A Tale of Three Gorges in the Yangtze River: Comparing the Prevalence of Metabolic Syndrome According to ATPIII, WHO, and IDF Criteria and the Association with Vascular Health in Modernizing China.

BACKGROUND: Metabolic syndrome (MS) is associated with atherosclerotic diseases. The prevalence of MS according to the Adult Treatment Panel III (ATPIII), World Health Organization (WHO), and International Diabetes Federation (IDF) criteria are variable but increasing in western countries and modernizing China. This study aimed to evaluate the prevalence of MS according to these three criteria, in farmers or ex-farming residents in three-gorges territories undergoing rapid lifestyle changes. METHODS: We compared 95 residents (ex-farmers) in Wu Shan (WS) (28.4% men, aged 49.7 ± 9 years) resettled uphill for 3-5 years, and 87 age- and gender-matched farmers in Da Chang (DC) (27.6% men, aged 48.8 ± 10 years) before migration. MS and other traditional risk factors were assessed and carotid intima-media thickness (IMT) measured. RESULTS: Ninety-nine percent of WS residents were retired or adopted nonfarming jobs. Compared with DC farmers, WS ex-farmers had higher waist circumference, low density lipoprotein-cholesterol, and triglycerides (P < 0.0001), but their blood pressures, HDL-cholesterol, and fasting glucose were similar. MS were identified in 43.2% (IDF), 36.8% (WHO), and 29.5% (ATPIII) respectively in WS ex-farmers, compared with 17.2%, 13.8%, and 11.5% respectively in DC farmers. Carotid IMT was significantly higher in WS ex-farmers (0.74 ± 0.16 mm) than in DC farmers (0.64 ± 0.11 mm) (P < 0.0001). On multivariate regression analysis, prevalence of MS was correlated with job nature (beta = 0.425, P < 0.0001). Carotid IMT was better correlated with IDF MS criteria (beta = 0.208, P = 0.021), independent of age and WS location (regression adjusted R2 = 0.444, F-value 12.0, P < 0.0001), but not with the ATPIII or WHO criteria. CONCLUSIONS: IDF MS criteria is more sensitive, better correlates with atherosclerosis surrogate, and accordingly is more readily applicable to modernizing China.

Long-term exposure to ambient particulate matter (PM2.5) is associated with platelet counts in adults.

BACKGROUND: The prothrombotic effects of particulate matter (PM) may underlie the association of air pollution with increased risks of cardiovascular disease. This study aimed to investigate the association between long-term exposure to PM with an aerodynamic diameter ≤2.5 µm (PM2.5) and platelet counts, a marker of coagulation profiles. METHODS: The study participants were from a cohort consisting of 362,396 Taiwanese adults who participated in a standard medical examination program between 2001 and 2014. Platelet counts were measured through Complete Blood Count tests. A satellite-based spatio-temporal model was used to estimate 2-year average ambient PM2.5 concentration at each participant's address. Mixed-effects linear regression models were used to investigate the association between PM2.5 exposure and platelet counts. RESULTS: This analysis included 175,959 men with 396,248 observations and 186,437 women with 397,877 observations. Every 10-µg/m3 increment in the 2-year average PM2.5 was associated with increases of 0.42% (95% CI: 0.38%, 0.47%) and 0.49% (95% CI: 0.44%, 0.54%) in platelet counts in men and women, respectively. A series of sensitivity analyses, including an analysis in participants free of cardiometabolic disorders, confirmed the robustness of the observed associations. Baseline data analyses showed that every 10-µg/m3 increment in PM2.5 was associated with higher risk of 17% and 14% of having elevated platelet counts (≥90th percentile) in men and women, respectively. CONCLUSIONS: Long-term exposure to PM2.5 appears to be associated with increased platelet counts, indicating potential adverse effects on blood coagulability.

Long-Term Exposure to Fine Particulate Matter, Blood Pressure, and Incident Hypertension in Taiwanese Adults.

