Kidney function trajectories, associated factors, and outcomes in multiethnic Asian patients with type 2 diabetes

BACKGROUND

We examined the trajectory of estimated glomerular filtrate rate (eGFR), associated risk factors, and its relationship with end-stage kidney disease (ESKD) among a multiethnic patient population with type 2 diabetes in Singapore.

METHODS

A follow-up study included 62 080 individuals with type 2 diabetes aged ≥18 years in a multi-institutional SingHealth Diabetes Registry between 2013 and 2019. eGFR trajectories were analyzed using latent class linear mixed models. Factors associated with eGFR trajectories were evaluated using multinomial logistic regression. The association of eGFR trajectories with ESKD was assessed via competing risk models.

RESULTS

Trajectory of kidney function, determined by eGFR, was nonlinear. The trajectory pattern was classified as stable initially then gradual decline (75%), progressive decline (21.9%), and rapid decline (3.1%). Younger age, female sex, Malay ethnicity, lower-income housing type, current smoking, higher glycated hemoglobin, lower low-density lipoprotein, higher triglyceride, uncontrolled blood pressure, albuminuria, cardiovascular disease, hypertension, and higher eGFR levels each were associated with progressive or rapid decline. Compared with the trajectory of stable initially then gradual eGFR decline, progressive decline increased the hazard of ESKD by 6.14-fold (95% confidence interval [CI]: 4.96-7.61)) and rapid decline by 82.55 folds (95% CI: 55.90-121.89).

CONCLUSIONS

Three nonlinear trajectory classes of kidney function were identified among multiethnic individuals with type 2 diabetes in Singapore. About one in four individuals had a progressive or rapid decline in eGFR. Our results suggest that eGFR trajectories are correlated with multiple social and modifiable risk factors and inform the risk of ESKD.

The Association between Baseline Serum Lipids and Mortality in Peritoneal Dialysis Patients

INTRODUCTION

Lipid disturbances are common in ESRD patients. In peritoneal dialysis (PD) patients, dyslipidemia is even more common. This study aimed to examine whether serum lipids were associated with prognosis of PD patients.

METHODS

Patients from a multicenter retrospective cohort were used for the present study. The primary endpoint was all-cause mortality. Cox regression was used to analyze the association between serum lipids including total cholesterol, low-density lipoprotein (LDL), high-density lipoprotein, and triglycerides and the prognosis.

RESULTS

The results showed that lower total cholesterol and LDL levels at the initiation of PD predicted higher all-cause mortality in PD patients. Multivariate analysis reveal that the association disappeared after adjusting for age, gender, albumin, prealbumin, protein catabolic rate normalized to body weight, C-reactive protein, and residual renal function. Further analysis showed that patients with lower total cholesterol/LDL had a higher mortality only during the first 24 months of follow-up. In the patients who survived >2 years after PD, lower total cholesterol/LDL was not associated with higher long-term all-cause mortality any more.

CONCLUSION

Lower total cholesterol/LDL levels at the initiation of PD were associated with overall mortality in PD patients. The association could be potentially modified by malnutrition, inflammation, and residual renal function or disappeared after 24 months.

Hyperlipidemia and mortality associated with diabetes mellitus co-existence in Chinese peritoneal dialysis patients

Background

To evaluate associations between diabetes mellitus (DM) coexisting with hyperlipidemia and mortality in peritoneal dialysis (PD) patients.

Methods

This was a retrospective cohort study with 2939 incident PD patients in China from January 2005 to December 2018. Associations between the DM coexisting with hyperlipidemia and mortality were evaluated using the Cox regression.

Results

Of 2939 patients, with a median age of 50.0 years, 519 (17.7%) died during the median of 35.1 months. DM coexisting with hyperlipidemia, DM, and hyperlipidemia were associated with 1.93 (95% CI 1.45 to 2.56), 1.86 (95% CI 1.49 to 2.32), and 0.90 (95% CI 0.66 to 1.24)-time higher risk of all-cause mortality, compared with without DM and hyperlipidemia, respectively (P for trend < 0.001). Subgroup analyses showed a similar pattern. Among DM patients, hyperlipidemia was as a high risk of mortality as non-hyperlipidemia (hazard ratio 1.02, 95%CI 0.73 to 1.43) during the overall follow-up period, but from 48-month follow-up onwards, hyperlipidemia patients had 3.60 (95%CI 1.62 to 8.01)-fold higher risk of all-cause mortality than those non-hyperlipidemia (P interaction = 1.000).

