Racial variation of factor VII activity and antigen levels and their correlates in healthy Chinese and Indians at low and high risk for coronary artery disease

Insulin resistance syndrome in South Asians

Although South Asians express increased features (conventional) of insulin resistance syndrome, these do not fully explain the increased mortality both from ischaemic heart disease and ischaemic stroke in South Asians compared to Whites. Thrombotic risk factors for vascular disease, as a part of insulin resistance syndrome in South Asians, are being investigated and are an important moiety. The management of the epidemic of ischaemic vascular disease in South Asians is a major global endeavour.

Associations of the SREBP-1c gene polymorphism with gender-specific changes in serum lipids induced by a high-carbohydrate diet in healthy Chinese youth

We investigated the possible association between the sterol regulatory element-binding protein-1c gene (SREBP-1c) rs2297508 polymorphism and the changes in lipid profiles in a high-carbohydrate and low-fat (high-CHO/LF) diet in a Chinese population well characterized by a lower incidence of coronary heart disease and a diet featuring higher carbohydrate and lower fat. Fifty-six healthy youth (aged 22.89 ± 1.80 years) were given wash-out diets of 31% fat and 54% carbohydrate for 7 days, followed by the high-CHO/LF diet of 15% fat and 70% carbohydrate for 6 days, without total energy restriction. Fasting blood samples were collected. Serum variables of lipid and glucose metabolism after the wash-out and high-CHO/LF diets, as well as the rs2297508 polymorphism, were analyzed. Compared with the male subjects on the wash-out diet, significantly elevated levels of high-density lipoprotein cholesterol (HDL-C) and decreased levels of apolipoprotein B-100 were observed in the male carriers of the C allele after the high-CHO/LF diet. In the female subjects, significantly increased triacylglycerol levels, insulin, and homeostasis model assessment of insulin resistance (HOMA-IR) were found in the GG genotype after the high-CHO/LF diet. These results suggest that the C allele of the rs2297508 polymorphism is associated with a retardation of the increases in serum triacylglycerol, serum insulin, and HOMA-IR in females and with the elevated serum HDL-C in males after the high-CHO/LF diet.

TaqIB polymorphism in the CETP gene modulates the impact of HC/LF diet on the HDL profile in healthy Chinese young adults

The aim of this study was to investigate the interactions of genetic variants in the genes of cholesterol ester transfer protein (CETP) and low-density lipoprotein receptor (LDLR) with high carbohydrate and low fat (HC/LF) diet on lipid profiles in a young and healthy Chinese Han population. Fifty-six healthy subjects (22.89±1.80 years) were given washout diets of 31% fat and 54% carbohydrate for 7 days, followed by HC/LF diets of 15% fat and 70% carbohydrate for 6 days, with no total energy restriction. Serum lipid profiles at baseline, after washout and following HC/LF diets, as well as CETP and LDLR polymorphisms were analyzed. Carriers of B2 allele of CETP TaqIB polymorphism had significantly higher levels of high density lipoprotein cholesterol (HDL-C) and apo A-I in the whole study population after the diet intervention. Notably, males with CETP TaqIB B1B1 experienced significantly increased HDL-C and apo A-I after HC/LF diet. Regarding the LDLR Pvu II polymorphism, both P1P1 subjects and P2 carriers experienced decreased total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) levels after HC/LF diet with no statistically significant differences between the genotypes. Our results demonstrate that the elevated HDL-C levels after HC/LF diet in healthy Chinese Han youth are associated with CETP TaqI B2 allele while males with B1B1 genotype are more susceptible to the influence of HC/LF diet on their HDL-C levels. The decreased TC and LDL-C levels after HC/LF diet are not associated with LDLR Pvu II polymorphism.

From farm to pharma: public health challenges of nutrigenomics

Nutrigenomics is speculated to be the next big dimension of genomic sciences geared toward improving public and personal health through nutritional and dietary interventions. This article traces how public health nutrition has been used as an agenda both in agriculture genomics and now in biomedicine. The centrality and importance of food in health and well-being is well recognized and, with the developments in genomics, it has also been used as a tool for public health-related policies and commercialization. This perspective discusses nutrigenomics from four public health perspectives; novel foods and the public health agenda; the epidemic of lifestyle-related diseases, such as obesity, diabetes and cardiovascular diseases; commercialization; and conceptual issues. Several ethical and governance issues in applying nutrigenomics to public health and the implications for public policy will also be considered.

