Methodological Challenges in Studies Examining the Effects of Breakfast on Cognitive Performance and Appetite in Children and Adolescents.

Breakfast is purported to confer a number of benefits on diet quality, health, appetite regulation, and cognitive performance. However, new evidence has challenged the long-held belief that breakfast is the most important meal of the day. This review aims to provide a comprehensive discussion of the key methodological challenges and considerations in studies assessing the effect of breakfast on cognitive performance and appetite control, along with recommendations for future research. This review focuses on the myriad challenges involved in studying children and adolescents specifically. Key methodological challenges and considerations include study design and location, sampling and sample section, choice of objective cognitive tests, choice of objective and subjective appetite measures, merits of providing a fixed breakfast compared with ad libitum, assessment and definition of habitual breakfast consumption, transparency of treatment condition, difficulty of isolating the direct effects of breakfast consumption, untangling acute and chronic effects, and influence of confounding variables. These methodological challenges have hampered a clear substantiation of the potential positive effects of breakfast on cognition and appetite control and contributed to the debate questioning the notion that breakfast is the most important meal of the day.

Postprandial Metabolism of Macronutrients and Cardiometabolic Risk: Recent Developments, Emerging Concepts, and Future Directions.

Cardiovascular disease (CVD) is the leading cause of death in the United States. Although the role of habitual lifestyle factors such as physical activity and dietary patterns in increasing CVD risk has long been appreciated, less is known about how acute daily activities may cumulatively contribute to long-term disease risk. Here, the term acute refers to metabolic responses occurring in a short period of time after eating, and the goal of this article is to review recently identified stressors that can occur after meals and during the sleep-wake cycle to affect macronutrient metabolism. It is hypothesized that these events, when repeated on a regular basis, contribute to the observed long-term behavioral risks identified in population studies. In this regard, developments in research methods have supported key advancements in 3 fields of macronutrient metabolism. The first of these research areas is the focus on the immediate postmeal metabolism, spanning from early intestinal adsorptive events to the impact of incretin hormones on these events. The second topic is a focus on the importance of meal components on postprandial vasculature function. Finally, some of the most exciting advances are being made in understanding dysregulation in metabolism early in the day, due to insufficient sleep, that may affect subsequent processing of nutrients throughout the day. Key future research questions are highlighted which will lead to a better understanding of the relations between nocturnal, basal (fasting), and early postmeal events, and aid in the development of optimal sleep and targeted dietary patterns to reduce cardiometabolic risk.

A randomized, controlled, crossover trial to assess the acute appetitive and metabolic effects of sausage and egg-based convenience breakfast meals in overweight premenopausal women.

BACKGROUND: Dietary protein at breakfast has been shown to enhance satiety and reduce subsequent energy intake more so than carbohydrate or fat. However, relatively few studies have assessed substitution of protein for carbohydrate on indicators of appetite and glucose homeostasis simultaneously. METHODS: The acute appetitive and metabolic effects of commercially-prepared sausage and egg-based breakfast meals at two different protein levels (30 g and 39 g/serving), vs. a low-protein pancake breakfast (3 g protein) and no breakfast (water), were examined in premenopausal women (N = 35; age 32.5 ± 1.6 yr; BMI 24.8 ± 0.5 kg/m(2)). Test products provided ~280 kcal/serving and similar fat (12-14 g) and fiber contents (0-1 g). Visual Analog Scale ratings for appetite (hunger, fullness, prospective consumption, desire to eat) and repeated blood sampling for plasma glucose and insulin concentrations were assessed throughout each test day. Energy intake was recorded at an ad libitum lunch meal at 240 min. RESULTS: Results showed increased satiety ratings for both the 30 and 39 g protein meals vs. the low-protein and no breakfast conditions (p < 0.001 for all). Postprandial glucose and insulin excursions were lower following the 30 g and 39 g protein conditions vs. the low-protein condition, with smaller responses following the 39 g vs. 30 g protein condition (p < 0.05 for all). Energy intake at lunch was significantly less (p < 0.001) following the 39 g protein meal (692 kcal) vs. the low-protein and no breakfast conditions (789 and 810 kcal, respectively). Total energy intake from the test condition + lunch was higher (p < 0.01) for the 30 and 39 g meals (982 and 983 kcal, respectively) vs. no breakfast (810 kcal), and less than the low protein breakfast (1064 kcal; p < 0.01 vs. 39 g condition only). CONCLUSIONS: Results suggest that convenience meals providing 30 or 39 g protein/serving produce greater appetite control, lower postprandial glycemia and insulinemia, and reduced subsequent intake at lunch relative to a low-protein control, or no breakfast. TRIAL REGISTRATION: NCT01713114.

