Physical activity and cardiovascular risk: a cross-sectional study of middle-aged premenopausal women

The relationship between self-reported physical activity and cardiovascular risk factors was evaluated in a population-based sample. The sample included 541 premenopausal women recruited for a study of the natural history of risk factor change associated with change in sex hormone status. Physical activity was assessed using the Paffenbarger Activity Questionnaire. Women were classified according to quartile of weekly energy expenditure into groups of 0-500, 501-999, 1,000-1,999, and 2,000 kcal or greater. Results showed that the more active the women, the lower their blood pressure and heart rate. More active women had lower cholesterol and triglycerides, and higher high-density lipoprotein (HDL) cholesterol. Tricep and suprailiac skinfolds, fasting insulin, and insulin/glucose levels were also lower among the more active women. When the analysis was repeated controlling for the effect of education and body mass index, the statistical test for linear trend remained significant except for the trend for heart rate, total cholesterol, and triglycerides. Women reporting activity of 1,000 kcal/week had higher high-density lipoprotein cholesterol and lower diastolic blood pressure, body mass index, skinfolds, fasting insulin, and fasting insulin/glucose ratios compared with women reporting lower levels of activity. Only those women who reported 2,000 kcal/week had significantly lower total cholesterol, triglycerides, and low-density lipoprotein cholesterol, and higher HDL2 cholesterol; women reporting less activity did not differ with regard to these lipids and lipoproteins. The study suggests that physical activity is associated with improved cardiovascular risk profiles among middle-aged women and that the beneficial effects of activity are seen at different levels for specific risk factors.     

Associations of body mass index and percentage body fat by bioelectrical impedance analysis with cardiovascular risk factors in Japanese male office workers

To determine whether body mass index (BMI, kg/m2) or percentage body fat (%BF) by bioelectrical impedance analysis (BIA) better reflects the cardiovascular risk profile, we examined the associations among BMI, %BF by BIA, and cardiovascular risk factors (systolic blood pressure (SBP), diastolic blood pressure (SBP), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), LDL-C/HDL-C ratio, and triglycerides (TG)) in 1,217 Japanese male office workers aged 25 to 59 years. From stepwise regression analyses of cardiovascular risk factors on age, BMI, alcohol intake, and cigarette smoking, significant correlates were, in the order of relative importance: age, BMI, and alcohol intake for SBP and DBP (the cumulative percentage of variation; 14.9% and 21.3%, respectively); age, BMI, and alcohol intake (negative) for LDL-C (11.0%); BMI (negative), alcohol, and cigarette smoking (negative) for HDL-C (19.9%); BMI, alcohol intake (negative), age, and cigarette smoking for LDL-C/HDL-C ratio (23.1%); and BMI, age, cigarette smoking, and alcohol intake for Log TG (21.7%). From stepwise regression analyses using %BF by BIA as an independent factor, %BF by BIA was also significantly associated with each cardiovascular risk factor, but the decrease in explained variance for each cardiovascular risk factor was 0.2-4.5%, compared with the model using BMI as an independent factor. These results suggest that BMI may better reflect blood pressure or serum lipid profile than %BF by BIA.     

Increases in serum lipid and lipoprotein levels with movement from the supine to standing position in adult men and women

The effect of movement from the supine to the standing position on the magnitude of change in serum lipid and lipoprotein levels and its impact on the prediction of risk for coronary heart disease was investigated in 23 male and 18 female subjects. The mean age and body weight of the men was 34 years and 93 kg, respectively, while those of women were 36 years and 71 kg. Thirty minutes of standing following thirty minutes in the supine position was associated with hemoconcentration and a significant (P less than 0.05) plasma volume reduction of -13.8% for men and women combined. Posture-related increases in serum lipids and lipoproteins were similar among both men and women and averaged +12% for triglycerides, +9.3% for total cholesterol, +9.0% for low-density lipoprotein + very low-density lipoprotein cholesterol, and +10.4% for high-density lipoprotein cholesterol. Among men, the latter increased from 41.4 to 45.6 mg X dl-1 while among women, the increase was from 58.0 to 64.3 mg X dl-1. The total cholesterol/high-density lipoprotein cholesterol ratio was unaffected by the change in body position, thus strengthening the reliability of this ratio as a coronary heart disease risk measure. Our findings indicate that body position at time of blood withdrawal significantly influences lipid and lipoprotein levels, and, depending on the absolute concentration values of total or high-density lipoprotein cholesterol, can alter the predictive risk for coronary heart disease. Heart disease. Heart disease risk based on the Framingham probability tables and the multiplier for high-density lipoprotein cholesterol is unaffected by the change in body position.     

