Enhanced prediction of renal function decline by replacing waist circumference with "A Body Shape Index (ABSI)" in diagnosing metabolic syndrome: a retrospective cohort study in Japan.

BACKGROUND: Abdominal obesity as a risk factor for diagnosing metabolic syndrome (MetS) is conventionally evaluated using waist circumference (WC), although WC does not necessarily reflect visceral adiposity. OBJECTIVE: To examine whether replacing WC with "A Body Shape Index (ABSI)", an abdominal obesity index calculated by dividing WC by an allometric regression of weight and height, in MetS diagnosis is useful for predicting renal function decline. SUBJECTS/METHODS: In total, 5438 Japanese urban residents (median age 48 years) who participated in a public health screening program for 4 consecutive years were enrolled. Systemic arterial stiffness was assessed by cardio-ankle vascular index (CAVI). The predictability of the new-onset renal function decline (eGFR < 60 mL/min/1.73 m2) by replacing high WC with high ABSI (ABSI ≥ 0.080) was examined using three sets of MetS diagnostic criteria: Japanese, IDF and NCEP-ATPIII. RESULTS: In Japanese and NCEP-ATPIII criteria, MetS diagnosed using ABSI (ABSI-MetS) was associated with significantly higher age-adjusted CAVI compared to non-MetS, whereas MetS diagnosed using WC (WC-MetS) showed no association. Kaplan-Meier analysis of the rate of new-onset renal function decline over 4 years (total 8.7%) showed remarkable higher rate in subjects with ABSI-MetS than in those without (log-rank test p < 0.001), but almost no difference between subjects with and without WC-MetS (p = 0.014-0.617). In gender-specific Cox-proportional hazards analyses including age, proteinuria, and treatments of metabolic disorders as confounders, ABSI-MetS (Japanese criteria for both sexes, IDF criteria for men) contributed independently to the new-onset renal function decline. Of these, the contribution of IDF ABSI-MetS disappeared after adjustment by high CAVI in the subsequent analysis. CONCLUSION: In this study, replacing WC with ABSI in MetS diagnostic criteria more efficiently predicted subjects at risk of renal function decline and arterial stiffening.

Precise risk-prediction model including arterial stiffness for new-onset atrial fibrillation using machine learning techniques.

Atrial fibrillation (AF) is the most common clinically significant cardiac arrhythmia and is an important risk factor for ischemic cerebrovascular events. This study used machine learning techniques to develop and validate a new risk prediction model for new-onset AF that incorporated the use electrocardiogram to diagnose AF, data from participants with a wide age range, and considered hypertension and measures of atrial stiffness. In Japan, Industrial Safety and Health Law requires employers to provide annual health check-ups to their employees. This study included 13 410 individuals who underwent health check-ups on at least four successive years between 2005 and 2015 (new-onset AF, n = 110; non-AF, n = 13 300). Data were entered into a risk prediction model using machine learning methods (eXtreme Gradient Boosting and Shapley Additive Explanation values). Data were randomly split into a training set (80%) used for model construction and development, and a test set (20%) used to test performance of the derived model. The area under the receiver operator characteristic curve for the model in the test set was 0.789. The best predictor of new-onset AF was age, followed by the cardio-ankle vascular index, estimated glomerular filtration rate, sex, body mass index, uric acid, γ-glutamyl transpeptidase level, triglycerides, systolic blood pressure at cardio-ankle vascular index measurement, and alanine aminotransferase level. This new model including arterial stiffness measure, developed with data from a general population using machine learning methods, could be used to identify at-risk individuals and potentially facilitation the prevention of future AF development.

Relationship of Serum Uric Acid with Kidney Function Decline Mediated by Systemic Arterial Stiffness: A Retrospective Cohort Study in Japan.