Sugar-sweetened product consumption alters glucose homeostasis compared with dairy product consumption in men and women at risk of type 2 diabetes mellitus.

BACKGROUND: Dietary patterns characterized by high intakes of fruits and vegetables, whole grains, low-fat dairy products, and low glycemic load have been associated with lower type 2 diabetes mellitus (T2DM) risk. In contrast, dietary patterns that include high intakes of refined grains, processed meats, and high amounts of added sugars have been associated with increased T2DM risk. OBJECTIVE: This randomized, 2-period crossover trial compared the effects of dairy and sugar-sweetened product (SSP) consumption on insulin sensitivity and pancreatic ß-cell function in men and women at risk of the development of T2DM who habitually consume sugar-sweetened beverages. METHODS: In a randomized, controlled crossover trial, participants consumed dairy products (474 mL/d 2% milk and 170 g/d low-fat yogurt) and SSPs (710 mL/d nondiet soda and 108 g/d nondairy pudding), each for 6 wk, with a 2-wk washout between treatments. A liquid meal tolerance test (LMTT) was administered at baseline and the end of each period. RESULTS: Participants were 50% female with a mean age and body mass index of 53.8 y and 32.2 kg/m(2), respectively. Changes from baseline were significantly different between dairy product and SSP conditions for median homeostasis model assessment 2-insulin sensitivity (HOMA2-%S) (1.3 vs. -21.3%, respectively, P = 0.009; baseline = 118%), mean LMTT disposition index (-0.03 vs. -0.36, respectively, P = 0.011; baseline = 2.59), mean HDL cholesterol (0.8 vs. -4.2%, respectively, P = 0.015; baseline = 44.3 mg/dL), and mean serum 25-hydroxyvitamin D [25(OH)D] (11.7 vs. -3.3, respectively, P = 0.022; baseline = 24.5 µg/L). Changes from baseline in LMTT Matsuda insulin sensitivity index (-0.10 vs. -0.49, respectively; baseline = 4.16) and mean HOMA2-ß-cell function (-2.0 vs. 5.3%, respectively; baseline = 72.6%) did not differ significantly between treatments. CONCLUSION: These results suggest that SSP consumption is associated with less favorable values for HOMA2-%S, LMTT disposition index, HDL cholesterol, and serum 25(OH)D in men and women at risk of T2DM vs. baseline values and values during dairy product consumption. This trial was registered at clinicaltrials.gov as NCT01936935.

Dietary protein is important in the practical management of prediabetes and type 2 diabetes.

Many misconceptions surround the role of dietary protein in the management of diabetes. Although dietary recommendations for managing diabetes have changed greatly over the centuries, recommended protein intake has remained relatively constant. Currently, recommendations for protein intake are based on individual assessment and the consideration of other health issues and implications, such as the extent of glycemic control, the presence of kidney disease, overweight and obesity, and the age of the patient. Two common misconceptions about dietary protein in diabetes management are that a certain amount of the protein consumed is converted into blood glucose and that consuming too much protein can lead to diabetic kidney disease. These misconceptions have been disproven. For many people with type 2 diabetes, aiming for 20-30% of total energy intake as protein is the goal. Exceptions may be for those individuals with impaired renal function. A protein intake of this amount can be beneficial by improving glycemic control, aiding in satiety and preservation of lean body mass during weight loss in those with both diabetes and prediabetes, and providing for the increased protein requirements of the older adult. Health care providers should discuss the role of dietary protein with their patients, reinforce sources of protein in the diet, and use simple but effective teaching tools, such as the plate method, to convey important nutrition messages. In addition, health care providers should recognize that persons with diabetes are attempting to manage many other aspects of their diabetes, including blood glucose monitoring, physical activity, taking of medication, risk reduction, and problem solving.

