New index of abdominal obesity, a body shape index, is BMI-independently associated with systemic arterial stiffness in real-world Japanese population.

OBJECTIVE: To clarify that the new index of abdominal obesity, a body shape index (ABSI), is associated with obesity-related metabolic disorders and arterial stiffness. MATERIALS: We analyzed the cross-sectional data from 62,514 Japanese subjects (mean age 44.4 years, mean body mass index (BMI) 22.2 kg/m2) without a past history of cardiovascular disease, stroke, or treatment for obesity-related metabolic disorders. METHODS: Various body adiposity indices including BMI, waist circumference (WC), and ABSI were evaluated for abilities to indicate metabolic disorders and arterial stiffness assessed by cardio-ankle vascular index (CAVI). RESULTS: WC, WC/height ratio, and WC/BMI ratio correlated with BMI regardless of gender or obesity, whereas ABSI hardly correlated with BMI. ROC analyses demonstrated that ABSI had the highest discriminatory power in predicting high CAVI (≥ 90th percentile) compared to other body adiposity indices, and the cut-off value was 0.080. Increases in ABSI as well as BMI reflected severity of metabolic disorders. After adjusting for confounders identified by multiple regression analysis, adjusted CAVI correlated positively with ABSI, whereas an inverted relationship was observed between adjusted CAVI and BMI. Additionally, the contribution of high ABSI (≥ 0.080) for high CAVI was independent of gender, age, obesity, and obesity-related metabolic disorders in the multivariate logistic regression model. CONCLUSION: ABSI is an easily calculated index of abdominal obesity which reflects metabolic disorders and systemic arterial stiffening, and may be useful in primary health screening even without any medical equipment for visceral fat quantification.

The Background of Calculating CAVI: Lesson from the Discrepancy Between CAVI and CAVI0.

Arterial stiffness is a good predictor of cardiovascular events. As a substitute for elastic modulus representing stiffness, pulse wave velocity (PWV) has been used for over a century as it is easy to measure; however, PWV is known to essentially depend on blood pressure at the time of measurement. The cardio-ankle vascular index (CAVI) is a relatively new index of global arterial stiffness of the origin of the aorta to the ankle arteries. The characteristic feature is its independency from blood pressure at the measuring time. Recently, a variant index CAVI0 was proposed, which was claimed to be a more accurate arterial stiffness index than CAVI, considering independency from blood pressure. The purpose of this review is to evaluate the properties of CAVI more precisely by comparing with CAVI0, and to confirm the true meaning of CAVI as an index of arterial stiffness. First, the properties of PWV depending on the blood pressure and the variation of PWV values in the cardiac cycle were analyzed. Then, we attempted to clarify the point at which the PWV, adopted in CAVI or in CAVI0, was measured in cardiac cycle. A comprehensive comparison of the clinical data of CAVI and CAVI0 showed that CAVI is more appropriate than CAVI0. In conclusion, CAVI is reconfirmed to be a reliable and useful index of blood pressure-independent arterial stiffness composed of both organic and functional stiffness.

Comparison of Cardio-Ankle Vascular Index (CAVI) and CAVI0 in Large Healthy and Hypertensive Populations.

AIM: The cardio-ankle vascular index (CAVI) represents the blood pressure-independent arterial stiffness from the origin of the aorta to the ankle. CAVI0 has been proposed as a variant index. We aimed to clarify the difference between CAVI and CAVI0 among large populations, and to explore reasons of the difference. METHODS: The subjects were 5,293 Japanese healthy and 3,338 hypertensive people. Simple and multiple regression analyses were performed using age, sex, body mass index, systolic, and diastolic blood pressure (Pd) as variables. Sub-group analysis was performed by sex and age. The CAVI values with and without adjustment by reference pressure were also compared. RESULTS: CAVI had a positive correlation with Pd, while CAVI0 had a negative correlation with Pd in the healthy population. The CAVI values of the hypertensive group were higher than those of healthy group in both men and women, but the CAVI0 values in women of the hypertensive group in the 30-39 age group was significantly lower than that of the corresponding healthy group. Differences of CAVI values with or without modification using the reference pressure were 1.09%±1.38% for the healthy group and 3.68%±1.66% for the hypertensive group. CONCLUSION: CAVI showed the expected values, but CAVI0 showed inexplicable results in the healthy and hypertensive populations. The differences were due to the strong dependency of CAVI0 on Pd. Differences of CAVI values with or without reference pressure were negligible. These results indicate that CAVI obtained by the VaSera system is appropriate, but CAVI0 is not.

Brain activation associated with changes in heart rate, heart rate variability, and plasma catecholamines during rectal distention.

