Obesity and the Metabolic Syndrome: implications for dietetics practitioners

Proteomics Insights into the Gene Network of cis9, trans11-Conjugated Linoleic Acid Biosynthesis in Bovine Mammary Gland Epithelial Cells

The objective of the study was to elucidate the stearoyl-coenzyme A desaturase (SCD1)-dependent gene network of c9, t11-CLA biosynthesis in MAC-T cells from an energy metabolism perspective. The cells were divided into the CAY group (firstly incubated with CAY10566, a chemical inhibitor of SCD1, then incubated with trans-11-octadecenoic acid, (TVA)), the TVA group (only TVA), and the control group (without CAY, TVA). The c9, t11-CLA, and TVA contents were determined by gas chromatography. The mRNA levels of SCD1 and candidate genes were analyzed via real-time PCR. Tandem mass tag (TMT)-based quantitative proteomics, bioinformatic analysis, parallel reaction monitoring (PRM), and small RNA interference were used to explore genes involved in the SCD1-dependent c9, t11-CLA biosynthesis. The results showed that the SCD1 deficiency led by CAY10566 blocked the biosynthesis of c9, t11-CLA. In total, 60 SCD1-related proteins mainly involved in energy metabolism pathways were primarily screened by TMT-based quantitative proteomics analysis. Moreover, 17 proteins were validated using PRM analysis. Then, 11 genes were verified to have negative relationships with SCD1 after the small RNA interference analysis. Based on the above results, we concluded that genes involved in energy metabolism pathways have an impact on the SCD1-dependent molecular mechanism of c9, t11-CLA biosynthesis.

Insulin Resistance and Urolithiasis as a Challenge for a Dietitian

Many obesity and diet-related diseases have been observed in recent years. Insulin resistance (IR), a state of tissue resistance to insulin due to its impaired function, is a common coexisting condition. The most important predisposing factors are excessive visceral fat and chronic low-grade inflammatory response. However, IR’s pathogenesis is not fully understood. Hence, the diagnosis of IR should be carried out carefully because many different diagnostic paths do not always give equivalent results. An additional disease that is often associated with IR is urolithiasis. The common feature of these two conditions is metabolic acidosis and mild inflammation. A patient diagnosed with IR and urolithiasis is a big challenge for a dietitian. It is necessary to check a thorough dietary history, make an appropriate anthropometric measurement, plan a full-fledged diet, and carry out the correct nutritional treatment. It is also essential to conduct proper laboratory diagnostics to plan nutritional treatment, which is often a big challenge for dietitians. The diet’s basic assumptions are based on the appropriate selection of carbohydrates, healthy fats, and wholesome protein sources. It is also essential to properly compose meals, prepare them, and plan physical activities tailored to the abilities. The study aims to summarise the necessary information on IR with concomitant urolithiasis, which may be helpful in dietary practice.

The Influence of Physical Activity on the Bioactive Lipids Metabolism in Obesity-Induced Muscle Insulin Resistance

High-fat diet consumption and lack of physical activity are important risk factors for metabolic disorders such as insulin resistance and cardiovascular diseases. Insulin resistance is a state of a weakened response of tissues such as skeletal muscle, adipose tissue, and liver to insulin, which causes an increase in blood glucose levels. This condition is the result of inhibition of the intracellular insulin signaling pathway. Skeletal muscle is an important insulin-sensitive tissue that accounts for about 80% of insulin-dependent glucose uptake. Although the exact mechanism by which insulin resistance is induced has not been thoroughly understood, it is known that insulin resistance is most commonly associated with obesity. Therefore, it is believed that lipids may play an important role in inducing insulin resistance. Among lipids, researchers’ attention is mainly focused on biologically active lipids: diacylglycerols (DAG) and ceramides. These lipids are able to regulate the activity of intracellular enzymes, including those involved in insulin signaling. Available data indicate that physical activity affects lipid metabolism and has a positive effect on insulin sensitivity in skeletal muscles. In this review, we have presented the current state of knowledge about the impact of physical activity on insulin resistance and metabolism of biologically active lipids.

Molecular inflammation and oxidative stress are shared mechanisms involved in both myocardial infarction and periodontitis

BACKGROUND AND OBJECTIVE

Our aims were to improve the understanding of the pathogenic relationship between cardiovascular diseases and periodontitis and to generate new perspectives in the prevention and treatment of acute myocardial infarction (AMI) and periodontitis. The present study evaluates possible differences in inflammation, oxidative stress, and autophagy markers among subject suffering AMI, periodontitis, or both, to explore possible common pathogenic mechanisms.

