Visceral fat level is an independent risk factor for cardiovascular mortality in hemodialysis patients

Lean-to-fat tissue ratio as a risk factor for cognitive impairment in patients undergoing maintenance hemodialysis

OBJECTIVE

The relationship between body mass index (BMI) and cognitive impairment (CI) remains controversial, and no research has been done to explore the effect of lean-to-fat (L/F) tissue ratio on the risk of CI in patients undergoing maintenance hemodialysis (MHD) so far. This study aimed to explore the effect of L/F tissue ratio on the risk of incident CI in patients undergoing MHD.

METHODS

In this observational cohort study, 3356 patients were recruited and followed up for a median of 2 years. Global cognitive function was measured using Mini-Mental State Examination score. Lean tissue mass (LTM) and fat tissue mass (FTM) were analyzed using body composition monitor based on bioimpedance spectroscopy (BCM-BIS), and L/F tissue ratio was calculated by LTM divided by FTM. Hazard ratios (HRs) for incident CI were determined by Cox regression.

RESULTS

The median age of the cohort was 55 years, and 68.7% patients were less educated. During the follow-up period, 1249 patients (37.2%) experienced incident CI. Patients with lower L/F tissue ratios had significantly higher risks of CI (HR 1.51, 95% confidence interval 1.24-1.84; p < 0.001) than those with higher L/F tissue ratios. The association between L/F tissue ratio and incident CI persisted in all subgroups stratified by sex, age, education status, especially in older and less educated participants. Both in all our patients and subgroups, BMI and CI occurrence were not independently relevant.

CONCLUSION

The L/F tissue ratio rather than BMI was an independent risk factor of incident cognitive impairment in patients undergoing MHD.

Malnutrition and Insulin Resistance May Interact with Metabolic Syndrome in Prevalent Hemodialysis Patients

Background: We sought to determine the prevalence of metabolic syndrome (Mets) and whether 100 cm2 of visceral fatty area (VFA) measured by computed tomography (CT) validates the criteria of waist circumference (WC) in hemodialysis (HD) patients. Methods: The study comprised 141 HD patients. Mets was defined according to the criteria of Adult Treatment Panel III (ATP III) and the modified criteria of National Cholesterol Education Program (NCEP) that defines abdominal obesity as a WC of >=85 cm in men and >=90 cm in women. Results: The prevalence of Mets was 31.9% in men and 13.6% in women. However, the prevalence of patients with a body mass index over 25 in all HD patients was only 11.2%. The visceral fatty area (VFA) measured by CT showed a strong positive correlation with WC. The patients with Mets, comparing with those without Mets, have significantly shorter duration of HD, higher high-sensitive C-reactive protein, and higher Homeostatic Model Assessment for Insulin Resistance (HOMA-IR). In the patients with Mets, there was a significant negative correlation between HOMA-IR and serum albumin levels. Multivariate logistic regression analysis showed that HOMA-IR and short duration of HD were chosen as independent risk factors for Mets. Conclusions: Mets is more prevalent in HD patients. In Japanese HD patients, 100 cm2 of VFA corresponded to a WC of 85 cm in men and 90 cm in women, thus confirming the validity of the modified criteria. HOMA-IR and serum albumin were significantly correlated in HD patients with Mets.

Cut points of the conicity index as an indicator of abdominal obesity in individuals undergoing hemodialysis: An analysis of latent classes

OBJECTIVES

Abdominal obesity favors the involvement of cardiometabolic complications in renal patients on hemodialysis. Thus, the aim of the study was to identify the cut-points of the conicity index in individuals undergoing hemodialysis.

METHODS

This was a cross-sectional study carried out with 953 individuals undergoing hemodialysis in clinics in a metropolitan region of southeastern Brazil. The conicity index was calculated using the following mathematical equation: waist circumference/0.109 × √weight/height. The receiver operating characteristic (ROC) curve was calculated from the analysis of latent classes by cross-validation through a latent variable of abdominal obesity. This latent variable was defined using the response pattern of the observed anthropometric variables considering the presence and absence of abdominal obesity: waist circumference, waist-to-height ratio, and body shape index. The cut-points identified were elucidated by the area under the curve (AUC), Youden index, sensitivity, and specificity.

RESULTS

The cut-points for the conicity index found for both sexes were similar, resulting in a cut-point for men of 1.275 (AUC, 0.921; Youden index, 0.666), with a sensitivity and specificity of 83% and 83.6%, and a cut-point for women of 1.285 (AUC, 0.921; Youden index, 0.679), with a sensitivity and specificity of 78.6% and 89.3%, respectively.