Conclusions

PD patients with DM coexisting with hyperlipidemia were at the highest risk of all-cause mortality, followed by DM patients and hyperlipidemia patients, and hyperlipidemia may have an adverse effect on long-term survival in DM patients.

The predictive study of the relation between elevated low-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio and mortality in peritoneal dialysis

BACKGROUND

The low-density lipoprotein cholesterol to high-density lipoprotein cholesterol (LDL-C/HDL-C) ratio constitutes a strong risk predictor of cardiovascular events. However, the association between this ratio and cardiovascular death in peritoneal dialysis (PD) patients is uncertain. The study aimed to investigate whether a high LDL-C/HDL-C ratio could predict both cardiovascular and all-cause mortalities in patients on PD.

METHODS

A total of 1616 incident patients on PD included from January 1, 2006 to December 31, 2013 were followed up with until 31 December 2018 in this single-center prospective cohort study. Participants were divided into three categories according to LDL-C/HDL-C ratio tertile. The primary endpoint was cardiovascular mortality; the secondary endpoint was all-cause mortality.

RESULTS

The mean age of the study cohort was 47.5 years and the mean body mass index (BMI) was 21.6 kg/m2. During a median follow-up period of 47.6 months, 492 patients died, including 246 (50.0%) due to cardiovascular disease (CVD). A multivariate analysis revealed that the highest LDL-C/HDL-C ratio tertile was significantly associated with increased CVD mortality [hazard ratio (HR): 1.69, 95% CI: 1.24-2.29; P = 0.001] and all-cause mortality (HR: 1.46, 95% CI: 1.18-1.81; P = 0.001) relative to the lowest tertile. After adjusting for covariates, the HRs of cardiovascular and all-cause mortalities were 1.84 (95% CI: 1.25-2.71; P = 0.002) and 1.35 (95% CI: 1.03-1.77; P = 0.032). Subgroup analysis showed that the risk of CVD death rose with a higher LDL-C/HDL-C ratio among PD patients who were female, younger than 65 years old, without being malnourished (BMI ≥ 18.5 kg/m2 or albumin ≥35 g/L), and with a history of diabetes or CVD, respectively.

CONCLUSIONS

A high LDL-C/HDL-C ratio is an independent risk factor for both cardiovascular and all-cause mortalities among PD patients.

Circulating metabolic biomarkers of renal function in diabetic and non-diabetic populations

Using targeted NMR spectroscopy of 227 fasting serum metabolic traits, we searched for novel metabolic signatures of renal function in 926 type 2 diabetics (T2D) and 4838 non-diabetic individuals from four independent cohorts. We furthermore investigated longitudinal changes of metabolic measures and renal function and associations with other T2D microvascular complications. 142 traits correlated with glomerular filtration rate (eGFR) after adjusting for confounders and multiple testing: 59 in diabetics, 109 in non-diabetics with 26 overlapping. The amino acids glycine and phenylalanine and the energy metabolites citrate and glycerol were negatively associated with eGFR in all the cohorts, while alanine, valine and pyruvate depicted opposite association in diabetics (positive) and non-diabetics (negative). Moreover, in all cohorts, the triglyceride content of different lipoprotein subclasses showed a negative association with eGFR, while cholesterol, cholesterol esters (CE), and phospholipids in HDL were associated with better renal function. In contrast, phospholipids and CEs in LDL showed positive associations with eGFR only in T2D, while phospholipid content in HDL was positively associated with eGFR both cross-sectionally and longitudinally only in non-diabetics. In conclusion, we provide a wide list of kidney function-associated metabolic traits and identified novel metabolic differences between diabetic and non-diabetic kidney disease.

Association of very Low-density Lipoprotein Cholesterol with All-cause and Cardiovascular Mortality in Peritoneal Dialysis

BACKGROUND/AIMS

Cardiovascular disease (CVD) is the leading cause of death in dialysis patients. Little is known about the relationship between very low-density lipoprotein cholesterol (VLDL-C) and cardiovascular mortality in these patients.

METHODS

A total of 1324 incident patients who began continuous ambulatory peritoneal dialysis (CAPD) therapy at our hospital between January 1, 2005, and September 30, 2014, with baseline serum VLDL-C values were investigated. The associations of the VLDL-C levels with all-cause and cardiovascular mortality were assessed.