MATERIAL AND METHODS

A total of 260 subjects were enrolled in the study: 106 subjects that survived to a first AMI (AMI group) and 154 subjects had no cardiac events in their clinical record (control group). A questionnaire was used to assess age, height, weight, blood pressure, and heart rate. The clinical probing depth, clinical attachment loss, number of remaining teeth, and average number of sites with bleeding on probing were assessed. Lipid peroxidation and protein levels of phosphorylated AMP-activated protein kinase (p-AMPK) and microtubule-associated proteins 1A/1B-light chain 3-II (LC3-II) were determined in isolated peripheral blood mononuclear cells by thiobarbituric acid reactive substances (TBARS) assay and Western blot, respectively. Plasma levels of interleukin-1β were determined using a commercial ELISA kit. All the obtained variables were compared between subjects suffering an AMI with or without periodontitis and control subject periodontal healthy or with periodontitis.

RESULTS

A higher proportion of subjects suffering AMI + periodontitis than only AMI (without periodontitis) was found. Higher levels of TBARS were found in subjects with periodontitis than in subjects without periodontitis in both AMI and control subjects. Positive correlations between IL-1β levels and TBARS and between IL-1β levels and LC3-II were found only in control subjects.

CONCLUSION

Results from the present study are consistent with the suggestion of periodontitis as a potential risk factor for AMI. Periodontitis association with circulating lipid peroxides in both AMI and control subjects were found. The absence of differences in IL-1β levels between AMI subjects (only AMI vs AMI + periodontitis) suggests that oxidative stress could be the main pathogenic link between AMI and periodontitis.

The Role of Ceramides in Insulin Resistance

Resistance to insulin is a pathophysiological state related to the decreased response of peripheral tissues to the insulin action, hyperinsulinemia and raised blood glucose levels caused by increased hepatic glucose outflow. All the above precede the onset of full-blown type 2 diabetes. According to the World Health Organization (WHO), in 2016 more than 1.9 billion people over 18 years of age were overweight and about 600 million were obese. Currently, the primary hypothesis explaining the probability of occurrence of insulin resistance assigns a fundamental role of lipids accumulation in adipocytes or nonadipose tissue (muscle, liver) and the locally developing chronic inflammation caused by adipocytes hypertrophy. However, the major molecular pathways are unknown. The sphingolipid ceramide is the main culprit that combines a plethora of nutrients (e.g., saturated fatty acids) and inflammatory cytokines (e.g., TNFα) to the progression of insulin resistance. The accumulation of sphingolipid ceramide in tissues of obese humans, rodents and Western-diet non-human primates is in line with diabetes, hypertension, cardiac failure or atherosclerosis. In hypertrophied adipose tissue, after adipocytes excel their storage capacity, neutral lipids begin to accumulate in nonadipose tissues, inducing organ dysfunction. Furthermore, obesity is closely related to the development of chronic inflammation and the release of cytokines directly from adipocytes or from macrophages that infiltrate adipose tissue. Enzymes taking part in ceramide metabolism are potential therapeutic targets to manipulate sphingolipids content in tissues, either by inhibition of their synthesis or through stimulation of ceramides degradation. In this review, we will evaluate the mechanisms responsible for the development of insulin resistance and possible therapeutic perspectives.

Traditional Chinese manual acupuncture for management of obesity: A systematic review

AIM: To evaluate the effectiveness and safety of acupuncture for the treatment of obesity by reviewing currently available randomised controlled trials.

METHODS: This review followed the Cochrane Handbook for Systematic Reviews of Interventions. Fifteen English and three Chinese databases were searched from their respective inceptions until July 2014. Key words used in the search consisted of acupuncture, needles, obesity, overweight, randomised trial and their synonyms. The risk of bias of included studies was assessed. The differences in effect size between acupuncture and control (including sham, no treatment, western medicine and dietary therapy/exercise) groups were compared using Cochrane Collaboration’s RevMan 5.3 software.

RESULTS: Two thousand six hundred and twenty-one records were identified; after full-text articles assessed for eligibility, 9 of them met inclusion criteria. Majority of included studies had unclear or high risk of bias across all domains. All included studies had high or unclear risk of bias in randomisation, blinding and outcome data. Meta-analysis showed that acupuncture was more effective for reducing body weight and body mass index than no treatment group. Manual acupuncture was also superior to dietary therapy alone for decreasing body weight. With dietary therapy as co-intervention, combined acupuncture group achieved lower body mass index than combined sham acupuncture group or dietary therapy alone group at the end of treatment period. No severe adverse events from acupuncture group were reported from all included studies.

