Postprandial endothelial activation in healthy subjects and in type 2 diabetic patients: role of fat and carbohydrate meals

Postprandial hyperglycemia and endothelial function in type 2 diabetes: focus on mitiglinide

The risk of cardiovascular complication in a diabetes patient is similar to that in a nondiabetic patient with a history of myocardial infarction. Although intensive control of glycemia achieved by conventional antidiabetic agents decreases microvascular complications such as retinopathy and nephropathy, no marked effect has been reported on macrovascular complications or all-cause mortality. Evidence from VADT, ACCORD, and ADVANCE would suggest that glycemic control has little effect on macrovascular outcomes. Moreover, in the case of ACCORD, intensive glycemic control may be associated with an increased risk of mortality. There is sufficient evidence that suggests that postprandial hyperglycemia may be an independent risk factor for cardiovascular disease in diabetes patients. However, there are no prospective clinical trials supporting the recommendation that lowering postprandial blood glucose leads to lower risk of cardiovascular outcomes. Mitiglinide is a short-acting insulinotropic agent used in type 2 diabetes treatment. It has a rapid stimulatory effect on insulin secretion and reduces postprandial plasma glucose level in patients with type 2 diabetes. Because of its short action time, it is unlikely to exert adverse effects related to hypoglycemia early in the morning and between meals. Mitiglinide reduces excess oxidative stress and inflammation, plays a cardioprotective role, and improves postprandial metabolic disorders. Moreover, mitiglinide add-on therapy with pioglitazone favorably affects the vascular endothelial function in type 2 diabetes patients. These data suggest that mitiglinide plays a potentially beneficial role in the improvement of postprandial hyperglycemia in type 2 diabetes patients and can be used to prevent cardiovascular diseases. Although the results of long-term, randomized, placebo-controlled trials for determining the cardiovascular effects of mitiglinide on clinical outcomes are awaited, this review is aimed at summarizing substantial insights into this topic.

The role of dietary fatty acids in the pathology of metabolic syndrome

Dysfunctional lipid metabolism is a key component in the development of metabolic syndrome, a very frequent condition characterized by dyslipidemia, insulin resistance, abdominal obesity and hypertension, which are related to an elevated risk for type 2 diabetes mellitus. The prevalence of metabolic syndrome is strongly associated with the severity of obesity; its physiopathology is related to both genetics and food intake habits, especially the consumption of a high-caloric, high-fat and high-carbohydrate diet. With the progress of scientific knowledge in the field of nutrigenomics, it was possible to elucidate how the majority of dietary fatty acids influence plasma lipid metabolism and also the genes expression involved in lipolysis and lipogenesis within hepatocytes and adipocytes. The aim of this review is to examine the relevant mechanistic aspects of dietary fatty acids related to blood lipids, adipose tissue metabolism, hepatic fat storage and inflammatory process, all of them closely related to the genesis of metabolic syndrome.

Moderate-intensity, premeal cycling blunts postprandial increases in monocyte cell surface CD18 and CD11a and endothelial microparticles following a high-fat meal in young adults

High-fat meals promote transient increases in proatherogenic factors, implicating the postprandial state in cardiovascular disease (CVD) progression. Although low-grade inflammation is associated with CVD, little research has assessed postprandial inflammation. Because of its anti-inflammatory properties, premeal exercise may counteract postprandial inflammation. The purpose of this study was to determine postprandial alterations in monocytes and circulating markers of endothelial stress and inflammation following a high-fat meal in young adults with or without premeal cycle exercise. Each subject completed two trials and was randomized to rest or cycle at a moderate intensity prior to eating a high-fat meal. Flow cytometry was used to assess monocyte cell surface receptor expression and concentration of endothelial microparticles (EMP). Plasma cytokines were assessed using Luminex MagPix. Statistical analysis was completed using separate linear mixed models analyses with first-order autoregressive (AR(1)) heterogeneous covariance structure. Significance was set at P ≤ 0.05. Percentage increases in classic monocyte CD11a and CD18 were greater overall in the postprandial period in the meal-only condition compared with the meal + exercise condition (P < 0.05). EMP concentration was 47% greater 3 h after the meal compared with premeal values in the meal-only condition (P < 0.05); no significant increase was observed in the meal + exercise condition. Premeal cycling blunted postprandial increases in EMP and CD11a and CD18. Acute, moderate-intensity exercise may help counteract possibly deleterious postprandial monocyte and endothelial cell activation.

High-intensity exercise attenuates postprandial lipaemia and markers of oxidative stress

Regular exercise can reduce the risk of CVD (cardiovascular disease). Although moderate-intensity exercise can attenuate postprandial TAG (triacylglycerol), high-intensity intermittent exercise might be a more effective method to improve health. We compared the effects of high-intensity intermittent exercise and 30 min of brisk walking on postprandial TAG, soluble adhesion molecules and markers of oxidative stress. Nine men each completed three 2-day trials. On day 1, subjects rested (control), walked briskly for 30 min (walking) or performed 5×30 s maximal sprints (high-intensity). On day 2, subjects consumed a high-fat meal for breakfast and 3 h later for lunch. Blood samples were taken at various times and analysed for TAG, glucose, insulin, ICAM-1 (intracellular adhesion molecule-1), VCAM-1 (vascular adhesion molecule-1), TBARS (thiobarbituric acid- reactive substances), protein carbonyls and β-hydroxybutyrate. On day 2 of the high-intensity trial, there was a lower (P<0.05) incremental TAG AUC (area under the curve; 6.42±2.24 mmol/l per 7 h) compared with the control trial (9.68±4.77 mmol/l per 7 h) with no differences during day 2 of the walking trial (8.98±2.84 mmol/l per 7 h). A trend (P=0.056) for a reduced total TAG AUC was also seen during the high-intensity trial (14.13±2.83 mmol/l per 7 h) compared with control (17.18±3.92 mmol/l per 7 h), walking showed no difference (16.33±3.51 mmol/l per 7 h). On day 2 of the high-intensity trial plasma TBARS and protein carbonyls were also reduced (P<0.05) when compared with the control and walking trials. In conclusion, high-intensity intermittent exercise attenuates postprandial TAG and markers of oxidative stress after the consumption of a high-fat meal.