Cost savings of reduced constipation rates attributed to increased dietary fiber intakes: a decision-analytic model.

BACKGROUND: Nearly five percent of Americans suffer from functional constipation, many of whom may benefit from increasing dietary fiber consumption. The annual constipation-related healthcare cost savings associated with increasing intakes may be considerable but have not been examined previously. The objective of the present study was to estimate the economic impact of increased dietary fiber consumption on direct medical costs associated with constipation. METHODS: Literature searches were conducted to identify nationally representative input parameters for the U.S. population, which included prevalence of functional constipation; current dietary fiber intakes; proportion of the population meeting recommended intakes; and the percentage that would be expected to respond, in terms of alleviation of constipation, to a change in dietary fiber consumption. A dose-response analysis of published data was conducted to estimate the percent reduction in constipation prevalence per 1 g/day increase in dietary fiber intake. Annual direct medical costs for constipation were derived from the literature and updated to U.S. $ 2012. Sensitivity analyses explored the impact on adult vs. pediatric populations and the robustness of the model to each input parameter. RESULTS: The base case direct medical cost-savings was $12.7 billion annually among adults. The base case assumed that 3% of men and 6% of women currently met recommended dietary fiber intakes; each 1 g/day increase in dietary fiber intake would lead to a reduction of 1.9% in constipation prevalence; and all adults would increase their dietary fiber intake to recommended levels (mean increase of 9 g/day). Sensitivity analyses, which explored numerous alternatives, found that even if only 50% of the adult population increased dietary fiber intake by 3 g/day, annual medical costs savings exceeded $2 billion. All plausible scenarios resulted in cost savings of at least $1 billion. CONCLUSIONS: Increasing dietary fiber consumption is associated with considerable cost savings, potentially exceeding $12 billion, which is a conservative estimate given the exclusion of lost productivity costs in the model. The finding that $12.7 billion in direct medical costs of constipation could be averted through simple, realistic changes in dietary practices is promising and highlights the need for strategies to increase dietary fiber intakes.

Limitations of observational evidence: implications for evidence-based dietary recommendations.

Data from randomized controlled trials (RCTs) provide the strongest evidence for establishing relations between exposures, including dietary exposures, and health outcomes. However, not all diet and health outcome relations can be practically or ethically evaluated by using RCTs; therefore, many dietary recommendations are supported by evidence primarily from observational data, particularly those from prospective cohort studies. Although such evidence is of critical importance, limitations are often underappreciated by nutrition scientists and policymakers. This editorial review is intended to 1) highlight some of these limitations of observational evidence for diet-disease relations, including imprecise exposure quantification, collinearity among dietary exposures, displacement/substitution effects, healthy/unhealthy consumer bias, residual confounding, and effect modification; and 2) advocate for greater caution in the communication of dietary recommendations for which RCT evidence of clinical event reduction after dietary intervention is not available.

Effects of low-fat dairy intake on blood pressure, endothelial function, and lipoprotein lipids in subjects with prehypertension or stage 1 hypertension.