The Effects of Three Factor VII Polymorphisms on Factor VII Coagulant Levels in Healthy Singaporean Chinese, Malay and Indian Newborns

Factor VII (FVII) is an independent risk factor for coronary artery disease. Three polymorphisms of the factor VII gene (F7) were studied in a group of healthy newborns comprising 561 Chinese, 398 Malays and 226 Asian Indians from Singapore. The allele frequencies of 3 polymorphisms (R353Q, Promoter 0/10bp Del/Ins and Intron 7) in the FVII gene were ascertained through genotyping by polymerase chain reaction and restriction digestion of amplified fragments. In Chinese the minor allele frequencies are Q: 0.04, Ins: 0.03, R7: 0.44; Malays, Q: 0.06, Ins: 0.10, R7: 0.41; and Indians, Q: 0.25, Ins: 0.23, R7: 0.43. Strong linkage disequilibrium (Delta > 0.7) is observed between the 0/10 bp and the R353Q sites in all ethnic groups. We conclude that: (i) the prevalence of the minor Q and Ins alleles of the R353Q and 0/10 bp polymorphisms are significantly higher in the Indian newborns than the Chinese and Malays; (ii) the Q allele is significantly associated (p = 0.01) with a lower plasma FVII coagulant level in the Indian and Malay neonates; and this polymorphism explains up to 3.8% of the variance in FVII coagulant levels; (iii) there is no significant difference in allele frequencies of the three polymorphisms between neonates with and without family histories of CAD.

Public health nutrition and genetics: implications for nutrition policy and promotion

The unravelling of the human genome has the potential to radically extend many of the strategies used in public health nutrition to improve health and to increase food availability, accessibility and utilization. The present paper divides nutrigenomics into two broad but differing areas in asking about possible public health applications: (1) the increasing mismatch between population growth and global food security, on top of the already approximately 800 million of the world population who are food insecure; (2) possible responses to the rising prevalence of non-communicable diseases as the Western diet becomes increasingly inappropriate to the needs of those consuming it. It is clear that complex interactions of multiple polymorphisms play a role in how individuals and sub-populations respond to dietary interventions. All these applications present public health and ethical challenges, particularly in ensuring that any benefits that do come from nutrigenomics are not restricted to the wealthy minority of only the affluent nations. The present paper concludes that the public health applications of nutrigenomics are probably at least a decade away, especially for developing countries. Clinical applications are likely to be more immediate, probably resulting in 'designer diets' for individuals with particular polymorphisms, but unless governments take on the role of ensuring some extent of equity in access, any benefits are most likely to go to those who can afford the screening, tests and treatment. At the same time, greatly increased international efforts are needed towards the continuing, and in some cases worsening, global malnutrition, as genetic manipulation of crops is unlikely to provide more than part of the solution.

A life course approach to diet, nutrition and the prevention of chronic diseases

OBJECTIVE

To briefly review the current understanding of the aetiology and prevention of chronic diseases using a life course approach, demonstrating the life-long influences on the development of disease.

DESIGN

A computer search of the relevant literature was done using Medline-'life cycle' and 'nutrition' and reviewing the articles for relevance in addressing the above objective. Articles from references dated before 1990 were followed up separately. A subsequent search using Clio updated the search and extended it by using 'life cycle', 'nutrition' and 'noncommunicable disease' (NCD), and 'life course'. Several published and unpublished WHO reports were key in developing the background and arguments.

SETTING

International and national public health and nutrition policy development in light of the global epidemic in chronic diseases, and the continuing nutrition, demographic and epidemiological transitions happening in an increasingly globalized world. RESULTS OF REVIEW: There is a global epidemic of increasing obesity, diabetes and other chronic NCDs, especially in developing and transitional economies, and in the less affluent within these, and in the developed countries. At the same time, there has been an increase in communities and households that have coincident under- and over-nutrition.

CONCLUSIONS

The epidemic will continue to increase and is due to a lifetime of exposures and influences. Genetic predisposition plays an unspecified role, and with programming during fetal life for adult disease contributing to an unknown degree. A global rise in obesity levels is contributing to a particular epidemic of type 2 diabetes as well as other NCDs. Prevention will be the most cost-effective and feasible approach for many countries and should involve three mutually reinforcing strategies throughout life, starting in the antenatal period.