Cardiovascular risk factors in young,overweight, and obese European adults and associations with physical activity and omega-3 index

Excess body fat is associated with increased cardiovascular disease (CVD) risk. The hypothesis of the study was that physical activity and omega-3 index, a marker of past long chain n-3 polyunsaturated fatty acids consumption, counteract the negative associations between fatness and CVD risk factors in young overweight and obese adults. A total of 324 subjects (20-40 years, body mass index [BMI], 27.5-32.5 kg/m², from Iceland, Spain, and Ireland) were investigated cross-sectionally. Dietary intake, anthropometric measurements, blood pressure, CVD risk factors, and fatty acids in erythrocyte membrane were analyzed. Information on physical activity was collected. Linear models were constructed to find out the associations of BMI, physical activity (quartiles), and omega-3 index with CVD risk factors. The most frequently increased risk factors were blood lipids (41.4%) and blood pressure (32.1%); fewer participants experienced disturbed glucose metabolism (11.8%). Body mass index was significantly associated with increased CVD risk factors (P = .001-.029), with the exception of total cholesterol, low-density lipoprotein, and high-density lipoprotein. The highest physical activity quartile had a lower fat mass (P = .005, at a given BMI), leptin (P = .008, in male participants only), and interleukin 6 (P = .021) but higher high-density lipoprotein (P = .020) than other quartiles; however, an approximate dose-response relationship could only be observed for leptin. The omega-3 index was not associated with lower low-density lipoprotein (P = .056), but docosahexaenoic acid in erythrocyte membrane was associated to it (P = .016). It is concluded that physical activity and docosahexaenoic acid diminish some of the negative health effects associated with overweight and obesity; however, body fatness remains the most important variable associated with increased CVD risk factors in young overweight and obese adults.     

Changes in frequency of premature complexes and heart rate variability related to shift work

OBJECTIVES—To investigate whether an increased risk of cardiovascular disease might be caused by increased arrhythmogeneity and by unfavourable changes in autonomic cardiac control the changes in the occurrence of premature complexes (PVCs) and in heart rate variability (HRV) were studied in subjects who started to work in shifts.
METHODS—1 Year changes in frequency of PVCs and HRV were measured in 49 shift workers and 22 control subjects working in daytime. All respondents were starting in a new job in integrated circuit or waste incinerator plants.
RESULTS—The incidence of PVC increased significantly in shift workers over the 1 year follow up, compared with daytime workers. The frequency of ventricular extrasystoles increased in 48.9% of the shift workers, and in 27.3% of the daytime workers. The Spearman correlation coefficient between the number of nights worked and the change in PVCs was 0.33 (p=0.004). A small non-significant unfavourable change in HRV was found in both the shift and daytime workers.
CONCLUSIONS—A change in arrhythmogeneity, but not in cardiac autonomic control, might explain the increased risk of cardiovascular disease in shift workers.


Keywords: arrhythmia; heart rate; shift work     

Effect of a moderately hypoenergetic Mediterranean diet and exercise program on body cell mass and cardiovascular risk factors in obese women

OBJECTIVE: To assess the effects of a moderately hypoenergetic Mediterranean diet (MHMD) and exercise program on body cell mass (BCM) and cardiovascular disease risk factors in obese women. SUBJECTS/METHODS: Forty-seven obese women, 39.7+/-13.2 years of age, with a body mass index (BMI)=30.7+/-6.0 kg/m(2), completed the study. The following were measured at baseline, 2 and 4 months: BCM, BCM index (BCMI), body weight, BMI, fat-free mass (FFM), fat mass (FM), total body water (TBW), extracellular water (ECW) and intracellular water (ICW) using bioelectrical impedance analysis; fasting blood glucose (FBG), serum total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triglyceride (TG) concentrations; systolic (SBP) and diastolic (DBP) blood pressure. RESULTS: Body weight, BMI, FM, TC and TG significantly decreased (P<0.001; P<0.002 (TG)) at 2 and 4 months. FFM, TBW, ECW, FBG and DBP significantly decreased at 2 months (P<0.05 (FFM); P<0.001). LDL-C significantly decreased (P<0.001), while HDL-C significantly increased (P<0.002) at 4 months. BCM, BCMI, ICW and SBP remained stable over time. CONCLUSION: BCM was preserved and cardiovascular disease risk factors improved in obese women placed on a MHMD and exercise program for 4 months.     