OBJECTIVE: This randomized crossover trial assessed the effects of 5 weeks of consuming low-fat dairy (one serving/day each of 1% fluid milk, low-fat cheese, and low-fat yogurt) versus nondairy products (one serving/day each of apple juice, pretzels, and cereal bar) on systolic and diastolic blood pressures (SBP and DBP), vascular function (reactive hyperemia index [RHI] and augmentation index), and plasma lipids. METHODS: Patients were 62 men and women (mean age 54.5 years, body mass index 29.2 kg/m(2)) with prehypertension or stage 1 hypertension (mean resting SBP/DBP 129.8 mmHg/80.8 mmHg) while not receiving antihypertensive medications. A standard breakfast meal challenge including two servings of study products was administered at the end of each treatment period. RESULTS: Dairy and nondairy treatments did not produce significantly different mean SBP or DBP in the resting postprandial state or from premeal to 3.5 hours postmeal (SBP, 126.3 mmHg versus 124.9 mmHg; DBP, 76.5 mmHg versus 75.7 mmHg), premeal (2.35 versus 2.20) or 2 hours postmeal (2.33 versus 2.30) RHI, and premeal (22.5 versus 23.8) or 2 hours postmeal (12.4 versus 13.2) augmentation index. Among subjects with endothelial dysfunction (RHI ≤ 1.67; n = 14) during the control treatment, premeal RHI was significantly higher in the dairy versus nondairy condition (2.32 versus 1.50, P = 0.002). Fasting lipoprotein lipid values were not significantly different between treatments overall, or in subgroup analyses. CONCLUSION: No significant effects of consuming low-fat dairy products, compared with low-fat nondairy products, were observed for blood pressures, measures of vascular function, or lipid variables in the overall sample, but results from subgroup analyses were consistent with the hypothesis that dairy foods might improve RHI in those with endothelial dysfunction.

Consumption of stearidonic acid-rich oil in foods increases red blood cell eicosapentaenoic acid.

BACKGROUND: Consumption of soybean oil enriched with stearidonic acid was previously shown to increase eicosapentaenoic acid (EPA) in red blood cells (RBC). OBJECTIVE: This study was designed to evaluate the effect of stearidonic acid oil used as a food ingredient in baked products and beverages on the RBC fatty acid profile. DESIGN: This was a randomized, double-blind, controlled, parallel-arm study. PARTICIPANTS: Healthy men and women 21 to 65 years of age were included. INTERVENTION: Participants consumed either negative control (1.5 g/day high-oleic sunflower ethyl ester oil softgel capsules+foods containing 7 g/day high-oleic sunflower oil), positive control (1.5 g/day EPA oil ethyl ester softgel capsules+foods containing 7 g/day high-oleic sunflower oil), or active (1.5 g/day high-oleic sunflower ethyl ester oil softgel capsules+foods containing 7 g/day stearidonic acid soybean oil) for 12 weeks. MAIN OUTCOME MEASURES: RBC membrane fatty acid profile (at weeks 0, 2, 4, 6, 8, 10, and 12); fasting serum lipids (weeks -2, 0, 6, 10, and 12); and fasting plasma glucose and insulin (weeks -2, 0, 10, and 12) were assessed. STATISTICAL ANALYSES PERFORMED: A repeated measures analysis of covariance was used for continuous variables, and pair-wise comparisons between treatments were adjusted using a step-down Bonferroni method. Fisher's exact or χ(2) tests were used for categorical data. RESULTS: RBC %EPA throughout the 12-week study were significantly different between all groups. Means at 12 weeks were 0.50%±0.03%, 2.17%±0.21%, and 0.85%±0.05% for control, EPA, and stearidonic acid, respectively. Other efficacy outcome measures were not significantly different among treatment groups. CONCLUSIONS: Consumption of stearidonic acid-enriched soybean oil incorporated into common foods increased RBC %EPA in healthy men and women. Stearidonic acid soybean oil, a sustainable and accessible source of long-chain n-3, can effectively be used to increase EPA in RBC.

Fibermalt is well tolerated in healthy men and women at intakes up to 60 g/d: a randomized, double-blind, crossover trial.

In this randomized, double-blind crossover trial, the digestive tolerance of a novel dietary fibre (fibermalt, an indigestible maltose alternan oligosaccharide) was assessed in healthy men and women. Twenty-nine subjects consumed 0 (control), 45 or 60 g of fibre in two doses per day for 2-week treatment periods, each separated by a 2-week washout. Results indicated no differences between treatments in composite gastrointestinal (GI) symptom scores (sum of six GI symptom ratings), individual GI symptoms (nausea, bloating, GI rumbling, gas/flatulence, abdominal pain, diarrhoea), bowel characteristics (frequency, faecal consistency, faecal hardness, straining, discomfort and incomplete evacuation) or average daily faecal output. The symptom scores were consistently low for each treatment period with means averaging below 1 out of a possible range of 0-12 for the composite score. The results of this study suggest that fibermalt is well tolerated at intakes up to 60 g of fibre per day.