CONCLUSIONS

The conicity index showed high discriminatory power for the identification of abdominal obesity in hemodialysis patients, therefore it can be a simple and easily accessible tool to be incorporated into clinical practice in this population.

Cholecalciferol supplementation effectively improved tertiary hyperparathyroidism, FGF23 resistance and lowered coronary calcification score: a prospective study

Introduction

Tertiary hyperparathyroidism (THPT) and vitamin D deficiency are commonly seen in kidney transplant recipients, which may result in persistently elevated fibroblast growth factor 23 (FGF23) level after transplantation and decreased graft survival. The aim of this study is to evaluate the effect of vitamin D supplementation on THPT, FGF23-alpha Klotho (KLA) axis and cardiovascular complications after transplantation.

Materials and methods

Two hundred nine kidney transplant recipients were included and further divided into treated and untreated groups depending on whether they received vitamin D supplementation. We tracked the state of THPT, bone metabolism and FGF23-KLA axis within 12 months posttransplant and explored the predictors and risk factors for intact FGF23 levels, KLA levels, THPT and cardiovascular complications in recipients.

Results

Vitamin D supplementation significantly improved FGF23 resistance, THPT and high bone turnover status, preserved better graft function and prevented coronary calcification in the treated group compared to the untreated group at month 12. The absence of vitamin D supplementation was an independent risk factor for THPT and a predictor for intact FGF23 and KLA levels at month 12. Age and vitamin D deficiency were independent risk factors for coronary calcification in recipients at month 12.

Conclusion

Vitamin D supplementation effectively improved THPT, FGF23 resistance and bone metabolism, preserved graft function and prevented coronary calcification after transplantation.

The site of waist measurement impacts the estimation of visceral fat: results from three-dimensional photonic body scanning

Currently, various protocols regarding the site of waist circumference (WC) measurement are in place. This study aimed to analyse the effect of the site of WC measurement on visceral adipose tissue (VAT) estimation. WC was obtained at 7 anatomical sites in 211 German volunteers (103 males) aged 23-81 years using three-dimensional photonic body scanning (PBS). At one site, WC was additionally measured by tape. The quantity of VAT was assessed by MRI. Models to estimate VAT based on WC were developed; the precision of the estimation is represented by R². The influence of the applied method of WC assessment (tape v. PBS) on the estimations is reported. Results show that the amount of estimated VAT and the precision of VAT estimation were dependent on the site of measurement. VAT was estimated most precisely by WC taken at the level of the lowest rib (WC_rib: R² = 0·75 females; 0·79 males), the minimum circumference (WC_min: R² = 0·75 females; 0·77 males) and at the narrowest part of the torso (WC_nar: R² = 0·76 females; 0·77 males), and least precisely by WC assessed at the top of iliac crest (WC_iliac: R² = 0·61 females; 0·60 males). VAT estimates based on WC obtained by PBS were smaller and estimations were slightly less precise compared to estimates based on tape measures. Our results indicate that the method and the site of waist measurement should be considered when estimating VAT based on WC. The implementation of a standardised protocol using either WC_rib, WC_min or WC_nar could improve the precision of VAT estimation.

Relationship between sex and cardiovascular mortality in chronic kidney disease: A systematic review and meta-analysis

Chronic kidney disease (CKD) is a significant health challenge associated with high cardiovascular mortality risk. Historically, cardiovascular mortality risk has been found to higher in men than women in the general population. However, recent research has highlighted that this risk may be similar or even higher in women than men in the CKD population. To address the inconclusive and inconsistent evidence regarding this relationship between sex and cardiovascular mortality within CKD patients, a systematic review and meta-analysis of articles published between January 2004 and October 2020 using PubMed/Medline, EMBASE, Scopus and Cochrane databases was performed. Forty-eight studies were included that reported cardiovascular mortality among adult men relative to women with 95% confidence intervals (CI) or provided sufficient data to calculate risk estimates (RE). Random effects meta-analysis of reported and calculated estimates revealed that male sex was associated with elevated cardiovascular mortality in CKD patients (RE 1.13, CI 1.03-1.25). Subsequent subgroup analyses indicated higher risk in men in studies based in the USA and in men receiving haemodialysis or with non-dialysis-dependent CKD. Though men showed overall higher cardiovascular mortality risk than women, the increased risk was marginal, and appropriate risk awareness is necessary for both sexes with CKD. Further research is needed to understand the impact of treatment modality and geographical distribution on sex differences in cardiovascular mortality in CKD.

