Prevention of coronary artery disease: the south Asian paradox

South Asians and Anglo Australians with heart disease in Australia

Objectives The aim of the present study was to determine cardiovascular disease (CVD) risk factors and compare presentation and severity of ischaemic heart disease (IHD) among South Asians (SAs) and Anglo Australians (AAs). Methods A retrospective clinical case audit was conducted at a public tertiary hospital. The study population included SA and AA patients hospitalised for IHD. Baseline characteristics, evidence of diabetes and other CVD risk factors were recorded. Angiography data were also included to determine severity, and these were assessed using a modified Gensini score. Results SAs had lower mean (± s.d.) age of IHD presentation that AAs (52 ± 9 vs 55 ± 9 years, respectively; P = 0.02), as well as a lower average body mass index (BMI; 26 ± 4 vs 29 ± 6 kg/m2, respectively; P = 0.005), but a higher prevalence of type 2 diabetes (57% vs 31%, respectively; P = 0.001). No significant differences were found in coronary angiography parameters. There were no significant differences in the median (interquartile range) Gensini score between SAs and AAs (43.5 (27–75) vs 44 (26.5–68.5), respectively), median vessel score (1 (1–2) vs 2 (1–3), respectively) or multivessel score (37% (33/89) vs 54% (22/41), respectively). Conclusions The findings show that in those with established IHD, cardiovascular risk factors, such as age at onset and BMI, differ between SAs and AAs and these differences should be considered in the prevention and management of IHD. What is known about the topic? There is much evidence on CVD and SAs, it being a leading cause of mortality and morbidity for this population both in their home countries and in countries they have migrated to. Studies conducted in Western nations other than Australia have suggested a difference in the risk profiles and presentations of CVD among SA migrants compared with the host populations in developed countries. Although this pattern of cardiovascular risk factors among SAs has been well documented, there is insufficient knowledge about this population, currently the largest population of incoming migrants, and CVD in the Australian setting. What does this paper add? This paper confirms that a similar pattern of CVD exists in Australia among SAs as does in other Western nations they have migrated to. The CVD pattern found in this population is that of an earlier age of onset at lower BMI compared with the host AA population, as well as a differing cardiovascular risk profile, with higher rates of type 2 diabetes and lower smoking rates. In addition, this study finds similar angiographic results for both the SAs and AAs; however, the SAs exhibit these similar angiographic patterns at younger ages. What are the implications for practitioners? SAs in Australia represent a high cardiovascular risk group and should be targeted for more aggressive screening at younger ages. Appropriate preventative strategies should also be considered bearing in mind the differing risk factors for this population, namely low BMI and high rates of type 2 diabetes. More intensive treatment strategies should also be regarded by practitioners. Importantly, both policy makers and health professionals must consider that all these strategies should be culturally targeted and tailored to this population and not assume a ‘one-size fits all’ approach.

Metabolic syndrome: a brain disease

Recent research indicates an association between brain dysfunction and the pathogenesis of metabolic syndrome. To investigate this, we created a Medline search (up to December 2011) of articles in PubMed. The results indicated that refined carbohydrates, saturated and total fat, high levels of ω-6 fatty acids, and low levels of ω-3 fatty acids and other long chain polyunsaturated fatty acids (PUFA), all in conjunction with sedentary behaviour and mental stress can predispose to inflammation. Increased sympathetic activity, with increased secretion of catecholamine, cortisol, and serotonin can cause oxidative stress, which may damage the arcuate nucleus as well as the hypothalamus and macrophages, and the liver may release pro-inflammatory cytokines. These, in conjunction with an underlying deficiency in long chain PUFA, may damage the arcuate nucleus as well as neuropeptide-Y and pro-opiomelanocortin neurons and insulin receptors in the brain, especially during fetal life, infancy, and childhood, resulting in their dysfunction. Of the fatty acids in the brain, 30%-50% are long chain PUFA, which are incorporated in the cell membrane phospholipids. Hence, ω-3 fatty acids, which are also known to enhance parasympathetic activity and increase the secretion of anti-inflammatory cytokines interleukin (IL)-4 and IL-10 as well as acetylcholine in the hippocampus, may be protective. Therefore, treatment with ω-3 fatty acids may be applied for the prevention of metabolic syndrome.

