Visceral fat thickness is associated with carotid atherosclerosis in peritoneal dialysis patients

The Impact of Dietary Diversity, Lifestyle, and Blood Lipids on Carotid Atherosclerosis: A Cross-Sectional Study

Carotid atherosclerosis is a common arterial wall lesion that causes narrowing and occlusion of the arteries and is the basis of cardiovascular events. Dietary habits, lifestyle, and lipid metabolism should be considered integrally in the context of carotid atherosclerosis (CAS). However, this area has been investigated less often in China. To understand the prevalence of CAS in China and the impact of dietary diversity and habits, lifestyle, and lipid metabolism on CAS as well as its predictive factors, a cross-sectional study was performed in two northern and southern Chinese tertiary hospitals from 2017 to 2019. Included participants underwent carotid artery color Doppler ultrasonography, blood lipid examination and dietary evaluation. In total, 11,601 CAS patients and 27,041 individuals without carotid artery lesions were included. The prevalence of CAS was 30.0% in this group. High BMI (OR: 1.685, 95% CI [1.315-2.160]), current (1.148 [1.077-1.224]) or ex-smoking (1.349 [1.190-1.529]), abstinence from alcohol ((1.223 [1.026-1.459]), social engagement (1.122 [1.050-1.198]), hypertension (1.828 [1.718-1.945]), and total cholesterol (1.438 [1.298-1.594]) were risk factors for CAS, while higher dietary diversity according to DDS-2 (0.891 [0.805-0.989]), HDL-C (0.558 [0.487-0.639]), sugar-sweetened beverages (0.734 [0.696-0.774]), and no midnight snack consumption (0.846 [0.792-0.903]) were protective factors. This current study demonstrated that higher dietary diversity was a protective factor against CAS in a healthy population. In addition, current recommendations of healthy lifestyle and dietary habits for preventing CAS should be strengthened. In addition, dietary diversity should concentrate on food attributes and dietary balance, rather than increased quantities.

Serum osteoprotegerin level in hemodialysis patients using low-flux reused dialyzer in relation to atherosclerosis

AIMS

To assess the relation of high serum OPG level and carotid atherosclerosis in maintenance hemodialysis (MHD) patients using low-flux reused dialyzer.

MATERIALS AND METHODS

We examined 209 MHD patients with and without carotid atherosclerosis (83 patients and 126 patients) to establish the relation between OPG and atherosclerosis.

RESULTS

The proportion of carotid atherosclerosis was 39.7%. The median serum OPG level was 45.3 pmol/L. Serum OPG had a good predicting value for atherosclerosis in MHD patients using low-flux reused dialyzer (AUC = 0.934, p < 0.001, cutoff value = 43.35 pmol/L, Se = 81.3%, Sp = 90.9%).

CONCLUSIONS

In this study, serum OPG had a good predicting value for atherosclerosis in MHD patients using low-flux reused dialyzer.

High muscle-to-fat ratio is associated with lower risk of chronic kidney disease development

BACKGROUND

Obesity, a known risk factor for chronic kidney disease (CKD), is generally assessed using body mass index (BMI). However, BMI may not effectively reflect body composition, and the impact of muscle-to-fat (MF) mass balance on kidney function has not been elucidated. This study evaluated the association between body muscle and fat mass balance, represented as the MF ratio, and incident CKD development.

METHODS

Data were retrieved from a prospective community-based cohort study (Korean Genome and Epidemiology Study). Muscle and fat mass were measured using multifrequency bioelectrical impedance analysis. The study endpoint was incident CKD (estimated glomerular filtration rate <60 mL/min/1.73 m2 in at least two or more consecutive measurements during the follow-up period).

RESULTS

Totally, 7682 participants were evaluated. Their mean age was 51.7 ± 8.7 years, and 48% of the subjects were men. During a median follow-up of 140.0 (70.0-143.0) months, 633 (8.2%) subjects developed incident CKD. When the association between body composition and incident CKD was investigated, multivariable Cox proportional hazard analysis revealed that increase in MF ratio was related with a decreased risk of CKD development [per 1 increase in MF ratio: hazard ratio (HR), 0.86; 95% confidence interval (CI), 0.77-0.96; P = 0.008]. This association was also maintained when MF ratio was dichotomized according to sex-specific median values (high vs. low: HR, 0.83; 95% CI, 0.70-0.98; P = 0.031). Analyses preformed in a propensity score matched group also revealed a similar decreased risk of incident CKD in high MF ratio participants (high vs. low: HR, 0.84; 95% CI, 0.71-0.98; P = 0.037). This relationship between MF ratio and incident CKD risk was consistently significant across subgroups stratified by age, sex, hypertension, estimated glomerular filtration rate categories, and proteinuria. Among different BMI groups (normal, overweight, and obese), the relationship between high MF ratio and lower incident CKD risk was significant only in overweight and obese subjects.