Serum leptin concentration can predict cardiovascular outcomes and all-cause death in maintenance hemodialysis patients

BACKGROUND

We explored the associations between serum leptin concentration and cardiovascular prognosis in maintenance hemodialysis patients.

METHODS

In our prospective study with no intervention, demographics data at baseline were collected from electronic medical records. Serum leptin concentration was determined by ELISA. Patients underwent body composition assessment and echocardiographic measurements after hemodialysis. The primary endpoints were defined as cardiovascular events (CVEs), cardiovascular death (CVD) and all-cause death.

RESULTS

A total of 165 eligible patients aged 51(43-65) y were enrolled and the mean serum leptin concentration was 35.49 (29.98) ng/ml. During a median follow-up of 18 (12-22) months, CVEs occurred in 37 (22.42%) patients and the cardiovascular and all-cause mortality was 10.91% and 21.82%. Serum leptin concentration was associated with CVEs (HR = 0.982, p = 0.003), CVD (HR = 0.934, p = 0.002) and all-cause death (HR = 0.943, p < 0.001). Decreased serum leptin concentration was an independent risk factor for the development of left ventricular hypertrophy (LVH, OR = 0.98, p = 0.007) and peripheral vascular disease (PVD, OR = 0.974, p = 0.007).

CONCLUSION

Serum leptin concentration can independently predict cardiovascular outcomes and all-cause death in MHD patients. The effects that serum leptin concentration on development of LVH and PVD maybe the potential mechanism.

Significance of Adipose Tissue Maintenance in Patients Undergoing Hemodialysis

In the general population, obesity is known to be associated with adverse outcomes, including mortality. In contrast, high body mass index (BMI) may provide a survival advantage for hemodialysis patients, which is known as the obesity paradox. Although BMI is the most commonly used measure for the assessment of obesity, it does not distinguish between fat and lean mass. Fat mass is considered to serve as an energy reserve against a catabolic condition, while the capacity to survive starvation is also thought to be dependent on its amount. Thus, fat mass is used as a nutritional marker. For example, improvement of nutritional status by nutritional intervention or initiation of hemodialysis is associated with an increase in fat mass. Several studies have shown that higher levels of fat mass were associated with better survival in hemodialysis patients. Based on body distribution, fat mass is classified into subcutaneous and visceral fat. Visceral fat is metabolically more active and associated with metabolic abnormalities and inflammation, and it is thus considered to be a risk factor for cardiovascular disease and mortality. On the other hand, subcutaneous fat has not been consistently linked to adverse phenomena and may reflect nutritional status as a type of energy storage. Visceral and subcutaneous adipose tissues have different metabolic and inflammatory characteristics and may have opposing influences on various outcomes, including mortality. Results showing an association between increased subcutaneous fat and better survival, along with other conditions, such as cancer or cirrhosis, in hemodialysis patients have been reported. This evidence suggests that fat mass distribution (i.e., visceral fat and subcutaneous fat) plays a more important role for these beneficial effects in hemodialysis patients.

Effect of Long-term Peritoneal Dialysis on Change in Visceral Fat Area: A Single-Center Experience

INTRODUCTION

Visceral fat area (VFA) is known to increase after initiation of peritoneal dialysis (PD). However, the factors contributing to the increase in VFA in long-term PD patients have not been sufficiently elucidated. The present study investigated factors that affect VFA in patients who continue PD for ≥3 years.

METHODS

Twenty patients (63.1 ± 10.3 years, 9 men, 11 diabetic patients) between January 2008 and January 2015 were included. VFA, subcutaneous fat area (SFA) and waist circumference at initiation and follow-up were measured at the level of the umbilicus by computed tomography using an image analysis system. Change in VFA was defined as the value obtained by dividing VFA at the final follow-up by that at the initiation. The correlations between clinical parameters at initiation and changes in VFA were analyzed.

RESULTS

There was no significant change in body weight (57.6 ± 10.4 vs 58.3 ± 7.8 kg, P = 0.296) during the mean final follow-up period of 55 ± 13 months, although VFA increased significantly (103.6 ± 39.2 vs 122.6 ± 38.3 cm2, P = 0.030). Although subcutaneous fat area (SFA) did not change (124.7 ± 52.3 vs 124.5 ± 49.2 cm2, P = 0.989), waist circumference increased significantly (79.4 ± 8.4 vs 83.7 ± 6.9 cm, P = 0.010). SFA (r = -0.735, P < 0.001), waist circumference (r = - 0.644, P = 0.002), high-density lipoprotein cholesterol (HDL-C) (r = 0.487, P = 0.029), and age (r = 0.507, P = 0.023) correlated significantly with changes in VFA.