CONCLUSION: Due to the poor quality of included studies the effectiveness of acupuncture cannot be concluded. Better-designed, large-scale, randomised, sham-controlled clinical trials with long-term follow-up are needed.

Effects of pectin pentaoligosaccharide from Hawthorn ( Crataegus pinnatifida Bunge. var. Major) on the activity and mRNA levels of enzymes involved in fatty acid oxidation in the liver of mice fed a high-fat diet

The regulatory effects of haw pectin pentaoligosaccharide (HPPS) on fatty acid oxidation-related enzyme activities and mRNA levels were investigated in the liver of high fat diet induced hyperlipidemic mice. Results showed that HPPS (150 mg/kg for 10 weeks) significantly suppresses weight gain (32.3 ± 0.26 and 21.1 ± 0.14 g for high-fat diet and HPPS groups, respectively), decreases serum triacylglycerol levels (1.64 ± 0.09 and 0.91 ± 0.02 mmol/L, respectively), and increases lipid excretion in feces (55.7 ± 0.38 and 106.4 ± 0.57 mg/g for total lipid, respectively), compared to high-fat diet as control. HPPS significantly increased the hepatic fatty acid oxidation-related enzyme activities of acyl-CoA oxidase, carnitine palmitoyltransferase I, 3-ketoacyl-CoA thiolase, and 2,4-dienoyl-CoA reductase by 53.8, 74.2, 47.1, and 24.2%, respectively. Meanwhile, the corresponding mRNAs were up-regulated by 89.6, 85.8, 82.9, and 30.9%, respectively. Moreover, HPPS was able to up-regulate the gene and protein expressions of peroxisome proliferator-activated receptor α. Results suggest that continuous HPPS ingestion may be used as dietary therapy to prevent obesity and cardiovascular diseases.

Dietary management of the metabolic syndrome - one size fits all?

Diagnosis of metabolic syndrome includes a set of laboratory and physical findings, including central adiposity, elevated TAG, reduced HDL-cholesterol, hypertension and elevated fasting glucose or insulin resistance. While definitions have varied slightly, from a practical point of view, identifying dietary and lifestyle factors, including low levels of physical activity, are important in designing a diet and exercise programme that can help individuals with the metabolic syndrome to reduce the associated detrimental health consequences. Specific features of the metabolic syndrome require intervention, whether dietary or otherwise, to move towards normal ranges. It is important to remember that no one size or treatment fits all. While central obesity is perceived as the hallmark of the metabolic syndrome, other features need to be treated independently if they do not respond to lifestyle change. The future may hold treatments for the metabolic syndrome that involve modulation of inflammation.

Sugar-sweetened beverages and hypertension

Consumption of sugar-sweetened beverages has been associated with the development and maintenance of obesity, as well as the risk for multiple obesity-related comorbidities. Some experts have hypothesized that the effect is entirely associated with excess caloric intake, while others suggest that a component of sweeteners may have a physiologic impact on the development of hypertension, insulin resistance and nonalcoholic fatty liver disease. Chen et al. have presented the first, large-scale clinical trial, assessing the direct effect of modest changes in sweetened drink consumption on blood pressure in a racially diverse population. The study team utilized data from the PREMIER: Lifestyle Interventions for Blood Pressure Control trial, in which 810 adult subjects were randomized to three groups: advice only; comprehensive lifestyle modification aimed at weight loss, increased exercise and dietary sodium reduction; or comprehensive lifestyle modification with incorporation of the Dietary Approach to Stop Hypertension (DASH) diet. Sweetened drink intake was estimated from 24-h subject recall, assessed by unscheduled phone calls to subjects at baseline, 6 months and 18 months. Over the duration of the study, a reduction of one 12-oz serving of sugar-sweetened beverages per day was associated with an average of 1.8 mmHg reduction in systolic blood pressure and an average of 1.1 mmHg reduction in diastolic blood pressure.