CONCLUSIONS

Lower fat mass relative to muscle mass may lower the risk of CKD development in individuals with normal renal function. This relationship seems more prominent in overweight and obese subjects than in normal weight subjects.

Normal body mass index with central obesity has increased risk of coronary artery calcification in Korean patients with chronic kidney disease

In chronic kidney disease (CKD), overweight and mild obesity have shown the lowest cardiovascular (CV) risk. However, central obesity has been directly associated with CV risk in these patients. This bidirectional relationship of body mass index (BMI) and central obesity prompted us to evaluate CV risk based on a combination of BMI and waist-to-hip ratio (WHR) in nondialysis CKD patients. We included 1078 patients with CKD stage 2 through 5 (nondialysis) enrolled in a nationwide prospective cohort of Korea. Patients were divided into 3 groups by BMI (normal BMI, 18.5-22.9; overweight, 23.0-27.4; and obese, 27.5 and over kg/m²) and were dichotomized by a sex-specific median WHR (0.92 in males and 0.88 in females). Coronary artery calcification (CAC) was determined by multislice computed tomography. CAC (score above 10 Agatston units) was found in 477 patients. Multivariate logistic regression analysis indicated that BMI was not independently associated with CAC. However, WHR showed an independent linear and significant association with CAC (odds ratio, 1.036; 95% confidence interval, 1.007-1.065 per 0.01 increase). Furthermore, when patients were categorized into 6 groups according to a combination of BMI and WHR, normal BMI but higher WHR had the highest risk of CAC compared with the normal BMI with lower WHR group (2.104; 1.074-4.121). Thus, a normal BMI with central obesity was associated with the highest risk of CAC, suggesting that considering BMI and WHR, 2 surrogates of obesity, can help to discriminate CV risk in Korean nondialysis CKD patients.

Neck circumference predicts renal function decline in overweight women: A community-based prospective cohort study

Chronic kidney disease (CKD) is characterized by increased risks of morbidity and mortality. Upper-body subcutaneous fat, which is commonly estimated from the neck circumference (NC), was revealed to be the main reservoir of circulating nonesterified fatty acids in overweight patients. Despite a close association between NC and metabolic complications, the relationship of NC with renal function has not been fully investigated. In this study, the impact of NC on the development of incident CKD was elucidated.The data were retrieved from the Korean Genome and Epidemiology Study cohort. The subjects were followed at 2-year intervals from 2003 to 2011. Overweight was defined as a body mass index of ≥23 kg/m. A total of 4298 cohort subjects were screened. After exclusion, 2268 overweight subjects were included for the final analysis. The primary end point was incident CKD, which was defined as a composite of estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m or the development of proteinuria.The mean patient age was 36.3 ± 3.0 years, and 1285 (56.7%) were men. They were divided into 2 groups according to the median NC in male and female subjects, separately. In both sexes, hypertension (men, P < 0.001; women, P = 0.009) and diabetes (men, P = 0.002; women, P < 0.001) were significantly more prevalent in the big NC group than in the small NC group. In contrast, eGFR was significantly lower only in male subjects of the big NC group (P < 0.001), whereas it was comparable between the small and big NC groups (P = 0.167). In multivariate Cox proportional hazards regression analysis, NC values were independently associated with incident CKD development in female subjects after adjusting for multiple confounding factors (per 1 cm increase, hazard ratio [95% confidence interval] = 1.159 [1.024-1.310], P = 0.019) but not in male subjects.NC is independently associated with the development of CKD in overweight female subjects, suggesting that it could be a practical risk factor for CKD.

