Obesity, inflammatory markers and cardiovascular disease: distinguishing causality from confounding

Modification of Breakfast Fat Composition Can Modulate Cytokine and Other Inflammatory Mediators in Women: A Randomized Crossover Trial

Previous trials have demonstrated that modifying dietary fat composition can influence the production of inflammation-related factors. Additionally, it has been suggested that not only the type of fat, but also the timing of fat intake can impact these factors. Therefore, the objective of the present study was to evaluate the effect of altering breakfast fat composition on inflammatory parameters. A 3-month crossover randomized trial was designed, involving 60 institutionalized women who alternately consumed a breakfast rich in polyunsaturated fatty acids (PUFA) (margarine), monounsaturated fatty acids (MUFA) (virgin olive oil), or saturated fatty acids (SFA) (butter), based on randomization. The following inflammatory markers were evaluated: epidermal growth factor (EGF), interferon (IFN)-α, interleukin (IL)-1α, IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, monocyte chemoattractant protein-1 (MCP-1), tumor necrosis factor (TNF)-α, C-reactive protein (CRP), and vascular/endothelial growth factor (VEGF). The results showed that the most significant effects were observed with the high-MUFA breakfast, as there was a statistically significant decrease in plasma IL-6 (p = 0.016) and VEGF values (p = 0.035). Other factors, such as IL-1α and CRP, also decreased substantially, but did not reach the statistically significant level. On the other hand, the high-PUFA breakfast induced a significant decrease in EGF levels (p < 0.001), whereas the high-SFA breakfast had no apparent effect on these factors. In conclusion, modifying breakfast fat, particularly by increasing MUFA or PUFA intake, appears to be sufficient for promoting a lower inflammatory marker synthesis profile and may be beneficial in improving cardiovascular complications.

Cardiovascular Drugs and Osteoarthritis: Effects of Targeting Ion Channels

Osteoarthritis (OA) and cardiovascular diseases (CVD) share many similar features, including similar risk factors and molecular mechanisms. A great number of cardiovascular drugs act via different ion channels and change ion balance, thus modulating cell metabolism, osmotic responses, turnover of cartilage extracellular matrix and inflammation. These drugs are consumed by patients with CVD for many years; however, information about their effects on the joint tissues has not been fully clarified. Nevertheless, it is becoming increasingly likely that different cardiovascular drugs may have an impact on articular tissues in OA. Here, we discuss the potential effects of direct and indirect ion channel modulating drugs, including inhibitors of voltage gated calcium and sodium channels, hyperpolarization-activated cyclic nucleotide-gated channels, β-adrenoreceptor inhibitors and angiotensin-aldosterone system affecting drugs. The aim of this review was to summarize the information about activities of cardiovascular drugs on cartilage and subchondral bone and to discuss their possible consequences on the progression of OA, focusing on the modulation of ion channels in chondrocytes and other joint cells, pain control and regulation of inflammation. The implication of cardiovascular drug consumption in aetiopathogenesis of OA should be considered when prescribing ion channel modulators, particularly in long-term therapy protocols.

Elevated resting heart rate as a predictor of inflammation and cardiovascular risk in healthy obese individuals

The role of leukocyte inflammatory markers and toll like receptors (TLRs)2/4 in pathologies associated with elevated resting heart rate (RHR) levels in healthy obese (HO) individuals is not well elucidated. Herein, we investigated the relationship of RHR with expression of leukocyte-inflammatory markers and TLRs in HO individuals. 58-obese and 57-lean participants with no history of a major medical condition, were recruited in this study. In HO individuals, the elevated-RHR correlated positively with diastolic blood pressure, cholesterol, pro-inflammatory monocytes CD11b⁺CD11c⁺CD206⁻ phenotype (r = 0.52, P = 0.0003) as well as with activated T cells CD8⁺HLA-DR⁺ phenotype (r = 0.27, P = 0.039). No association was found between RHR and the percentage of CD16⁺CD11b⁺ neutrophils. Interestingly, elevated RHR positively correlated with cells expressing TLR4 and TLR2 (CD14⁺TLR4⁺, r = 0.51, P ≤ 0.0001; and CD14⁺TLR2⁺, r = 0.42, P = 0.001). TLR4⁺ expressing cells also associated positively with the plasma concentrations of proinflammatory or vascular permeability/matrix modulatory markers including TNF-α (r = 0.36, P = 0.005), VEGF (r = 0.47, P = 0.0002), and MMP-9 (r = 0.53, P ≤ 0.0001). Multiple regression revealed that RHR is independently associated with CD14⁺TLR4⁺ monocytes and VEGF. We conclude that in HO individuals, increased CD14⁺TLR4⁺ monocytes and circulatory VEGF levels associated independently with RHR, implying that RHR monitoring could be used as a non-invasive clinical indicator to identify healthy obese individuals at an increased risk of developing inflammation and cardiovascular disease.