Hyperuricemia is associated with kidney function decline (KFD), although whether hyperuricemia directly causes nephrotoxicity or is indirectly mediated by systemic arterial stiffening remains unclear. We examined the detailed relationship of serum uric acid (SUA) with KFD and potential mediation by arterial stiffness. Study population was 27,648 urban residents with an estimated glomerular filtration rate (eGFR) of ≥60 mL/min/1.73 m2 at baseline, and they participated in a median of three consecutive annual health examinations. Arterial stiffness was assessed using cardio-ankle vascular index (CAVI). KFD was defined as a decrease in eGFR to below 60. Multivariate analysis showed an association between baseline SUA and CAVI independent of eGFR. During the study period, 6.6% of participants developed KFD. Stratified analysis revealed a linear relationship between the contribution of CAVI or SUA and KFD. ROC analysis determined a cutoff CAVI of 8.0 (males) or 7.9 (females) and a cutoff SUA of 6.3 (males) or 4.5 mg/dL (females) for predicting KFD. The linkage between SUA and CAVI was associated with a greater increase in the hazard ratio for KFD with an increase in SUA. CAVI showed the mediating effect on the relationship of SUA with KFD after an adjustment for confounders. SUA was associated positively with CAVI-mediated KFD. Further studies should verify whether intensive SUA-lowering treatment prevents KFD via improving vascular function.

Relationship of serum lipid parameters with kidney function decline accompanied by systemic arterial stiffness: a retrospective cohort study.

Background: Dyslipidemia is associated with kidney function decline (KFD), although the non-linear relationship of lipid parameters to KFD has not been fully elucidated. We aimed to determine the detailed relationship of baseline lipid parameters with KFD, considering the mediation of arterial stiffness. Methods: A total of 27 864 urban residents with estimated glomerular filtration rate (eGFR) ≥60 mL/min/1.73 m2 at baseline, who participated in a median of three (range two to eight) consecutive annual health examinations were studied. Arterial stiffness was assessed by cardio-ankle vascular index (CAVI). KFD was defined as development of eGFR <60 mL/min/1.73 m2. Results: During the study period, 1837 participants (6.6%) developed KFD. Receiver operating characteristic analysis determined that the cutoff values independently associated with KFD are 123 mg/dL for low-density lipoprotein cholesterol (LDL-C) [area under the curve (95% confidence interval) 0.570 (0.557-0.583)], 65 mg/dL for high-density lipoprotein cholesterol (HDL-C) [0.552 (0.539-0.566)], 82 mg/dL for triglycerides (TG) [0.606 (0.593-0.618)] and 1.28 for TG/HDL-C ratio [0.600 (0.587-0.612)]. These cut-offs were independently associated with KFD in Cox analysis. Regarding the contribution of each lipid parameter to KFD, a linear relationship was observed for both TG and TG/HDL-C, and a U-shaped relationship for HDL-C. A adjusted mediating effect of CAVI on the relationship of TG or TG/HDL-C ratio with KFD was observed (mediating rate: 2.9% in TG, 2.5% in TG/HDL-C ratio). Regarding the association to KFD, a linear relationship was observed for both TG and TG/HDL-C, and a U-shaped relationship for HDL-C. A mediating effect of CAVI on the relationship of TG or TG/HDL-C ratio with KFD was observed after adjustment for confounders. Conclusions: TG and TG/HDL-C ratio related linearly to KFD and this was partially mediated by CAVI. A U-shaped relationship was observed between HDL-C and KFD risk. LDL-C showed no significant association. Further study should investigate whether intensive TG-lowering treatment prevents KFD via decreasing CAVI.

Cumulative Cigarette Consumption is Associated with Cardio-Ankle Vascular Index (CAVI) Mediated by Abdominal Obesity Assessed by A Body Shape Index (ABSI): A Cross-Sectional Study.

AIM: To elucidate the mechanism by which cigarette smoking causes vascular damage, we examined the relationship between cumulative cigarette consumption and abdominal obesity, and the possible mediating effect of smoking on arterial stiffness. METHODS: Cross-sectional data from 19499 never smokers and 5406 current smokers receiving health screening was analyzed. Abdominal obesity was assessed by ABSI, and arterial stiffness by CAVI. High CAVI was defined as CAVI ≥ 9.0. RESULTS: Current smoker showed higher ABSI than never smokers after propensity score matching. Cumulative cigarette consumption expressed in pack-years correlated with ABSI (Rs: 0.312 in men, 0.252 in women), and was also extracted as an independent factor associated with ABSI by multiple regression analysis. A linear relationship between pack-year and CAVI was observed (Rs: 0.544 in men, 0.423 in women). Pack-year had almost equal discriminatory power in predicting high CAVI in both sexes (C-statistic: 0.774 in men, 0.747 in women), and the best cut-offs of pack-year for high CAVI were 24.5 in men and 14.7 in women. Bivariate logistic regression models revealed that the association between pack-year higher than cut-off and high CAVI was independent of traditional risks. A mediating effect of ABSI (mediation rate: 9.9% in men and 11.2% in women), but not waist circumference (WC), on the association of pack-year with CAVI was observed, after adjusting for traditional risks. CONCLUSION: Cumulative cigarette smoking in pack-years was independently associated with ABSI. ABSI partially mediates the association between pack-year and CAVI, suggesting that abdominal obesity partially mediates smoking-related vascular dysfunction.