Relation between visceral fat and carotid intimal media thickness in Mexican postmenopausal women: a preliminary report

Aim of the study

To investigate the relationship between visceral fat and carotid IMT (intima media thickness) in Mexican postmenopausal women.

Material and methods

In 71 postmenopausal women divided in two groups: group 1, IMT > 1 mm and group 2, IMT ≤ 1 mm, blood pressure, body mass index (BMI), waist hip ratio (WHR), visceral and subcutaneous fats and carotid IMT were analyzed. Descriptive statistics were used and the comparison among those with abnormal and normal IMT was carried out using Mann-Whitney U test; also Spearman's correlation analysis was done.

Results

When comparing group 1 (n = 9, 12.7%) with group 2 (n = 62, 87.3%), it was found that the subcutaneous fat, visceral fat and systolic blood pressure were significantly greater in group 1 (p < 0.018, p < 0.001 and p < 0.006, respectively), and also in this group there was a correlation between BMI and subcutaneous fat (ρ = 0.686, p < 0.041) and between visceral fat and the systolic blood pressure (ρ = 0.712, p < 0.031). In group 2, there was a correlation between IMT and diastolic blood pressure (ρ = 0.251, p < 0.049).

Conclusion

Subcutaneous and visceral fat have an unfavorable effect in the carotid IMT and in blood pressure.

Abdominal fat distribution and carotid atherosclerosis in a general population: a semi-automated method using magnetic resonance imaging

PURPOSE

Available evidence suggests functional differences in visceral and subcutaneous fat. We investigated the association between quantitative measures of central adiposity with indicators of carotid atherosclerosis including intima-media thickness (IMT) and plaque in a general population using a semi-automated method on magnetic resonance imaging (MRI) data.

METHODS

In this cross-sectional study 200 subjects (52 % female), aged 50-77 years, were randomly selected from Golestan Cohort Study. Participants underwent ultrasound examination of carotid arteries and abdominal MRI. Segmentation and calculation of visceral (VFA) and subcutaneous fat area (SFA) were performed on three levels using semi-automated software. Various conventional anthropometric indices were also measured.

RESULTS

Among 191 enrolled subjects, 77 (40 %) participants had IMT ≥0.8 mm. Carotid plaques were detected in 86 (44 %) subjects. In separate multivariate analysis models, unlike SFA and other anthropometric indices, the last tertile of VFA values was associated with at least threefold excess risk for IMT ≥0.8 mm (OR 3.8, 95 % CI 1.36-6.94, p = 0.02). There was no significant difference between mean values of categorized obesity indices in subjects with and without plaque, while participants in the highest tertile of VFA values were demonstrated to have higher risk of more than one plaque (OR 4.57, 95 % CI 1.03-20.11, p = 0.034).

CONCLUSIONS

A higher amount of visceral fat, measured by a semi-automated technique using MRI, is associated with increased IMT and having more than one carotid plaque in a general population, while subcutaneous fat measures are poor indicators for identifying carotid atherosclerosis.

Visceral Adiposity is Preferentially Associated with Vascular Stiffness Rather than Thickness in Men with Type 2 Diabetes

Aim: Visceral fat accumulation is known to underlie the clustering of cardiovascular risk factors. However, it is not completely understood how visceral fat accumulation influences the development of cardiovascular disease. In this study, we investigated the clinical impact of visceral adiposity on vascular stiffness and thickness in patients with type 2 diabetes (T2D).

Methods: One hundred and sixty-one patients with T2D, including 92 men and 69 women, were included in this cross-sectional study. Visceral fat area (VFA) and subcutaneous fat area (SFA) were measured by dual bioelectrical impedance analysis. Stiffness parameter β and intima-media thickness (IMT) of the common carotid artery were measured by ultrasonography.

Results: The mean age and duration of diabetes in the study population were 61 years and 13.9 years, respectively. In men, VFA and waist circumference (WC) were positively correlated with stiffness parameter β, whereas body mass index (BMI), WC, and SFA were negatively correlated with IMT. In contrast, in women, none of the obesity-related indices were significantly correlated with stiffness parameter β or IMT. In multiple regression analyses, VFA as well as WC, BMI, and SFA were independently associated with stiffness parameter β after adjustment for age and other potential confounders in men but not in women. None of the obesity-related indices were independently associated with IMT for either sex.

Conclusion: In men with T2D, visceral adiposity is associated with carotid arterial stiffness but not thickness.