Dietary sodium and potassium and risk of diabetes: A prospective study using data from the China Health and Nutrition Survey

AIMS

Dietary sodium and potassium intakes are well-known risk factors for cardiovascular outcomes. However, the associations between dietary sodium and potassium and diabetes are still controversial. Our study aimed to examine whether dietary sodium, potassium and the sodium-potassium ratio are associated with the risk of diabetes, based on a large sample of Chinese adults.

METHODS

The study data were from the 2004-2009 China Health and Nutrition Survey (CHNS), and 5867 participants were eligible for analysis. Sodium and potassium intakes were estimated based on three consecutive 24-h recalls at an individual level combined with a food inventory at a household level performed over the same 3-day period. Diabetes was defined as fasting glucose ≥7.0mmol/L (≥126mg/dL), HbA_1c ≥6.5% or use of antidiabetic drugs.

RESULTS

Over a mean follow-up of 4.7 years, there were 611 (10.4%) incident cases of diabetes. Participants in the higher quartiles (Q3 and Q4) of sodium intake had significantly higher risks of diabetes than those with the lowest sodium intake [Q3, RR: 1.41, 95% CI: 1.06-1.86 and Q4, RR: 1.35, 95% CI: 1.02-1.80; P<0.001 for trend]. In addition, high sodium intakes were significantly associated with levels of fasting glucose and HbA_1c (P<0.05 for trend), with similar associations also found with sodium-potassium ratios (P<0.05 for trend), but not for potassium intakes.

CONCLUSION

This study found that higher sodium intakes and sodium-potassium ratios were significantly associated with a higher risk of diabetes. Further clinical research is now necessary to confirm these results.

High-Sensitive C-Reactive Protein Levels in a Group of Syrian University Male Students and Its Associations with Smoking, Physical Activity, Anthropometric Measurements, and Some Hematologic Inflammation Biomarkers

In Syria, health risk data on young males are limited. Hence, the aim of the present study was to evaluate cardiovascular disease (CVD) risk factors along with C-reactive protein levels measured by high-sensitive method (hsCRP) in a group of healthy males of university students (n = 101, 18–25 years old). Participants' anthropometric characteristics; alcohol drinking, smoking, and physical activity habits; parents medical history; and some inflammatory biomarkers were inspected for their associations with hsCRP. Results. Regarding hsCRP level, 19 participants were at average (1–3 mg/L) and 13 were at high (>3 mg/L) risk of CVD. Nonparametric statistical tests (p value < 0.05) revealed that hsCRP level was higher in participants who had high body mass index (BMI), had high BMI with high waist-to-hip ratio (WHR), or did not practice sport frequently. Unexpectedly, it did not vary between smokers and nonsmokers. In general, it correlated positively with anthropometric and erythrocyte sedimentation rate (ESR) measurements. Nevertheless, it negatively correlated with sports practicing in overall and nonsmoker groups and in participants whose parents were without medical history. Finally, when participants with high BMI were smokers, did not practice sport frequently, or had a parent with medical history, their hsCRP levels were higher than others who had the same circumstances but with low BMI.

