Distributions of C-Reactive Protein and its Association With Metabolic Syndrome in Middle-Aged and Older Chinese People

OBJECTIVES

We evaluated the distributions of C-reactive protein (CRP) and its association with metabolic syndrome (MetS) in middle-aged and older Chinese people.

BACKGROUND

Several studies have suggested that CRP is a risk factor of MetS. However, it remains unclear how CRP levels are distributed and whether they are associated with MetS in Chinese people.

METHODS

We conducted a population-based cross-sectional survey in 2005 in Beijing and Shanghai, with a total of 1,458 men and 1,831 women age 50 to 70 years. Metabolic syndrome was defined according to the updated National Cholesterol Education Program Adult Treatment Panel III criteria for Asian Americans.

RESULTS

The median CRP level was 0.68 mg/l among the study population. The CRP levels were significantly higher among participants from Beijing or from urban areas than those in participants from Shanghai or from rural areas (p < 0.01). No gender difference in CRP levels was observed. The prevalence of MetS progressively increased with elevated CRP levels (p < 0.0001 for trend). In the highest quartile of CRP levels (>1.50 mg/l), the risk for MetS was substantially higher (odds ratio 5.97; 95% confidence interval 4.75 to 7.51) compared with that in the lowest quartile of CRP levels (< or =0.33 mg/l) after adjustment for age, gender, geographic location, lifestyle factors, educational attainment, and family history of chronic diseases. This association was observed in both obese and nonobese participants.

CONCLUSIONS

The overall plasma level of CRP is low but highly associated with the MetS among the middle-aged and elderly Chinese population. Prospective studies are needed to investigate the role of CRP in the development of MetS and related chronic diseases among Chinese people.

Stroke in China: epidemiology, prevention, and management strategies

In this review, we examine the current status of stroke epidemiology, prevention, and management strategies in mainland China. The main findings suggested that total age-adjusted incidence of first-ever stroke in China is not very different from that in developed countries. Stroke incidence, mortality, and prevalence varied widely among different regions within China, with a noticeable north-south gradient. The proportion of intracerebral haemorrhage was high and reached 55% in one city. Hypertension is the most important risk factor for stroke. The mass approach combined with a high-risk approach for stroke prevention showed encouraging effects, and various unconventional local therapeutic traditions are commonly used to treat stroke in China. Several national guidelines on stroke prevention and treatment have been developed. Because of methodological limitations in the epidemiology studies, data are unreliable in terms of making any firm conclusions. Up-to-date, well-designed, and well-done epidemiological studies and therapeutic trials in China are urgently needed.

Different definitions of the metabolic syndrome and risk of first-ever acute ischaemic non-embolic stroke in elderly subjects

To investigate which of the three recently proposed definitions of the metabolic syndrome (MetS) is related to the excessive risk of ischaemic non-embolic stroke in elderly individuals, and thus may be more appropriate to implement in clinical practice. In a population-based case-control study of subjects aged older than 70 years (163 patients vs. 166 controls), we evaluated the association of first-ever acute ischaemic non-embolic stroke with the MetS defined by using recent definitions as proposed by the National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III), the International Diabetes Federation (IDF) and the National Heart, Lung and Blood Institute/American Heart Association (NHLBI/AHA). By applying the NCEP ATP III, NHLBI/AHA and IDF definitions, the prevalence of MetS in the patient group was 46%, 57.1% and 69.9%, respectively, compared with 15.7%, 18.1% and 30.7% in the control group (p < 0.001 for all comparisons). After adjusting for multiple risk factors, the odds ratio (OR) for ischaemic stroke was 2.59 [95% confidence interval (CI): 1.24-5.42, p = 0.012] for NCEP ATP III-defined MetS and 3.18 (95% CI: 1.58-6.39, p = 0.001) for NHLBI/AHA-defined MetS. However, the association of IDF-defined MetS with ischaemic stroke was not significant (OR 1.18, 95% CI: 0.50-2.78, p = 0.71). The implementation of the IDF (unlike NCEP ATP III and NHLBI/AHA) MetS definition substantially increases the number of elderly subjects labelled as having MetS without contributing to the identification of those at high risk of stroke.