The tsim tsoum approaches for prevention of cardiovascular disease

The Tsim Tsoum Concept means that humans evolved on a diet in which nature recommends to ingest fatty acids in a balanced ratio (polyunsaturated(P) : saturated(S) =w-6 : w-3 = 1 : 1)as part of dietary lipid pattern where monounsaturated fatty acids(MUFA) is the major fatty acid(P : M : S = 1 : 6 : 1) in the background of other dietary factors; antioxidants, vitamins, minerals and fiber as well as physical activity and low mental stress. Several hundred years ago, our diet included natural foods; fruits, vegetables, green vegetables, seeds, eggs and honey. Fish, and wild meat were also available to pre-agricultural humans which shaped modern human genetic nutritional requirement. Cereal grains (refined), and vegetable oils that are rich in w-6 fatty acids are relatively recent addition to the human diet that represent dramatic departure from those foods to which we are adapted. Excess of linoleic acid, trans fatty acids (TFA), saturated and total fat as well as refined starches and sugar are proinflammatory. Low dietary MUFA and n-3 fatty acids and other long chain polyunsarurated fatty acids (LCPUFA) are important in the pathogenesis of metabolic syndrome. Increased sympathetic activity with greater secretion of neurotransmitters in conjunction of underlying long chain PUFA deficiency, and excess of proinflammatory nutrients, may damage the neurons via proinflammatory cytokines, in the ventromedial hypothalamus and insulin receptors in the brain.Since, 30–50% of the fatty acids in the brain are LCPUFA, especially omega-3 fatty acids, which are incorporated in the cell membrane phospholipids, it is possible that their supplementation may be protective.Blood lipid composition does reflect one's health status: (a) circulating serum lipoproteins and their ratio provide information on their atherogenicity to blood vessels and (b) circulating plasma fatty acids, such as w-6/w-3 fatty acid ratio, give indication on proinflammatory status of blood vessels, cardiomyocytes, liver cells and neurones; (a) and (b) are phenotype-related and depend on genetic, environmental and developmental factors. As such, they appear as universal markers for holistic health and these may be important in the pathogenesis of cardiovascular diseases and cancer, which is the main consideration of Tsim Tsoum concept.

Quality Changes During Storage of Minced Fish Products Containing Dietary Fiber and Fortified with ω3 Fatty Acids

Two ready-to-eat minced fish products from hake were developed, their proximate composition and fatty acid profiles determined and their quality changes followed during 3.5 months under refrigeration at 2 ± 1 °C and 10 ± 1 °C. These products contain dietary fiber and are innovative and healthy. The formulation was identical, except vegetable oil (VO), 5.6% (w/w) in one group and 2.7% (w/w) plus 2.9% (w/w) cod liver oil (CLO) in the other. CLO products had a higher ω3/ω6 ratio (0.54 ± 0.02 versus 0.08 ± 0.02) and ensured, per 100 g serving, the 500 mg recommended daily intake of eicosapentaenoic and docosahexaenoic acids. CLO products showed lower gel strength (p ≤ 0.05), however, other textural properties were similar to those of the VO group. Thiobarbituric acid reactive substances values were higher in CLO products. All groups presented acceptable sensory scores and no microbiological growth. During storage products became redder and less yellow, while seafood aroma and flavor declined and saltiness perception augmented. Temperature had a negative effect on sensory elasticity and instrumental texture.

Knowledge of modifiable risk factors of Coronary Atherosclerotic Heart Disease (CASHD) among a sample in India

Background

The prevalence of Coronary Atherosclerotic Heart Disease (CASHD) is increasing in India. Several modifiable risk factors contribute directly to this disease burden. Public knowledge of such risk factors among the urban Indian population is largely unknown. This investigation attempts to quantify knowledge of modifiable risk factors of CASHD as sampled among an Indian population at a large metropolitan hospital.