Comparison of Predictive Ability of Arterial Stiffness Parameters Including Cardio-Ankle Vascular Index, Pulse Wave Velocity and Cardio-Ankle Vascular Index0.

Cardio-ankle vascular index (CAVI) was developed to reflect the stiffness of the arterial tree from the aortic origin to the ankle. This arterial stiffness parameter is useful for assessing the severity of cardiovascular disease (CVD) and its risk. However, compared to pulse wave velocity (PWV), the conventional gold standard of arterial stiffness parameter, there has been a concern regarding CAVI that there are fewer longitudinal studies for CVD. Furthermore, the accuracy of CAVI for atherosclerotic diseases compared to other parameters has not been well validated. This review article aims to summarize recent findings to clarify the predictive ability of CAVI in longitudinal studies. First, several large longitudinal studies have found that not only baseline CAVI but also CAVI changes during the observation period predict cardiovascular events. Second, CAVI may have superior discriminatory power for all-cause mortality and major adverse cardiovascular endpoints compared to PWV. Furthermore, one large longitudinal study found CAVI to be a stronger predictor for renal function decline compared to PWV as well as CAVI0, a variant of CAVI that mathematically excludes BP dependence. Additionally, CAVI shows the properties that allow the elucidation of specific hemodynamics in aortic valve disease or hypovolemia. In conclusion, CAVI may be a modifiable arterial stiffness parameter not only for predicting and preventing atherosclerotic diseases but also for elucidating specific hemodynamic pathophysiology.

Predictive ability of arterial stiffness parameters for renal function decline: a retrospective cohort study comparing cardio-ankle vascular index, pulse wave velocity and cardio-ankle vascular index 0.

OBJECTIVE: The relative usefulness of arterial stiffness parameters on renal function remains controversial. This study aimed to compare the predictive ability of three arterial stiffness parameters at baseline; cardio-ankle vascular index (CAVI), heart-ankle pulse wave velocity (haPWV) and CAVI 0 , a variant of CAVI that theoretically excludes dependence on blood pressure, for renal function decline in Japanese general population. METHODS: A total of 27 864 Japanese urban residents without renal impairment at baseline who participated in two to eight consecutive (mean 3.5 ±â€Š1.7 times) annual health examinations were studied. RESULTS: During the study period, 6.6% of participants developed renal function decline (estimated glomerular filtration rate <60 ml/min per 1.73 m 2 ), all of whom had relatively high values in all arterial stiffness parameters. In receiver-operating characteristic curve analysis, the discriminatory power for renal function decline showed a decreasing trend of CAVI to haPWV to CAVI 0 (C-statistic: 0.740 vs. 0.734 vs. 0.726). The cut-offs were CAVI 8.0, haPWV 7.23 and CAVI 0 11.6. In Cox-proportional hazards analysis for increase of each parameter above cut-off or by 1 standard deviation (SD) adjusted for two models of confounders, only CAVI always contributed significantly to renal function decline. Restricted cubic spline regression analysis suggested that CAVI most accurately reflected the risk of renal function decline. CONCLUSION: Increase in arterial stiffness parameters, especially CAVI, may represent a major modifiable risk factor for renal function decline in the general population. Further research is needed to examine whether CAVI-lowering interventions contribute to the prevention of chronic kidney disease.

Issue of Waist Circumference for the Diagnosis of Metabolic Syndrome Regarding Arterial Stiffness: Possible Utility of a Body Shape Index in Middle-Aged Nonobese Japanese Urban Residents Receiving Health Screening.