Effect of Berberine on Cardiovascular Disease Risk Factors: A Mechanistic Randomized Controlled Trial

Cardiovascular disease (CVD) is a major contributor to the global burden of disease. Berberine, a long-standing, widely used, traditional Chinese medicine, is thought to have beneficial effects on CVD risk factors and in women with polycystic ovary syndrome. The mechanisms and effects, specifically in men, possibly via testosterone, have not been examined previously. To assess the effect of berberine on CVD risk factors and any potential pathway via testosterone in men, we conducted a randomized, double-blind, placebo-controlled, parallel trial in Hong Kong. In total, 84 eligible Chinese men with hyperlipidemia were randomized to berberine (500 mg orally, twice a day) or placebo for 12 weeks. CVD risk factors (lipids, thromboxane A2, blood pressure, body mass index and waist–hip ratio) and testosterone were assessed at baseline, and 8 and 12 weeks after intervention. We compared changes in CVD risk factors and testosterone after 12 weeks of intervention using analysis of variance, and after 8 and 12 weeks using generalized estimating equations (GEE). Of the 84 men randomized, 80 men completed the trial. Men randomized to berberine had larger reductions in total cholesterol (−0.39 mmol/L, 95% confidence interval (CI) −0.70 to −0.08) and high-density lipoprotein cholesterol (−0.07 mmol/L, 95% CI −0.13 to −0.01) after 12 weeks. Considering changes after 8 and 12 weeks together, berberine lowered total cholesterol and possibly low-density lipoprotein-cholesterol (LDL-c), and possibly increased testosterone. Changes in triglycerides, thromboxane A2, blood pressure, body mass index and waist–hip ratio after the intervention did not differ between the berberine and placebo groups. No serious adverse event was reported. Berberine is a promising treatment for lowering cholesterol. Berberine did not lower testosterone but instead may increase testosterone in men, suggesting sex-specific effects of berberine. Exploring other pathways and assessing sex differences would be worthwhile, with relevance to drug repositioning and healthcare.     

Lifetime overweight status in relation to serial changes in body composition and risk factors for cardiovascular disease: The Fels Longitudinal Study

OBJECTIVE: The aims were to determine if 1) individuals who became and maintained overweight during their entire lifetime differ from those who were never-overweight in terms of annual changes in adiposity and concurrent changes in cardiovascular disease (CVD) risk factors; 2) the changes and their relationships to each other varied between these groups or by sex within the groups; and 3) alcohol usage, smoking habits, and level of physical activity differed between groups. RESEARCH METHODS AND PROCEDURES: Data from 16,315 examinations of 414 individuals were utilized to assess lifetime overweight (body mass index [BMI] > 25 kg/m2) status. A regressive analytic approach was used to determine the average annual changes for each individual over an adult serial interval ranging from 4 to 20 years. RESULTS: Men and women who have become and maintained overweight have higher blood pressure and a poorer lipid/lipoprotein risk profile than those who have never been overweight. There is an accelerated deterioration in the atherogenic profile of overweight men and women as indicated by annual changes in CVD risk factors about double that of their never-overweight counterparts. In women, increased risk is derived from increasing systolic and diastolic blood pressure, whereas in men the increased risk comes not only from increasing diastolic blood pressure but also cholesterol, triglycerides, and low-density lipoprotein cholesterol levels and, to a lesser extent, decreasing high-density lipoprotein cholesterol. DISCUSSION: The reduced physical activity observed in the overweight adults may be related to their accumulation of adipose tissue at a rate about double their never-overweight counterparts, and this may be driving the higher rate of increase of CVD risk factors in the overweight groups.     