Methods

A hospital-based, cross sectional study was conducted at All India Institute of Medical Sciences (AIIMS), a major tertiary care hospital in New Delhi, India. Participants (n = 217) recruited from patient waiting areas in the emergency room were provided with standardized questionnaires to assess their knowledge of modifiable risk factors of CASHD. The risk factors specifically included smoking, hypertension, elevated cholesterol levels, diabetes mellitus and obesity. Identifying 3 or less risk factors was regarded as a poor knowledge level, whereas identifying 4 or more risk factors was regarded as a good knowledge level. A multiple logistic regression model was used to isolate independent demographic markers predictive of a participant's level of knowledge.

Results

41% of the sample surveyed had a good level of knowledge. 68%, 72%, 73% and 57% of the population identified smoking, obesity, hypertension, and high cholesterol correctly, respectively. 30% identified diabetes mellitus as a modifiable risk factor of CASHD. In multiple logistic regression analysis independent demographic predictors of a good knowledge level with a statistically significant (p < 0.05) adjusted odds ratio (aOR) were: routine exercise of moderate intensity, aOR 8.41 (compared to infrequent or no exercise), no history of smoking, aOR 8.25, and former smokers, aOR 48.28 (compared to current smokers). Although statistically insignificant, a trend towards a good knowledge level was associated with higher levels of education.

Conclusion

An Indian population in a hospital setting shows a lack of knowledge pertaining to modifiable risk factors of CASHD. By isolating demographic predictors of poor knowledge, such as current smokers and persons who do not exercise regularly, educational interventions can be effectively targeted and implemented as primary and secondary prevention strategies to reduce the burden of CASHD in India.

n-3 PUFAs-From dietary supplements to medicines

Although there has been a great progress in the prevention of cardiovascular diseases, the mortality of patients with acute myocardial infarction (AMI) still remains high. One of the most important underlying causes explaining this phenomenon is the sudden cardiac death. Nearly half of all cardiovascular deaths in the USA each year is attributed to this unpredictable and unexpected complication of AMI. Hence, there is an urgent medical need for a targeted therapy to reduce the incidence of sudden cardiac death. Since 1980 there have been several epidemiological and other studies concerning the benefits of n-3 polyunsaturated fatty acids (n-3 PUFAs) in cardiovascular health and prevention. Results from one of the largest studies, GISSI Prevenzione Trial show that adding the n-3 PUFAs to standard therapy of patients who survived AMI reduces sudden cardiac death (44% risk reduction, p=0.0006). In addition, significant decline in all-cause cardiovascular mortality (21% risk reduction, p=0.0064) further emphasizes the role of n-3 PUFA in cardiovascular prevention. To date, beneficial effects of n-3 PUFA are attributed to their antiarrhythmic, lipid lowering, antithrombotic and anti-inflammatory properties. To conclude, EPA and DHA improve the prognosis of cardiovascular patients in the secondary prevention of sudden cardiac death without any documented side effects.

Needs to Change the Direction of Cholesterol-related Medication—A Problem of Great Urgency

The cholesterol hypothesis implies that reducing the intake of saturated fatty acids and cholesterol and increasing that of polyunsaturated fatty acid are effective in lowering serum total cholesterol (TC), and thereby reducing the incidence of coronary heart disease (CHD). However, these dietary recommendations are essentially ineffective in reducing TC in the long run, but rather increase mortality rates from CHD and all causes. The reported "apparent relative risk of high TC in CHD mortality" (the ratio of mortality at the highest/lowest TC levels) varied several-fold among populations studied. The incidence of familial hypercholesterolemia (FH) in a population was proposed to be a critical factor in the observed variability, which could be accounted for by assuming that 1) the high CHD mortality rate in high-TC groups is mainly a reflection of the incidence and severity of FH, and 2) high TC is not a causative factor of CHD in non-FH cases. This interpretation is supported by recent observations that high TC is not positively associated with high CHD mortality rates among general populations more than 40-50 years of age. More importantly, higher TC values are associated with lower cancer and all-cause mortality rates among these populations, in which relative proportions of FH are likely to be low (circa 0.2%). Although the effectiveness of statins in preventing CHD has been accepted in Western countries, little benefit seems to result from efforts to limit dietary cholesterol intake or to TC values to less than approximately 260 mg/dl among the general population and the elderly. Instead, an unbalanced intake of omega6 over omega3 polyunsaturated fats favors the production of eicosanoids, the actions of which lead to the production of inflammatory and thrombotic lipid mediators and altered cellular signaling and gene expression, which are major risk factors for CHD, cancers, and shorter longevity. Based on the data reviewed here, it is urgent to change the direction of current cholesterol-related medication for the prevention of CHD, cancer, and all-cause mortality.