Postprandial blood cell transcriptomics in response to the ingestion of dairy products by healthy individuals

The aim of this intervention study was to measure genome-wide postprandial gene expression in human blood cells after the ingestion of a single serving of milk, to identify the downstream physiological processes regulated by the differentially expressed genes, and to use this gene expression signature as a reference to compare it with the response following the ingestion of a transformed dairy product, namely, yogurt. We conducted a randomized, controlled, single-blinded, crossover study on six healthy male individuals. After an overnight fast, 540 g of milk or yogurt was ingested by the subjects. Blood samples were collected before (0 h) and after (2 h/4 h/6 h) ingestion, and the blood cell transcriptome was analyzed using a linear kinetic analysis that increases the statistical power of the study. The differentially expressed transcripts identified after the ingestion of milk (575 transcripts) and yogurt (625 transcripts) modulated similar biological processes. In particular, genes involved in protein biosynthesis and mitochondrial activities followed biphasic kinetics being down-regulated at 2 h and more pronouncedly up-regulated at 6 h. The opposite kinetics were observed for inflammatory and apoptotic processes during the same time frame. The human blood cell transcriptome appeared to be specifically modulated by specific nutrients present in bovine milk, a property that was further modified when milk was fermented to yogurt. The coordinated changes in postprandial expression of genes involved in basic biological processes suggest that postprandial blood cell transcriptomics may allow insight into the nutritional effects of selected foods in the prevention or development of chronic metabolic and inflammatory disorders.

Hyperglycemia in nondiabetic patients presenting with acute myocardial infarction

Hyperglycemia is common in nondiabetic patients with acute myocardial infarction (AMI). Elevated blood glucose level may reflect a response to stress, an underlying abnormal glucometabolic state or both. Regardless of mechanism, hyperglycemia complicating AMI is associated with an inflammatory and prothrombotic state, depressed myocardial contractility and increased short- and long-term mortality. Studies are needed to define optimal monitoring and management of hyperglycemia in nondiabetic patients with AMI.

Chronic inflammatory diseases are stimulated by current lifestyle: how diet, stress levels and medication prevent our body from recovering

Serhan and colleagues introduced the term "Resoleomics" in 1996 as the process of inflammation resolution. The major discovery of Serhan's work is that onset to conclusion of an inflammation is a controlled process of the immune system (IS) and not simply the consequence of an extinguished or "exhausted" immune reaction. Resoleomics can be considered as the evolutionary mechanism of restoring homeostatic balances after injury, inflammation and infection. Under normal circumstances, Resoleomics should be able to conclude inflammatory responses. Considering the modern pandemic increase of chronic medical and psychiatric illnesses involving chronic inflammation, it has become apparent that Resoleomics is not fulfilling its potential resolving capacity. We suggest that recent drastic changes in lifestyle, including diet and psycho-emotional stress, are responsible for inflammation and for disturbances in Resoleomics. In addition, current interventions, like chronic use of anti-inflammatory medication, suppress Resoleomics. These new lifestyle factors, including the use of medication, should be considered health hazards, as they are capable of long-term or chronic activation of the central stress axes. The IS is designed to produce solutions for fast, intensive hazards, not to cope with long-term, chronic stimulation. The never-ending stress factors of recent lifestyle changes have pushed the IS and the central stress system into a constant state of activity, leading to chronically unresolved inflammation and increased vulnerability for chronic disease. Our hypothesis is that modern diet, increased psycho-emotional stress and chronic use of anti-inflammatory medication disrupt the natural process of inflammation resolution ie Resoleomics.

Plasma metabolomics and proteomics profiling after a postprandial challenge reveal subtle diet effects on human metabolic status

We introduce the metabolomics and proteomics based Postprandial Challenge Test (PCT) to quantify the postprandial response of multiple metabolic processes in humans in a standardized manner. The PCT comprised consumption of a standardized 500 ml dairy shake containing respectively 59, 30 and 12 energy percent lipids, carbohydrates and protein. During a 6 h time course after PCT 145 plasma metabolites, 79 proteins and 7 clinical chemistry parameters were quantified. Multiple processes related to metabolism, oxidation and inflammation reacted to the PCT, as demonstrated by changes of 106 metabolites, 31 proteins and 5 clinical chemistry parameters. The PCT was applied in a dietary intervention study to evaluate if the PCT would reveal additional metabolic changes compared to non-perturbed conditions. The study consisted of a 5-week intervention with a supplement mix of anti-inflammatory compounds in a crossover design with 36 overweight subjects. Of the 231 quantified parameters, 31 had different responses over time between treated and control groups, revealing differences in amino acid metabolism, oxidative stress, inflammation and endocrine metabolism. The results showed that the acute, short term metabolic responses to the PCT were different in subjects on the supplement mix compared to the controls. The PCT provided additional metabolic changes related to the dietary intervention not observed in non-perturbed conditions. Thus, a metabolomics based quantification of a standardized perturbation of metabolic homeostasis is more informative on metabolic status and subtle health effects induced by (dietary) interventions than quantification of the homeostatic situation. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11306-011-0320-5) contains supplementary material, which is available to authorized users.

Interindividual and intraindividual variations in postprandial glycemia peak time complicate precise recommendations for self-monitoring of glucose in persons with type 1 diabetes mellitus

BACKGROUND

In glycemic control, postprandial glycemia may be important to monitor and optimize as it reveals glycemic control quality, and postprandial hyperglycemia partly predicts late diabetic complications. Self-monitoring of blood glucose (SMBG) may be an appropriate technology to use, but recommendations on measurement time are crucial.

METHOD

We retrospectively analyzed interindividual and intraindividual variations in postprandial glycemic peak time. Continuous glucose monitoring (CGM) and carbohydrate intake were collected in 22 patients with type 1 diabetes mellitus. Meals were identified from carbohydrate intake data. For each meal, peak time was identified as time from meal to CGM zenith within 40-150 min after meal start. Interindividual (one-way Anova) and intraindividual (intraclass correlation coefficient) variation was calculated.

RESULTS

Nineteen patients were included with sufficient meal data quality. Mean peak time was 87 ± 29 min. Mean peak time differed significantly between patients (p = 0.02). Intraclass correlation coefficient was 0.29.

CONCLUSIONS

Significant interindividual and intraindividual variations exist in postprandial glycemia peak time, thus hindering simple and general advice regarding postprandial SMBG for detection of maximum values.

Postprandial glucose monitoring further improved glycemia, lipids, and weight in persons with type 2 diabetes mellitus who had already reached hemoglobin A1c goal

BACKGROUND

Postprandial hyperglycemia contributes to poor glucose control and is associated with increased cardiovascular risk in type 2 diabetes mellitus (T2DM). The objective of the study was to determine the effect of postprandial self-monitoring of blood glucose (pp-SMBG) on glucose control, lipids, body weight, and cardiovascular events.