Effects of an Encapsulated Fruit and Vegetable Juice Concentrate on Obesity-Induced Systemic Inflammation: A Randomised Controlled Trial

Phytochemicals from fruit and vegetables reduce systemic inflammation. This study examined the effects of an encapsulated fruit and vegetable (F&V) juice concentrate on systemic inflammation and other risk factors for chronic disease in overweight and obese adults. A double-blinded, parallel, randomized placebo-controlled trial was conducted in 56 adults aged ≥40 years with a body mass index (BMI) ≥28 kg/m². Before and after eight weeks daily treatment with six capsules of F&V juice concentrate or placebo, peripheral blood gene expression (microarray, quantitative polymerase chain reaction (qPCR)), plasma tumour necrosis factor (TNF)α (enzyme-linked immunosorbent assay (ELISA)), body composition (Dual-energy X-ray absorptiometry (DEXA)) and lipid profiles were assessed. Following consumption of juice concentrate, total cholesterol, low-density lipoprotein (LDL) cholesterol and plasma TNFα decreased and total lean mass increased, while there was no change in the placebo group. In subjects with high systemic inflammation at baseline (serum C-reactive protein (CRP) ≥3.0 mg/mL) who were supplemented with the F&V juice concentrate (n = 16), these effects were greater, with decreased total cholesterol, LDL cholesterol and plasma TNFα and increased total lean mass; plasma CRP was unchanged by the F&V juice concentrate following both analyses. The expression of several genes involved in lipogenesis, the nuclear factor-κB (NF-κB) and 5' adenosine monophosphate-activated protein kinase (AMPK) signalling pathways was altered, including phosphomevalonate kinase (PMVK), zinc finger AN1-type containing 5 (ZFAND5) and calcium binding protein 39 (CAB39), respectively. Therefore, F&V juice concentrate improves the metabolic profile, by reducing systemic inflammation and blood lipid profiles and, thus, may be useful in reducing the risk of obesity-induced chronic disease.

Lifecourse socioeconomic status and type 2 diabetes: the role of chronic inflammation in the English Longitudinal Study of Ageing

We examined the association between lifecourse socioeconomic status (SES) and the risk of type 2 diabetes at older ages, ascertaining the extent to which adult lifestyle factors and systemic inflammation explain this relationship. Data were drawn from the English Longitudinal Study of Ageing (ELSA) which, established in 2002, is a representative cohort study of ≥50-year olds individuals living in England. SES indicators were paternal social class, participants’ education, participants’ wealth, and a lifecourse socioeconomic index. Inflammatory markers (C-reactive protein and fibrinogen) and lifestyle factors were measured repeatedly; diabetes incidence (new cases) was monitored over 7.5 years of follow-up. Of the 6218 individuals free from diabetes at baseline (44% women, mean aged 66 years), 423 developed diabetes during follow-up. Relative to the most advantaged people, those in the lowest lifecourse SES group experienced more than double the risk of diabetes (hazard ratio 2.59; 95% Confidence Interval (CI) = 1.81–3.71). Lifestyle factors explained 52% (95%CI:30–85) and inflammatory markers 22% (95%CI:13–37) of this gradient. Similar results were apparent with the separate SES indicators. In a general population sample, socioeconomic inequalities in the risk of type 2 diabetes extend to older ages and appear to partially originate from socioeconomic variations in modifiable factors which include lifestyle and inflammation.

Modulation of adipose tissue inflammation by bioactive food compounds

Adipose tissue has an important endocrine function in the regulation of whole-body metabolism. Obesity leads to a chronic low-grade inflammation of the adipose tissue, which disrupts this endocrine function and results in metabolic derangements, such as type-2 diabetes. Dietary bioactive compounds, such as polyphenols and certain fatty acids, are known to suppress both systemic and adipose tissue inflammation and have the potential to improve these obesity-associated metabolic disorders. Mechanistically, polyphenolic compounds including non-flavonoids, such as curcumin and resveratrol, and flavonoids, such as catechins (tea-polyphenols), quercetin and isoflavones, suppress nuclear factor-κB (NF-κB) and mitogen-activated protein (MAP) kinases (MAPK) pathways while activating the 5' adenosine monophosphate-activated protein kinase (AMPK) pathway in adipose tissue. Dietary polyunsaturated fatty acids, such as eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), conjugated linoleic acid (CLA) and monounsaturated fatty acids (MUFA), such as oleic acid, also impart anti-inflammatory effects through several mechanisms. These include activation of AMPK and peroxisome proliferator-activated receptor gamma (PPAR-γ), as well as suppression of toll-like receptors (TLRs) and NF-κB pathway. This review discusses the major molecular mechanisms of dietary polyphenols and fatty acids, alone or in combination, which are responsible for adipose tissue-associated anti-inflammatory effects.