A meta-analysis of randomized controlled trials that compare the lipid effects of beef versus poultry and/or fish consumption.

BACKGROUND: Limited consumption of red meat, including beef, is one of many often-suggested strategies to reduce the risk of coronary heart disease (CHD). However, the role that beef consumption specifically plays in promoting adverse changes in the cardiovascular risk factor profile is unclear. OBJECTIVE: A meta-analysis of randomized, controlled, clinical trials (RCTs) was conducted to evaluate the effects of beef, independent of other red and processed meats, compared with poultry and/or fish consumption, on lipoprotein lipids. METHODS: RCTs published from 1950 to 2010 were considered for inclusion. Studies were included if they reported fasting lipoprotein lipid changes after beef and poultry/fish consumption by subjects free of chronic disease. A total of 124 RCTs were identified, and 8 studies involving 406 subjects met the prespecified entry criteria and were included in the analysis. RESULTS: Relative to the baseline diet, mean ± standard error changes (in mg/dL) after beef versus poultry/fish consumption, respectively, were -8.1 ± 2.8 vs. -6.2 ± 3.1 for total cholesterol (P = .630), -8.2 ± 4.2 vs. -8.9 ± 4.4 for low-density lipoprotein cholesterol (P = .905), -2.3 ± 1.0 vs. -1.9 ± 0.8 for high-density lipoprotein cholesterol (P = .762), and -8.1 ± 3.6 vs. -12.9 ± 4.0 mg/dL for triacylglycerols (P = .367). CONCLUSION: Changes in the fasting lipid profile were not significantly different with beef consumption compared with those with poultry and/or fish consumption. Inclusion of lean beef in the diet increases the variety of available food choices, which may improve long-term adherence with dietary recommendations for lipid management.

Vitamin D intake and status are associated with lower prevalence of metabolic syndrome in U.S. adults: National Health and Nutrition Examination Surveys 2003-2006.

BACKGROUND: Previous reports have shown that metabolic syndrome and some metabolic syndrome components are associated with serum 25-hydroxyvitamin D [25(OH)D]. METHODS: Using the National Health and Nutrition Examination Surveys (NHANES), 2003-2006, we evaluated the associations of vitamin D intake (n=3543) and vitamin D status [25(OH)D; n=3529], with the prevalence of metabolic syndrome and its components in adults 20 years and older. Exclusion criteria included nonfasted subjects, those pregnant and/or lactating, and, for intake analyses, those with unreliable 24-h recall records. Subjects were separately classified into quartiles of vitamin D intake (both including and excluding supplements) and serum 25(OH)D. Logistic regression was used to determine odds ratios (OR) for metabolic syndrome after adjusting for multiple confounders. RESULTS: Those in the highest quartile of serum 25(OH)D had 60% lower odds for metabolic syndrome as compared to those in the lowest quartile [OR=0.40; 95% confidence interval (CI) 0.27, 0.59]. Elevated waist circumference (OR=0.57; 95% CI 0.39, 0.84), low high-density lipoprotein cholesterol (HDL-C) (OR=0.54; 95% CI 0.39, 0.75), and high homeostasis model assessment of insulin resistance (HOMA-IR) (OR=0.40; 95% CI 0.29, 0.55) were the main components associated with serum 25(OH)D. Compared with the lowest vitamin D intake quartile (excluding supplements), those in the highest intake quartile had 28% lower odds for metabolic syndrome (OR=0.72; 95% CI 0.58, 0.90). No components of metabolic syndrome were significantly associated with dietary intake of vitamin D with supplements included or excluded. CONCLUSIONS: We conclude that higher 25(OH)D, and, to a lesser degree, greater dietary vitamin D intake, are associated with reduced prevalence of metabolic syndrome.