Specific elevation in plasma tissue plasminogen activator antigen concentrations in South Asians relative to Europeans

Elevated levels of haemostatic factors including tissue plasminogen activator (t-PA) antigen are associated with coronary heart disease in Europeans but data in South Asians are sparse. We performed a cross-sectional study of 111 healthy men and women aged 40-55 years (56 European and 55 Asian) frequency matched across a wide range of body mass index (17-34 kg/m2). All subjects had detailed adiposity and metabolic measurements, and five haemostatic factors were determined. South Asians had greater insulin resistance than Europeans (fasting insulin geometric mean, 7.1 versus 4.7 microU/ml, and 2-h insulin, 37.3 versus 14.1 microU/ml, respectively). There were no significant ethnic differences in the mean concentrations of fibrinogen, factor VII, von Willebrand factor, or fibrin D-dimer (P > 0.10). However, the t-PA antigen concentration was significantly elevated in South Asians compared with Europeans (mean, 10.6 versus 8.2 ng/ml, P = 0.001). t-PA correlated positively in both ethnic groups with features of the metabolic syndrome but the ethnic difference in t-PA persisted after adjustment for adiposity, metabolic and inflammatory variables (beta = 2.0, 95% confidence interval = 0.5-3.6, P = 0.012). We therefore hypothesize that elevated t-PA antigen may be a novel mechanism contributing to increased cardiovascular risk in South Asians.

Genotype associations of factor VII gene with plasma factor VII coagulant activity and antigen levels in healthy Chinese

A raised plasma factor VII (FVII) level is one of the risk factors for coronary artery disease. The R353Q polymorphism at codon 353 and the 10 base pair (bp) insertion (0/10 bp) polymorphism of the FVII gene have been reported to be associated with plasma FVII levels in several populations. We investigated these two polymorphisms in 209 male and 214 female healthy Chinese. The allele frequencies of 10 bp and Q were 0.036 and 0.045, respectively. Strong linkage disequilibrium was observed between these two sites (Delta = 0.85, P < 0.001). There were significant genotype associations of these two loci with FVII coagulant activity (FVIIc) and antigen (FVIIAg) levels. Heterozygous individuals had lower FVIIc and FVIIAg levels than those homozygous for the common alleles. When analyzed separately by gender, the 0/10 bp polymorphism was strongly associated with FVIIAg levels in males and females. However, both polymorphisms were significantly associated with FVIIc levels only in the females. The effect of 0/10 bp polymorphism predominated over that of the R353Q polymorphism in a two-way analysis of variance procedure. In the Chinese, the 10 bp insertion may reduce transcription of the FVII gene, leading to the decreased synthesis of FVII protein and thus FVIIc.

Influence of two apo A4 polymorphisms at codons 347 and 360 on non-fasting plasma lipoprotein-lipids and apolipoproteins in Asian Indians

Apolipoprotein A-IV (apo A-IV, protein; apo A4, gene) is a major constituent of triglyceride-rich and high-density lipoprotein particles and may, therefore, play an important role in lipid metabolism. We studied the distribution of two apo A4 polymorphisms at codons 347 (alleles A and T) and 360 (alleles 1 and 2) in relation to plasma lipoprotein-lipid and apolipoprotein levels in 176 non-fasting male blood donors from New Delhi, Northern India. The frequencies of the T allele at codon 347 and the 2 allele at codon 360 were 0.12 and 0.03 respectively. Carriers of the T allele (AT and TT genotypes) had significantly lower plasma total cholesterol (P = 0.04) and low density lipoprotein (LDL)-cholesterol (P = 0.02) levels than individuals homozygous for the A allele (AA genotype). The codon 347 polymorphism explained 2.2 and 2.6% of the phenotypic variation in total cholesterol and LDL-cholesterol, respectively. The 2 allele at codon 360 was associated with marginally reduced plasma LDL-cholesterol (P = 0.09) and increased triglyceride (P = 0.05) levels compared to the 1 allele. To further elucidate the combined effects of the two polymorphism we constructed two-site haplotypes. The haplotype data showed a stronger influence and explained 3.0 and 5.2% of the phenotypic variation in total cholesterol and LDL-cholesterol, respectively. The two uncommon haplotypes, T1 and A2, were associated with 24.2 and 23.5 mg/dl lower total cholesterol and 22.5 and 42.0 mg/dl lower LDL-cholesterol levels, respectively. The accentuated effect of apo A4 polymorphisms on non-fasting plasma cholesterol suggest that apo A-IV may play an important role in regulating the postprandial metabolism of lipoproteins.