OBJECTIVE: To test the hypothesis that gut stimulation provokes autonomic arousal via activation of regional cerebral cortices. How the human brain processes interoceptive signals and forms initial autonomic arousal is one of the key questions to be answered in research on emotion. METHODS: Twelve healthy males participated in this study. A barostat bag was inserted in the rectum and intermittently inflated with 0, 20, or 40 mm Hg at random for 80 seconds. H(2)(15)O positron emission tomography (PET) of the brain, electrocardiography, and blood sampling for catecholamines were performed. Changes in regional cerebral blood flow were interpreted using statistical parametric mapping. RESULTS: Rectal distention with 40 mm Hg induced a significant increase in heart rate, low frequency (LF)/high frequency (HF) ratio of heart rate variability, and plasma adrenaline. Activated brain areas that were associated with increased heart rate during rectal distention were the right insula, right operculum, right dorsolateral prefrontal cortex, putamen, thalamus, periaqueductal gray, and cerebellum (p < .001, uncorrected), whereas those that were associated with an increased LF/HF ratio were the bilateral insula, putamen, thalamus, midbrain, pons, and cerebellum (p < .001, uncorrected). Activated brain areas that were associated with increased plasma adrenaline were the right insula, right orbitofrontal cortex, right parahippocampal gyrus, putamen, thalamus, periaqueductal gray, pons, and cerebellum (p < .001, uncorrected). CONCLUSION: Our results suggest that the right insula and the related body mapping regions may form the functional module of sympathetic arousal in response to gut stimulation.

Atherosclerosis is accelerated in patients with long-term well-controlled systemic lupus erythematosus (SLE).

BACKGROUND: It is uncertain whether atherosclerosis is accelerated in premenopausal and postmenopausal patients with long-term well-controlled systemic lupus erythematosus (SLE). METHODS: We measured the intima-media thickness (IMT) of the carotid arteries and the cardio-ankle vascular index (CAVI) in 39 women with SLE and in age- and sex-matched controls. RESULTS: In the premenopausal state, carotid plaque was detected only in SLE patients (36%). In the postmenopausal state, the maximum IMT was about 2-fold greater in SLE patients than in control subjects (1.3+/-0.7 vs. 0.7+/-0.2 mm, p<0.001). CAVI was higher in both the premenopausal and postmenopausal SLE patients. The serum amyloid A protein (SAA) was higher in SLE patients in the premenopausal state (p=0.025), while remnant like particle-cholesterol (RLP-C), the homeostasis model assessment of insulin resistance (HOMA-IR), and SAA were significantly increased in postmenopausal SLE patients (p=0.001, p<0.001 and p<0.05, respectively). Multiple regression analysis revealed that the maximum IMT was associated with cumulative PSL dosage (p=0.027) and SAA (p=0.074) in the premenopausal SLE patients, and with HOMA-IR (p<0.001) in the postmenopausal SLE patients. CONCLUSION: Atherosclerosis is accelerated in long-term well-controlled SLE. More attention should be given to subclinical inflammation and insulin resistance in the management of SLE patients.

Impact of type A behavior on brachial-ankle pulse wave velocity in Japanese.

Pulse wave velocity (PWV) is the velocity of a pulse wave traveling a given distance between 2 sites in the arterial system, and is a well-known indicator of arteriosclerosis. Brachial-ankle PWV (baPWV) is a parameter more simple to obtain, compared with the conventional PWV, and is an easy and effective means of evaluating arteriosclerosis. BaPWV can be obtained by only wrapping the four extremities with blood pressure cuffs, and it can be easily used to screen a large number of subjects. Type A behavior has been confirmed as an independent risk factor for the development of coronary heart disease. To examine the relationship between Type A behavior and arteriosclerosis, 307 normal Japanese subjects were classified into either a Type A group (n = 90) or a non-Type A group (n = 217) by using Maeda's Type A Scale. BaPWV was evaluated using a PWV diagnosis device. The baPWV in the Type A group was significantly higher than that obtained in the non-Type A group. The baPWV showed a positive correlation with age both in the Type A group and in the non-Type A group; however, the straight-line regression slope of baPWV versus age in the Type A group was significantly larger than that in the non-Type A group. Therefore, our results suggest that arteriosclerosis might be promoted earlier in subjects expressing the Type A behavior pattern. Type A behavior pattern is confirmed as a risk factor for arteriosclerosis, and may increase the risk of the cardiovascular disease related to arteriosclerosis.

Comparison of brachial-ankle pulse wave velocity in Japanese and Russians.

Pulse wave velocity (PWV) is a well-known indicator of arterial stiffness and a marker of the presence of vascular lesions. Cardiovascular mortality in Russia has become the highest in the world. The Japanese are enjoying long lives, and the mortality caused by cardiovascular diseases has thus far remained at lower levels than that in Russia. In this study, we focused on brachial-ankle pulse wave velocity (baPWV) obtained from normal human subjects in Russia as well as in Japan, and compared their respective cardiovascular risks. We evaluated baPWV in 337 Japanese and 138 Russian healthy subjects. The baPWV was recorded using a PWV diagnosis device. BaPWV was measured between 2 locations of the arterial tree. The baPWV in the Russian group was significantly higher than that obtained in the Japanese of two groups categorized by age (40-59 years and 60- years). Further, body mass index (BMI), systolic blood pressure (SBP) and diastolic blood pressure in the Russian group were significantly higher than those obtained in Japanese in three age groups (under 39 years, 40-59 years, and 60- years). Moreover, the baPWV indicated a positive correlation with age, BMI and SBP in both Japanese and Russians, although the increasing trend of the baPWV against age of the Russian group had a larger value than that of the Japanese. Therefore, we suggest that arterial stiffness might be promoted earlier in the Russian group, which might be the main cause of the increased cardiovascular risk in Russia.