Resistant starch from high-amylose maize increases insulin sensitivity in overweight and obese men.

This study evaluated the effects of 2 levels of intake of high-amylose maize type 2 resistant starch (HAM-RS2) on insulin sensitivity (S(I)) in participants with waist circumference ≥89 (women) or ≥102 cm (men). Participants received 0 (control starch), 15, or 30 g/d (double-blind) of HAM-RS2 in random order for 4-wk periods separated by 3-wk washouts. Minimal model S(I) was assessed at the end of each period using the insulin-modified i.v. glucose tolerance test. The efficacy evaluable sample included 11 men and 22 women (mean ± SEM) age 49.5 ± 1.6 y, with a BMI of 30.6 ± 0.5 kg/m2 and waist circumference 105.3 ± 1.3 cm. A treatment main effect (P = 0.018) and a treatment × sex interaction (P = 0.033) were present. In men, least squares geometric mean analysis for S(I) did not differ after intake of 15 g/d HAM-RS2 (6.90 × 10⁻5 pmol⁻¹ · L⁻¹ × min⁻¹) and 30 g/d HAM-RS2 (7.13 × 10⁻5 pmol⁻¹ · L⁻¹ × min⁻¹), but both were higher than after the control treatment (4.66 × 10⁻5 pmol⁻¹ · L⁻¹ × min⁻¹) (P < 0.05). In women, there was no difference among the treatments (overall least squares ln-transformed mean ± pooled SEM = 1.80 ± 0.08; geometric mean = 6.05 × 10⁻5 pmol⁻¹ · L⁻¹ × min⁻¹). These results suggest that consumption of 15-30 g/d of HAM-RS2 improves S(I) in men. Additional research is needed to understand the mechanisms that might account for the treatment × sex interaction observed.

Stearidonic acid raises red blood cell membrane eicosapentaenoic acid.

The consumption of EPA and DHA has been associated with reduced risk for cardiovascular disease morbidity and mortality. Mean intakes of EPA and DHA in the United States and elsewhere are below levels recommended by health authorities. The main non-marine source of dietary (n-3) fatty acids (α-linolenic acid) is poorly converted to EPA in humans. Stearidonic acid (SDA) is a non-marine fatty acid that appears to be more readily converted to EPA in humans. Results from previous studies suggested that SDA, relative to EPA, increases RBC EPA, with reported efficiencies ranging from ~16 to 30%. A recently published, randomized, single-blind, controlled, parallel group study in healthy men and women characterized the relationships between intakes of SDA and EPA and EPA enrichment of RBC membranes over a 12-wk period. %EPA in RBC membranes was greater after EPA (0.44, 1.3, or 2.7 g/d, respectively) and SDA (1.3, 2.6, or 5.2 g/d, respectively) consumption compared to a safflower control (all P < 0.02). Based on quadratic response surface models, for EPA intakes of 0.25, 0.50, and 0.89 g/d, SDA intakes of 0.61, 1.89, and 5.32 g/d, respectively, would be required to produce equivalent values for RBC %EPA, translating to relative efficiencies of 41.0, 26.5, and 16.7%. Thus, dietary SDA over a range of intakes increases RBC %EPA, with declining relative efficiency as SDA intake increases.

Prescription omega-3-acid ethyl esters reduce fasting and postprandial triglycerides and modestly reduce pancreatic ß-cell response in subjects with primary hypertriglyceridemia.