METHOD

Subjects with T2DM hemoglobin A1c (A1C) between 6.5 to 7.0% were randomized into the study group (at least two pp-SMBG a day and dietary modification based on glucose readings) and control group (dietary modification based on glucose readings but no mandatory pp-SMBG) for a 6-month, observational study. Oral antidiabetic drugs or insulin regimen was unchanged in either group if A1C remained less than 7.0% during the study. End points included A1C, lipids, body weight, and cardiovascular events.

RESULTS

One hundred sixty-nine subjects, mean age 63 years, and body weight 88 kg were recruited. Hemoglobin A1c, weight, low-density lipoprotein (LDL), and triglycerides (TGs) were similar in the groups at baseline. By the end of 6 months, A1C (6.7 ± 0.1 to 6.4 ± 0.1%, p < .05), body weight (88.5 ± 7.3 to 85.2 ± 6.3 kg, p < .05), LDL (92.3 ± 2 8.4 to 81.1 ± 22.6 mg/dl, p < .05), and TGs (141 ± 21 to 96 ± 17 mg/dl, p < .05) decreased in the study group, but did not change in the control group. No cardiovascular events were observed in either group during the 6-month study period.

CONCLUSIONS

In T2DM subjects who had already reached their A1C goal, pp-SMBG at least twice a day was associated with further improvement in glycemia, lipids, and weight, as well as exercise and dietary habit. We assume that lifestyle modification promoted by postprandial hyperglycemia awareness may underlie these findings. These results substantiate the importance of implementing pp-SMBG into lifestyle modification, and emphasize that pp-SMBG is critical in the control of T2DM.

Of microbes and meals: the health consequences of dietary endotoxemia

The human intestinal tract comprises a rich and complex microbial ecosystem. This intestinal microbota provides a large reservoir of potentially toxic molecules, including bacterial endotoxin (ie, lipopolysaccharide [LPS]). This potent inflammatory molecule is detectable in the circulation of healthy individuals, and levels transiently increase following ingestion of energy-rich meals. Chronic exposure to circulating endotoxin has been associated with obesity, diabetes, and cardiovascular disease. Western-style meals augment LPS translocation and by this mechanism may contribute to the pathogenesis of these diseases. By contrast, the gut and other organs have evolved mechanisms to detoxify endotoxin and neutralize the potentially inflammatory qualities of circulating endotoxin. Of specific interest to clinicians is evidence that acute postprandial elevation of circulating endotoxin is dependent on meal composition. In this review, the authors present an overview of the biochemical and cellular mechanisms that lead to endotoxemia, with emphasis on the interplay between microbial and nutrition determinants of this condition. The link between endotoxemia, diet, and changes in the intestinal microbiota raise the possibility that dietary interventions can, at least in part, ameliorate the detrimental outcomes of endotoxemia.

Acute effects of dietary fat on inflammatory markers and gene expression in first-degree relatives of type 2 diabetes patients

BACKGROUND

Subjects with type 2 diabetes (T2D) and their relatives (REL) carry an increased risk of cardiovascular disease (CVD). Low-grade inflammation, an independent risk factor for CVD, is modifiable by diet. Subjects with T2D show elevated postprandial inflammatory responses to fat-rich meals, while information on postprandial inflammation in REL is sparse.

AIM

To clarify whether medium-chain saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA) have differential acute effects on low-grade inflammation in REL compared to controls (CON).

METHODS

In randomized order, 17 REL and 17 CON ingested two fat-rich meals, with 72 energy percent from MUFA and 79 energy percent from mainly medium-chain SFA, respectively. Plasma high sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), adiponectin, and leptin were measured at baseline, 15 min, 60 min, and 240 min postprandially. Muscle and adipose tissue biopsies were taken at baseline and 210 min after the test meal, and expression of selected genes was analyzed.

RESULTS

Plasma IL-6 increased (p < 0.001) without difference between REL and CON and between the meals, whereas plasma adiponectin and plasma hs-CRP were unchanged during the 240 min observation period. Plasma leptin decreased slightly in response to medium-chain SFA in both groups, and to MUFA in REL. Several genes were differentially regulated in muscle and adipose tissue of REL and CON.

CONCLUSIONS

MUFA and medium-chain SFA elicit similar postprandial circulating inflammatory responses in REL and CON. Medium-chain SFA seems more proinflammatory than MUFA, judged by the gene expression in muscle and adipose tissue of REL and CON.

Lifestyle Measures to Reduce Inflammation

Chronic low-grade inflammation associated with cardiovascular disease and type 2 diabetes (T2D) may be ameliorated with exercise and/or diet. High levels of physical activity and/or cardiorespiratory fitness are associated with reduced risk of low-grade inflammation. Both aerobic and resistance exercise have been found to improve inflammatory status, with the majority of evidence suggesting that aerobic exercise may have broader anti-inflammatory effects. In particular, aerobic exercise appears to improve the balance between pro- and anti-inflammatory markers. Improvement in inflammatory status is most likely to occur in persons with elevated levels of pro-inflammatory markers prior to intervention. A number of dietary factors, including fiber-rich foods, whole grains, fruits (especially berries), omega-3 fatty acids, antioxidant vitamins (eg, C and E), and certain trace minerals (eg, zinc) have been documented to reduce blood concentrations of inflammatory markers. Anti-inflammatory foods may also help mitigate the pro-inflammatory postprandial state that is particularly evident after ingestion of meals high in saturated fat. Intensive lifestyle interventions involving both exercise and diet appear to be most effective. For the most part, anti-inflammatory effects of exercise and diet are independent of weight loss. Thus overweight and obese men and women, who are most likely to have a pro-inflammatory profile, do not necessarily have to normalize body mass index to improve inflammatory status and reduce risk of type 2 diabetes and cardiovascular disease.

Effects of acute ingestion of different fats on oxidative stress and inflammation in overweight and obese adults

Background

Studies show that obese individuals have prolonged elevations in postprandial lipemia and an exacerbated inflammatory response to high fat meals, which can increase risk for cardiovascular diseases. As epidemiological studies indicate an association between type of fat and circulating inflammatory markers, the purpose of this study was to investigate the acute effect of different fat sources on inflammation and oxidative stress in overweight and obese individuals.

Methods

Eleven overweight and obese subjects consumed three high fat milkshakes rich in monounsaturated fat (MFA), saturated fat (SFA), or long-chain omega 3 polyunsaturated fat (O3FA) in random order. Blood samples collected at baseline, 1, 2, 4, and 6 hours postprandial were analyzed for markers of inflammation (soluble intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), tumor necrosis factor- α (TNF-α), and C-reactive protein (CRP)), oxidative stress (8-epi-prostaglandin-F2α (8-epi) and nuclear factor-κB (NF-κB)), and metabolic factors (glucose, insulin, non-esterified free fatty acids, and triglycerides (TG)).