CONCLUSIONS

VFA might increase with long-term PD in patients with end-stage kidney disease who have high HDL-C, small SFA, and small waist circumference at initiation.

Visceral Fat Area Is a Better Predictor Than Coronary Artery Calcification Score for Cardiovascular Outcomes and All-Cause Death in Patients on Hemodialysis

OBJECTIVES

The aim of this study is to compare the prognostic effects of visceral fat area (VFA) with coronary artery calcification score (CACs) in patients on maintenance hemodialysis.

DESIGN AND METHODS

In the prospective study with no intervention, clinical characteristics and serum biochemical indexes at baseline for each patient were collected through the electronic medical records. Body composition assessment using bioelectrical impedance analysis, computed tomography examination with the Agatston scoring method, and echocardiographic measurements were performed at enrollment. Primary endpoints included cardiovascular events (CVEs), cardiovascular death (CVD), and all-cause death.

RESULTS

A total of 97 Chinese patients aged 48 (35-62) years were enrolled from our Hemodialysis Center, of which 61.9% were male and 20.6% had diabetes. The median of VFA and CACs at baseline was 64.5 (43.5-88.7) cm² and 0.9 (0-467.6), respectively. CVEs occurred in 20 (20.6%) patients during a median follow-up of 26.4 (13-27.7) months. The cardiovascular and all-cause mortality was 8.2% (8 patients) and 11.3% (11 patients), respectively. VFA was associated with CVEs (hazard ratio [HR] = 9.21 for VFA ≥71.3 cm² vs. VFA <71.3 cm², P = .017), CVD (HR = 1.11 for 1 cm² increase, P = .035), and all-cause mortality (HR = 1.08 for 1 cm² increase, P = .011). Also, VFA was significantly correlated with cardiac structure parameters and the development of left ventricular hypertrophy (odds ratio = 1.02 for 1 cm² increase, P = .03). Yet, CACs were not correlated with CVEs, CVD, or all-cause mortality.

CONCLUSIONS

Increased VFA can be used as an independent predictor for CVEs, CVD, and all-cause mortality. The effect VFA exerts on cardiac reconstruction might be the underlying mechanism. Further studies are warranted for the management of VFA in the hemodialysis population.

Metabolic syndrome in haemodialysis patients: prevalence, determinants and association to cardiovascular outcomes

BACKGROUND

In the general population, metabolic syndrome (MetS) is predictive of major adverse cardiovascular events (MACE). Waist circumference (WC), a component of the MetS criteria, is linked to visceral obesity, which in turn is associated with MACE. However, in haemodialysis (HD) patients, the association between MetS, WC and MACE is unclear.

METHODS

In a cross-sectional study of 1000 HD patients, we evaluated the prevalence and characterised the clinical predictors of MetS. The relationship between MetS and its components, alone or in combination, and MACE (coronary diseases, peripheral arteriopathy, stroke or cardiac failure), was studied using receiver operating characteristics (ROC) curves and logistic regression.

RESULTS

A total of 753 patients were included between October 2011 and April 2013. The prevalence of MetS was 68.5%. Waist circumference (> 88 cm in women, 102 cm in men) was the best predictor of MetS (sensitivity 80.2; specificity 82.3; AUC 0.80; p <  0.05). In multivariate analysis, MetS was associated with MACE (OR: 1.85; 95CI 1.24-2.75; p <  0.01), but not WC alone. There was a stronger association between the combination of abdominal obesity, hypertriglyceridaemia and low high-density lipoprotein cholesterol with MACE after exclusion of impaired fasting glucose and hypertension.

CONCLUSIONS

MetS is frequent and significantly associated with MACE in our haemodialysis cohort and probably in other European dialysis populations as well. In HD patients, a new simplified definition could be proposed in keeping with the concept of the "hypertriglyceridaemic waist".

Three compartment bioimpedance spectroscopy in the nutritional assessment and the outcome of patients with advanced or end stage kidney disease: What have we learned so far?