Association of glycemic load with cardiovascular disease risk factors: The Women's Health Initiative Observational Study

ObjectiveAssociations between dietary glycemic load (GL) and cardiovascular disease risk factors, including plasma lipoprotein/lipid levels, blood pressure, and glucose metabolism factors, in the Women's Health Initiative Observational Study were examined.MethodsA random sample of 878 Observational Study participants (postmenopausal women 50–79 y of age) with baseline blood measurements (647 white, 104 black, 127 Hispanic) was included. Dietary GL was estimated from baseline food-frequency questionnaires, which assessed dietary intake over the previous 3 mo. At the baseline visit, participants completed demographic and health habit questionnaires, fasting blood samples were collected, anthropometric measurements were completed, and blood pressure was assessed.ResultsIn all participants combined, GL was inversely associated with high-density lipoprotein cholesterol (P for trend = 0.004) and positively associated with log₁₀-transformed triacylglycerols (P = 0.008). Although there were no statistically significant interactions of race/ethnicity with associations between GL and cardiovascular disease risk factors, stratified results were suggestive, showing that GL was positively associated with total cholesterol (P = 0.018) and low-density lipoprotein cholesterol (P = 0.038) in Hispanics. In white subjects, there was a trend of reduced high-density lipoprotein cholesterol with higher GL (P = 0.003), whereas GL was positively associated with log₁₀-transformed triacylglycerols (P = 0.015). Associations between GL and high-density lipoprotein cholesterol and between GL and triacylglycerols also differed by body mass index, although the interactions were not statistically significant.ConclusionAmong these generally healthy postmenopausal women, GL was associated with high-density lipoprotein cholesterol and triacylglycerols. Suggestive effects of race/ethnicity and body mass index on these associations need to be confirmed in larger studies.     

Impact of multiple cardiovascular risk factors on the carotid intima-media thickness in young adults: the Kangwha Study.

OBJECTIVES: Although risk factors for coronary artery disease are also associated with increased carotid intima-media thickness (IMT), there is little information available on the asymptomatic, young adult population. We examined the association between multiple cardiovascular risk factors and the common carotid IMT in 280 young Korean adults. METHODS: The data used for this study was obtained from 280 subjects (130 men and 150 women) aged 25 years who participated in the Kangwha Study follow-up examination in 2005. We measured cardiovascular risk factors, including anthropometrics, blood pressure, blood chemistry, carotid ultrasonography, and reviewed questionnaires on health behaviors. Risk factors were defined as values above the sex-specific 75th percentile of systolic blood pressure, body mass index, total cholesterol/high-density lipoprotein cholesterol ratio, fasting blood glucose and smoking status. RESULTS: The mean carotid IMT +/- standard deviation observed was 0.683 +/- 0.079 mm in men and 0.678 +/- 0.067 mm in women (p=0.567) and the evidence of plaque was not observed in any individuals. Mean carotid IMT increased with an increasing number of risk factors(p for trend <0.001) and carotid IMT values were 0.665 mm, 0.674 mm, 0.686 mm, 0.702 mm, and 0.748 mm for 0, 1, 2, 3, and 4 to 5 risk factors, respectively. The odds ratio for having the top quartile carotid IMT in men with 3 or more risk factors versus 0-2 risk factors was 5.09 (95% CI, 2.05-12.64). CONCLUSIONS: Current findings indicate the need for prevention and control of cardiovascular risk factors in young adults and more focus on those with multiple cardiovascular risk factors.     

中老年人血清瘦素与脂联素水平及其相关危险因素研究

目的 探讨相对健康的中老年人血清瘦素与脂联素水平与心脑血管疾病危险因素的相关性.方法 从"广州生物库队列研究"中收集1515名相对健康的50岁及以上的中老年人个人资料及病史、体格检查并测定血清空腹血糖、血脂、瘦素和脂联素的水平.结果 (1)广州市1515名的血清瘦素水平(x-±s)男女性分别为(3.90±2.36)ng/ml和(12.17±2.01)ng/ml;脂联素水平男女性分别为(5.33±2.78)mg/L和(7.18±2.58)mg/L.(2)男女性血清瘦素和脂联素水平均随年龄增长而升高;在调整BMI后,男性瘦素水平仍随年龄增长而显著升高(趋势检验P＜0.001),而女性其脂联素水平也随年龄增长而显著升高(趋势检验P＜0.05).(3)在调整年龄后,男女性血清瘦素和脂联素水平均与吸烟状态无明显相关(P=0.09～0.76).(4)血清瘦素水平,男女性均随腰围、BMI、SBP、LDL-C和TG增加而显著升高(P=0.04,＜0.001),同时还随男性的DBP和空腹血糖升高及HDL-C降低而显著升高(P=0.03～0.02).(5)血清脂联素水平男女性均随腹围以及TG升高而下降(P=0.003,＜0.001),而男性血清脂联素水平还随BMI与空腹血糖升高及HDL-C水平下降而下降(P=0.05,＜0.001),女性则随SBP和TC上升而下降(P=0.05～0.006).结论 广州市相对健康的中老年人血清瘦素和脂联索水平男性比女性低;男性瘦素水平和女性脂联素水平同年龄增加呈显著相关.血清瘦素升高和脂联素下降与传统心脑血管危险因素上升有关.     