Results

O3FA enhanced NF-kB activation compared to SFA, but did not increase any inflammatory factors measured. Conversely, SFA led to higher ICAM-1 levels than MFA (p = 0.051), while MFA increased TG more than SFA (p < 0.05). CRP increased while TNF-α and 8-epi decreased with no difference between treatments.

Conclusions

While most of the inflammatory factors measured had modest or no change following the meal, ICAM-1 and NF-κB responded differently by meal type. These results are provocative and suggest that type of fat in meals may differentially influence postprandial inflammation and endothelial activation.

Differential effects of low-carbohydrate and low-fat diets on inflammation and endothelial function in diabetes

OBJECTIVE

To characterize acute (postprandial) and chronic (after a 6-month period of weight loss) effects of a low-carbohydrate vs. a low-fat diet on subclinical markers of cardiovascular disease (CVD) in adults with type 2 diabetes.

DESIGN

At baseline and 6 months, measures of C-reactive protein (CRP), interleukin-6 (IL-6), soluble intercellular adhesion molecule (sICAM) and soluble E-selectin were obtained from archived samples (n = 51) of participants randomized in a clinical trial comparing a low-carbohydrate and a low-fat diet. In a subset of participants (n = 27), postprandial measures of these markers were obtained 3 h after a low-carbohydrate or low-fat liquid meal. Endothelial function was also measured by reactive hyperemic peripheral arterial tonometry during the meal test. Paired t tests and unpaired t tests compared within- and between-group changes.

RESULTS

There were no significant differences observed in postprandial measures of inflammation or endothelial function. After 6 months, CRP (mean ± S.E.) decreased in the low-fat arm from 4.0 ± 0.77 to 3.0 ± 0.77 (P = .01). In the low-carbohydrate arm, sICAM decreased from 234 ± 22 to 199 ± 23 (P = .001), and soluble E-selectin decreased from 93 ± 10 to 82 ± 10 (P = .05.) A significant correlation between change in high-density lipoprotein and change in soluble E-selectin (r = -0.33, P = .04) and with the change in ICAM (r = -0.43, P = .01) was observed.

CONCLUSIONS

Low-carbohydrate and low-fat diets both have beneficial effects on CVD markers. There may be different mechanisms through which weight loss with these diets potentially reduces CVD risk.

Culinary plants and their potential impact on metabolic overload

Contemporary human behavior has led a large proportion of the population to metabolic overload and obesity. Postprandial hyperlipidemia and hyperglycemia evoke redox imbalance in the short term and lead to complex chronic disease in the long term with repeated occurrence. Complex diseases are best prevented with complex components of plants; thus, current nutrition research has begun to focus on the development of plant-based functional foods and dietary supplements for health and well-being. Furthermore, given the wide range of species, parts, and secondary metabolites, culinary plants can contribute significant variety and complexity to the human diet. Although understanding the health benefits of culinary plants has been one of the great challenges in nutritional science due to their inherent complexity, it is an advantageous pursuit. This review will address the challenges and opportunities relating to studies of the health benefits of culinary plants, with an emphasis on obesity attributed to metabolic overload.

Resistance to type 2 diabetes mellitus: a matter of hormesis?

Type 2 diabetes mellitus is characterized by subclinical systemic inflammation and impaired regulation of blood glucose levels. Interestingly, impairment of glycemic control occurs despite substantial insulin secretion early in the course of this disease. Dysfunction of several organs (including pancreatic islets, liver, skeletal muscle, adipose tissue, gut, hypothalamus and the immune system) has been implicated in the pathogenesis of type 2 diabetes mellitus. However, diabetes-promoting lifestyle factors do not inevitably cause disease in all persons exposed. Hence, defense mechanisms must exist that can keep the detrimental influence of these risk factors at bay. Hormesis describes the phenomenon that exposure to a mild stressor confers resistance to subsequent, otherwise harmful, conditions of increased stress. This Review discusses the emerging concept that the effectiveness of an adaptive (hormetic) response to detrimental lifestyle factors determines the extent of protection from progression to type 2 diabetes mellitus. Further analysis of these protective hormetic responses at the molecular level should help to identify novel targets for preventive or therapeutic intervention in patients at risk of developing type 2 diabetes mellitus or those with overt disease.

Effects of blackcurrant-based juice on atherosclerosis-related biomarkers in cultured macrophages and in human subjects after consumption of a high-energy meal

Regular consumption of fruit and vegetables may be associated with decreased CVD risk. In the present study, we investigated the effects of blackcurrant (BC) juice, rich in polyphenols and ascorbic acid, on oxidative and inflammatory biomarkers in cultured macrophages in vitro and in human subjects with an atherosclerosis-prone phenotype (after consumption of a high-energy meal). In cultured macrophages (RAW264.7), BC treatment significantly inhibited lipopolysaccharide-induced inflammation as indicated by lower mRNA levels of TNF-α, IL-1β and inducible NO synthase (iNOS) and lower nuclear p65 levels indicating decreased NF-κB activity. iNOS protein levels were lower and haem oxygenase 1 levels higher in BC-treated cells when compared with untreated controls. Subjects given a high-energy meal had elevated serum glucose and insulin levels with no significant difference between the BC-based juice and placebo treatment groups. TAG following meal ingestion tended to be attenuated after the BC treatment. Plasma ascorbic acid and radical-scavenging capacity were decreased following placebo meal consumption; however, BC significantly elevated both parameters compared with baseline and placebo ingestion. Plasma oxidised LDL, α-tocopherol and paraoxonase activity were unchanged in both treatment groups. Furthermore, production of TNF-α and IL-1β was not significantly changed by BC meal consumption. The present results suggest potential antioxidative and anti-inflammatory properties of BC in vitro in cultured macrophages. Although the observations were not directly transferable to a postprandial in vivo situation, the present results show that BC juice consumption may improve postprandial antioxidant status as indicated by higher ascorbic acid levels and free radical-scavenging capacity in plasma.

Meal-induced increases in C-reactive protein, interleukin-6 and tumour necrosis factor α are attenuated by prandial + basal insulin in patients with Type 2 diabetes

AIM

To determine if a regimen with prandial + basal insulin compared with basal insulin attenuates post-meal inflammatory and glycative biomarkers in patients with Type 2 diabetes.