Bioimpedance spectroscopy (BIS) is an easily applicable tool to assess body composition. The three compartment model BIS (3C BIS) conventionally expresses body composition as lean tissue index (LTI) (lean tissue mass [LTM]/height in meters squared) and fat tissue index (FTI) (adipose tissue mass/height in meters squared), and a virtual compartment reflecting fluid overload (FO). It has been studied extensively in relation to diagnosis and treatment guidance of fluid status disorders in patients with advanced‐stage or end‐stage renal disease. It is the aim of this article to provide a narrative review on the relevance of 3C BIS in the nutritional assessment in this population. At a population level, LTI decreases after the start of hemodialysis, whereas FTI increases. LTI below the 10th percentile is a consistent predictor of outcome whereas a low FTI is predominantly associated with outcome when combined with a low LTI. Recent research also showed the connection between low LTI, inflammation, and FO, which are cumulatively associated with an increased mortality risk. However, studies toward nutritional interventions based on BIS data are still lacking in this population. In conclusion, 3C BIS, by disentangling the components of body mass index, has contributed to our understanding of the relevance of abnormalities in different body compartments in chronic kidney disease patients, and appears to be a valuable prognostic tool, at least at a population level. Studies assessing the effect of BIS guided nutritional intervention could further support its use in the daily clinical care for renal patients.

Abdominal obesity in normal weight versus overweight and obese hemodialysis patients: Associations with nutrition, inflammation, muscle strength, and quality of life

OBJECTIVE

The biological basis of abdominal obesity leading to more severe outcomes in patients with normal body mass index (BMI) on maintenance hemodialysis (MHD) is unclear. The aim of this study was to compare the properties of abdominal obesity in different BMI categories of patients on MHD.

METHODS

We performed a cross-sectional study of 188 MHD patients (52.7% women; mean age, 69.4 ± 11.5 y) with abdominal obesity in different BMI groups using criteria from the World Health Organization. Appetite and dietary intake, body composition, handgrip strength, malnutrition inflammation score (MIS), inflammatory biomarkers, adipokines, and health-related quality-of-life (QoL) questionnaires were studied.

RESULTS

According to multivariable analyses, abdominally obese patients with normal BMIs consumed less protein per day (P = 0.04); had lower measurements of surrogates of lean (P < 0.001) and fat mass (P < 0.001); and had higher total cholesterol, tumor necrosis factor-α (P < 0.05), and ratios of adiponectin to leptin (P = 0.003) than overweight and obese patients with abdominal obesity. Multivariable analyses showed no differences in handgrip strength among the study groups.The abdominally obese study participants with normal weight had significantly lower scores in role physical (P = 0.003) and pain (P = 0.04) scales after multivariable adjustments.

CONCLUSIONS

Normal-weight MHD patients with abdominal obesity exhibited a more proatherogenic profile in terms of inflammatory markers and adipokine expression, lower body composition reserves, and lower physical ability than patients with abdominal obesity with overweight and obesity. This at least partially explains the abdominal obesity paradox in the MHD population in which worse clinical outcomes are seen in abdominally obese patients with normal BMIs, as opposed to overweight and obese patients who are also abdominally obese.

Central Obesity and Visceral Adipose Tissue Are Not Associated With Incident Atherosclerotic Cardiovascular Disease Events in Older Men

Background Visceral adipose tissue ( VAT ) and other measures of central obesity predict incident atherosclerotic cardiovascular disease ( ASCVD ) events in middle-aged individuals, but these associations are less certain in older individuals age 70 years and older. Our objective was to estimate the associations of VAT and the android-gynoid fat mass ratio, another measure of central obesity, with incident ASCVD events among a large cohort of older men. Methods and Results Two thousand eight hundred ninety-nine men (mean [ SD ] age 76.3 [5.5] years) enrolled in the Outcomes of Sleep Disorders in Older Men study had rigorous adjudication of incident ASCVD events (myocardial infarction, coronary heart disease death, or fatal or nonfatal stroke). We used proportional hazards models to estimate the hazard ratios for incident ASCVD per SD increase of VAT or android-gynoid fat mass ratio (measured at baseline with dual-energy absorptiometry), adjusted for age, race, education, systolic blood pressure, smoking status, oxidized low-density lipoprotein level, treatment for hypertension, statin use, aspirin use, presence of diabetes mellitus, and study enrollment site. Over a mean ( SD ) follow-up period of 7.9 (3.4) years, 424 men (14.6%) had an incident ASCVD event. Neither VAT nor android-gynoid fat mass ratio were associated with incident ASCVD events, either unadjusted or after multivariable-adjustment (hazard ratios [95% confidence interval ] per SD increase 1.02 [0.92-1.13] and 1.05 [0.95-1.17], respectively). Conclusions Central adipose tissue, as measured by VAT or android-gynoid fat mass ratio, was not associated with incident ASCVD events in this study of older men.