Association of lifecourse socioeconomic status with chronic inflammation and type 2 diabetes risk: the Whitehall II prospective cohort study

BACKGROUND

Socioeconomic adversity in early life has been hypothesized to "program" a vulnerable phenotype with exaggerated inflammatory responses, so increasing the risk of developing type 2 diabetes in adulthood. The aim of this study is to test this hypothesis by assessing the extent to which the association between lifecourse socioeconomic status and type 2 diabetes incidence is explained by chronic inflammation.

METHODS AND FINDINGS

We use data from the British Whitehall II study, a prospective occupational cohort of adults established in 1985. The inflammatory markers C-reactive protein and interleukin-6 were measured repeatedly and type 2 diabetes incidence (new cases) was monitored over an 18-year follow-up (from 1991-1993 until 2007-2009). Our analytical sample consisted of 6,387 non-diabetic participants (1,818 women), of whom 731 (207 women) developed type 2 diabetes over the follow-up. Cumulative exposure to low socioeconomic status from childhood to middle age was associated with an increased risk of developing type 2 diabetes in adulthood (hazard ratio [HR] = 1.96, 95% confidence interval: 1.48-2.58 for low cumulative lifecourse socioeconomic score and HR = 1.55, 95% confidence interval: 1.26-1.91 for low-low socioeconomic trajectory). 25% of the excess risk associated with cumulative socioeconomic adversity across the lifecourse and 32% of the excess risk associated with low-low socioeconomic trajectory was attributable to chronically elevated inflammation (95% confidence intervals 16%-58%).

CONCLUSIONS

In the present study, chronic inflammation explained a substantial part of the association between lifecourse socioeconomic disadvantage and type 2 diabetes. Further studies should be performed to confirm these findings in population-based samples, as the Whitehall II cohort is not representative of the general population, and to examine the extent to which social inequalities attributable to chronic inflammation are reversible.

n-3 and n-6 polyunsaturated fatty acids differentially regulate adipose angiotensinogen and other inflammatory adipokines in part via NF-κB-dependent mechanisms

Excessive secretion of proinflammatory adipokines has been linked to metabolic disorders. We have previously documented anti-inflammatory effects of n-3 polyunsaturated fatty acids (n-3 PUFAs) in adipose tissue; however, the mechanisms by which these fatty acids regulate adipokine secretion remain unclear. Here, we determined differential effects of eicosapentaenoic acid (EPA, n-3 PUFA) vs. arachidonic acid (AA, n-6 PUFA) on expression and secretion of angiotensinogen (Agt), interleukin 6 (IL-6) and monocyte chemotactic protein (MCP-1) in 3T3-L1 adipocytes. While both PUFAs increased intracellular Agt protein and mRNA expression, Agt secretion into culture media was increased only by AA treatment, which in turn was prevented by co-treatment with EPA. At various AA/EPA ratios, increasing AA concentrations significantly increased secretion of the above three adipokines, whereas increasing EPA dose-dependently, while lowering AA, decreased their secretion. Moreover, IL-6 and MCP-1 were more significantly reduced by EPA treatment compared to Agt (IL-6>MCP>Agt). Next, we tested whether nuclear factor-κB (NF-κB), a major proinflammatory transcription factor, was involved in regulation of these adipokines by PUFAs. EPA significantly inhibited NF-κB activation compared to control or AA treatments. Moreover, EPA attenuated tumor necrosis factor-α-induced MCP-1 and further reduced its secretion in the presence of an NF-κB inhibitor. Taken together, we reported here novel beneficial effects of EPA in adipocytes. We demonstrated direct anti-inflammatory effects of EPA, which are at least in part due to the inhibitory effects of this n-3 PUFA on the NF-κB pathway in adipocytes. In conclusion, these studies further support beneficial effects of n-3 PUFAs in adipocyte inflammation and metabolic disorders.

Different exercise protocols improve metabolic syndrome markers, tissue triglycerides content and antioxidant status in rats

BACKGROUND

An increase in the prevalence of obesity entails great expenditure for governments. Physical exercise is a powerful tool in the combat against obesity and obesity-associated diseases. This study sought to determine the effect of three different exercise protocols on metabolic syndrome and lipid peroxidation markers and the activity of antioxidant enzymes in adult Wistar rats (120 days old).