Association of Suboptimal Health Status and Cardiovascular Risk Factors in Urban Chinese Workers

Suboptimal health status (SHS) has become a new public health challenge in urban China. Despite indications that SHS may be associated with progression or development of chronic diseases such as cardiovascular and metabolic diseases, there are few reports on SHS investigations. To explore the relationship between SHS and traditional cardiovascular risk factors, a cross-sectional study was conducted in a sample of 4,881 workers employed in 21 companies in urban Beijing. Blood pressure, glucose, lipid levels (total cholesterol, high-density lipoprotein [HDL] cholesterol, low-density lipoprotein [LDL] cholesterol and triglycerides), cortisol, and body mass index were measured. SHS score was derived from data collection in the SHS questionnaire (SHSQ-25). Univariate analysis and linear two-level model were used to analyze the association of SHS with the cardiovascular risk factors. Serum cortisol level was much higher among the SHS high-score group than that among the low SHS score group (204.31 versus 161.33 ng/ml, P < 0.001). In a linear two-level model, we found correlation between SHS and systolic blood pressure, diastolic blood pressure, plasma glucose, total cholesterol, and HDL cholesterol among men, and correlation between SHS and systolic blood pressure, diastolic blood pressure, total cholesterol, triglyceride, and HDL cholesterol among women after controlling for age, education background, occupation, smoking, and physical activity. SHS is associated with cardiovascular risk factors and contributes to the development of cardiovascular disease. SHS should be recognized in the health care system, especially in primary care.     

Mother-daughter correlations of obesity and cardiovascular disease risk factors in black and white households: the NHLBI Growth and Health Study.

OBJECTIVES. This study sought to evaluate obesity as a potential explanatory factor for the increased relative risk for cardiovascular disease in Black compared with White women. METHODS. Familial associations for obesity and cardiovascular disease risk factors were assessed in 720 White and 580 Black mother-daughter pairs from the National Heart, Lung, and Blood Institute's Growth and Health Study by using Pearson's chi square, Spearman's correlations, and partial correlations. RESULTS. Black girls and mothers were significantly heavier and had higher body mass indices than their White counterparts. In each racial group, significant, positive mother-daughter correlations existed for weight, body mass index, and triceps skinfolds, and for all cardiovascular disease risk factors. Obesity measures correlated positively with systolic blood pressure and triglycerides and inversely with high-density lipoprotein cholesterol in girls and mothers of both races. Correlations between mothers and daughters for exercise and ideal body shape were weak and did not explain obesity associations. CONCLUSIONS. Intrafamilial associations of obesity, cardiovascular disease risk factors, and the obesity-cardiovascular disease risk factor relationship support the position that increased cardiovascular disease morbidity and mortality rates in Black women may be linked to excess obesity in Black women compared with White ones.     

In a prospective study in young people, associations between changes in smoking behavior and risk factors for cardiovascular disease were complex

OBJECTIVE: This study investigates how voluntary changes in tobacco consumption are related to changes in biological risk factors for cardiovascular disease in 21- to 36-year-old men and women. STUDY DESIGN AND SETTING: Data of the Amsterdam Growth and Health Longitudinal Study (AGAHLS) were used to study the association between voluntary changes in tobacco consumption and changes in biological risk factors for cardiovascular disease (CVD) during 4-6 years of follow-up in 165 men and 195 women aged 21-36 years. We used multiple linear regression analyses with corrections for age and changes in other lifestyles. RESULTS: In both sexes, we found trends for a reduction in blood pressure, high-density lipoprotein cholesterol (HDL-C), body weight, and waist-to-hip ratio (WHR) and a rise in the ratio between total serum cholesterol (TC) and HDL-C (TC/HDL-C) with increasing tobacco consumption. Opposite trends were found with reducing tobacco consumption. In women, body weight, WHR, and waist circumference reduced significantly and independently with increasing tobacco consumption and increased significantly with decreasing tobacco consumption. CONCLUSION: These results suggest that voluntary changes in tobacco consumption go together with both healthy and unhealthy changes in biological risk factors for CVD.     