The Impact of Abdominal Fat Levels on All-Cause Mortality Risk in Patients Undergoing Hemodialysis

Although an increased body mass index is associated with lower mortality in patients undergoing hemodialysis (HD), known as the “obesity paradox,” the relationship of abdominal fat levels with all-cause mortality has rarely been studied. We investigated the impact of computed-tomography-measured abdominal fat levels (visceral fat area (VFA) and subcutaneous fat area (SFA)) on all-cause mortality in this population. A total of 201 patients undergoing HD were enrolled and cross-classified by VFA and SFA levels according to each cutoff point, VFA of 78.7 cm² and SFA of 93.2 cm², based on the receiver operator characteristic (ROC) curve as following; group 1 (G1): lower VFA and lower SFA, G2: higher VFA and lower SFA, G3: lower VFA and higher SFA, G4: higher VFA and higher SFA. During a median follow-up of 4.3 years, 67 patients died. Kaplan–Meier analysis revealed 10-year survival rates of 29.0%, 50.0%, 62.6%, and 72.4% in G1, G2, G3, and G4 (p < 0.0001), respectively. The adjusted hazard ratio was 0.30 (95% confidence interval [CI] 0.05–1.09, p = 0.070) for G2 vs. G1, 0.37 (95% CI 0.18–0.76, p = 0.0065) for G3 vs. G1, and 0.21 (95% CI 0.07–0.62, p = 0.0035) for G4 vs. G1, respectively. In conclusion, combined SFA and VFA levels were negatively associated with risks for all-cause mortality in patients undergoing HD. These results are a manifestation of the “obesity paradox.”

Body fat distribution is more predictive of all-cause mortality than overall adiposity

AIMS

The relationship between directly measured body fat and all-cause mortality has been rarely studied. The aim of this study was to evaluate the predictive significance of computed tomography (CT)-measured body fat, including both visceral fat area (VFA) and subcutaneous fat area (SFA), for mortality.

METHODS

The study included 36 656 participants who underwent abdominal CT as part of a health check-up at a single university-affiliated healthcare center in 2007 to 2015. Of those, 32 593 participants with data regarding vital status as of May 2016 were included in the final analysis. The main factors evaluated were VFA, SFA and visceral-to-subcutaneous fat area ratio (VSR), and the primary outcome was all-cause mortality.

RESULTS

There were 253 deaths during a mean follow-up of 5.7 years. Increased SFA was associated with decreased all-cause mortality, whereas an increased VFA and VSR were related to increased all-cause mortality. Compared with the predictive power of body mass index (BMI), SFA and VSR showed a larger area under the curve than did BMI. In Kaplan-Meier survival curve analysis, increased SFA and VSR were associated with decreased and increased hazard of all-cause death, respectively. However, in multivariate Cox proportional hazard regression analysis, only VSR was independently associated with all-cause mortality. Moreover, this relationship was paralleled by the harmful impact of increased VSR on metabolic profiles.

CONCLUSION

Increased VSR was an independent predictor of all-cause mortality. This suggests that the location of fat deposits may be more important than the actual amount of body fat.

Assessment of the 10-year risk of cardiovascular disease among a group of patients on maintenance hemodialysis: A cross-sectional study from Cameroon

Objective

To assess the 10-year risk of cardiovascular disease and potential impacting factors among patients undergoing hemodialysis in Yaoundé, Cameroon.

Design

A cross-sectional study in January 2016.

Setting

Patients were recruited at the dialysis unit of the Yaoundé University Teaching Hospital, Cameroon.

Participants

These were hemodialysis patients aged 20 years and above, dialyzing in the above unit since at least 3 months and volunteering to be enrolled in the study.

Main outcome measures

The risk of cardiovascular disease was assessed using the Framingham risk score.

Results

We included 44 patients. The risk of cardiovascular disease ranged from less than 1% to more than 30% with a median of 12.3% (interquartile range 4.9–24.4). Twenty hemodialysis patients (45.5%) had a low risk of cardiovascular disease (<10%), 10 (22.7%), a moderate risk (10–20%), and 14 (31.8%) presented a high risk of cardiovascular disease (>20%). In multivariable linear regression analysis, duration on dialysis (adjusted β = 0.11; p = 0.003), number of weekly sessions of physical activity (adjusted β = −1.35; p = 0.018), fasting serum glucose levels (adjusted β = 4.22; p = 0.022), serum triglycerides levels (adjusted β = 5.94; p = 0.033), and serum urea levels (adjusted β = −2.08; p = 0.039) were independently impacting our patients’ risk of cardiovascular disease.

