Biomedical subjects

M Rosvall

Publications and source records attributed to M Rosvall.

11 recordsLinked to original sources

PubMed2006

Area social characteristics and carotid atherosclerosis.

OBJECTIVES: To explore the effect of social characteristics of residential areas on carotid atherosclerosis prevalence. METHODS AND RESULTS: The associations among area social characteristics and B-mode ultrasound determined carotid plaque-score (a semi-quantitative scale measuring the degree of atherosclerosis in the carotid bifurcation area) were cross-sectionally investigated in a general population sample of 4033 men and women. Area socioeconomic circumstances were described through a social deprivation index calculated from migration rate, percentage residents with foreign citizenship among those with foreign background, dependency on social welfare support, and employment rate. Living in socially deprived areas was associated with an increased carotid plaque-score in both men (P for trend = 0.004) and women (P for trend = 0.007). These associations were only slightly reduced after adjustment for individual level indicators with a decrease of the absolute mean difference in carotid plaque-score between worse-off and better-off areas of 9% for men and 13% for women, whereas adjustment for risk factors turned the trend non-significant in women, however, not in men. CONCLUSIONS: Those living in socially deprived areas in general had more extensive carotid atherosclerosis. However, in these areas there were a substantial number of individuals with low degrees of carotid atherosclerosis and vice versa. Thus, with regard to conceptual ideas of causal inference, the social characteristics of an area seem to be associated with the prevalence of carotid atherosclerosis. However, with regard to benefits of prevention, focusing on geographical areas would probably give a restricted benefit, where only some high-risk individuals would be reached.

Aged↗

PubMed2006

The role of low grade inflammation as measured by C-reactive protein levels in the explanation of socioeconomic differences in carotid atherosclerosis.

BACKGROUND: The role of inflammation as part of the explanation of socioeconomic differences in carotid atherosclerosis has not been specifically investigated. METHODS AND RESULTS: The associations between socioeconomic position (SEP), C-reactive protein (CRP), and preclinical carotid atherosclerosis were investigated in a general population sample of 3921 middle-aged Swedish men and women. Common carotid intima-media thickness (IMT) and presence of carotid plaque (focal IMT > 1.2 mm) were determined by B-mode ultrasound. The results showed that low SEP was associated with increased levels of CRP, independently of established risk factors. Furthermore, common carotid IMT increased with increasing CRP-levels. Presence of carotid plaque increased with increasing CRP-levels in men, but not in women. While the socioeconomic differences in carotid IMT were weak, there were associations between low educational level and carotid plaque prevalence with an age- and sex-adjusted odds ratio (OR) of 1.39 (95% CI: 1.21, 1.59). A similar association was seen for having a manual occupation, OR = 1.23 (95% CI: 1.07, 1.42). The age- and sex-adjusted absolute differences in carotid plaque prevalence were 9% with regard to educational level and 7% with regard to occupational status. Adjustment for CRP caused only a minor attenuation of the association between SEP and carotid atherosclerosis. CONCLUSIONS: The association between SEP and carotid atherosclerosis as measured by carotid IMT and carotid plaque could only to a minor extent be referred to differences in low grade inflammation as measured by CRP.

C-Reactive Protein↗

PubMed2006

Modeling self-organization of communication and topology in social networks.

This paper introduces a model of self-organization between communication and topology in social networks, with a feedback between different communication habits and the topology. To study this feedback, we let agents communicate to build a perception of a network and use this information to create strategic links. We observe a narrow distribution of links when the communication is low and a system with a broad distribution of links when the communication is high. We also analyze the outcome of chatting, cheating, and lying, as strategies to get better access to information in the network. Chatting, although only adopted by a few agents, gives a global gain in the system. Contrary, a global loss is inevitable in a system with too many liars.

Journal Article↗

PubMed2005

Searchability of networks.