Metabolic syndrome, or What you will: definitions and epidemiology

The metabolic syndrome is a clustering of risk factors which predispose an individual to cardiovascular morbidity and mortality. There is general consensus regarding the main components of the syndrome (glucose intolerance, obesity, raised blood pressure and dyslipidaemia [elevated triglycerides, low levels of high-density lipoprotein cholesterol]) but different definitions require different cut points and have different mandatory inclusion criteria. Although insulin resistance is considered a major pathological influence, only the World Health Organization (WHO) and European Group for the study of Insulin Resistance (EGIR) definitions include it amongst the diagnostic criteria and only the International Diabetes Federation (IDF) definition has waist circumference as a mandatory component. The prevalence of metabolic syndrome within individual cohorts varies with the definition used. Within each definition, the prevalence of metabolic syndrome increases with age and varies with gender and ethnicity. There is a lack of diagnostic concordance between different definitions. Only about 30% of people could be given the diagnosis of metabolic syndrome using most definitions, and about 3540% of people diagnosed with metabolic syndrome are only classified as such using one definition. There is currently debate regarding the validity of the term metabolic syndrome, but the presence of one cardiovascular risk factor should raise suspicion that additional risk factors may also be present and encourage investigation. Individual risk factors should be treated.

The Metabolic Syndrome and the Carotid Artery Structure in Noninstitutionalized Elderly Subjects

Background and Purpose— In contrast to the young adult population, limited data are presently available regarding the epidemiology of the metabolic syndrome (MetS) and its relationship with cardiovascular disease risk in the elderly. We have investigated the frequency of the MetS and its association with the carotid artery structure in an elderly free-living population.

Methods— The study population consists of 5585 French noninstitutionalized elderly men and women aged 65 to 85 years, free of diabetes, who participated in the multicenter Three City Study and who underwent ultrasound examination of the carotid arteries at baseline examination between March 1999 and March 2001. The MetS was defined according to the National Cholesterol Education Program Adult Treatment Panel III criteria.

Results— The MetS was present in 12.1% of the study participants, with slightly higher rates in men. Subjects with the MetS had higher frequency of carotid plaques (odds ratio, 1.30; 95% CI, 1.09 to 1.55), higher intima-media thickness of the common carotid artery (odds ratio, 1.81; 95% CI, 1.37 to 2.41), and higher lumen diameter (odds ratio, 2.17; 95% CI, 1.61 to 2.94) (upper quintiles) after adjustment for other cardiovascular risk factors. This association was observed in both genders and in subjects without prevalent cardiovascular disease. Elevated blood pressure as defined in the MetS was the main determinant of the relations between the MetS and the carotid parameters, especially the lumen diameter.

Conclusions— The present data suggest that noninstitutionalized elderly subjects with the MetS have altered structure of the carotid arteries.

Prevalence, agreement and classification of various metabolic syndrome criteria among ethnic Chinese: a report on the hospital-based health diagnosis of the adult population

OBJECTIVES

Many criteria of metabolic syndrome have been made available to practitioners in the recent past. This study has been designed to investigate the distribution, agreement and classification patterns of these criteria among the ethnic Chinese population.

METHODS

A total of 6610 (women, 42.5%) adults (mean, 52.3 years) were recruited from the hospital-based health diagnosis program during 2004. We divided criteria of metabolic syndrome into two groups: those with a major component required (WHO, EGIR, AACE, IDF) and those with equal component (ATP III, AHA, with modifications).

RESULTS

The highest standardized rates were in Asian AHA criterion, up to 29.8% in men and 25.6% in women. The lowest rates were in WHO criterion, 8.8% in men and 8.0% in women. The kappa values using all criteria were 0.59 in men and 0.65 in women and decreased in the major component group (0.50 in men, 0.54 in women), while increased in the equal component group (0.83 in men, 0.81 in women). Using hierarchical cluster analysis and dendrograms, two large clusters were identified in men (major components and equal components); however, mixed sub-clusters of major and equal components apparently grouped by insulin resistance and obesity criteria in women.

CONCLUSIONS

There is substantial agreement and grouping of metabolic syndrome models among ethnic Chinese.

A prospective community-based study of stroke in Kolkata, India

BACKGROUND AND PURPOSE

Information on essential stroke parameters are lacking in India. This population-based study on stroke disorder was undertaken in the city of Kolkata, India, to determine the subtypes, prevalence, incidence, and case fatality rates of stroke.