Conclusion

Around 55% of our study population presented a moderate or high risk of cardiovascular disease. Duration on dialysis, number of physical activity sessions per week, fasting serum glucose, serum triglycerides, and serum urea levels may impact our hemodialysis patients’ risk of cardiovascular disease.

Comparison of Associations of DXA and CT Visceral Adipose Tissue Measures With Insulin Resistance, Lipid Levels, and Inflammatory Markers

Visceral adipose tissue (VAT) measured by computed tomography (CT) is related to insulin resistance, lipids, and serum inflammatory markers. Our objective was to compare the strength of the associations of VAT measured using dual-energy X-ray absorptiometry (DXA-VAT) and CT (CT-VAT) with insulin resistance, serum lipids, and serum markers of inflammation. For 1117 men aged 65 and older enrolled in the Osteoporotic Fractures in Men Study, the cross-sectional associations of DXA-VAT and CT-VAT with homeostasis model assessment of insulin resistance (homa2ir), C-reactive protein, and high-density lipoprotein (HDL) cholesterol were estimated with regression models and compared using a Hausman test. Adjusted for age and body mass index, DXA-VAT was moderately associated with homa2ir (effect size 0.38, 95% confidence interval [CI]: 0.28-0.47) and modestly associated with HDL cholesterol (DXA effect size -0.29, 95% CI: -0.38 to -0.21). These associations were significantly greater than those for CT-VAT with homa2ir (0.30, 95% CI: 0.24-0.37; p value for effect size difference 0.03) and CT-VAT with HDL cholesterol (-0.22, 95% CI: -0.29 to -0.15; p value for difference 0.005). Neither DXA-VAT nor CT-VAT was associated with C-reactive protein after adjustment for age and body mass index (DXA-VAT effect size 0.14, 95% CI: -0.04 to 0.32; CT-VAT effect size 0.08, 95% CI: -0.08 to 0.25; p value for difference 0.35). DXA-VAT has similar or greater associations with insulin resistance and HDL cholesterol as does CT-VAT in older men, confirming the concurrent validity of DXA-VAT. Investigations of how well DXA measurements of VAT predict incident cardiovascular disease events are warranted.

The association between body mass index and mortality among Asian peritoneal dialysis patients: A meta-analysis

BACKGROUND

Previous studies have revealed that increased body mass index (BMI) is associated with decreased mortality among hemodialysis patients. However, few studies have dealt with the association between BMI and mortality among patients undergoing peritoneal dialysis (PD) and even fewer studies have focused on the Asian PD patients. The reported studies were often non-conclusive and some even yielded contradictory results. This paper, to our best knowledge, registers the first attempt to systematically review the current literature and summarize new results on the association between BMI and mortality among the Asian PD population.

METHOD

A systematic literature review was performed in Medline and EMBASE to identify relevant cohort studies on all-cause and cardiovascular disease (CVD) mortality stratified by BMI categories tailored to Asians among the Asian PD population. We meta-analyzed individual results based on a random effect model, strictly complying with Preferred Reporting Items for Systematic Reviews and Meta-analysis.

RESULTS

The paper reviews seven cohort studies with a total of 3,610 Asian PD patients. Obese group (BMI = 25-29.9 kg/m2) was associated with higher risk of all-cause mortality (HR = 1.46, 95%CI [1.07-1.98]; p = 0.02) and CVD mortality (HR = 2.01, 95%CI [1.14-3.54]; p = 0.02), compared to the normal group (BMI = 18.5-22.9 kg/m2). The underweight group (BMI<18.5kg/m2) was also associated with an elevated risk of all-cause mortality (HR = 2.11, 95%CI [1.46-3.07]; p<0.001). No significant associations between BMI with all-cause mortality were found among the overweight group (23-24.9 kg/m2) (HR = 1.00, 95%CI [0.76-1.32]; p = 0.9). The association between BMI and CVD mortality risk among the underweight and overweight groups was found nonsignificant (p = 0.5 and 0.6 respectively).

CONCLUSION

Obesity is associated with increased mortality in Asian PD patients. The study indicates a "V-shaped" trend in the association between BMI and mortality in these patients.