METHODS

Animals were randomly divided into four groups: the control (C) group was kept sedentary throughout the study; the aerobic group (A) swam1 h per day, 5 days per week, at 80% lactate threshold intensity; the strength group (S) performed strength training with four series of 10 jumps, 5 days per week; and the Concurrent group (AS) was trained using the aerobic protocol three days per week and the strength protocol two days per week.

RESULTS

Groups A and S exhibited a reduction in body weight compared to group C. All exercised animals showed a reduction in triglyceride concentrations in fatty tissues and the liver. Exercised animals also exhibited a reduction in lipid peroxidation markers (TBARS) and an increase in serum superoxide dismutase activity. Animals in group A had increased levels of liver catalase and superoxide dismutase activities.

CONCLUSIONS

We concluded that all physical activity protocols improved the antioxidant systems of the animals and decreased the storage of triglycerides in the investigated tissues.

Abdominal and gynoid adipose distribution and incident myocardial infarction in women and men

OBJECTIVE

The relationships between objectively measured abdominal and gynoid adipose mass with the prospective risk of myocardial infarction (MI) has been scarcely investigated. We aimed to investigate the associations between fat distribution and the risk of MI.

SUBJECTS

Total and regional fat mass was measured using dual-energy X-ray absorptiometry (DEXA) in 2336 women and 922 men, of whom 104 subsequently experienced an MI during a mean follow-up time of 7.8 years.

RESULTS

In women, the strongest independent predictor of MI was the ratio of abdominal to gynoid adipose mass (hazard ratio (HR)=2.44, 95% confidence interval (CI) 1.79-3.32 per s.d. increase in adipose mass), after adjustment for age and smoking. This ratio also showed a strong association with hypertension, impaired glucose tolerance and hypertriglyceridemia (P<0.01 for all). In contrast, the ratio of gynoid to total adipose mass was associated with a reduced risk of MI (HR= 0.57, 95% CI 0.43-0.77), and reduced risk of hypertension, impaired glucose tolerance and hypertriglyceridemia (P<0.001 for all). In men, gynoid fat mass was associated with a decreased risk of MI (HR=0.69, 95% CI 0.48-0.98), and abdominal fat mass was associated with hypertriglyceridemia (P for trend 0.02).

CONCLUSION

In summary, fat distribution was a strong predictor of the risk of MI in women, but not in men. These different results may be explained by the associations found between fat distribution and hypertension, impaired glucose tolerance and hypertriglyceridemia.

Visfatin, low-grade inflammation and body mass index (BMI)

OBJECTIVE

Visfatin is an adipokine with revealing roles in inflammatory mechanisms but its implication in inflammation related to excessive adiposity/obesity is not studied yet. Our aim was to investigate the relations of visfatin with inflammation markers and body mass index (BMI) in the peripheral blood mononuclear cells (PBMCs), a type of cells closely related to inflammatory mechanisms.

DESIGN

Cross-sectional study, quantification of visfatin, TNF-alpha, IL-6 mRNA in PBMCs.

PATIENTS

Eighty-three supposed healthy individuals from the STANISLAS cohort, belonging in three BMI categories: BMI < 25 kg/m(2) (lean), 25 kg/m(2) <or= BMI < 30 kg/m(2) (overweight) or BMI >or= 30 kg/m(2) (obese).

MEASUREMENTS

We measured visfatin gene expression (by real-time quantitative PCR), in relation to gene expression of the pro-inflammatory cytokines TNF-alpha, IL-6 in PBMCs and to anthropometric parameters (weight, BMI, waist : hip ratio), blood pressure, lipid profile, glucose and inflammatory markers (C-reactive protein, lymphocyte count).

RESULTS

Visfatin expression in PBMCs was significantly associated with BMI in a negative way (r = -0.21, P = 0.05). Global anova analysis test for lean and over-weight/obese individuals showed a negative significant association between visfatin expression in PBMCs and BMI both for men and women (P = 0.05 and P = 0.01, respectively) and these associations remained significant after separating subjects in three groups (lean, overweight, obese) for men and women (P = 0.02 and P = 0.05, respectively). Correlation analysis between levels of expression of visfatin and TNF-alpha showed a significant positive linear association (r(2) = 0.27, P < 0.0001).

CONCLUSION

These findings reveal a probable new role of visfatin in inflammation reflected in PBMCs, in the context of obesity.