Low-Intensity swimming training after weaning improves glucose and lipid homeostasis in MSG hypothalamic obese mice

Low-intensity swimming training, started at an early age, was undertaken to observe glycemic control in hypothalamic obese mice produced by neonatal monosodium l-glutamate (MSG) treatment. Although swimming exercises by weaning pups inhibited hypothalamic obesity onset and recovered sympathoadrenal axis activity, this event was not observed when exercise training is applied to young adult mice. However, the mechanisms producing this improved metabolism are still not fully understood. Current work verifies whether, besides reducing fat tissue accumulation, low-intensity swimming in MSG-weaned mice also improves glycemic control. Although MSG and control mice swam for 15 min/day, 3 days a week, from the weaning stage up to 90 days old, sedentary MSG and normal mice did not exercise at all. After 14 h of fasting, animals were killed at 90 days of age. Retroperitonial fat accumulation was measured to estimate obesity. Fasting blood glucose and insulin concentrations were also measured. Mice were also submitted to ipGTT. MSG obese mice showed fasting hyperglycemia, hyperinsulinemia, and glucose intolerance and insulin resistance. However, the exercise was able to block MSG treatment effects. Higher total cholesterol and triglycerides observed in MSG mice were normalized by exercise after weaning. Exercised MSG animals had higher HDLc than the sedentary group. Data suggest that early exercise training maintains normoglycemia, insulin tissue sensitivity, and normal lipid profile in mice programmed to develop metabolic syndrome.

Functions for pro-opiomelanocortin-derived peptides in obesity and diabetes

Melanocortin peptides, derived from POMC (pro-opiomelanocortin) are produced in the ARH (arcuate nucleus of the hypothalamus) neurons and the neurons in the commissural NTS (nucleus of the solitary tract) of the brainstem, in anterior and intermediate lobes of the pituitary, skin and a wide range of peripheral tissues, including reproductive organs. A hypothetical model for functional roles of melanocortin receptors in maintaining energy balance was proposed in 1997. Since this time, there has been an extraordinary amount of knowledge gained about POMC-derived peptides in relation to energy homoeostasis. Development of a Pomc-null mouse provided definitive proof that POMC-derived peptides are critical for the regulation of energy homoeostasis. The melanocortin system consists of endogenous agonists and antagonists, five melanocortin receptor subtypes and receptor accessory proteins. The melanocortin system, as is now known, is far more complex than most of us could have imagined in 1997, and, similarly, the importance of this system for regulating energy homoeostasis in the general human population is much greater than we would have predicted. Of the known factors that can cause human obesity, or protect against it, the melanocortin system is by far the most significant. The present review is a discussion of the current understanding of the roles and mechanism of action of POMC, melanocortin receptors and AgRP (agouti-related peptide) in obesity and Type 2 diabetes and how the central and/or peripheral melanocortin systems mediate nutrient, leptin, insulin, gut hormone and cytokine regulation of energy homoeostasis.

Combined effects of body mass index and cardio/respiratory fitness on serum vaspin concentrations in Korean young men

Little information is available regarding how body fatness and cardio/respiratory fitness (CRF) are associated with serum vaspin. The purpose of the study was to investigate the combined effect of body mass index (BMI) and CRF on serum vaspin in Korean young men. In a cross-sectional study, we examined 490 Korean young men (mean age 23.8 +/- 2.5 years) who were voluntarily recruited. Body fatness and fasting levels of serum insulin, adiponectin, and vaspin were measured. CRF was quantified as the minute volume of oxygen consumption (VO(2)) measured during a graded treadmill test. We assigned individuals to either low or middle or high third CRF tertiles based on age-adjusted VO(2max). We also assigned individuals to either a lean weight (LN) or obese (OB) group based on body fatness levels, in which a BMI value >/=25 kg/m(2) was used as an indicator of Pacific-Asian obesity. Group analyses showed significant interaction effects between fatness and CRF on fasting insulin and serum vaspin such that the OB group with low CRF levels had significantly higher insulin and vaspin concentrations than the OB counterparts with moderate to high CRF levels, and no such CRF-based sub-group differences in insulin and vaspin were found in the LN groups. Regression analyses show that BMI, waist circumference, VO(2), and fasting insulin explain approximately 18% of the individual variations in serum vaspin concentration in this study population. This is the first study to show that high body fatness along with low CRF might contribute to increased vaspin concentrations in Korean young men.

Nutrition Review: Diet and Metabolic Syndrome

Since most components of metabolic syndrome are related to lifestyle, exercise and diet are critical aspects of treatment. Most patients will need to reduce body weight. Some flexibility in dietary macronutrients is allowed, depending on the patient's metabolic profile and responsiveness. Types of fats and carbohydrates are particularly important. Artificial trans fats should be eliminated as much as possible and saturated fats minimized. Carbohydrates should be mainly unrefined and unprocessed, emphasizing fiber and low glycemic index, while keeping added sugars low. Monounsaturated fats are the best replacements for saturated fats and refined carbohydrates within energy and total fat limits. Micronutrients that may be beneficial for metabolic syndrome include vitamin D, calcium, magnesium, and potassium from whole food sources. Excess sodium chloride, as well as meal skipping, should be avoided.