METHODS

This test-meal sub-study in the USA is from a previously reported clinical trial comparing the effect on glycaemic control of 24 weeks of thrice-daily pre-meal insulin lispro mix 50 (50% insulin lispro, 50% insulin lispro protamine suspension) or bedtime insulin glargine, both plus metformin. In the sub-study, glucose, insulin, triglycerides, high-sensitivity C-reactive protein, tumour necrosis factor α, interleukin-6, methylglyoxal and 3-deoxyglucosone were measured during the post-meal period of a mixed-meal breakfast at the final visit. Prandial + basal (n = 25) and basal (n = 21) insulin were administered at the same times as during the previous 24 weeks.

RESULTS

Post-meal, the prandial + basal insulin group had significantly higher insulin, lower glucose and triglycerides, as well as lower high-sensitivity C-reactive protein, tumour necrosis factor α and interleukin-6, than the basal insulin group. Glucose incremental area under the concentration curve significantly correlated with high-sensitivity C-reactive protein, tumour necrosis factor α, interleukin-6, methylglyoxal and 3-deoxyglucosone incremental area under the concentration curve. Insulin incremental area under the concentration curve correlated inversely with high-sensitivity C-reactive protein and tumour necrosis factor α incremental area under the concentration curve. However, after adjusting for glucose incremental area under the concentration curve, these inverse correlations were no longer significant. Triglyceride incremental area under the concentration curve was not correlated with any biomarker incremental area under the concentration curve.

CONCLUSIONS

Controlling post-meal hyperglycaemia with prandial + basal insulin in patients with Type 2 diabetes attenuates meal-induced increases in high-sensitivity C-reactive protein, interleukin-6 and tumour necrosis factor α compared with basal insulin. The rise in post-meal glucose, but not triglycerides, significantly correlated with the rise in post-meal inflammatory and glycative biomarkers.

Use of autologous blood-derived endothelial progenitor cells at point-of-care to protect against implant thrombosis in a large animal model

Titanium (Ti) is commonly utilized in many cardiovascular devices, e.g. as a component of Nitinol stents, intra- and extracorporeal mechanical circulatory assist devices, but is associated with the risk of thromboemboli formation. We propose to solve this problem by lining the Ti blood-contacting surfaces with autologous peripheral blood-derived late outgrowth endothelial progenitor cells (EPCs) after having previously demonstrated that these EPCs adhere to and grow on Ti under physiological shear stresses and functionally adapt to their environment under flow conditions ex vivo. Autologous fluorescently-labeled porcine EPCs were seeded at the point-of-care in the operating room onto Ti tubes for 30 min and implanted into the pro-thrombotic environment of the inferior vena cava of swine (n = 8). After 3 days, Ti tubes were explanted, disassembled, and the blood-contacting surface was imaged. A blinded analysis found all 4 cell-seeded implants to be free of clot, whereas 4 controls without EPCs were either entirely occluded or partially thrombosed. Pre-labeled EPCs had spread and were present on all 4 cell-seeded implants while no endothelial cells were observed on control implants. These results suggest that late outgrowth autologous EPCs represent a promising source of lining Ti implants to reduce thrombosis in vivo.

Dietary saturated fat/cholesterol, but not unsaturated fat or starch, induces C-reactive protein associated early atherosclerosis and ectopic fat deposition in diabetic pigs

BACKGROUND

Diabetes is thought to accelerate cardiovascular disease depending on the type of diet. This study in diabetic subjects was performed to investigate the metabolic, inflammatory and cardiovascular effects of nutritional components typically present in a Western, Mediterranean or high glycaemic diet.

METHODS

Streptozotocin-diabetic pigs (~45 kg) were fed for 10 weeks supplemental (40% of dietary energy) saturated fat/cholesterol (SFC), unsaturated fat (UF) or starch (S) in an eucaloric dietary intervention study.

RESULTS

Fasting plasma total, LDL and HDL cholesterol concentrations were 3-5 fold higher (p < 0.01) in SFC compared to UF and S pigs. Fasting plasma NEFA concentrations (mmol/L) were highest (p < 0.05) in SFC (1.09 ± 0.17), intermediate in UF (0.80 ± 0.14) and lowest in S pigs (0.58 ± 0.14) whereas plasma glucose (~13 mmol/L), triglyceride (~0.5 mmol/L) and insulin (~24 pmol/L) concentrations were comparable among SFC, UF and S pigs. The postprandial response area under the curves (AUC, 0-4 h) for glucose but not for insulin and triglyceride responses were intermediate in SFC (617 ± 144) and lowest (p < 0.05) in UF (378 ± 157) compared to S pigs (925 ± 139). Fasting hepatic glucose production, hepatic and peripheral insulin sensitivity and blood pressure were not different among pigs. C-reactive protein (CRP) concentrations (mg/L) were highest (p < 0.05) in SFC (25 ± 4), intermediate in S (21 ± 3) and lowest in UF pigs (14 ± 2). Liver weights, liver and muscle triglyceride concentrations, and the surface area of aorta fatty streaks were highest (p < 0.01) in SFC pigs. A positive correlation between postprandial plasma CRP and aorta fatty streaks was observed in SFC pigs (R(2) = 0.95). Retroperitoneal fat depot weight (g) was intermediate in SFC (260 ± 72), lowest in S (135 ± 51) and highest (p < 0.05) in UF (571 ± 95) pigs.

CONCLUSION

Dietary saturated fat/cholesterol induces inflammation, atherosclerosis and ectopic fat deposition whereas an equally high dietary unsaturated fat load does not induce these abnormalities and shows beneficial effects on postprandial glycaemia in diabetic pigs.

Inflammatory markers in population studies of aging

PURPOSE

To review findings from major epidemiologic studies regarding risk factors for and consequences of elevated markers of inflammation in older adults.

RESULTS

Most large, current epidemiologic studies of older adults have measured serum interleukin-6 (IL-6), C-reactive protein (CRP) and tumor necrosis factor alpha (TNF-alpha) and some studies also include more extensive batteries of measures including soluble receptors. There are few defined risk factors for the modest elevations in inflammatory markers seen with aging. These include visceral adiposity, lower sex steroid hormones, smoking, depression and periodontal disease. Of the markers assessed, IL-6 is most robustly associated with incident disease, disability and mortality.

CONCLUSION

Though correlated with age, the etiology of elevated inflammatory markers remains incompletely defined. Inflammation, especially IL-6 may be a common cause of multiple age-related diseases or a final common pathway by which disease leads to disability and adverse outcomes in older adults. Future research targeting inflammation should examine these pathways.