RESULTS

The mean age of the cohort was 50.2 ± 14.8 years, and the mean VLDL-C level was 33.6 ± 18.0 mg/dl. One hundred sixty-five (12.5%) patients died during the study period. Multivariable models revealed that the high VLDL-C group was associated with significantly higher all-cause (HR, 2.08, 95% CI, 1.13 to 3.29, P = 0.002) and cardiovascular mortality (HR, 1.92, 95% CI, 1.18 to 4.29, P = 0.013) compared with the low VLDL-C group even after adjusting for various covariates. Using the VLDL-C level as a continuous variable, the hazard ratios (HRs) of all-cause and cardiovascular mortality associated with a 10-mg/dl increase in VLDL-C level were 1.12 (95% CI, 1.02 to 1.26, P = 0.025) and 1.11 (95% CI, 1.02 to 1.22, P = 0.029), respectively. VLDL-C was associated more strongly to all-cause (e.g., Akaike information criteria of 1990.205 vs. 1994.451) and cardiovascular (e.g., Akaike information criteria of 984.146 vs. 985.634) mortality than triglyceride (TG) levels.

CONCLUSIONS

An elevated VLDL-C level is an independent risk factor for all-cause and cardiovascular mortality in peritoneal dialysis (PD) patients.

Low-density lipoprotein cholesterol and survival in pulmonary arterial hypertension

Low-density lipoprotein cholesterol(LDL-C) is a well established metabolic marker of cardiovascular risk, however, its role in pulmonary arterial hypertension (PAH) has not been determined. Therefore we assessed whether LDL-C levels are altered in PAH patients, if they are associated with survival in this group and whether pulmonary hypertension (PH) reversal can influence LDL-C levels. Consecutive 46 PAH males and 94 females were age matched with a representative sample of 1168 males and 1245 females, respectively. Cox regression models were used to assess the association between LDL-C and mortality. The effect of PH reversal on LDL-C levels was assessed in 34 patients with chronic thromboembolic pulmonary hypertension (CTEPH) undergoing invasive treatment. LDL-C was lower in both PAH (2.6 ± 0.8 mmol/l) and CTEPH (2.7 ± 0.7 mmol/l) patients when compared to controls (3.2 ± 1.1 mmol/l, p < 0.001). In PAH patients lower LDL-C significantly predicted death (HR:0.44/1 mmol/l, 95%CI:0.26-0.74, p = 0.002) after a median follow-up time of 33(21-36) months. In the CTEPH group, LDL-C increased (from 2.6[2.1-3.2] to 4.0[2.8-4.9]mmol/l, p = 0.01) in patients with PH reversal but remained unchanged in other patients (2.4[2.2-2.7] vs 2.3[2.1-2.5]mmol/l, p = 0.51). We concluded that LDL-C level is low in patients with PAH and is associated with an increased risk of death. Reversal of PH increases LDL-C levels.

Estimating the glomerular filtration rate in the Spanish working population: chronic kidney disease prevalence and its association with risk factors

OBJECTIVE

This study aims to investigate the influence of estimated glomerular filtration rate (eGFR) with two equations (and by one or two separate measurements), on the prevalence of chronic kidney disease (CKD) and its association with blood pressure, and cardiovascular and metabolic risk factors.

METHODS

Between January 2010 and October 2011, the Ibermutuamur CArdiovascular RIsk Assessment project included 128 588 workers (77.2% men, mean age 39.3 years, range 16-75), who underwent two consecutive yearly medical check-ups and had information for eGFR according to the MDRD-IDMS and CKD-EPI equations (serum creatinine was measured by a isotope-dilution mass spectrometry traceable method in a single central laboratory). CKD was defined by an eGFR less than 60 ml/min per 1.73 m. Subclinical (occult) renal disease was defined as an eGFR less than 60 ml/min per 1.73 m in patients with serum creatinine below 1.3 mg/dl and below 1.2 mg/dl in men and women, respectively.

RESULTS

In this working population, prevalence of CKD was very low, but two to six times lower when two separate eGFRs below 60 ml/min per 1.73 m were used. The prevalence of CKD was significantly lower with the CKD-EPI compared to the MDRD-IDMS equation. The same applies to occult CKD. In male workers, occult CKD was practically nonexistent.Multivariate analyses show that blood pressure, total serum cholesterol, and serum glucose (positively), and high-density lipoprotein and low-density lipoprotein (negatively) were associated with CKD, with both equations. Another metabolic factor (waist circumference) was only associated (positively) with CKD defined by the CKD-EPI equation, which appears to be associated with most components of the metabolic syndrome.

CONCLUSIONS

The CKD-EPI formula, calculated on the basis of two reported blood samples, may provide the most specific definition of CKD.

Pre-ESRD changes in body weight and survival in nursing home residents starting dialysis

BACKGROUND AND OBJECTIVES

Among patients receiving maintenance dialysis, weight loss at any body mass index is associated with mortality. However, it is not known whether weight changes before dialysis initiation are associated with mortality and if so, what risks are associated with weight gain or loss.

DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS

Linking data from the US Renal Data System to a national registry of nursing home residents, this study identified 11,090 patients who started dialysis between January of 2000 and December of 2006. Patients were categorized according to weight measured between 3 and 6 months before dialysis initiation and the percentage change in body weight before dialysis initiation (divided into quintiles). The outcome was mortality within 1 year of starting dialysis.

RESULTS

There were 361 patients (3.3%) who were underweight (Quételet's [body mass] index<18.5 kg/m(2)) and 4046 patients (36.5%) who were obese (body mass index ≥ 30 kg/m(2)) before dialysis initiation. The median percentage change in body weight before dialysis initiation was -6% (interquartile range=-13% to 1%). There were 6063 deaths (54.7%) over 1 year of follow-up. Compared with patients with minimal weight changes (-3% to 3%, quintile 4), patients with weight loss ≥ 15% (quintile 1) had 35% higher risk for mortality (95% confidence interval, 1.25 to 1.47), whereas those patients with weight gain ≥ 4% (quintile 5) had a 24% higher risk for mortality (95% confidence interval, 1.14 to 1.35) adjusted for baseline body mass index and other confounders.

CONCLUSIONS

Among nursing home residents, changes in body weight in advance of dialysis initiation are associated with significantly higher 1-year mortality.

Changes in serum inflammatory markers are associated with changes in apolipoprotein A1 but not B after the initiation of dialysis

BACKGROUND

Few studies have examined the changes in lipoproteins over time and how inflammation is associated with lipoprotein concentrations among patients with end-stage renal disease on dialysis. One possible explanation for the association of low LDL cholesterol concentration and adverse outcomes is that inflammation reduces selected apolipoprotein concentrations.

METHODS

Serum samples were collected from a subsample of patients enrolled into the Comprehensive Dialysis Study every 3 months for up to 1 year. We examined the relation between temporal patterns in levels of inflammatory markers and changes in apolipoproteins (apo) A1 and B and the apo B/A1 ratio using linear mixed effects modeling and adjusting for potential confounders.

RESULTS

We enrolled 266 participants from 56 dialysis facilities. The mean age was 62 years, 45% were women and 26% were black. Apo A1 was lower among patients with higher Quetelet's (body mass) index (BMI), diabetes mellitus and atherosclerosis. Apo B was lower among older patients, patients with higher serum creatinine and patients with lower BMI. Over the course of a year, apo A1 changed inversely with serum concentrations of the acute phase proteins C-reactive protein (CRP) and α1 acid glycoprotein (α1AG), while apo B did not. Changes in α1AG were more strongly associated with changes in apolipoprotein concentrations than were changes in CRP; increases in α1AG were associated with decreases in apo A1 and increases in the apo B/A1 ratio.

CONCLUSIONS

Changes in inflammatory markers were associated with changes in apo A1, but not apo B over 1 year, suggesting that reductions in high-density lipoprotein cholesterol are associated with inflammation, either of which could mediate cardiovascular risk, but not supporting a hypothesis linking increased risk of low levels of apo B containing lipoproteins to the risk associated with inflammation.

Association of physical activity with survival among ambulatory patients on dialysis: the Comprehensive Dialysis Study

BACKGROUND AND OBJECTIVES

Despite high mortality and low levels of physical activity (PA) among patients starting dialysis, the link between low PA and mortality has not been carefully evaluated.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The Comprehensive Dialysis Study was a prospective cohort study that enrolled patients who started dialysis between June 2005 and June 2007 in a random sample of dialysis facilities in the United States. The Human Activity Profile (HAP) was administered to estimate PA among 1554 ambulatory enrolled patients in the Comprehensive Dialysis Study. Patients were followed until death or September 30, 2009, and the major outcome was all-cause mortality.

RESULTS

The average age was 59.8 (14.2) years; 55% of participants were male, 28% were black, and 56% had diabetes mellitus. The majority (57.3%) had low fitness estimated from the HAP score. The median follow-up was 2.6 (interquartile range, 2.2-3.1) years. The association between PA and mortality was linear across the range of scores (1-94). After multivariable adjustment, lower adjusted activity score on the HAP was associated with higher mortality (hazard ratio, 1.30; 95% confidence interval, 1.23-1.39 per 10 points). Patients in the lowest level of fitness experienced a 3.5-fold (95% confidence interval, 2.54-4.89) increase in risk of death compared with those with average or above fitness.

CONCLUSIONS

Low levels of PA are strongly associated with mortality among patients new to dialysis. Interventions aimed to preserve or enhance PA should be prospectively tested.