Can brain dysfunction be a predisposing factor for metabolic syndrome?

The various mechanisms that may explain the association between brain dysfunction and the pathogenesis of metabolic syndrome (MS) leading to cardiovascular disease and type 2 diabetes have been reviewed. A Medline search was conducted until September 2003, and articles published in various national and international journals were reviewed. Experts working in the field were also consulted. Compelling evidence was found that saturated and total fat and low dietary n-3 fatty acids and other long-chain polyunsaturated fatty acids (PUFAs) in conjunction with sedentary behavior and mental stress combined with various personality traits can enhance sympathetic activity and increase the secretion of catecholamine, cortisol and serotonin, all of which appear to be underlying mechanisms involved in MS. Excess secretion of these neurotransmitters in conjunction with underlying long-chain PUFA deficiency may damage the neurons in the ventromedial hypothalamus and insulin receptors in the brain, in particular during fetal life, infancy and childhood, and lead to their dysfunction. Since 30-50% of the fatty acids in the brain are long-chain PUFAs, especially omega-3 fatty acids which are incorporated in the cell membrane phospholipids, it is possible that their supplementation may have a protective effect. Omega-3 fatty acids are also known to enhance parasympathetic activity and to increase the secretion of anti-inflammatory cytokines as well as acetylecholine in the hippocampus. It is possible that a marginal deficiency of long-chain PUFAs, especially n-3 fatty acids, due to poor dietary intake during the critical period of brain growth and development in the fetus, and later in the infant and also possibly in the child, adolescent and adult may enhance the release of tumor necrosis factor-alpha (TNF-alpha) interleukin (IL)-1, 2 and 6 and cause neuronal dysfunction. Experimental studies indicate that ventromedial hypothalamic lesions in rats induce hyperphagia, resulting in glucose intolerance and insulin resistance. Treatment with neuropeptide Y abolished hyperphagia and ob mRNA (leptin mRNA) in this animal model. Long-term infusion of norepinephrine and serotonin into the ventromedial hypothalamus impaired pancreatic islet function inasmuch as ventromedial hypothalamic norepinephrine and serotonin levels were elevated in hyperinsulinemic and insulin-resistant animals. Treatment with insulin was associated with restoration of hypothalamic neurotransmitter abnormalities, indicating that ventromedial hypothalamus dysfunction can impair pancreatic beta cells resulting in metabolic abnormalities consistent with MS. Treatment with omega-3 fatty acids, beta blockers, ACE inhibitors, estrogen, and meditation may have a beneficial effect on insulin receptors and ventromedial hypothalamic dysfunction. However, no definite or precise insight into the pathophysiological link between MS, brain function and nutrition is available. Despite this, epidemiological studies and intervention trials indicate that treatment with n-3 fatty acids may be adopted in clinical practice and used to direct therapy for prevention of type 2 diabetes, hypertension, coronary artery disease (CAD), and atherosclerosis, thereby indicating that MS may also respond to this treatment.

Chronomics: circadian and circaseptan timing of radiotherapy, drugs, calories, perhaps nutriceuticals and beyond

We suggest a putative benefit from timing nutriceuticals (substances that are both nutrients and pharmaceuticals) such as antioxidants for preventive or curative health care, based on the proven merits of timing nutrients, drugs, and other treatments, as documented, i.a., in India. The necessity of timing melatonin, a major antioxidant, is noted. A protocol to extend the scope of chronoradiotherapy awaits testing. Imaging in time by mapping rhythms and broader time structures, chronomes, for earliest diagnoses, for example detection of vascular disease risk, is recommended. The study of rhythms and broader chronomes leads to a dynamic functional genomics, guided by imaging in time of free radicals and antioxidants, amongst many other variables.