BACKGROUND: Long-term exposure to particulate matter (PM) air pollution may increase blood pressure and the risk of hypertension. However, epidemiological evidence is scarce and inconsistent. OBJECTIVES: We investigated the associations between long-term exposure to PM with an aerodynamic diameter <2.5µm (PM2.5), blood pressure, and incident hypertension in a large Taiwanese cohort. METHODS: We studied 361,560 adults ≥18y old from a large cohort who participated in a standard medical examination program during 2001 to 2014. Among this group, 125,913 nonhypertensive participants were followed up. A satellite-based spatiotemporal model was used to estimate the 2-y average PM2.5 concentrations at each participant's address. Multivariable linear regression was used in the cross-sectional data analysis with the 361,560 participants to investigate the associations between PM2.5 and systolic blood pressure (SBP), diastolic blood pressure (DBP), and pulse pressure (PP), and Cox proportional hazard regression was used in the cohort data analysis with the 125,913 participants to investigate the associations between PM2.5 and incident hypertension. RESULTS: Each 10-µg/m3 increment in the 2-y average PM2.5 concentration was associated with increases of 0.45 mmHg [95% confidence interval (CI): 0.40, 0.50], 0.07 mmHg (95% CI: 0.04, 0.11), and 0.38 mmHg (95% CI: 0.33, 0.42) in SBP, DBP, and PP, respectively, after adjusting for a wide range of covariates and possible confounders. Each 10-µg/m3 increment in the 2-y average PM2.5 concentration was associated with an increase of 3% in the risk of developing hypertension [hazard ratio=1.03 (95% CI: 1.01, 1.05)]. Stratified and sensitivity analyses yielded similar results. CONCLUSIONS: Long-term exposure to PM2.5 air pollution is associated with higher blood pressure and an increased risk of hypertension. These findings reinforce the importance of air pollution mitigation strategies to reduce the risk of cardiovascular disease. https://doi.org/10.1289/EHP2466.

Effects of diet and exercise on obesity-related vascular dysfunction in children.

BACKGROUND: The prevalence of obesity in both adults and children is increasing rapidly. Obesity in children is independently associated with arterial endothelial dysfunction and wall thickening, key early events in atherogenesis that precede plaque formation. METHODS AND RESULTS: To evaluate the reversibility of obesity-related arterial dysfunction and carotid intima-media thickening by dietary and/or exercise intervention programs, 82 overweight children (body mass index, 25+/-3), 9 to 12 years of age, were randomly assigned to dietary modification only or diet plus a supervised structured exercise program for 6 weeks and subsequently for 1 year. The prospectively defined primary end points were ultrasound-derived arterial endothelial function (endothelium-dependent dilation) of the brachial artery and intima-media thickness of common carotid artery. At 6 weeks, both interventions were associated with decreased waist-hip ratio (P<0.02) and cholesterol level (P<0.05) as well as improved arterial endothelial function. Diet and exercise together were associated with a significantly greater improvement in endothelial function than diet alone (P=0.01). At 1 year, there was significantly less thickening of the carotid wall (P<0.001) as well as persistent improvements in body fat content and lipid profiles in the group continuing an exercise program. Vascular function was significantly better in those children continuing exercise (n=22) compared with children who withdrew from the exercise program (n=19) (P<0.05). CONCLUSIONS: Obesity-related vascular dysfunction in otherwise healthy young children is partially reversible with diet alone or particularly diet combined with exercise training at 6 weeks, with sustained improvements at 1 year in those persisting with diet plus regular exercise.

Deleterious impact of "high normal" glucose levels and other metabolic syndrome components on arterial endothelial function and intima-media thickness in apparently healthy Chinese subjects: the CATHAY study.

OBJECTIVE: Endothelial vasodilator dysfunction and carotid intima-media thickening are useful surrogate markers of cardiovascular disease, a major cause of morbidity and mortality in type 2 diabetic patients. However, because most studies reporting the relationships between endothelial function, intima-media thickness (IMT), and hyperglycemia have compared diabetic patients with healthy controls, we report their relationship with glycemia as a continuum. METHODS AND RESULTS: Brachial artery endothelial function (flow-mediated dilatation [FMD]) and carotid IMT were measured noninvasively by high-resolution ultrasound B-mode imaging in 228 apparently healthy Chinese subjects recruited from Hong Kong and Macau. FMD and IMT were significantly associated with increasing levels of glycemia, particularly in the "high normal" glycemic range, with IMT increasing and endothelium-independent dilatation decreasing linearly across the glucose tertiles, and endothelium-dependent dilatation significantly lower in the upper glucose tertile compared with the other 2 groups (P<0.01). Using multiple linear regression, fasting glucose level was identified as an independent predictor of each of these markers of vascular function (P<0.004). Additionally, other conventional cardiovascular risk factors, including obesity, blood pressure, and an adverse lipid profile, were also related to levels of glycemia (P<0.05), further contributing to impaired vascular function. CONCLUSIONS: Increasing levels of glycemia and the coexistence of other cardiovascular risk factors in apparently healthy subjects are adversely associated with arterial endothelial dysfunction and intima-media thickening.

Long-term improvement in homocysteine levels and arterial endothelial function after 1-year folic acid supplementation.