Obesity indices in relation to cardiovascular disease risk factors among young adult female students

The objective of the present study was to compare the percentage of body fat (%BF), BMI, and central fat distribution anthropometric measures as indices of obesity and to assess the respective associations with cardiovascular risk factors in young female students. Subjects were 220 healthy Greek female students. Dual-energy X-ray absorptiometry was used to estimate %BF, anthropometric measurements were obtained and blood samples were analysed for CVD risk factors. Results showed that 48·6 % of students had increased adiposity, while a considerable proportion was characterised by central fat distribution irrespective of the anthropometric index used. The proportion of subjects with at least one metabolic risk factor present was 60·4 %. Although %BF was not associated with any of the CVD risk factors, waist circumference, waist:hip ratio and waist:height ratio were all associated with CVD risk factors. Higher levels of these anthropometric variables demonstrated higher prevalence of CVD risk factors. The lack of association between %BF and CVD risk factors could be attributed to the fact that females with undesirable adiposity had a tendency for the gynaecoid type of obesity. In contrast, the present results suggest that central body fat distribution in young women may reflect increased risk due to high visceral and particularly intra-abdominal fat levels. Recent epidemiological data from Greece show a high prevalence of overweight and obesity in young adults. Therefore, assessing the risk for the presence of CVD risk factors is of particular importance. Central obesity anthropometric indices seem to be valuable screening tools for young women.

Effects of PREMIER Lifestyle Modifications on Participants With and Without the Metabolic Syndrome

Lifestyle modification can reduce blood pressure and lower cardiovascular risk. Established recommendations include weight loss, sodium reduction, and increased physical activity. PREMIER studied the effects of lifestyle interventions based on established recommendations alone and with the addition of the Dietary Approaches to Stop Hypertension (DASH) dietary pattern. This analysis aimed to assess the interventions’ impact on cardiometabolic variables in participants with, compared with those without, metabolic syndrome. The primary outcome was 6-month change in systolic blood pressure. Participants with prehypertension or stage-1 hypertension were randomly assigned to an advice only control group, a 6-month intensive behavioral intervention group of established recommendations (EST), or an established recommendations plus DASH group (EST+DASH). Metabolic syndrome was defined per National Cholesterol and Education Program Adult Treatment Panel III. We used general linear models to test intervention effects on change in blood pressure, lipids, and insulin resistance (homeostasis model assessment), in subgroups defined by the presence or absence of metabolic syndrome. Of 796 participants, 399 had metabolic syndrome. Both EST and EST+DASH reduced the primary outcome variable, systolic blood pressure. Within the EST+DASH group, those with and without metabolic syndrome responded similarly ( P =0.231). However, within EST, those with metabolic syndrome had a poorer response, with a decrease in systolic blood pressure of 8.4 mm Hg versus 12.0 mm Hg in those without metabolic syndrome ( P =0.002). Thus, metabolic syndrome attenuated the systolic blood pressure reduction of EST, but this attenuation was overcome in EST+DASH. Finally, diastolic blood pressure, lipids, and homeostasis model assessment responded similarly to both interventions regardless of metabolic syndrome status. Our data suggest that strategies for lowering BP in individuals with metabolic syndrome may be enhanced by recommendations to adopt the DASH dietary pattern.

Conjugated linoleic acid: a functional nutrient in the different pathophysiological components of the metabolic syndrome?

PURPOSE OF REVIEW

Much attention has focused on the therapeutic potential of conjugated linoleic acid with the most abundant isomers being cis-9,trans-11 conjugated linoleic acid and trans-10,cis-12 conjugated linoleic acid. Initial animal studies associated conjugated linoleic acid with beneficial health properties, such as reducing the risk of cancer, diabetes, atherosclerosis, inflammation and obesity. This review has appraised the evidence in relation to the effect of conjugated linoleic acid on components of the metabolic syndrome (clinically or experimentally), in particular, obesity, insulin resistance, atherosclerosis and inflammation.

RECENT FINDINGS

More recent human conjugated linoleic acid supplementation studies have often shown conflicting and less convincing health benefits. The marked variation between studies may reflect the isomer-specific effect of the individual conjugated linoleic acid isomers, which can often have opposing effects. Detrimental effects have been observed in some studies, in particular after supplementation with the trans-10,cis-12 conjugated linoleic acid isomer.

