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.

P5301Impacts of lifestyle behavior and shift Work on visceral fat accumulation and progression of atherosclerosis in middle-aged workers

Background

Work style, and particularly shift work, can affect an individual's health through disrupting circadian rhythms. Moreover, lifestyle habits including dietary and exercise routines might be altered by irregular shift hours. We thus hypothesized that an individual's lifestyle including working habits could influence the prevalence of visceral fat obesity and the progression of atherosclerosis.

Purpose

The present study investigated how lifestyle and shift work affect the accumulation of visceral fat and the progression of subclinical atherosclerosis in middle-aged workers.

Methods

This study enrolled employees undergoing their periodic health check-up (n=10883). The Cardio-Ankle Vascular Index (CAVI) was measured to assess arterial stiffness, followed by ultrasound examination and computed tomography imaging to measure carotid intima-media thickness (IMT) and visceral fat area (VFA), respectively. 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. With regard to work factors, subjects were categorized into fixed daytime workers or shift workers (including subjects working with an irregular schedule, outside of daytime hours, or at nighttime).

Results

Among all subjects enrolled, 6820 subjects were fixed daytime workers and 4063 subjects were shift workers. Most of the employees engaged in fixed daytime work were clerical workers, while the employees engaged in shift work were mainly physical workers in this company. Fixed daytime workers had significantly greater VFA than shift workers, but the prevalence of metabolic syndrome, CAVI values, and carotid IMT were similar between groups. Reduced regular exercise, long sleeping hours, and fixed daytime work were independently associated with visceral fat accumulation by both multivariate regression and logistic regression analyses. However, the logistic regression analysis with the presence of metabolic syndrome as the endpoint revealed that skipping breakfast, reduced regular exercise, long sleeping hours, and short working hours were independent determinants of metabolic syndrome. On the other hand, univariate and multivariate regression analysis showed that habitual smoking, but not shift work, were significantly associated with CAVI and carotid IMT. Logistic regression analysis with the endpoint of carotid atherosclerosis (presence of plaque) showed that habitual smoking was an independent determinant of carotid atherosclerosis.

Conclusions

Reduced regular exercise, long sleeping hours, and fixed daytime work were significantly associated with visceral fat accumulation, while habitual smoking has a consistent association with the progression of atherosclerosis. These findings support the concept that unhealthy lifestyles should be modified before considering intervention in work styles.

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.