Relationship between blood mercury concentration and waist-to-hip ratio in elderly Korean individuals living in coastal areas

Objectives

This study investigated the relationship between the blood mercury concentration and cardiovascular risk factors in elderly Korean individuals living in coastal areas.

Methods

The sample consisted of 477 adults (164 males, 313 females) aged 40 to 65 years who visited a Busan health promotion center from June to September in 2009. The relationship between blood mercury concentration and cardiovascular risk factors including metabolic syndrome, cholesterol profiles, blood pressure, body mass index (BMI), waist circumference and waist-to-hip ratio (WHR), was investigated. Variables related to blood mercury concentration were further evaluated using multiple regression analysis.

Results

The blood mercury concentration of the study population was 7.99 (range, 7.60 to 8.40) µg/L. In males, the blood mercury concentration was 9.74 (8.92 to 10.63) µg/L, which was significantly higher than that in females (7.21, [6.80 to 7.64] µg/L). The blood mercury concentration of the study population was related to several cardiovascular risk factors including low-density lipoprotein (LDL) cholesterol (p=0.044), high-density lipoprotein (HDL) cholesterol (p=0.034), BMI (p = 0.006), waist circumference (p = 0.031), and WHR (p < 0.001). In males, the blood mercury concentration was significantly correlated with WHR in the multiple regression analysis.

Conclusions

In males, the blood mercury concentration was related to waist-to-hip ratio, which is a central obesity index and cardiovascular risk factor. Our finding suggests that cardiovascular disease risk in males was increased by mercury exposure via an obesity-related mechanism.     

健康体检1084例踝臂指数与心血管危险因素关系的分析

目的了解踝臂指数（ABI）与心血管疾病各相关因素之间的关系。方法对1084例门诊体检人群,检测空腹血糖、血清总胆固醇、三酰甘油、低密度脂蛋白胆固醇、高密度脂蛋白胆固醇、体重指数、收缩压、舒张压,并计算不同性别、不同ABI分组条件下各组的患病率。结果男性和女性在不同ABI组中的分布不相同（x^2=52．130,P〈0．05）。按ABI分组,心血管各危险因素中年龄、体重指数、收缩压、舒张压、总胆固醇、三酰甘油及空腹血糖在三组中比较,差异有统计学意义（F值分别为28．268、24．826、192．950、88．213、7．602、14．802、199．216,P〈0．05）。其中年龄、血压及空腹血糖随着ABI的减低而逐渐增加。随着ABI分级的增加,同时并存多个危险因素的例数逐渐增加。结论ABI是预测心血管疾病的重要因子,有利于心血管疾病的发现和监控。     

Effects of a tailored health promotion program to reduce cardiovascular disease risk factors among middle-aged and advanced-age bus drivers

A tailored health promotion program was developed and applied to reduce cardiovascular disease risk factors among middle-aged and advanced-age bus drivers. The participants were 248 bus drivers from 2 transportation companies, in whom the authors surveyed health behaviors (physical activity, diet, smoking habit, and alcohol consumption), health status (body mass index, systolic blood pressure, triglycerides, total cholesterol, high-density lipoprotein, and low-density lipoprotein), and job stress. The tailored health promotion program consisted of exercise, diet, temperance, and smoking cessation education; the program was developed to reduce cardiovascular disease risk factors and was administered for 6 months. After the program, health behaviors, such as physical activity, dietary habits, smoking habits, and alcohol consumption, and health status indicators, such as blood pressure, had significantly improved (P < .05). The authors did not find an association between job stress and health behavior and status. This suggests that a tailored health promotion program for middle-aged and advanced-age bus drivers was effective.     