SUMMARY

Further studies and long-term clinical trials will be required to determine the efficacy and safety of conjugated linoleic acid isomers before conjugated linoleic acid could be considered as a functional nutrient in humans.

Whole-Grain Diets Reduce Blood Pressure in Mildly Hypercholesterolemic Men and Women

The objective of this study was to compare the effects on blood pressure of predominantly insoluble fiber (whole wheat and brown rice) and soluble fiber (barley) in a whole-grain diet. Subjects (seven men, nine premenopausal women, and nine postmenopausal women) consumed a controlled Step I diet for 2 weeks; then about 20% of energy was replaced with whole wheat/brown rice, barley, or half wheat-rice/half barley, for 5 weeks each. Blood pressure was determined weekly and weight daily before breakfast. Urinary excretions of minerals that might affect blood pressure and urea nitrogen were determined each period. Systolic pressure was lower after the wheat/rice and half-and-half diets. Diastolic and mean arterial pressures were reduced by all whole-grain diets. No differences were observed in urinary measurements. In a healthful diet, increasing whole-grain foods, whether high in soluble or insoluble fiber, can reduce blood pressure and may help to control weight.

Association between chronic undernutrition and hypertension

In developing countries nutritional deficit during prenatal and continuing in post-natal life is very common. This condition leads to stunting and important metabolic changes. Over 30% of children in the world are stunted. The metabolic resultants of nutritional deficit during growth are classically known to aim at energy conservation. This review summarizes data from Brazil, a developing country undergoing the double burden of obesity and undernutrition, especially among the poor, and suggests that stunting or chronic undernutrition increases the risk of obesity and hypertension later in life. Around 60 million people are under the poverty line in Brazil. In São Paulo, the richest city of the country, 20% of the population live in slums and in Maceió, the capital of one of the poorest states, this percentage reaches 50%. Undernutrition in this population is around 20% among children, with high frequency of infections, anemia, and parasitic infestations, associated with poor sanitation. Among stunted adolescents, we found a high prevalence of hypertension (21%) that is a considerably higher estimate compared to non-stunted adolescents (less than 10%). The prevalence of hypertension in undernourished pre-school children, or in those who recovered from undernutrition, was higher than that in controls (29%, 20% and 2%, respectively, P < 0.001). Among stunted adults eating no more than 66% of the requirements (adjusted for stature), overweight/obesity was 35% in women and 25% in men. The prevalence of hypertension was 44% among stunted women and 18% among stunted men. Fifty per cent of stunted and obese women had hypertension. These data reinforce the important association between undernutrition and hypertension from childhood through adulthood. Health policies for preventing and combating childhood undernutrition should have an impact on the morbidity and mortality related to hypertension during adulthood.

Effects of dietary genistein on hepatic lipid metabolism and mitochondrial function in mice fed high-fat diets

OBJECTIVE

Genistein has been suggested to prevent insulin resistance and its related diseases. We investigated the effects of dietary genistein at different levels on hepatic lipid levels and mitochondrial functions in mice fed high-fat diets.

METHODS

C57BL/6J mice were randomly divided into four groups and fed a high-fat diet containing genistein at levels of 0%, 0.1%, 0.2%, and 0.4% (HF, HF + 0.1G, HF + 0.2G, and HF + 0.4G) for 12 wk. We measured lipid levels in the blood and liver. We also observed messenger RNA (mRNA) expression of genes encoding proteins related to lipid and energy metabolism and antioxidant defense system and mitochondrial enzyme activities in the liver.

RESULTS

The induction of fatty liver by HF was substantially decreased in the HF + 0.2G and HF + 0.4G groups. Peroxisome proliferator-activated receptorgamma coactivator mRNA was increased by HF + 0.4G. Although genistein did not affect peroxisomal acyl-CoA oxidase mRNA expression, it increased medium-chain acyl-CoA dehydrogenase mRNA expression in a dose-dependent manner and HF + 0.2G increased uncoupling protein-2 mRNA expression two-fold relative to HF mice. Genistein decreased malondialdehyde levels and increased glutathione levels in liver homogenates, regardless of dose. The HF + 0.1G diet increased mitochondrial glutathione peroxidase activity and mitochondrial succinate dehydrogenase activity.

CONCLUSIONS

Although genistein at higher levels decreased hepatic fat accumulation possibly by increasing fatty acid oxidation and uncoupling protein, low-dose genistein increased mitochondrial enzyme activities in mice with fatty liver and obesity induced by high-fat diets.