Metabolic syndrome and obesity in peritoneal dialysis

Metabolic syndrome (MS) refers to clustering of features related to increased risk of cardiovascular disease, which include obesity or central obesity, dyslipidemia, diabetes mellitus or insulin resistance, together with hypertension. The prevalence of MS in end-stage renal failure patients on peritoneal dialysis is quite common, ranging from 40% to 60%, depending on the population studied and the definition used. However, there are controversies about the clinical outcome of patients with MS, particularly in the area of obesity. Whether peritoneal dialysis predisposes patients to MS is another unsolved issue. Despite these controversies, preventing patients from developing MS is important, at least from a theoretical point of view.

Causes of changes in carotid intima-media thickness: a literature review

Atherosclerosis causes significant morbidity and mortality. Carotid intima-media thickness (CIMT) predicts future cardiovascular and ischaemic stroke incidence. CIMT, a measure of atherosclerotic disease, can be reliably determined in vivo by carotid ultrasound. In this review, we determined that CIMT is associated with traditional cardiovascular risk factors such as age, sex, race, smoking, alcohol consumption, habitual endurance exercise, blood pressure, dyslipidemia, dietary patterns, risk-lowering drug therapy, glycemia, hyperuricemia, obesity-related anthropometric parameters, obesity and obesity-related diseases. We also found that CIMT is associated with novel risk factors, including heredity, certain genotypic indices, anthropometric cardiovascular parameters, rheumatoid arthritis, immunological diseases, inflammatory cytokines, lipid peroxidation, anthropometric hemocyte parameters, infectious diseases, vitamin D, matrix metalloproteinases, and other novel factors and diseases. However, the conclusions are inconsonant; the underlying causes of these associations remain to be further explored.

Visceral fat area is associated with HbA1c but not dialysate-related glucose load in nondiabetic PD patients

Factors associated with increased visceral fat area (VFA) have been well documented in the general population but rarely explored in nondiabetic individuals on peritoneal dialysis (PD). As glycosylated hemoglobin (HbA1c) is positively correlated with VFA in diabetic patients, we hypothesized that the same correlation would exist in nondiabetic PD patients. We enrolled 105 nondiabetic patients who had undergone chronic PD for more than 3 months. Each subject underwent an abdominal computed tomography (CT) scan, and the umbilicus cut was analyzed for VFA. VFA values, corrected for body mass index and subjected to natural logarithm transformations, were examined to determine whether they were correlated with HbA1c and other parameters. PD dialysates prescribed at the time of enrollment were recorded to calculate glucose load. We found that when 105 nondiabetic PD patients were classified according to tertiles of HbA1c, higher HbA1c was associated with larger VFA. Multiple linear regression analysis revealed that HbA1c was an independent determinant of VFA, while glucose load and other PD-specific factors were not. In summary, HbA1c, but not PD-related glucose load, was positively correlated with VFA in nondiabetic PD patients, suggesting clinical utility of HbA1c in the PD population.

Insulin resistance is associated with new-onset cardiovascular events in nondiabetic patients undergoing peritoneal dialysis

BACKGROUND

Chronic exposure to high glucose-containing peritoneal dialysis solution and consequent abdominal obesity are potential sources of insulin resistance in patients requiring prevalent peritoneal dialysis. The aim of this study was to elucidate the prognostic values of insulin resistance on new-onset cardiovascular events in nondiabetic patients undergoing prevalent peritoneal dialysis.

METHODS

A total of 201 nondiabetic patients undergoing prevalent peritoneal dialysis were recruited. Insulin resistance was assessed by homeostatic model assessment of insulin resistance (HOMA-IR). The primary outcome was new-onset cardiovascular events during the follow-up period. Cox proportional hazard analysis was performed to ascertain the independent prognostic value of HOMA-IR for the primary outcome.

RESULTS

The mean age was 53.1 years and male was 49.3% (n=99). The mean HOMA-IR was 2.6±2.1. In multivariate linear regression, body mass index (β=0.169, P=0.011), triglyceride level (β=0.331, P<0.001), and previous cardiovascular diseases (β=0.137, P=0.029) were still significantly associated with HOMA-IR. During a mean follow-up duration of 36.8±16.2 months, the primary outcome was observed in 36 patients (17.9%). When patients were divided into tertiles according to HOMA-IR, the highest tertile group showed a significantly higher incidence rate for new-onset cardiovascular events compared to the lower two tertile groups (P=0.029). Furthermore, multivariate Cox analysis revealed that HOMA-IR was an independent predictor of the primary outcome (hazard ratio=1.18, 95% confidence interval=1.03-1.35, P=0.014).