METHODS

This was a longitudinal descriptive study comprising 2-stage door-to-door survey of a stratified randomly selected sample of the city population, conducted twice per year for 2 successive years from March 2003 to February 2005.

RESULTS

Out of the screened population of 52,377 (27 626 men, 24 751 women), the age standardized prevalence rate of stroke to world standard population is 545.10 (95% CI, 479.86 to 617.05) per 100,000 persons. The age standardized average annual incidence rate to world standard population of first-ever-in-a-lifetime stroke is 145.30 (95% CI, 120.39 to 174.74) per 100,000 persons per year. Thirty-day case fatality rate is 41.08% (95% CI, 30.66 to 53.80). Women have higher incidence and case fatality rates. Despite divergence on socioeconomic status between the slum and nonslum dwellers, stroke parameters were not significantly different.

CONCLUSIONS

The age standardized prevalence and incidence rates of stroke in this study are similar to or higher than many Western nations. The overall case fatality rate is among the highest category of stroke fatality in the world. The women have higher incidence and case fatality rates compared with men.

The effect of socioeconomic status on three-year mortality after first-ever ischemic stroke in Nanjing, China

Background

Low socioeconomic status (SES) is associated with increased mortality after stroke in developed countries. This study was performed to determine whether a similar association also exists in China.

Methods

A total of 806 patients with first-ever ischemic stroke were enrolled in our study. From August 1999 to August 2005, the three-year all-cause mortality following the stroke was determined. Level of education, occupation, taxable income and housing space were used as indicators for SES. Stepwise univariate and multivariate COX proportional hazards models were used to study the association between the SES measures and the three-year mortality.

Results

Our analyses confirmed that occupation, taxable income and housing space were significantly associated with three-year mortality after first-ever stroke. Manual workers had a significant hazard ratio of 5.44 (95% CI 2.75 to 10.77) for death within three years when compared with non-manual workers. Those in the zero income group had a significant hazard ratio of 5.35 (95% CI 2.95 to 9.70) and those in the intermediate income group 2.10 (95% CI 1.24 to 3.58) when compared with those in the highest income group. Those in two of the three groups with the smallest housing space also had significant hazard ratios of 2.06 (95% CI 1.16 to 3.65) and 1.68 (95% CI 1.12 to 2.52) when compared with those in group with the largest housing space. These hazard ratios remained largely unchanged after multivariate adjustment for age, gender, baseline cardiovascular disease risk factors, and stroke severity. The analyses did not confirm an association with educational level.

Conclusion

Lower SES has a negative impact on the outcome of first-ever stroke in Nanjing, China. This confirms the need to improve preventive and secondary care for stroke among low SES groups.

Development of complex interventions in stroke care: a systematic review

BACKGROUND AND PURPOSE

Stroke care is complex, requiring input from professionals, patients and carers. Identifying and developing appropriate intervention components to meet these complex needs is difficult. The Medical Research Council (MRC) Framework for developing and evaluating 'complex' (nonpharmacological) interventions aims to improve intervention development. This study uses the Framework to review complex interventions in stroke care.

METHODS

Systematic review with multiple search strategies (electronic databases, recent journals, gray literature) was used. The MRC Framework was used to guide the search strategy and assess study quality. 'Complex interventions' were defined as educational/psychosocial interventions to change knowledge, beliefs or behaviors.

RESULTS

Sixty-seven studies were included: 39 randomized controlled trials (RCT) and 28 other designs. Complex interventions targeted healthcare professionals (17), and patients, carers and the general population (21 targeting primary or secondary prevention; 30 targeting adjustment and recovery after stroke). Compared with recovery studies, primary and secondary prevention studies were significantly less likely to have been evaluated in RCTs. Interventions evaluated in RCTs were significantly less likely to influence primary outcomes (26%) compared with other designs (44%). Theoretical grounding to support intervention choice was reported in 40 studies but only 14 were theoretically 'well developed'; 21 RCTs listed multiple primary outcome measures, with 10 listing 5 or more. Of these only 3 reported considering statistical power before recruitment and none was sufficiently powered.

CONCLUSIONS

Few complex interventions in stroke care have been adequately developed or evaluated. This may explain failures to demonstrate efficacy. In future, greater attention is needed to theoretical development and methodological quality.