Exchanging saturated fatty acids for (n-6) polyunsaturated fatty acids in a mixed meal may decrease postprandial lipemia and markers of inflammation and endothelial activity in overweight men

Postprandial lipemia, low-grade systemic inflammation, and endothelial activity are related to metabolic disorders. It is well known that dietary fatty acid composition modulates postprandial lipemia, but information on the other metabolic risk markers is limited. We therefore studied the acute effects of a meal rich in SFA compared with those of a meal rich in (n-6) PUFA on postprandial responses in overweight men who are at an increased risk to develop the metabolic syndrome and its comorbidities. In a crossover design, the effects of 50 g butter (rich in SFA) on lipemia and markers for inflammation and endothelial activity were compared with those of 50 g sunflower oil [rich in (n-6) PUFA] during an 8-h postprandial mixed meal tolerance test in 13 overweight men. Postprandial changes in serum TG were comparable between the meals (P = 0.38), except for a reduction in the incremental area under the curve (P = 0.046) in the late postprandial phase after (n-6) PUFA (125 ± 96 mmol⋅min⋅L(-1)) compared with SFA (148 ± 98 mmol⋅min⋅L(-1)). Compared with the SFA meal, the (n-6) PUFA meal decreased plasma IL-6 (P = 0.003), TNFα (P = 0.005), soluble TNF receptors I and II (sTNFr; P = 0.024 and P < 0.001, respectively), and soluble vascular cell adhesion molecule-1 (sVCAM-1; P = 0.030) concentrations. These results indicate that exchanging SFA from butterfat for (n-6) PUFA in a mixed meal may decrease postprandial lipemia and concentrations of IL-6, TNFα, sTNFr-I and -II, and sVCAM-1 in overweight men.

Slowly and rapidly digested fat emulsions are equally satiating but their triglycerides are differentially absorbed and metabolized in humans

Little is known about the effect of dietary fat emulsion microstructure on plasma TG concentrations, satiety hormones, and food intake. The aim of this study was to structure dietary fat to slow digestion and flatten postprandial plasma TG concentrations but not increase food intake. Emulsions were stabilized by egg lecithin (control), sodium sterol lactylate, or sodium caseinate/monoglyceride (CasMag) with either liquid oil or a liquid oil/solid fat mixture. In a randomized, double-blind, crossover design, 4 emulsions containing 30 g of fat in a 350-mL preload were consumed by 10 men and 10 women (BMI = 25.1 ± 2.8 kg/m(2); age = 58.8 ± 4.8 y). Pre- and postprandial plasma TG, cholecystokinin (CCK), glucagon-like peptide-1 (GLP-1), and peptide YY (PYY) concentrations and food intake were measured. In a second experiment in a subset of the participants (n = 8, 4 men and 4 women), (13)C-labeled mixed TG was incorporated into 2 different emulsions and breath (13)C was measured over 6 h. In the first experiment, the postprandial rise in plasma TG concentrations following the CasMag-stabilized emulsion containing 30% solid fat was lower than all other emulsions at 90 and 120 min (P < 0.05). Plasma CCK (P < 0.0001), GLP-1 (P < 0.01), and PYY (P < 0.001) concentrations were also reduced following this emulsion compared with control. Food intake at a test meal, eaten 3 h after the preload, did not differ among the emulsions. In the second experiment, when measured by the (13)C breath test, 25% of the TG in the CasMag emulsion was absorbed and metabolized compared with control. In conclusion, fat can be structured to decrease its effect on plasma TG concentrations without increasing food intake.

Chronic low back pain, sleep disturbance, and interleukin-6

OBJECTIVES

Sleep disturbance is a common comorbidity of chronic pain. Inflammatory processes are dysregulated in sleep disturbance and also contribute to pain sensitivity. Thus, inflammation may play an important role in bidirectional associations between pain and sleep. Little is known about concurrent relationships among chronic pain, sleep, and inflammation. The aim of our study was to examine associations between sleep disturbance and circulating levels of the inflammatory cytokine, interleukin-6 (IL-6), in individuals with and without chronic low back pain.

METHODS

Sex-matched and age-matched adults with chronic low back pain (CLBP; n=25) or without chronic pain (controls; n=25)completed measures of sleep quality in the past month and depressive symptoms in the past week, and provided a blood sample for IL-6. The next morning, participants reported their sleep quality the previous night and their current experience of morning pain.

RESULTS

Individuals with CLBP had more sleep disturbance than controls. Circulating IL-6 levels were similar for the 2 groups; however, in adults with CLBP, poorer sleep quality was associated with higher IL-6 levels, and both sleep and IL-6 related to pain reports. Unlike CLBP participants, controls showed normal, age-related increases in IL-6 levels, whereas sleep quality was unrelated to IL-6 levels. Depressive symptoms could not fully explain the observed associations.

DISCUSSION

Inflammatory processes may play a significant role in the cycles of pain and sleep disturbance. Clinical interventions that improve sleep and reduce concomitant inflammatory dysregulation hold promise for chronic pain management.

Lowering postprandial glycemia in children with type 1 diabetes after Italian pizza "margherita" (TyBoDi2 Study)

BACKGROUND

Continuous subcutaneous insulin infusion is considered a safe and effective way to administer insulin in pediatric patients with type 1 diabetes, but achieving satisfactory and stable glycemic control is difficult. Several factors contribute to control, including fine-tuning the basal infusion rate and bolus type and timing. We evaluated the most effective type and timing of a pump-delivered, preprandial bolus in children with type 1 diabetes for a pizza "margherita" meal.

SUBJECTS AND METHODS

We assessed the response of 38 children with type 1 diabetes to a meal based on pizza "margherita" (with mozzarella cheese and tomato sauce) after different types and timings of a bolus dose.

RESULTS

The glucose levels for 6 h after the meal were lower (i.e., closer to the therapeutic target of <140 mg/dL) when the bolus doses were administered as a simple bolus 15 min before the meal (area under the curve [AUC] 0-6 h, 6.9 ± 14.9 mg/dL/min) versus a simple bolus administered immediately before the meal (AUC 0-6 h, 4.2 ± 25.9 mg/dL/min) (P = not significant) versus a double-wave bolus 30/70 extended over a 6-h period administered 15 min before the meal (AUC 0-6 h, 1.9 ± 21.3 mg/dL/min) (P = not significant) versus a double-wave bolus 30/70 extended over a 6-h period administered immediately before the meal (AUC 0-6 h, 13.3 ± 15.6 mg/dL/min) (P = 0.01).

CONCLUSIONS

In the case of a pizza "margherita," our data support the injection of the simple bolus 15 min before a meal, rather than immediately before or delivered as a double-wave bolus, to control the glycemic rise usually observed.