PURPOSE: Hyperhomocysteinemia, a risk factor for atherosclerosis, is associated with endothelial dysfunction that can be improved with short-term folic acid supplementation. The current study aimed to assess whether folic acid supplementation could produce longer-term improvements in homocysteine levels and arterial endothelial function. SUBJECTS AND METHODS: Twenty-nine healthy adults with hyperhomocysteinemia were selected from 89 volunteers enrolled in a community-based atherosclerosis screening project. All subjects were given folic acid (10 mg/d) for 1 year. Fasting plasma homocysteine levels were measured by high-performance liquid chromatography. Arterial endothelial function was measured as flow-mediated dilation of the brachial artery using high-resolution B-mode ultrasound. RESULTS: Folic acid supplementation for 1 year was associated with a significant increase in mean (+/-SD) plasma folate levels (24 +/- 5 nmol/L to 40 +/- 5 nmol/L; P < 0.001) and a significant decline in homocysteine levels (9.0 +/- 1.7 micromol/L to 7.9 +/- 2.0 micromol/L; P < 0.001). Flow-mediated dilation also improved significantly, from 7.4% +/- 2.0% to 8.9% +/- 1.5% (P <0.0001), but there was no change in nitroglycerin-induced (endothelium-independent) responses. CONCLUSIONS: These results demonstrate that long-term folic acid improves arterial endothelial function and has potential implications for the prevention of atherosclerosis in adults with hyperhomocysteinemia.

Effect of N-acetylcysteine for prevention of contrast nephropathy in patients with moderate to severe renal insufficiency: a randomized trial.

BACKGROUND: The effect of N-acetylcysteine (NAC) to prevent contrast nephropathy (CN) in patients with moderate to severe renal insufficiency undergoing coronary angiography or interventions is not clear. METHODS: This is a prospective, open-label, randomized, controlled trial. Ninety-one consecutive patients with a serum creatinine level of 1.69 to 4.52 mg/dL (149 to 400 micromol/L) undergoing coronary procedures were recruited and randomly assigned to administration of either oral NAC, 400 mg, thrice daily the day before and day of the contrast procedure (the NAC group) or no drug (the control group). Serum creatinine was measured before and 48 hours after contrast exposure. The primary end point of this study was the development of CN, defined as an increase in serum creatinine concentration of 0.5 mg/dL or greater (> or =44 micromol/L) or a reduction in estimated glomerular filtration rate (GFR) of 25% or greater of the baseline value 48 hours after the procedure. RESULTS: There were no significant differences between the 2 groups (46 patients, NAC group; 45 patients, control group) in baseline characteristics or mean volume of contrast agent administered. Six patients (13.3%) in the control group and 8 patients (17.4%) in the NAC group developed CN (P = 0.8). Serum creatinine levels increased from 2.27 +/- 0.54 to 2.45 +/- 0.65 mg/dL (201 +/- 48 to 217 +/- 57 micromol/L; P = 0.003) in the NAC group and 2.37 +/- 0.61 to 2.40 +/- 0.70 mg/dL (210 +/- 54 to 212 +/- 62 micromol/L; P = 0.6) in the control group. The increase in serum creatinine levels between the 2 groups had no difference (P = 0.7). Estimated GFR decreased from 30.3 +/- 8.4 to 28.1 +/- 8.4 mL/min (P = 0.01) in the NAC group and 28.4 +/- 8.6 to 27.5 +/- 8.8 mL/min (P = 0.3) in the control group. The decline in estimated GFR between the 2 groups had no difference (P = 0.7). CONCLUSION: In the current study, oral NAC had no effect on the prevention of CN in patents with moderate to severe renal insufficiency undergoing coronary angiography or interventions. However, the sample size of our present study is small. Our findings highlight the need for a large-scale, randomized, controlled trial to determine the exact beneficial effect of NAC.

Vegan diet, subnormal vitamin B-12 status and cardiovascular health.

Vegetarian diets have been associated with atherosclerosis protection, with healthier atherosclerosis risk profiles, as well as lower prevalence of, and mortality from, ischemic heart disease and stroke. However, there are few data concerning the possible cardiovascular effects of a vegan diet (with no meat, dairy or egg products). Vitamin B-12 deficiency is highly prevalent in vegetarians; this can be partially alleviated by taking dairy/egg products in lact-ovo-vegetarians. However, metabolic vitamin B-12 deficiency is highly prevalent in vegetarians in Australia, Germany, Italy and Austria, and in vegans (80%) in Hong Kong and India, where vegans rarely take vitamin B-12 fortified food or vitamin B-12 supplements. Similar deficiencies exist in northern Chinese rural communities consuming inadequate meat, egg or dairy products due to poverty or dietary habits. Vascular studies have demonstrated impaired arterial endothelial function and increased carotid intima-media thickness as atherosclerosis surrogates in such metabolic vitamin B-12 deficient populations, but not in lactovegetarians in China. Vitamin B-12 supplementation has a favourable impact on these vascular surrogates in Hong Kong vegans and in underprivileged communities in northern rural China. Regular monitoring of vitamin B-12 status is thus potentially beneficial for early detection and treatment of metabolic vitamin B-12 deficiency in vegans, and possibly for prevention of atherosclerosis-related diseases.