We investigate the searchability of complex systems in terms of their interconnectedness. Associating searchability with the number and size of branch points along the paths between the nodes, we find that scale-free networks are relatively difficult to search, and thus that the abundance of scale-free networks in nature and society may reflect an attempt to protect local areas in a highly interconnected network from nonrelated communication. In fact, starting from a random node, real-world networks with higher order organization like modular or hierarchical structure are even more difficult to navigate than random scale-free networks. The searchability at the node level opens the possibility for a generalized hierarchy measure that captures both the hierarchy in the usual terms of trees as in military structures, and the intrinsic hierarchical nature of topological hierarchies for scale-free networks as in the Internet.

Journal Article↗

PubMed2005

Communication boundaries in networks.

We investigate and quantify the interplay between topology and the ability to send specific signals in complex networks. We find that in a majority of investigated real-world networks the ability to communicate is favored by the network topology at small distances, but disfavored at larger distances. We further suggest how the ability to locate specific nodes can be improved if information associated with the overall traffic in the network is available.

Information Storage and Retrieval↗

PubMed2005

Navigating networks with limited information.

We study navigation with limited information in networks and demonstrate that many real-world networks have a structure which can be described as favoring communication at short distance at the cost of constraining communication at long distance. This feature, which is robust and more evident with limited than with complete information, reflects both topological and possibly functional design characteristics. For example, the characteristics of the networks studied derived from a city and from the Internet are manifested through modular network designs. We also observe that directed navigation in typical networks requires remarkably little information on the level of individual nodes. By studying navigation or specific signaling, we take a complementary approach to the common studies of information transfer devoted to broadcasting of information in studies of virus spreading and the like.

Journal Article↗

PubMed2005

Networks and cities: an information perspective.

Traffic is constrained by the information involved in locating the receiver and the physical distance between sender and receiver. We here focus on the former, and investigate traffic in the perspective of information handling. We replot the road map of cities in terms of the information needed to locate specific addresses and create information city networks with roads mapped to nodes and intersections to links between nodes. These networks have the broad degree distribution found in many other complex networks. The mapping to an information city network makes it possible to quantify the information associated with locating specific addresses.

Journal Article↗

PubMed2005

Incident coronary events and case fatality in relation to common carotid intima-media thickness.

OBJECTIVES: To evaluate the incidence of coronary events (CE) and case fatality in relation to common carotid intima-media thickness (IMT) and carotid plaque over a median follow up of 7 years. SUBJECTS: A total of 5163 Swedish middle-aged men and women with no prior myocardial infarction and/or stroke. METHODS AND RESULTS: The associations amongst B-mode ultrasound determined common carotid IMT, carotid plaque (focal IMT > 1.2 mm) and carotid stenosis (lumen reduction of >15%) and incident CE, were investigated in relation to cardiovascular risk factor levels. Age- and sex-adjusted common carotid IMT, carotid plaque and carotid stenosis were significantly (P < 0.05) related to future CE. Adjustment for established risk factors generally reduced the hazard rate ratios. However, the continuous measure of common carotid IMT, carotid plaque and carotid stenosis were significantly related to incident CE, even after risk factor adjustment. The strength of the associations between common carotid IMT and CE was only to a small extent reduced after adjustment for presence of carotid plaque. There were no statistically significant associations between common carotid IMT, carotid plaque or carotid stenosis and short-term case-fatality rates (28-days mortality) or long-term case-fatality rates (5-years mortality). CONCLUSIONS: The results show an association between common carotid IMT and incident CE, independently of cardiovascular risk factors and carotid plaque. However, there was no association with short-term or long-term mortality after a CE.

Carotid Artery, Common↗

PubMed2004

Incidence of stroke is related to carotid IMT even in the absence of plaque.