Abdominal lean muscle is associated with lower mortality among kidney waitlist candidates

Morphometric assessments, such as muscle density and body fat distribution, have emerged as strong predictors of cardiovascular risk and postoperative morbidity and mortality. To date, no study has examined morphometric mortality risk prediction among kidney transplant (KT) candidates. KT candidates, waitlisted 2008-2009, were identified (n=96) and followed to the earliest of transplant, death, or administrative end of study. Morphometric measures, including abdominal adipose tissue, paraspinous and psoas muscle composition, and aortic calcification, were measured from CTs. Risk of waitlist mortality was examined using Cox proportional hazard regression. On adjusted analyses, radiologic measures remained independently and significantly associated with lower waitlist mortality; the addition of radiologic measures significantly improved model predictive ability over models containing traditional risk factors alone (net reclassification index: 0.56, 95% CI: 0.31-0.75). Higher psoas muscle attenuation (indicative of leaner muscle) was associated with decreased risk of death (aHR: 0.93, 95% CI: 0.91-0.96, P<.001), and for each unit increase in lean paraspinous volume, there was an associated 2% decreased risk for death (aHR: 0.98, 95% CI: 0.96-0.99, P=.03). Radiologic measures of lean muscle mass, such as psoas muscle attenuation and paraspinous lean volume, may improve waitlist mortality risk prediction and candidate selection.

Adipocytes play an etiological role in the podocytopathy of high-fat diet-fed rats

Obesity is a risk factor that promotes progressive kidney disease. Studies have shown that an adipocytokine imbalance contributes to impaired renal function in humans and animals, but the underlying interplay between adipocytokines and renal injury remains to be elucidated. We aimed to investigate the mechanisms linking obesity to chronic kidney disease. We assessed renal function in high-fat (HF) diet-fed and normal diet-fed rats, and the effects of preadipocyte- and adipocyte-conditioned medium on cultured podocytes. HF diet-fed and normal diet-fed Sprague Dawley rats were used to analyze the changes in plasma BUN, creatinine, urine protein and renal histology. Additionally, podocytes were incubated with preadipocyte- or adipocyte-conditioned medium to investigate the effects on podocyte morphology and protein expression. In the HF diet group, 24 h urinary protein excretion (357.5 ± 64.2 mg/day vs 115.9 ± 12.4 mg/day, P < 0.05) and the urine protein/creatinine ratio were significantly higher (1.76 ± 0.22 vs 1.09 ± 0.15, P < 0.05), increased kidney weight (3.54 ± 0.04 g vs 3.38 ± 0.04 g, P < 0.05) and the glomerular volume and podocyte effacement increased by electron microscopy. Increased renal expression of desmin and decreased renal expression of CD2AP and nephrin were also seen in the HF diet group (P < 0.05). Furthermore, we found that adipocyte-conditioned medium-treated podocytes showed increased desmin expression and decreased CD2AP and nephrin expression compared with that in preadipocyte-conditioned medium-treated controls (P < 0.05). These findings show that adipocyte-derived factor(s) can modulate renal function. Adipocyte-derived factors play an important role in obesity-related podocytopathy.

Comprehensive geriatric assessment: comparison of elderly hemodialysis patients and primary care patients

BACKGROUNDS

The quality of life and survival of elderly depend not only on their age but on many social and health factors. In the present study, comprehensive geriatric assessment (CGA) was made in elderly patients on regular hemodialysis (HD) and those without chronic kidney disease recruited in primary health care in order to compare their sociodemographic characteristics, physical health, functional ability and social support.

METHOD

The 106 HD patients and 300 primary care patients aged 70 years and more were studied. Data on sociodemographic characteristics, neurosensory deficits, pain, falls, polypharmacy, basic activities of daily living (ADL) questionnaire, instrumental activities of daily living (IADL) questionnaire were obtained during interview. The Timed Up and Go, Nutritional Health Checklist, Two Question Instrument for depression and Charlson comorbidity index (CCI) were applied.

RESULTS

No significant differences were found for age, gender, education level and dwelling between the two groups. A lower percentage of HD patients lived alone when compared with controls. BMI >25 kg/m(2) had 43.4% of HD patients and 49.3% of controls. CCI differed significantly between HD and primary care patients (median: 6 vs. 4) and significantly more HD patients reported depression. No significant difference was found between groups for cognitive dysfunction and ADL, but HD patients had significantly lower IADL scores than controls. The mobility of HD patients was worse; 45.7% of them reported falls in the previous year but only 9.7% from the controls.

CONCLUSIONS

CGA revealed that HD patients had significantly higher CCI, worse IADL score, mobility and reported more frequent falls, depression and impaired vision than primary care patients.