Cardiovascular disease in the developing world: prevalences, patterns, and the potential of early disease detection.

Over the past decade or more, the prevalence of traditional risk factors for atherosclerotic cardiovascular diseases has been increasing in the major populous countries of the developing world, including China and India, with consequent increases in the rates of coronary and cerebrovascular events. Indeed, by 2020, cardiovascular diseases are predicted to be the major causes of morbidity and mortality in most developing nations around the world. Techniques for the early detection of arterial damage have provided important insights into disease patterns and pathogenesis and especially the effects of progressive urbanization on cardiovascular risk in these populations. Furthermore, certain other diseases affecting the cardiovascular system remain prevalent and important causes of cardiovascular morbidity and mortality in developing countries, including the cardiac effects of rheumatic heart disease and the vascular effects of malaria. Imaging and functional studies of early cardiovascular changes in those disease processes have also recently been published by various groups, allowing consideration of screening and early treatment opportunities. In this report, the authors review the prevalences and patterns of major cardiovascular diseases in the developing world, as well as potential opportunities provided by early disease detection.

The efficacy and tolerability of adjunctive alternative herbal medicine (Salvia miltiorrhiza and Pueraria lobata) on vascular function and structure in coronary patients.

BACKGROUND: Danshen and gegen (D&G) have long been used in treatment of angina and other cardiac symptoms in Chinese materia medica. Recent pharmacological studies suggest their therapeutic values. We aimed to evaluate the efficacy and safety of Salvia miltiorrhiza (danshen) and Pueraria lobata (gegen) in secondary prevention. METHODS: One hundred (100) consecutive coronary patients (mean age 58 +/- 8 years) were randomized to adjunctive treatment with D&G combination (3 g) or placebo (6 capsules) for 24 weeks in double-blind parallel fashion, followed by optional open-label D&G (1.5 g/day) for 6 more months. Brachial flow-mediated dilation (FMD) and carotid intima-media thickness (IMT) were measured using ultrasound. RESULTS: Baseline characteristics were similar between the 2 groups. After 24 weeks and compared with baseline, there were no significant changes in blood pressures, blood hematological and biochemical profiles, or folate and homocysteine levels in both groups, but there was a mild decrease in low density lipoprotein (LDL) cholesterol in both groups (p < 0.05). Brachial FMD improved during D&G (p < 0.001) and less so during placebo treatment (p < 0.05), while improvement in carotid IMT was observed only in the D&G group (p < 0.05). After open-label D&G treatment for 6 more months (n = 45), further improvement in both brachial FMD (p < 0.0001) and carotid IMT (p < 0.0001) was observed. Eight (8) adverse events were reported-6 during placebo and 2 during D&G treatment-requiring treatment termination in 2 patients (on placebo). CONCLUSIONS: D&G adjunctive treatment in coronary patients was well tolerated and effective in improving vascular function and structure. These two herbs may become a novel agent for secondary prevention.

Smoking without exception adversely affects vascular structure and function in apparently healthy Chinese: implications in global atherosclerosis prevention.

BACKGROUND: Both active and passive smoking are prevalent in China but cardiovascular diseases were less prevalent in the past. We studied the current relationship between surrogate atherosclerosis markers and smoking in Chinese. METHODS: Endothelium-dependent flow-mediated dilation (FMD) of brachial artery and carotid intima-media thickness (IMT) were measured non-invasively by ultrasound in 616 apparently healthy Chinese (23% smokers), recruited from greater China and the USA. RESULTS: The Chinese smokers had significantly impaired FMD (7.0+/-2.3 vs. 8.2+/-2.5%, p<0.001) and endothelium-independent vasodilation (GTN, 17.4+/-3.9 vs. 18.7+/-4.1%, p=0.001) and thicker IMT (0.61+/-0.13 vs. 0.58+/-0.12 mm, p=0.025). 91% of the smokers were male. Both endothelium-dependent (6.9+/-2.2 vs. 8.0+/-2.5%, p<0.001) and independent (17.3+/-3.5 vs. 18.2+/-3.7%, p=0.047) vasodilation were significantly lower in the male smokers than non-smokers, although their age and cholesterol levels were lower. FMD-to-GTN ratio in the smokers were lower (0.41+/-0.12 vs. 0.45+/-0.13, p=0.005). Multivariate analyses confirmed an independent adverse impact of smoking on vascular functions. There were no consistent interactions between subject location and impact of smoking on FMD and IMT. CONCLUSION: In these apparently healthy native and overseas Chinese subjects, smoking is adversely associated with endothelial dysfunction and arterial wall thickening, with serious implication in atherosclerosis prevention.