BACKGROUND: The carotid intima-media thickness (IMT) has been associated with incidence of stroke. Whether this association is independent of carotid plaque is controversial. METHODS AND RESULTS: The associations among B-mode ultrasound determined common carotid IMT, carotid plaque (focal IMT>1.2mm) and incident stroke, were investigated in 5163 Swedish middle-aged men and women over a median follow-up of 7 years. Age and sex-adjusted carotid IMT, and carotid plaque were significantly (p<0.05) related to future stroke. Adjustment for cardiovascular risk factors generally reduced the hazard rate ratios, however more prominently so with regard to the carotid measure of plaque than with IMT. The associations between carotid IMT and stroke remained after adjustment for presence of carotid plaque, and graded associations between carotid IMT and stroke was found both among those with and without carotid plaque. CONCLUSIONS: In this population-based study, common carotid IMT was associated with incidence of stroke. This relation was independent of presence of carotid plaque.

Arteriosclerosis↗

PubMed2002

Work-related psychosocial factors and carotid atherosclerosis.

BACKGROUND: In order to better understand the role of work environment in the earlier stages of the cardiovascular disease process, we wanted to investigate the influence of work-related psychosocial factors on preclinical atherosclerosis. METHODS: Cross-sectional data was used to examine the association between psychological job demands, job decision latitude, and carotid atherosclerosis in 2658 vocationally-active Swedish men and women, ages 46-65, from the general population. Odds ratios of carotid plaque prevalence and carotid artery intima-media thickness (IMT), determined by B-mode ultrasound, were estimated across combinations of job demands and decision latitude. RESULTS: Women in job situations with high demands and low decision latitude ('job strain') showed a high plaque prevalence odds (odds ratio [OR] = 1.68, 95% CI: 1.14, 2.48), and a thicker IMT in the carotid bifurcation area (mean difference: 0.15 mm, 95% CI: 0.07, 0.23) compared with women in job situations with low demands and high decision latitude ('relaxed'). Adjustment for covariates only slightly reduced the magnitude of these associations. No such associations were seen in men. However, women in job situations with high demands and high decision latitude ('active') also showed high odds for carotid plaque, and a thicker IMT in the carotid bifurcation, compared with women in 'relaxed' job situations. In men, those in 'active' job situations had a low carotid plaque prevalence odds, while IMT in the carotid bifurcation did not differ from those in 'relaxed' job situations. Results showed only weak associations with IMT in the common carotid artery (CCA) in both men and women. CONCLUSION: The specific hypothesis that high job demands interact synergistically with low decision latitude in the development of carotid atherosclerosis could not be supported in this study, neither in men nor in women. Instead a more complex pattern of interaction between job demands and decision latitude was shown.

Aged↗

PubMed2000

Occupational status, educational level, and the prevalence of carotid atherosclerosis in a general population sample of middle-aged Swedish men and women: results from the Malmö Diet and Cancer Study.

The associations among educational level, occupational status, and atherosclerosis were investigated during 1992-1994 in a general population sample of 4,176 Swedish men and women. Carotid artery intima-media thickness (IMT) and carotid stenosis were determined by B-mode ultrasound. Socioeconomic differences in mean carotid IMT and odds ratios for carotid stenosis prevalence were estimated. In women, the associations among educational level, occupational status, and IMT were weak. In men, there was no association between education and IMT, while low occupational status was associated with a thicker IMT. Women with low education had an increased odds of carotid stenosis compared with women with high education (odds ratio (OR) = 2.04, 95% confidence interval (CI): 1.53, 2.73), while this pattern was weaker among men. Women in manual occupations had an increased odds of carotid stenosis compared with women in high- or medium-level nonmanual occupations (OR = 1.75, 95% CI: 1.29, 2.36), which could not be seen among men. After adjustment for risk factors, the association between IMT and occupational status in men disappeared, while the associations among educational level, occupational status, and carotid stenosis in women persisted. The results imply that the atherosclerotic process is associated with socioeconomic status in both sexes, and they also indicate the possibility of sex differences in the mechanisms connecting socioeconomic status to atherosclerosis.

Aged↗