Ectopic UCP1 gene expression in HepG2 cells affects ATP production

The UCP1 is an uncoupling protein located in the inner mitochondrial membrane of brown adipocytes, which has a well-documented role in diet-induced thermogenesis. The current study assessed whether UCP1 transfected liver cells demand more fuel substrates in the oxidative phosphorylation processes. Therefore, the purpose of this experiment was to achieve an ectopic expression of UCP1 in HepG2 cells to significantly decrease the production of ATP. The UCP1 gene was transferred into the hepatic cells by using a calcium phosphate precipitation protocol. The efficiency of the transfection was tested, 48 hours later, by bioluminescence of luciferase previously transfected, while the expression of mRNA of UCP1 was demonstrated by RT-PCR. In addition, measuring the production of ATP by using a bioluminescence procedure assessed the functionality of this protein. Transfected liver cells with UCP1 showed a decrease of 23% in ATP production in comparison with control cells without expression of UCP1 (2.23 vs. 2.90 RLU/pg protein, p=0.015). In conclusion, the ectopic expression of UCP1 decreased the production of ATP, possibly uncoupling the oxidative phosphorylation, which could be a novel approach for understanding thermogenic processes and eventually for energy metabolism and body weight management.

Unique Dietary Patterns and Chronic Disease Risk Profiles of Adult Men: The Framingham Nutrition Studies

OBJECTIVE

To identify the dietary patterns of adult men and examine their relationships with nutrient intake and chronic disease risk over long-term follow-up.

DESIGN/SUBJECTS

Baseline 145-item food frequency questionnaires from 1,666 Framingham Offspring-Spouse cohort men were used to identify comprehensive dietary patterns. Independent 3-day dietary records at baseline and 8 years later provided estimates of subjects' nutrient intake by dietary pattern. Chronic disease risk factor status was compared at baseline and 16-year follow-up across all male dietary patterns.

STATISTICAL ANALYSES

Cluster analysis was applied to food frequency data to identify non-overlapping male dietary patterns. Analysis of covariance and logistic regression were used to compare nutrient intake, summary nutritional risk scores, and chronic disease risk status at baseline and follow-up by male dietary pattern.

RESULTS

Five distinct and comprehensive dietary patterns of Framingham Offspring-Spouse men were identified and ordered according to overall nutritional risk: Transition to Heart Healthy, Higher Starch, Average Male, Lower Variety, and Empty Calories. Nutritional risk was high and varied by dietary pattern; key nutrient contrasts were stable over 8-year follow-up. Chronic disease risk also varied by dietary pattern and specific subgroup differences persisted over 16 years, notably rates of overweight/obesity and smoking.

CONCLUSIONS

Quantitative cluster analysis applied to food frequency questionnaire data identified five distinct, comprehensive, and stable dietary patterns of adult Framingham Offspring-Spouse cohort men. The close associations between the dietary patterns, nutritional risk, and chronic disease profiles of men emphasize the importance of targeted preventive nutrition interventions to promote health in the male population.

Life-threatening dermatoses due to metabolic and endocrine disorders

Cardiovascular heart disease due to atherosclerosis is the commonest cause of mortality and morbidity in the Western world. Atherosclerosis is directly related to disorders of lipid metabolism, diabetes mellitus (DM), and insulin resistance. Disorders of thyroid function and porphyrin metabolism occur less frequently but may cause life-threatening situations if unrecognized. All these disorders are associated with characteristic dermatoses, which should permit early diagnosis and meaningful intervention.

Comparison of Hormone and Glucose Responses of Overweight Women to Barley and Oats

OBJECTIVE

To determine the effect of particle size (flour vs. flakes) on glycemic responses after oats and barley (Prowashonupana cultivar), which contain high amounts of soluble fiber, are consumed by overweight women.

DESIGN

Ten women, average age 50 years and body mass index 30, consumed glucose (1 g/kg body weight) and four test meals (1 g carbohydrate/kg body weight; 2/3 of the carbohydrate from oat flour, oatmeal, barley flour, or barley flakes and 1/3 from pudding) in a Latin square design after consuming controlled diets for 2 days. Blood samples were collected at fasting and periodically after each meal.

RESULTS

Peak glucose and insulin levels after barley were significantly lower than those after glucose or oats. Glucose areas under the curve (AUCs) after test meals compared with AUCs after glucose were reduced after both oats and barley (29-36% by oats and 59-65% by barley) (p < 0.002). Insulin AUCs after test meals compared with glucose AUCs were significantly reduced only by barley (44-56%) (p < 0.005). Indexes for insulin resistance (HOMA, MFFM, Cederholm) after the oat and barley meals were not different from indexes after the glucose meal. Glucagon and leptin responses did not significantly differ for the carbohydrates tested.