INTRODUCTION: Abdominal obesity as a risk factor for diagnosing metabolic syndrome (MetS) is evaluated using waist circumference (WC), although WC does not necessarily reflect visceral adiposity. This cross-sectional study aimed to clarify whether replacing WC with "A Body Shape Index (ABSI)," an abdominal obesity index, in MetS diagnosis detects individuals with arterial stiffening assessed by cardio-ankle vascular index (CAVI). METHODS: A retrospective cross-sectional study was conducted in 46,872 Japanese urban residents (median age 40 years) who underwent health screening. Exclusion criteria were current treatments and a past history of cardiovascular disease (CVD). The Japanese, International Diabetes Federation, and NCEP-ATPIII criteria were used to diagnose MetS. High CAVI was defined as CAVI ≥9.0. RESULTS: CAVI correlated positively with ABSI (ß = 0.127), but negatively with WC (ß = -0.186), independent of age, sex, systolic blood pressure, fasting plasma glucose, and high-density lipoprotein--cholesterol. Receiver operating characteristic (ROC) analysis showed that ABSI had a stronger contribution to high CAVI (area under the ROC curve [AUC] = 0.730) than WC (AUC = 0.595) and body mass index (AUC = 0.520). ABSI ≥0.080 was defined as abdominal obesity based on the results of ROC analysis for high CAVI and estimated glomerular filtration rate <60 mL/min/1.73 m2. Logistic regression analysis revealed that replacing high WC with ABSI ≥0.080 in MetS diagnosis enhanced the detection of subjects with high CAVI. DISCUSSION/CONCLUSION: Use of ABSI can detect subjects with arterial stiffening, which may lead to efficient stratification of CVD risk. Further studies are needed to confirm whether MetS diagnosis using ABSI predicts CVD morbidity and mortality.

A Body Shape Index (ABSI) as a Variant of Conicity Index Not Affected by the Obesity Paradox: A Cross-Sectional Study Using Arterial Stiffness Parameter.

A body shape index (ABSI) is an abdominal obesity index developed based on epidemiological statistics and designed to correlate minimally with body mass index (BMI). We examined the approximation between ABSI and other abdominal obesity indices based on biophysical concepts. The cross-sectional data from 62,514 Japanese urban residents were analyzed. Body adiposity indices comprising BMI, waist circumference (WC), ABSI, conicity index (CI), waist-to-height ratio (WHtR), and WC/BMI ratio were examined. ABSI and CI more strongly correlated with age and arterial stiffness assessed by cardio-ankle vascular index (CAVI) compared to the other indices. The discriminative power for high CAVI (≥9.0) was the strongest for ABSI followed by CI and other indices, in that order. The range and distribution of WC corresponding to the cutoff of ABSI (0.0801), or CI (1.23) seemed reasonable. The correlation between ABSI and CI was the strongest compared to any other combination of indices. CI correlated moderately with BMI, whereas ABSI correlated minimally with BMI. ABSI correlates strongly and approximates closely with CI. Hence, ABSI may be considered to reflect the degree of body shape change from cylindricity to conicity and is currently the only abdominal obesity index not affected by the obesity paradox.

Cardio-Ankle Vascular Index is Associated with Prevalence and New-Appearance of Atrial Fibrillation in Japanese Urban Residents: A Retrospective Cross-Sectional and Cohort Study.

AIM: Physiological tests to assess systemic vascular function are not included in the risk score for atrial fibrillation (AF). We aimed to examine whether cardio-ankle vascular index (CAVI), a systemic arterial stiffness parameter, is associated with the presence of AF in Japanese general population. METHODS: A cross-sectional study (N = 47,687) and a cohort study (N = 5418, four consecutive years) in Japanese urban residents who participated in annual health screening were conducted. RESULTS: A total of 164 subjects (0.34%) had AF in the cross-sectional data. After propensity score matching for age and gender, logistic regression analysis revealed that CAVI is independently associated with AF, as are body mass index and estimated glomerular filtration rate. In a 4-year cohort study, 22 subjects (0.41%) with new-appearance of AF showed higher CAVI at baseline than those without. In the receiver-operating-characteristic curve analysis, the area under the curve, which is a measure of predictability, of CAVI for the new-appearance of AF was 0.747, and the cut-off value of CAVI was 8.0. Kaplan-Meier analysis revealed that the cumulative incidence of new-appearance of AF was higher in subjects with CAVI ≥8.0 compared to those with CAVI <8.0. In Cox-proportional hazards analysis, CAVI ≥8.0 as well as gender were identified as independent predictors for the new-appearance of AF, whereas age ≥65 years was not. CONCLUSION: Increased CAVI may represent a major modifiable risk factor for the development of AF. Studies are needed to confirm that CAVI is a predictor of AF independent of various AF risk factors and that CAVI-lowering interventions can prevent new-appearance or recurrence of AF.