Genetic variation: nutritional implications

Interleukin (IL)-6, tumour necrosis factor alpha (TNF-α) and soluble interleukin-2 receptors (sIL-2R) are elevated in patients with major depressive disorder: a meta-analysis and meta-regression

BACKGROUND

Many studies have explored the association between soluble interleukin-2 receptor (sIL-2R), cytokines and major depressive disorder (MDD). However, the results of these studies were not consistent. The aim of our study is to compare the levels of sIL-2R and cytokines in the blood between MDD patients and controls by a meta-analysis and to identify moderators accounting for potential heterogeneity in the levels of sIL-2R and cytokines in MDD patients versus controls by meta-regression analyses.

METHODS

A comprehensive literature search was performed to identify studies comparing the levels of sIL-2R and cytokines between MDD patients and controls. We pooled the effect sizes for standardized mean differences (SMD) of the levels of sIL-2R and cytokines. We also performed meta-regression and sensitivity analyses to investigate the roles of age, gender, sample type, ethnic origin and selected studies' quality in explaining potential heterogeneity and differences in results respectively.

RESULTS

Twenty-nine studies were selected for this analysis. The levels of sIL-2R, TNF-α and IL-6 in MDD patients were significantly higher than those of healthy controls (SMD=0.555, p<0.001, SMD=0.567, p=0.010; SMD=0.680, p<0.001). Mean age of all subjects was a significant moderator to explain the high heterogeneity of IL-6. Sensitivity analysis found that European but not non-European subjects have higher levels difference of sIL-2R, TNF-α and IL-1β between MDD patients and controls.

LIMITATION

The severity of MDD was not considered.

CONCLUSION

The blood levels of sIL-2R, TNF-α and IL-6 were significantly higher in MDD patients than controls. Age, samples source and ethnic origins may play a potential role in heterogeneity.

A practice model for personalized healthcare with a public health genomics perspective

Epidemiological and demographic transition has brought populations to an extended life expectancy in the 21st Century. The diseases of this century are complex, which stem mainly from the complex interactions of the human genome with lifestyle and environmental factors. These diseases are common, chronic and costly. Currently, the best-known prevention for complex diseases is adopting a healthy lifestyle. However, this is not achieved in many places in the world. Effective intervention models, including lifestyle changes for the prevention of these diseases, is urgently needed. In this report, we introduce a preventive healthcare model based on personalized healthcare. It is based on the application of public health genomics tools and concepts on an individual level, in order to stratify individuals according to risk groups, prevent diseases and detect them early.

Nutrigenomics--2006 update

The Human Genome and HapMap projects have provided the tools and information that will aid in understanding how nutrients alter the expression of an individual's genetic information and why individuals differ in metabolism of foods at the molecular level. The study of how genes and gene products interact with dietary chemicals to alter phenotype and, conversely, how genes and their products metabolize nutrients is called nutritional genomics or "nutrigenomics." This new field has received considerable attention in the last 6 years, most of which has been on the promise rather than on scientific results from nutrigenomic experiments. Funding for nutrigenomics research focused primarily on individual laboratory projects in the 1990s and early 2000s. The novelty of combining nutrition and genetics limited that funding to a relatively small number of laboratories. Only in the past 3 years have centers been funded to foster collaborations and conduct large-scale projects that are studying nutrient-gene interactions. The increase in interest and funding is beginning to generate the critical mass to realize the promise of nutritional genomics.

Geographical influences on the association between adherence to the Mediterranean diet and the prevalence of acute coronary syndromes, in Greece: the CARDIO2000 study

OBJECTIVE

We evaluated the interaction between adherence to the Mediterranean diet and region of Greece on the likelihood of having acute coronary syndromes (ACS).

METHODS

During 2000-2001, a random sample of 848 patients (61+/-10 years) with their first coronary heart disease event, and 1078 frequency matched (by age-sex) controls with no cardiovascular disease in their medical history, from all the country, entered into the study. Among several factors, adherence to the Mediterranean diet was assessed by a diet-score that incorporated the inherent characteristics of this diet.

RESULTS

The multi-adjusted analysis showed that a 10-unit increase in the diet score was associated with a 27% (95% CI 0.66 to 0.89) decrease of the odds of having ACS. Moreover, a highly significant interaction was observed between region and diet score (p<0.001). The odds ratios varied from roughly 0.5 in Southern to 1.2 or more in Northern Greek regions (p for heterogeneity<0.05). Differences in food patterns consumed did not explain the previous findings. In addition, when we stratified our analysis by rural and urban areas we found significant differences in the estimated odds ratios (p for interaction between diet score and area=0.01), since a 10-unit increase in the diet score was associated with 22% (95% CI 0.63 to 0.96) lower odds n urban areas and 31% (95% CI 0.48 to 0.98) lower odds in rural areas.

CONCLUSION

Our findings underline the significance of the Mediterranean diet on the primary prevention of ACS. Moreover, we revealed a geographical variation in the importance of this dietary pattern on coronary risk, independent from the composition of food patterns followed and the prevalence of the common cardiovascular risk factors.