CONCLUSION

Insulin resistance measured by HOMA-IR was an independent risk factor for new-onset cardiovascular events in nondiabetic patients undergoing prevalent peritoneal dialysis.

Association between carotid intima-media thickness and index of central fat distribution in middle-aged and elderly Chinese

Background

Evidence has demonstrated that central fat distribution produces the most profound metabolic abnormalities and is associated with an increased risk of atherosclerotic cardiovascular diseases. We aimed to investigate whether the indexes of central fat distribution, including waist-to-height ratio (WHtR) and visceral fat area (VFA), were stronger risk factors of subclinical atherosclerosis than body mass index (BMI) in Chinese adults.

Methods

A total of 3381 participants aged 40 years or older without history of cardiovascular diseases (CVD) were enrolled in the present cross-sectional study from the Songnan community, Shanghai, China. Height, weight and waist circumference (WC) were measured by experienced physicians. High-resolution B-mode ultrasonography was performed to measure carotid intima-media thickness (CIMT). Regional adiposity was measured by a dual-source computed tomography (CT) scanner.

Results

Normal weight but central obesity group (BMI < 23 kg/m² and WHtR > 0.5) had higher levels of systolic blood pressure (SBP), fasting plasma glucose (FPG), 2 h post-load glucose (2 h PG), Hemoglobin A1c (HbA1c), and CIMT, as well as an elevated prevalence of hypertension and diabetes compared with overweight/obesity but not central obesity group (BMI ≥ 23 kg/m² and WHtR ≤ 0.5). In logistic regression analysis, WHtR > 0.5 was significantly and independently associated with elevated CIMT (odds ratio [OR] 1.30, 95% confidence interval [CI] 1.01-1.68, p value = 0.044). Similar association was noted for each standard deviation (SD) increase of WHtR (OR 1.25, 95% CI 1.07-1.47, p value = 0.006). Stepwise multiple linear regression analysis revealed that both WHtR and VFA were important determinants of CIMT, independent of other well-recognized risk factors (both p values < 0.01).

Conclusions

WHtR and VFA were associated with CIMT, independent of BMI and conventional CVD risk factors. Given the relatively high cost and complexness of VFA measurement, WHtR could be a more convenient and appropriate measure of abdominal obesity in clinical practice.

Contribution of subcutaneous abdominal fat on ultrasonography to carotid atherosclerosis in patients with type 2 diabetes mellitus

BACKGROUND

Whereas visceral abdominal adipose tissue (VAT) is associated with cardiometabolic risk, there is debate regarding the role of subcutaneous abdominal adipose tissue (SAT). The aim of this study was to investigate the relationships of subcutaneous and visceral abdominal fat with carotid atherosclerosis in patients with type 2 diabetes mellitus (T2DM).

METHODS

A total of 234 patients (men 131, women 103, mean age: 53 years) with T2DM were enrolled. Carotid intima-media thickness (CIMT), abdominal subcutaneous fat thickness (SFT) and visceral fat thickness (VFT) were assessed by high-resolution B-mode ultrasonography (US).

RESULTS

Compared to women, men had significantly higher VFT and lower SFT (p = 0.002, p = 0.04, respectively). In partial correlation coefficient analyses between CIMT and abdominal fat thickness after adjustment for body mass index (BMI), SFT showed a negative correlation with CIMT in men (r = -0.27, p = 0.03). VFT was not correlated with CIMT in either men or women. In women, SFT was not correlated with CIMT (r = -0.01, p = 0.93). VFT/SFT ratio was not correlated with CIMT in either men or women. In multivariate regression analyses adjusted for BMI and other CVD risk factors, SFT but not VFT was independently inversely associated with CIMT in men but not in women (p < 0.001).

CONCLUSIONS

SFT assessed by US was inversely associated with carotid atherosclerosis in patients with T2DM, particularly men. Further research into the different roles of the two types of abdominal adipose tissue in both men and women is warranted.