Effects of shift rotation and the flexibility of a shift system on daytime alertness and cardiovascular risk factors

OBJECTIVES: A controlled intervention study was conducted to evaluate the effects of two changes in shift characteristics on alertness and cardiovascular risk factors: a change in shift rotation (direction and speed) and a change in the flexibility of the shift system. METHODS: Altogether 84 male workers currently working in a backward-rotating shift system volunteered for the study. A total of 40 men changed to a rapidly forward-rotating shift system, 22 changed to a more flexible shift system, and 22 remained with the old shift system. Health effects were studied with the use of clinical measurements, blood tests, and questionnaires before and after the shift changes. Analyses of variance were used with repeated measures to study associations of cardiovascular risk factors and daytime sleepiness according to the change in shift systems. RESULTS: The mean number of days on which the workers reported sleepiness decreased in the group with the forward-rotating shift system when compared with that of the group on the old shift system (from 2.9 to 2.1 days/week, P=0.02). Systolic blood pressure decreased (from 142 to 136 mm Hg, P=0.049), and heart rate showed a declining trend (from 66 to 60 beats/minute, P=0.06) in the flexible shift system when the three groups were compared. CONCLUSIONS: The study indicates that a faster speed, together with a change to the forward direction, in shift rotation alleviates daytime sleepiness. Combining individual flexibility with company-based flexibility in a shift system may have favorable effects on shift workers' blood pressure.     

Prevalence of risk factors for coronary artery disease among day and shift workers

Several recent studies have indicated that shift work is associated with increased risk of coronary artery disease. In this cross-sectional study 361 shift workers were examined with respect to some major risk factors for coronary artery disease; 240 day workers constituted the reference group. A higher proportion of shift workers smoked (54 versus 39%). Shift workers also had significantly higher levels of serum triglycerides (1.61 versus 1.43 mmol/l). Body mass index and the blood pressure and total cholesterol levels did not differ between the groups. Multiple regression analyses demonstrated that shift work was significantly related to serum triglyceride levels also when age, smoking, body mass index, and other variables were controlled for. It was concluded that shift work is associated with several risk factors for coronary artery disease.     

Prevalence of risk factors to coronary heart disease in an Arab-American population in southeast Michigan

Although significant advances have been made in the area of cardiovascular disease, few studies have targeted ethnic groups. There is a large and growing Arab-American (AA) population living in Southeast Michigan, whose risk of cardiovascular disease may be on the increase. The objective of this study was to evaluate the prevalence of cardiovascular disease risk factors and associated behavioral factors in an AA community with a large population of emigrants, subjected to significant lifestyle changes. Three hundred and fifty-two AA living in Southeast Michigan, mostly from the Middle East, were screened to determine their eating and smoking habits, body mass index (BMI) body fat analysis, blood pressure, and complete lipid profiling. Overweight was defined as a BMI greater than or equal to the 85th percentile value for age- and sex-specific reference data from the third National Health and Nutrition Examination Survey (NHANES III). Correlation analysis was used to examine factors associated with being overweight, with adjustment for age and sex. Blood cholesterol concentrations were compared with published data for Arabs from the Middle Eastern countries. The overall prevalence of being overweight in subjects aged 35 and older was significantly higher than NHANES III reference data (Men, 27.7% (95% confidence interval, 21.8-34.5); women, 33.7% (95% confidence interval, 27.9-40.1)). A mean cholesterol concentration of 210 +/- 4 mg/dl was observed in those over the age of 40. The mean high-density lipoprotein (HDL)-cholesterol levels for men and women were 38 and 48 mg/dl, respectively. Greater than 54.6% of all subjects had a total cholesterol:HDL ratio > 4.5. Although being overweight and obesity were prevalent in this population, the mean BMI for men was 25.7 +/- 0.34, compared with 27 +/- 0.58 for women. Increased BMI was significantly correlated (P < 0.01) with increased blood pressure, increased glucose levels, increased total cholesterol and decreased HDL-cholesterol levels (P < 0.01). Elevation in risk factors to cardiovascular disease is prevalent in this population and indicates a need for programs targeting primary prevention of obesity in men and women. These results, which could be attributed in part to lifestyle changes typical of most emigrant populations, suggest an increase in the risk for developing cardiovascular disease. In addition, this study provides a basis for future intervention to improve the health of this population.