Effect of a fatty meal on inflammatory markers in healthy volunteers with a family history of type 2 diabetes

A family history of type 2 diabetes (T2D) confers a high risk of developing the disease, independent of that due to other common risk factors. Postprandial state is a pro-inflammatory condition associated with a transiently impaired endothelial function; an increased oxidative stress is considered as a mediator of such effects in T2D. We evaluated the short-term effect of a lipid meal on markers of early vascular damage in subjects at risk of developing T2D. A total of thirty-two healthy volunteers, divided according to the presence (FHD+) or absence (FHD - ) of a family history of T2D, underwent a fatty meal test. We measured the monocyte mRNA expressions of IL-6, IL-8 and IL-1β, and IL-6, soluble CD40 ligand (sCD40L), vascular cellular adhesion molecule-1 (VCAM-1), intracellular adhesion molecule-1 (ICAM-1) and nitrotyrosine plasma concentrations at baseline and in the post-meal phase, relating them to the lipid profile and other biochemical parameters. The basal expression of the cytokines did not differ in FHD -  and FHD+ subjects; neither was it modified by the meal ingestion. IL-6 and sCD40L plasma levels, similar in the two groups in the fasting state, did not vary after the meal. VCAM-1 and ICAM-1 increased in FHD+ subjects but not in FHD -  subjects. Nitrotyrosine, similar between the FHD -  and FHD+ subjects at baseline, increased more in FHD+ subjects than in FHD -  subjects after the meal. In conclusion, the presence of a familial history of T2D confers an abnormal endothelial activation after an oral lipid meal, coupled with an increased oxidative stress, supporting the hypothesis of an early endothelial dysfunction already present in healthy individuals prone to develop T2D.

A high-fat challenge increases airway inflammation and impairs bronchodilator recovery in asthma

BACKGROUND

Dietary fat activates systemic innate immune responses, but the effect on airway responses is unknown.

OBJECTIVE

To examine effects of a high-fat versus low-fat meal on systemic and airway inflammation in asthma.

METHODS

Nonobese subjects with asthma were randomized to consume a high-fat (n = 19; 48% [49 g] fat) or low-fat (n = 18; 15% [3 g] fat) meal. Fourteen obese patients with asthma and 21 healthy controls also consumed a high-fat meal. Another group of patients with asthma consumed a high-trans (n = 5; 5.2 g trans fat) or nontrans (n = 5, <0.3 g trans fat) fatty acid meal. Lung function was measured at baseline (prebronchodilator) and 2, 3, and 4 hours after bronchodilator. Airway inflammation was assessed by using induced sputum cell counts and Toll-like receptor 4 mRNA expression by real-time PCR. Systemic inflammation was measured by ELISA quantification of plasma TNF-α, high-sensitivity C-reactive protein, and IL-6 concentrations.

RESULTS

In patients with asthma, at 4 hours postmeal, increases in sputum % neutrophils and Toll-like receptor 4 mRNA expression were higher and increases in FEV(1)/forced vital capacity (FVC) were lower in the high-fat versus low-fat groups. Changes in plasma fatty acids correlated with changes in sputum % neutrophils and were negatively associated with changes in % FEV(1), % FVC, and FEV(1)/FVC. After the high-trans fatty acid meal, sputum % neutrophils were significantly higher than after the nontrans meal.

CONCLUSION

A high-fat meal augments neutrophilic airway inflammation, with the effect dependent on the type of fat consumed. A high-fat meal also suppresses bronchodilator recovery in asthma. Modifying dietary fat intake may be useful in asthma.

Chronic Stress, Immune Dysregulation, and Health

In the past 40 years, a growing body of literature has shown that chronic psychological stress can lead to immune dysregulation. Notably, these stress-induced immune changes are large enough to be clinically relevant. Chronic stress has been associated with a state of chronic low-grade inflammation, delayed wound healing, poor responses to vaccine, and increased susceptibility to infectious illnesses. Activation of neuroendocrine and sympathetic systems provides physiological pathways linking stress and these immune outcomes. Behavioral changes under conditions of chronic stress also contribute to immune dysregulation. Behavioral and pharmacological interventions may attenuate stress-induced immune dysregulation.

Cardiovascular comorbidities of type 2 diabetes mellitus: defining the potential of glucagonlike peptide-1-based therapies

The global epidemic of diabetes mellitus (~95% type 2 diabetes) has been fueled by a parallel increase in obesity and overweight. Together, these metabolic disease epidemics have contributed to the increasing incidence and prevalence of cardiovascular disease. The accumulation of metabolic and cardiovascular risk factors in patients with type 2 diabetes--risk factors that may exacerbate one another--complicates treatment. Inadequate treatment, treatment that fails to achieve goals, increases the risk for cardiovascular morbidity and mortality. From a clinical perspective, type 2 diabetes is a cardiovascular disease, an observation that is supported by a range of epidemiologic, postmortem, and cardiovascular imaging studies. Vascular wall dysfunction, and particularly endothelial dysfunction, has been posited as a "common soil" linking dysglycemic and cardiovascular diseases. Vascular wall dysfunction promoted by environmental triggers (e.g., sedentary lifestyle) and metabolic triggers (chronic hyperglycemia, obesity) has been associated with the upregulation of reactive oxygen species and chronic inflammatory and hypercoagulable states, and as such with the pathogenesis of type 2 diabetes, atherosclerosis, and cardiovascular disease. Glucagon-like peptide-1 (GLP)-1, an incretin hormone, and synthetic GLP-1 receptor agonists represent promising new areas of research and therapeutics in the struggle not only against type 2 diabetes but also against the cardiovascular morbidity and mortality associated with type 2 diabetes. In a number of small trials in humans, as well as in preclinical and in vitro studies, both native GLP-1 and GLP-1 receptor agonists have demonstrated positive effects on a range of cardiovascular disease pathologies and clinical targets, including such markers of vascular inflammation as high-sensitivity C-reactive protein, plasminogen activator inhibitor-1, and brain natriuretic peptide. Reductions in markers of dyslipidemia such as elevated levels of triglycerides and free fatty acids have also been observed, as have cardioprotective functions. Larger trials of longer duration will be required to confirm preliminary findings. In large human trials, GLP-1 receptor agonists have been associated with significant reductions in both blood pressure and weight.