Sagittal abdominal diameter is an independent predictor of all-cause and cardiovascular mortality in incident peritoneal dialysis patients

Backgrounds and Aims

Visceral fat has a crucial role in the development and progression of cardiovascular disease, the major cause of death in end-stage renal disease (ESRD). Although sagittal abdominal diameter (SAD), as an index of visceral fat, significantly correlated with mortality in the general population, the impact of SAD on clinical outcomes has never been explored in ESRD patients. Therefore, we sought to elucidate the prognostic value of SAD in incident peritoneal dialysis (PD) patients.

Methods

We prospectively determined SAD by lateral abdominal X-ray at PD initiation, and evaluated the association of SAD with all-cause and cardiovascular mortality in 418 incident PD patients.

Results

The mean SAD was 24.5±4.3 cm, and during a mean follow-up of 39.4 months, 97 patients (23.2%) died, and 49.4% of them died due to cardiovascular disease. SAD was a significant independent predictor of all-cause [3rd versus 1st tertile, HR (hazard ratio): 3.333, 95% CI (confidence interval): 1.514–7.388, P = 0.01; per 1 cm increase, HR: 1.071, 95% CI: 1.005–1.141, P = 0.03] and cardiovascular mortality (3rd versus 1st tertile, HR: 8.021, 95% CI: 1.994–32.273, P = 0.01; per 1 cm increase, HR: 1.106, 95% CI: 1.007–1.214, P = 0.03). Multivariate fractional polynomial analysis also showed that all-cause and cardiovascular mortality risk increased steadily with higher SAD values. In addition, SAD provided higher predictive value for all-cause (AUC: 0.691 vs. 0.547, P<0.001) and cardiovascular mortality (AUC: 0.644 vs. 0.483, P<0.001) than body mass index (BMI). Subgroup analysis revealed higher SAD (≥24.2 cm) was significantly associated with all-cause mortality in men, women, younger patients (<65 years), and patients with lower BMI (<22.3 kg/m²).

Conclusions

SAD determined by lateral abdominal X-ray at PD initiation was a significant independent predictor of all-cause and cardiovascular mortality in incident PD patients. Estimating visceral fat by SAD could be useful to stratify mortality risk in these patients.

Metabolic syndrome and abdominal fat are associated with inflammation, but not with clinical outcomes, in peritoneal dialysis patients

Background

In the general population, metabolic syndrome (MetS) is correlated with visceral fat and a risk factor for cardiovascular disease (CVD); however, little is known about the significance of abdominal fat and its association with inflammation and medication use in peritoneal dialysis (PD) patients. We investigated the relationship of visceral fat area (VFA) with C-reactive protein (CRP) levels and medication use in PD patients and followed their clinical outcomes.

Methods

In a prospective study from February 2009 to February 2012, we assessed diabetes mellitus (DM) status, clinical and PD-associated characteristics, medication use, CRP levels, components of MetS, and VFA in 183 PD patients. These patients were categorized into 3 groups based on MetS and DM status: non-MetS (group 1, n = 73), MetS (group 2, n = 65), and DM (group 3, n = 45). VFA was evaluated by computed tomography (CT) and corrected for body mass index (BMI).

Results

Patients in group 1 had smaller VFAs than patients in groups 2 and 3 (3.2 ± 1.8, 4.6 ± 1.9, and 4.9 ± 2.0 cm²/[kg/m²], respectively, P < 0.05) and lower CRP levels (0.97 ± 2.31, 1.27 ± 2.57, and 1.11 ± 1.35 mg/dL, respectively, P < 0.05). VFA increased with the number of criteria met for MetS. After adjusting for age, body weight, and sex, CRP and albumin levels functioned as independent positive predictors of VFA; on other hand, the use of renin-angiotensin system blockers was inversely correlated with VFA in PD patients without DM. In the survival analysis, DM patients (group 3) had the poorest survival among the 3 groups, but no significant differences were found between groups 1 and 2.

Conclusion

This study showed that VFA and MetS are associated with CRP levels but cannot predict survival in PD patients without DM. The complex relationship of nutritional parameters to VFA and MetS may explain these results. The type of antihypertensive medication used was also associated with the VFA. The mechanisms behind these findings warrant further investigation.