Increased Impact of Serum Uric Acid on Arterial Stiffness and Atherosclerosis in Females.

AIMS: Serum uric acid increases with metabolic disorders; however, whether the effects of uric acid on atherosclerosis are different in females and males has not been sufficiently evaluated. Therefore, this study compared the impact of uric acid on arterial stiffness and atherosclerosis between females and males. METHODS: We enrolled 10196 untreated middle-aged subjects (46±8 years, 3021 females and 7175 males) who underwent periodic health check-ups. Serum uric acid levels were measured and arterial stiffness and atherosclerosis were assessed by the cardio-ankle vascular index (CAVI), carotid intima-media thickness (IMT), and plaque, using ultrasound imaging. RESULTS: Females with increased arterial stiffness (CAVI ≥ 8.0) or carotid plaques had higher uric acid than those without (P＜0.0001), but males did not. In multivariable regression analyses including overall participants, uric acid was significantly associated with the CAVI, where sex interacted with uric acid. In sex-specific analyses, uric acid was significantly associated with the CAVI, but not with carotid IMT, in both sexes. However, logistic regression analyses revealed that serum uric acid was independently associated with the presence of carotid plaques in females. The exclusion of subjects with abdominal obesity or metabolic syndrome from the analysis did not alter the results in females. CONCLUSIONS: Serum uric acid was significantly associated with the CAVI in both sexes, but the interaction of sex was confirmed and associated with a carotid plaque only in females. These findings support the increased impact of serum uric acid on arterial stiffness and atherosclerosis in females.

Examination of Large Artery Atherosclerosis could Reveal Small Artery Retinopathy in Untreated Middle-Aged Individuals.

AIMS: Small arteries can be visualized in the ocular fundus, and findings of retinopathy based on Scheie classification are often applied to evaluate the impact of hypertension and atherosclerosis. However, the relationship between damage in the large and small arteries has not been investigated sufficiently, especially in the early stages. The present study investigated possible associations between large artery atherosclerosis and small artery retinopathy in untreated middle-aged individuals. METHODS: Untreated middle-aged workers undergoing periodic health check-ups (n=7,730, 45±8 years) were enrolled in this study. The absence or presence and extent of retinopathy were characterized by ophthalmologists as hypertensive (H0-4) and atherosclerotic grades (S0-4) based on Scheie classification. Large artery atherosclerosis was examined based on functional assessment of the cardio-ankle vascular index (CAVI) and morphological assessment of the carotid intima-media thickness (IMT) by ultrasound. RESULTS: We found significant differences in CAVI and carotid IMT between individuals with and without hypertensive or atherosclerotic retinopathy. Multivariable regression analysis showed that the presence of hypertensive and atherosclerotic retinopathy was significantly associated with CAVI and carotid IMT. Logistic regression analysis with the endpoint of a hypertensive or atherosclerotic lesion revealed that CAVI and carotid IMT are independent determinants of retinopathy. CONCLUSIONS: CAVI and carotid IMT were significantly associated with the presence of retinopathy based on Scheie classification in untreated middle-aged subjects, implying that atherosclerotic examination in large arteries could reveal early-stage small artery retinopathy.

A body shape index could serve to identify individuals with metabolic syndrome and increased arterial stiffness in the middle-aged population.

BACKGROUND: A body shape index (ABSI) is a novel anthropometric measure calculated using waist circumference (WC), body mass index (BMI), and body height. This study investigated the usefulness of ABSI to identify individuals with metabolic syndrome (MetS) and increased arterial stiffness in the middle-aged population. METHODS: Middle-aged workers who underwent periodic health check-ups and who were without previous cardiovascular events were enrolled (n = 10,182). In addition to ABSI, visceral fat area (VFA) was evaluated using computed tomography. Obesity and MetS were diagnosed on the basis of WC, VFA, and ABSI. Arterial stiffness was examined by measuring the cardio-ankle vascular index (CAVI). RESULTS: ABSI was significantly associated with CAVI in multivariable regression analysis. Logistic regression analysis revealed that ABSI was independently associated with the presence of MetS diagnosed on the basis of WC or VFA after adjustment for potential confounders, including BMI. Subjects with MetS diagnosed on the basis of each obesity index showed higher CAVI values than those without. Among subjects with MetS diagnosed on the basis of WC or VFA, those with MetS who met the definition of ABSI obesity showed significantly higher CAVI than those who did not. The other logistic regression analysis demonstrated that CAVI was independently associated with MetS defined on the basis of ABSI. CONCLUSIONS: ABSI was significantly associated with CAVI and the presence of MetS in the middle-aged population and helped to discriminate individuals with MetS and increased CAVI. ABSI could serve to identify individuals with MetS and increased arterial stiffness.

Close Association between Subclinical Atherosclerosis and Pulmonary Function in Middle-Aged Male Smokers.