Acute effects of elevated NEFA on vascular function: a comparison of SFA and MUFA

There is emerging evidence to show that high levels of NEFA contribute to endothelial dysfunction and impaired insulin sensitivity. However, the impact of NEFA composition remains unclear. A total of ten healthy men consumed test drinks containing 50 g of palm stearin (rich in SFA) or high-oleic sunflower oil (rich in MUFA) on separate occasions; a third day included no fat as a control. The fats were emulsified into chocolate drinks and given as a bolus (approximately 10 g fat) at baseline followed by smaller amounts (approximately 3 g fat) every 30 min throughout the 6 h study day. An intravenous heparin infusion was initiated 2 h after the bolus, which resulted in a three- to fourfold increase in circulating NEFA level from baseline. Mean arterial stiffness as measured by digital volume pulse was higher during the consumption of SFA (P < 0·001) but not MUFA (P = 0·089) compared with the control. Overall insulin and gastric inhibitory peptide response was greater during the consumption of both fats compared with the control (P < 0·001); there was a second insulin peak in response to MUFA unlike SFA. Consumption of SFA resulted in higher levels of soluble intercellular adhesion molecule-1 (sI-CAM) at 330 min than that of MUFA or control (P ≤ 0·048). There was no effect of the test drinks on glucose, total nitrite, plasminogen activator inhibitor-1 or endothelin-1 concentrations. The present study indicates a potential negative impact of elevated NEFA derived from the consumption of SFA on arterial stiffness and sI-CAM levels. More studies are needed to fully investigate the impact of NEFA composition on risk factors for CVD.

The capacity of foodstuffs to induce innate immune activation of human monocytes in vitro is dependent on food content of stimulants of Toll-like receptors 2 and 4

The ingestion of fatty meals is associated with a transient, low-grade systemic inflammatory response in human subjects, involving the activation of circulating monocytes and the secretion of pro-inflammatory cytokines. However, it is not yet clear how different foodstuffs may promote inflammatory signalling. In a screen of forty filter-sterilised soluble extracts from common foodstuffs, seven were found to induce the secretion of TNF-α and IL-6 from human monocytes in vitro. To investigate what may differentiate inflammatory from non-inflammatory food extracts, stimulants of Toll-like receptor (TLR) 2 and TLR4 were quantified using human embryonic kidney-293 cells transfected with each TLR, and calibrated with defined bacterial lipopeptide (BLP) and lipopolysaccharide (LPS) standards. These assays revealed that while most foods contained undetectable levels of TLR2 or TLR4 stimulants, all TNF-α-inducing foods contained stimulants of either TLR2 (up to 1100 ng BLP-equivalent/g) or TLR4 (up to 2700 ng LPS-equivalent/g) in both the soluble and insoluble fractions. TLR stimulants were present mainly in meat products and processed foods, but were minimal or undetectable in fresh fruit and vegetables. The capacity of food extracts to induce TNF-α secretion in monocytes correlated with the content of both TLR2 (r 0·837) and TLR4 stimulants (r 0·748), and was completely abolished by specific inhibition of TLR2 and TLR4. LPS and BLP were found to be highly resistant to typical cooking times and temperatures, low pH and protease treatment. In conclusion, apparently unspoiled foodstuffs can contain large quantities of stimulants of TLR2 and TLR4, both of which may regulate their capacity to stimulate inflammatory signalling.

Current concepts in triglyceride metabolism, pathophysiology, and treatment

It is becoming more evident that age, gender, and race play a significant role in the metabolic profiles that are seen among individuals in a clinical setting. It is important to understand these variances in metabolic profiles; and with these variances in mind it is now possible to understand why a single diet might not decrease cardiovascular disease risk profiles uniformly for everyone. Much is now understood about triglyceride metabolism and its contribution to energy storage. In this review we will focus on triglycerides; their production, metabolism and influence on daily life, as well as the various methods for the treatment of hypertryglyceridemia and prevention of its sequelae.

Genetic effects on postprandial variations of inflammatory markers in healthy individuals

Circulating levels of inflammatory markers predict the risk of cardiovascular disease (CVD), mediated perhaps in part by dietary fat intake, through mechanisms only partially understood. To evaluate post-fat load changes in inflammatory markers and genetic influences on these changes, we administered a standardized high-fat meal to 838 related Amish subjects as part of the Heredity and Phenotype Intervention (HAPI) Heart Study and measured a panel of inflammatory markers, including C-reactive protein (CRP), interleukin-1beta (IL-1beta), matrix metalloproteinase-1 and -9 (MMP-1 and MMP-9), and white blood cell (WBC) count, before and 4 h after fat challenge (CRP prechallenge only). Heritabilities (h(2) +/- s.d.) of basal inflammatory levels ranged from 16 +/- 8% for MMP-9 (P = 0.02) to 90 +/- 7% for MMP-1 (P < 0.0001). Post-fat load, circulating levels of WBC, MMP-1, and MMP-9 increased by 16, 32, and 43% (all P < 0.0001), with no significant changes in IL-1beta. Postprandial changes over the 4-h period were modestly heritable for WBC (age- and sex-adjusted h(2) = 14 +/- 9%, P = 0.04), but the larger MMP-1 and MMP-9 changes appeared to be independent of additive genetic effects. These results reveal that a high-fat meal induces a considerable inflammatory response. Genetic factors appear to play a significant role influencing basal inflammatory levels but to have minimal influence on post-fat intake inflammatory changes.

Assessment of dietary fat intake and innate immune activation as risk factors for impaired lung function

BACKGROUND/OBJECTIVES

Preservation of lung health with aging is an important health issue in the general population, as loss of lung function with aging can lead to the development of obstructive lung disease and is a predictor of all-cause and cardiovascular mortality. Inflammation is increasingly linked to loss of lung function and evidence suggests that consumption of dietary fat exacerbates inflammation. We aimed to determine the association between dietary fat intake and lung function in older people.

SUBJECTS/METHODS

Participants from the Hunter community study, a population-based cohort, were recruited during 2004 and 2005. Participants received a clinical assessment, including spirometry, and provided a blood sample. Diets were analyzed using food-frequency questionnaires. Plasma interleukin (IL)-6 and C-reactive protein was measured by Enzyme-Linked immunosorbent assay.

RESULTS

Using backward stepwise linear regression, %energy from dietary fat, age and plasma IL-6 were considered as negative predictors of forced expiratory volume in one second (FEV(1)) in men. Also in men, % energy intake from dietary fat, age, body mass index and IL-6 were negative predictors of %predicted forced vital capacity (FVC). Smoking and age were negative predictors of FEV(1)/FVC. In women, plasma IL-6 and age were negative predictors of %FVC, whereas obesity was positively associated with FEV(1)/FVC.

CONCLUSIONS

An increased proportion of fat in the diet is associated with the reduced lung function in older men. Dietary-fat induced innate immune activation and IL-6 release may contribute to this effect. Dietary interventions involving fat restriction should be further investigated as means of preserving lung function with aging.