Proportions of Stroke Subtypes Among Men and Women ≥40 Years of Age in an Urban Japanese City in 1992, 1997, and 2002

Background and Purpose— Higher proportions of hemorrhagic stroke and lacunar infarction were reported in rural Japan compared with those in Western countries. We examined the relative proportions of stroke subtypes in an urban Japanese city where westernized lifestyles are more common than in rural areas.

Methods— Stroke registration was performed in 1992, 1997, and 2002 for residents ≥40 years of age who were admitted with acute strokes to all of the 10 hospitals with ≥90 beds in Yao City, Osaka, Japan. Strokes were classified as intraparenchymal hemorrhage, subarachnoid hemorrhage, or ischemic strokes (embolic infarction, large-artery occlusive infarction, lacunar infarction, and unclassified thrombotic infarction) by criteria using computed tomography or MRI.

Results— A total of 650 first-ever strokes were registered. The age-adjusted proportion of each stroke subtype was not significantly different among the 3 study periods in both men and women. Throughout the 3 periods, intraparenchymal hemorrhage, subarachnoid hemorrhage, and ischemic stroke accounted for 26%, 7%, and 65% in men, respectively. In women, the respective proportions were 29%, 21%, and 44%. The proportion of each subtype for total ischemic strokes was as follows: 51% to 61% lacunar infarction, 25% to 26% large-artery occlusive infarction, and 11% to 17% embolic infarction.

Conclusions— Our study showed that hemorrhagic stroke represented a large proportion of all strokes, especially among women, and lacunar infarction was the most common subtype of ischemic stroke among both men and women in Yao City, which differed from findings in Western countries.

Identification of contrastive and comparable school neighborhoods for childhood obesity and physical activity research

The neighborhood social and physical environments are considered significant factors contributing to children's inactive lifestyles, poor eating habits, and high levels of childhood obesity. Understanding of neighborhood environmental profiles is needed to facilitate community-based research and the development and implementation of community prevention and intervention programs. We sought to identify contrastive and comparable districts for childhood obesity and physical activity research studies.

We have applied GIS technology to manipulate multiple data sources to generate objective and quantitative measures of school neighborhood-level characteristics for school-based studies. GIS technology integrated data from multiple sources (land use, traffic, crime, and census tract) and available social and built environment indicators theorized to be associated with childhood obesity and physical activity. We used network analysis and geoprocessing tools within a GIS environment to integrate these data and to generate objective social and physical environment measures for school districts. We applied hierarchical cluster analysis to categorize school district groups according to their neighborhood characteristics. We tested the utility of the area characterizations by using them to select comparable and contrastive schools for two specific studies.

Incidence and trends of stroke and its subtypes in China: results from three large cities

BACKGROUND AND PURPOSE

To examine the incidence and trends of stroke and its major subtypes during the 1990s in 3 cities in China.

METHODS

Stroke cases registered between 1991 to 2000 were initially identified through the stroke surveillance networks established in Beijing, Shanghai, and Changsha, and then confirmed by neurologists.

RESULTS

The age-standardized incidence rates per 100,000 person years of overall first-ever stroke were 135.0 (95% CI, 126.5 to 144.6) in Beijing, 76.1 (70.6 to 82.6) in Shanghai, and 150.0 (141.3 to 160.0) in Changsha during the 1990s. Incidence of ischemic stroke (IS) was highest in Beijing, followed by Changsha and Shanghai; for intracerebral hemorrhage (ICH), the highest rate was found in Changsha, followed by Beijing and Shanghai. The same order as ICH was also observed for subarachnoid hemorrhage. The age-adjusted incidence of overall stroke and ICH for individuals > or =55 years of age in our populations was generally higher than that from Western populations. During the 1990s, ICH incidence decreased significantly at a rate of 12.0% per year in Beijing, 4.4% in Shanghai, and 7.7% in Changsha; in contrast, except for Changsha, IS incidence increased in Beijing (5.0% per year) and Shanghai (7.7%).

CONCLUSIONS

There is a geographic variation in the incidence of stroke and its subtypes among these 3 cities, but the incidence of overall and hemorrhagic stroke in China is generally higher than that in the Western countries. Interestingly, the decrease in ICH and increase in IS during the past decade may reflect some underlying changes of risk factors in Chinese populations.