AIMS: Cigarette smoking provokes deleterious influences on cardiovascular and pulmonary systems, although the underlying relationship has not been sufficiently investigated especially in early-stage disease. The present study investigated possible associations between subclinical atherosclerosis and pulmonary function in middle-aged male smokers. METHODS: Male smokers undergoing their periodic health check-up were enrolled in this study (n=3,775, 45±8 years). Pulmonary function was evaluated using spirometry by calculating forced vital capacity (FVC) as a percentage of predicted value (FVC%-predicted), forced expiratory volume in one second (FEV1) as a percentage of predicted value (FEV1%-predicted), and the ratio of FEV1 to FVC (FEV1/FVC). Subclinical atherosclerosis was assessed based on ankle-brachial pressure index (ABI), cardio-ankle vascular index (CAVI), ultrasound examination of the carotid intima-media thickness (IMT), and presence of plaque. RESULTS: Multivariate regression analysis showed that ABI was positively associated with FVC%-predicted and FEV1%-predicted after adjustment for confounders including smoking intensity, while CAVI or carotid IMT was inversely associated with both. Participants with chronic obstructive pulmonary disease (COPD, n=256) showed reduced ABI and increased CAVI or carotid IMT compared with those without COPD, and participants with carotid plaque had lower pulmonary function than those without plaque. Reduced FEV1/FVC was an independent determinant of carotid plaque and decreased ABI was an independent determinant of COPD, as revealed by logistic regression analysis with the endpoint of carotid plaque presence or a diagnosis of COPD revealed. CONCLUSIONS: Middle-aged male smokers showed a close association between subclinical atherosclerosis and pulmonary function, implying that smoking induced-vascular and pulmonary damage are interacting in early-stage disease.

Relationships of Obesity-Related Indices and Metabolic Syndrome with Subclinical Atherosclerosis in Middle-Aged Untreated Japanese Workers.

AIM: Obesity is a social problem due to the prevalence of the Western lifestyle. In particular, visceral fat accumulation, which is a main component of metabolic syndrome, is closely associated with the progression of atherosclerosis. This study aimed to investigate the relationships of obesity-related indices and metabolic syndrome with subclinical atherosclerosis in middle-aged untreated workers. METHODS: Employees undergoing their periodic health check-up but without previous cardiovascular events or cardiovascular medications were enrolled in this study (n=7,750). Body mass index (BMI), percent body fat, waist circumference, and visceral fat area were evaluated as obesity-related indices. Assessment of visceral fat area was performed by computed tomography (CT). Subclinical atherosclerosis was assessed by measuring arterial stiffness using cardio-ankle vascular index (CAVI) and by ultrasound examination of carotid intima-media thickness (IMT). RESULTS: Obesity-related indices were significantly correlated with each other and were positively associated with carotid IMT but negatively associated with CAVI in multivariate regression analysis. In a logistic regression analysis including CAVI and carotid IMT simultaneously, CAVI was negatively associated, but carotid IMT was positively associated, with obesity defined by each obesity-related index. In contrast, both CAVI and carotid IMT were positively associated with the presence of metabolic syndrome based on visceral fat accumulation. CONCLUSIONS: Obesity-related indices were negatively associated with CAVI and positively associated with carotid IMT in middle-aged untreated workers, while both CAVI and carotid IMT were worsened in the presence of metabolic syndrome.

Impacts of lifestyle behavior and shift work on visceral fat accumulation and the presence of atherosclerosis in middle-aged male workers.

Work style, and particularly shift work, can affect an individual's circadian rhythms. Moreover, lifestyle habits, including dietary and exercise routines, might be altered by irregular shift hours. The present study investigated how lifestyle and shift work affect the accumulation of visceral fat and the presence of atherosclerosis in middle-aged male workers. This study enrolled employees undergoing their periodic health check-up (n = 10,073). Visceral fat area (VFA) was evaluated by computed tomography. Atherosclerosis was assessed by the cardio-ankle vascular index (CAVI), carotid intima-media thickness (IMT), and carotid plaque. Lifestyle was evaluated by the following items: (1) eating breakfast, (2) nighttime eating, (3) regular exercise, (4) habitual drinking, (5) habitual smoking, (6) sleeping hours, and (7) working hours. Shift workers were defined as employees who were not engaged in fixed daytime work. The VFA and CAVI were significantly greater in fixed daytime workers than in shift workers, while the carotid IMT was lower in fixed daytime workers than in shift workers. Reduced regular exercise and fixed daytime work were independently associated with visceral fat accumulation by both multivariate regression and logistic regression analyses. Habitual smoking was independently associated with an increased CAVI and carotid atherosclerosis in both multivariate regression and logistic regression analyses. Reduced regular exercise and fixed daytime work were significantly associated with visceral fat accumulation, while habitual smoking had a consistent association with the presence of atherosclerosis. These findings support the idea that unhealthy lifestyles should be modified before considering an intervention in work style.

Rearing conditions required for behavioral compensation after unilateral cercal ablation in the cricket Gryllus bimaculatus.

The rearing condition necessary for behavioral compensation after sensory deprivation was investigated in the cricket Gryllus bimaculatus. The right-cercus-ablated cricket was reared in a glass vial with a slightly larger diameter than the body length of the cricket. After two weeks of rearing in the vial, the air-puff-evoked escape behavior of the cricket was investigated. The response rate (relative occurrence of the escape behavior after a standard air puff) obtained was identical with that of crickets reared in a large cage. On the other hand, unlike crickets reared in a large cage, the distorted escape directional property of the cricket reared in the vial was not compensated at all. Control experiments proved that the restraint in the vial did not affect the motor system, and the air motion from environments was not essential for the compensational recovery of the escape direction. Therefore, the ablated crickets required spontaneous walking in order to compensate the directionality of their escape. A self-generated wind caused by spontaneous walking appears necessary for the crickets to realize the defect of their sensory system and to compensate the related escape behavior. A hypothesis for the compensation mechanism based on the efference copy signal is proposed.