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Biomedical subjects

Ping Chook

Publications and source records attributed to Ping Chook.

7 recordsLinked to original sources
PubMed2006

Associations of apolipoprotein E exon 4 and lipoprotein lipase S447X polymorphisms with acute ischemic stroke and myocardial infarction.

BACKGROUND: Because apolipoprotein E (apoE) and lipopoprotein lipase (LPL) polymorphisms interact with each other and with other factors to affect lipid metabolism, we sought to determine their separate and combined effects in association with ischemic vascular disease. METHODS: We performed a case-control study of 816 subjects: 246 acute ischemic stroke patients, 234 acute myocardial infarction patients, and 336 controls. APOE exon 4 and LPL S447X genotypes were determined. RESULTS: APOE epsilon2 and epsilon4 homozygotes were increased in stroke (4.5% vs. 1.0%, p = 0.008), while in myocardial infarction the epsilon4 allele was increased (12.6% vs. 9.5%, p = 0.006) but epsilon2 was decreased (3.7% vs. 12.1%, p = 0.000006). For subjects with either APOE epsilon2 or epsilon4 alleles, LPL X alleles were increased in vascular disease (OR = 2.2, p = 0.01). LPL X alleles displayed opposite tendencies toward association with disease when subjects were divided by sex, smoking, or APOE genotype. Meta-analysis and regression analysis of previous studies supported the sex and smoking dichotomies. CONCLUSION: This is the first report of an association of vascular disease with an interaction of APOE exon 4 and LPL S447X genotypes. Therefore, APOE genotypes and LPL S447X interactions with apoE, sex, and smoking may affect the risk of myocardial infarction and ischemic stroke.

Aged↗
PubMed2004

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.

Arteriosclerosis↗
PubMed2004

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.

Adolescent↗
PubMed2002

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.

Adult↗
PubMedDate not supplied

Homocysteine, endothelial dysfunction, and coronary artery disease: emerging strategy for secondary prevention.

Atherosclerosis is an important medical problem of the 21st century, but traditional risk factors could only account for 50% of the problem. Hyperhomocysteinemia is emerging as an independent atherosclerosis risk factor, associated with folate deficiency, renal failure, and relative deficiency of MTHFR (C677T polymorphism) or other enzymes depending on gender, age, and smoking status. Hyperhomocysteinemia has been reported to occur in 11-22% of western people, in 3-5% of normal asymptomatic Chinese subjects aged 18-70 years in Hong Kong, Macau, Sydney, and San Francisco, 23-36% of Chinese in Hong Kong with premature coronary artery disease, and 29% of a nonselective series of coronary subjects in Hong Kong. Evidence is accumulating that documents its associations with atherosclerosis disease in both case-control observations and prospective cohort studies, in vitro experiments, and in vivo experimental models in both animals and human subjects, as well as the successful improvement by homocysteine-lowering of endothelial function as surrogate atherosclerosis endpoints in asymptomatic human and coronary patients (secondary prevention). A number of large scale homocysteine-lowering trials are currently underway for stroke and heart attacks prevention. Collectively these trials will include more than 65,000 patients at high-risk for cardiovascular and stroke events, and should provide a reliable evidence-base for prevention.

Adolescent↗