CONCLUSIONS

Particle size of the oats or barley had little effect on the glycemic responses. Both oat and barley meals reduced glycemic responses; the high soluble fiber content of this barley appeared to be a factor in the greater reduction observed.

Beyond Energy Balance: There Is More to Obesity than Kilocalories

Using an epidemiologic model of the interactions between environmental agents and human hosts to explain obesity, we explored food, medications, physical inactivity, toxins, and viruses as environmental agents that interact with a genetically programmed host to disturb energy balance and cause obesity. Large portion sizes, high fat intakes, easy access to calorically sweetened beverages, and lack of any need to be physically active all play a role in the toxic environment that leads to obesity. The genetic and physiologic responses of a host determine whether or not this toxic environment will produce obesity. Reversing the current trends of obesity requires a new look at the limits of the energy balance concept, and a better understanding of how environmental factors acutely and chronically change the responses of susceptible hosts.

Facial fat and its relationship to abdominal fat: a marker for insulin resistance?

Reports of relationships between measures of insulin sensitivity and measures of body fat and fat distribution suggest that abdominal fat accumulation is a predictor of insulin resistance. It has been previously suggested that facial fat (primarily in the cheeks and neck) is strongly associated with visceral abdominal fat accumulation. The facial fat is a rich vascular region, that seems to be metabolically active and resembles abdominal white adipose tissue. We, therefore, hypothesize that facial fat could be a good predictor of insulin resistance. Whether facial fat can be used as an accurate marker for insulin resistance remains to be determined.

Consumption of a high-fat diet alters the homeostatic regulation of energy balance

Humans in many countries are currently experiencing what has been called an epidemic of obesity. That is, the average body weight (and amount of fat stored in the body) is increasing over years, carrying with it a multitude of associated medical, psychological, and economic problems. While there is no shortage of possible causes of this epidemic, increased availability and consumption of high-fat (HF), calorically dense and generally quite palatable food is often touted as a likely culprit. In order to better assess the impact of consuming a diet with those qualities, we have developed a well-controlled animal model in which the effects of chronic consumption of a high-fat diet can be dissociated from those of becoming obese per se. Long-Evans rats are fed one of two semipurified pelleted diets, a HF diet that contains 20% fat by weight and a low-fat (LF) diet that contains 4% fat by weight. Pair-fed animals consume the HF diet but are limited to the daily caloric intake of LF rats. Another group receives pelleted chow. Relative to animals consuming diets low in fat, HF animals weigh more, have more carcass fat, are hyperinsulinemic and hyperleptinemic, and are insulin resistant. HF-fed animals, independent of whether they become obese or not, also have central insulin and MTII insensitivity. Finally, HF rats have a down-regulated hypothalamic apo A-IV system that could contribute to their hyperphagia.

The obesity epidemic: prospects for prevention

Some 20-25% of UK adults are obese according to the WHO criterion (BMI >/=30 kg/m(2)). Type 2 diabetes, increasingly recognized as a major complication of overweight and obesity, is beginning to appear in UK adolescents, following the trends in the US. Epidemiological data indicate that the prevalence of overweight and obesity has doubled or tripled in the past few decades in the US, in Europe, and even in many developing countries. Thus obesity is increasingly seen as a public health problem requiring concerted action by both governmental and non-governmental organizations. A sound understanding of the root causes is crucial, if strategies for the prevention and treatment of this epidemic are to be developed. Many epidemiological studies suggest that physical activity at work, school or at leisure has declined to minimal levels, and that sedentary behaviours such as television viewing and computer games have become major pastimes. Thus energy requirements are substantially less than those for recent generations. Further, the food industry produces high-calorie foods which children and adults consume as snack meals, giving a substantial surfeit to their daily energy requirement. In children, a few school-based, preventive intervention trials have shown some promising results. Many negative trials have also been reported, and practical difficulties remain in the widespread implementation of appropriate protocols. Initiatives have been introduced by the government to increase the physical education syllabus in school to a minimum of 2 h/week, and the promotion of fruit and vegetables. Further research is required on the physiological and psychological causes of overweight and obesity in children and adults, and randomized, controlled, school and community-based trials are required to pilot preventative initiatives. Monitoring of the progress in prevention at both organizational and outcome level is required, and also of adverse outcomes such as a rise in the prevalence of eating disorders.