilirubin level was linearly related to age, incidence of hypertension, and type 2 diabetes mellitus. At the end of the observation period with a mean follow‐up of 2.12±1.07 years, 1095 (30.6%) deaths were detected. Serum total bilirubin level and 3‐year mortality rate presented a U‐shaped relationship. Those with serum total bilirubin 0.5 to 0.6 mg/dL had the lowest 3‐year mortality rate (24%). After adjustment for age, sex, underlying systemic disorders, medications, and laboratory discrepancies, serum total bilirubin still played an independent role for predicting 3‐year mortality.

Conclusions

Baseline serum total bilirubin level is significantly associated with 3‐year mortality among patients receiving regular peritoneal dialysis.

Association of genetic variations in the lipid regulatory pathway genes FBXW7 and SREBPs with coronary artery disease among Han Chinese and Uygur Chinese populations in Xinjiang, China

Background

Hyperlipidemia is a major risk factor for coronary artery disease (CAD). The current study was designed to explore the possible correlation between single nucleotide polymorphisms (SNPs) in the lipid homeostasis regulatory genes F-box and WD repeat domain-containing 7 (FBXW7) and sterol regulatory element-binding proteins (SREBPs) with CAD among Han Chinese and Uygur Chinese populations in Xinjiang, China.

Results

In the Uygur Chinese population, rs9902941 in SREBP-1 and rs10033601 in FBXW7 were found to be associated with CAD in a recessive model (TT vs. CT + CC, P = 0.032; GG vs. AG + AA, P = 0.010, respectively), and rs7288536 in SREBP-2 was found to be associated with CAD in an additive model (CT vs. CC + TT, P = 0.045). The difference was statistically significant in the Uygur Chinese population after multivariate adjustments [Odds ratio (OR) = 1.803, 95% confidence interval (CI): 1.036~3.137, P = 0.037; OR = 1.628, 95% CI: 1.080~2.454, P = 0.020; OR = 1.368; and 95% CI: 1.018~1.837, P = 0.037, respectively]. There were also significant interactions between the above-mentioned models in the Uygur Chinese population. However, these relationships were not observed before or after multivariate adjustment in the Han Chinese population.

Materials and Methods

A total of 1,312 Han Chinese (650 CAD patients and 662 controls) and 834 Uygur Chinese (414 CAD patients and 420 controls) were enrolled in this case-control study. Three SNPs (rs9902941 in SREBP-1, rs7288536 in SREBP-2 and rs10033601 in FBXW7) were selected and genotyped using the improved multiplex ligase detection reaction (iMLDR) method.

Conclusions

The results of this study indicate that variations in the lipid regulatory pathway genes FBXW7 and SREBPs (rs9902941 in SREBP-1, rs7288536 in SREBP-2 and rs10033601 in FBXW7) are associated with CAD in the Uygur Chinese population in Xinjiang, China.

Effect of dialyzer membrane materials on survival in chronic hemodialysis patients: Results from the annual survey of the Japanese Nationwide Dialysis Registry

BACKGROUND

Little information is available regarding which type of dialyzer membrane results in good prognosis in patients on chronic hemodialysis. Therefore, we conducted a cohort study from a nationwide registry of hemodialysis patients in Japan to establish the association between different dialyzer membranes and mortality rates.

METHODS

We followed 142,412 patients on maintenance hemodialysis (female, 39.1%; mean age, 64.8 ± 12.3 years; median dialysis duration, 7 [4-12] years) for a year from 2008 to 2009. We included patients treated with seven types of high-flux dialyzer membranes at baseline, including cellulose triacetate (CTA), ethylene vinyl alcohol (EVAL), polyacrylonitrile (PAN), polyester polymer alloy (PEPA), polyethersulfone (PES), polymethylmethacrylate (PMMA), and polysulfone (PS). Cox regression was used to estimate the association between baseline dialyzers and all-cause mortality as hazard ratios (HRs) and 95% confidence intervals for 1-year mortality adjusting for potential confounders, and propensity score matching analysis was performed.

RESULTS

The distribution of patients treated with each membrane was as follows: PS (56.0%), CTA (17.3%), PES (12.0%), PEPA (7.5%), PMMA (4.9%), PAN (1.2%), and EVAL (1.1%). When data were adjusted using basic factors, with PS as a reference group, the mortality rate was significantly higher in all groups except for the PES group. When data were further adjusted for dialysis-related factors, HRs were significantly higher for the CTA, EVAL, and PEPA groups. When the data were further adjusted for nutrition-and inflammation-related factors, HRs were significantly lower for the PMMA and PES groups compared with the PS group. After propensity score matching, HRs were significantly lower for the PMMA group than for the PS group.

CONCLUSION

The results suggest that the use of different membrane types may affect mortality in hemodialysis patients. However, further long-term prospective studies are needed to clarify these findings, including whether the use of the PMMA membrane can improve prognosis.

Relationship between serum total bilirubin levels and mortality in uremia patients undergoing long-term hemodialysis: A nationwide cohort study

BACKGROUND AND AIMS

Previous studies show that serum bilirubin has potent antioxidant effect and is associated with protection from kidney damage and reduce cardiovascular events. The aim of this study was to examine the association of serum total bilirubin level and mortality in uremia patients who underwent hemodialysis.

METHODS

This is a nationwide retrospective long-term cohort study. Patients were registered in the Taiwan Renal Registry Data System (TWRDS) from 2005 to 2012. A total of 115,535 hemodialysis patients were surveyed and those with valid baseline total bilirubin (TB) data were enrolled. All-cause mortality was the primary outcome.

RESULTS

A total of 47,650 hemodialysis patients followed for 27.6 ± 12 months, were divided into 3 groups according to different baseline serum total bilirubin levels (0.1-0.3, 0.3-0.7, 0.7-1.2 mg/dL). Mean age was 61.4 ± 13.6 years, 50% were male, 13% were hepatitis B carriers, and 20% were hepatitis C carriers. Primary outcome was the 3-year mortality. The TB level 0.7-1.2 mg/dL group had high mortality, statistically significant hazard ratio of mortality was 1.14 (crude HR, 95% 1.07-1.20, p < 0.01), and adjusted HR was 1.18 (model 1, 95% CI 1.11-1.25), 1.21 (model 2, 95% CI 1.14-1.29, p < 0.01), 1.44 (model 3, 95% CI 1.06-1.96, p < 0.01), respectively. Sensitivity test showed that after excluding 14,899 patients with hepatitis B or C, or abnormal liver function, the highest level of TB associated with higher significant mortality was still robust.

CONCLUSIONS

In our study, high TB level is associated with mortality in uremia patients undergoing long-term hemodialysis, but further studies of the different effects of unconjugated or conjugated bilirubin on hemodialysis patients are needed.