Treatment with prescription omega-3-acid ethyl esters (POM3) reduces triglycerides (TG) and TG-rich lipoprotein particles, but has been associated with increased fasting glucose (2-6mg/dL). This double-blind, randomized, controlled crossover trial in 19 men and women with hypertriglyceridemia (fasting TG ≥150 and ≤499mg/dL) examined lipid responses and indices of insulin sensitivity and secretion following a liquid meal tolerance test. Six weeks treatment with POM3 vs. corn oil resulted in significant lower mean fasting (-50.1mg/dL, p<0.001) and postprandial TG (-76.1mg/dL, p<0.001), higher mean fasting glucose (2.8mg/dL, p=0.062), reduced mean disposition index (2.1 vs. 2.4, p=0.037), and no change in the median Matsuda composite insulin sensitivity index (3.3 vs. 3.2, p=0.959). These results suggest that POM3 slightly reduces pancreatic ß-cell responsiveness to plasma glucose elevation, which may contribute to the rise in fasting glucose sometimes observed with POM3.

Validation of insulin sensitivity and secretion indices derived from the liquid meal tolerance test.

BACKGROUND: A liquid meal tolerance test (LMTT) has been proposed as a useful alternative to more labor-intensive methods of assessing insulin sensitivity and secretion. OBJECTIVE: This substudy, conducted at the conclusion of a randomized, double-blind crossover trial, compared insulin sensitivity indices from a LMTT (Matsuda insulin sensitivity index [MISI] and LMTT disposition index [LMTT-DI]) with indices derived from minimal model analysis of results from the insulin-modified intravenous glucose tolerance test (IVGTT) (insulin sensitivity index [S(I)] and disposition index [DI]). RESULTS: Participants included men (n = 16) and women (n = 8) without diabetes but with increased abdominal adiposity (waist circumference ≥102 cm and ≥89 cm, respectively) and mean age of 48.9 years. The correlation between S(I) and the MISI was 0.776 (P < 0.0001). The respective associations between S(I) and MISI with waist circumference (r = -0.445 and -0.554, both P < 0.05) and body mass index were similar (r = -0.500 and -0.539, P < 0.05). The correlation between DI and LMTT-DI was 0.604 (P = 0.002). CONCLUSIONS: These results indicate that indices of insulin sensitivity and secretion derived from the LMTT correlate well with those from the insulin-modified IVGTT with minimal model analysis, suggesting that they may be useful for application in clinical and population studies of glucose homeostasis.

Fat mass, abdominal fat distribution, and C-reactive protein concentrations in overweight and obese men and women.

BACKGROUND: Previous work suggests a positive correlation between intraabdominal adipose tissue and high-sensitivity C-reactive protein (hsCRP). We sought to further explore the relationships between body fat mass/distribution and hsCRP levels in sedentary overweight and obese men and women. METHODS: Body composition and abdominal fat areas were measured using dual-energy X-ray absorptiometry and abdominal computed tomography, respectively. Concentrations of hsCRP were measured in serum by nephelometry. RESULTS: Values for hsCRP were 3.2 ± 0.3 mg/L and 4.8 ± 0.6 mg/L in men and women, respectively. Fat mass was nonsignificantly (P=0.09) higher in women (38.8 ± 1.0 kg) than men (36.2 ± 1.1 kg). Abdominal visceral adipose tissue (VAT) area was greater in men than women (104.5 ± 5.7 vs. 59.6 ± 4.3 cm(2), P<0.001) whereas women had greater abdominal subcutaneous adipose tissue (SAT) area compared to men (334.6 ± 11.6 vs. 285.0 ± 13.4 cm(2), P<0.01). Significant associations were present between hsCRP concentrations (natural log transformed) and total fat mass (r=0.502, P<0.01), VAT (r=0.241, P<0.05), and SAT (r=0.418, P<0.01) in men, whereas a significant association for women was found only for total fat mass (r=0.359, P<0.01). Multiple regression analyses showed that men and women had similar concentrations of hsCRP for a given age and fat mass. In both men and women, neither VAT nor SAT area independently predicted hsCRP when included individually or separately in models with age and fat mass. CONCLUSIONS: Results suggest that whole body fat mass, but not abdominal fat distribution, is associated with hsCRP concentrations in overweight and obese men and women.

Effects of prescription omega-3-acid ethyl esters on fasting lipid profile in subjects with primary hypercholesterolemia.

This double-blind, randomized crossover study investigated the effects of 6 weeks of treatment with prescription omega-3-acid ethyl esters (POM3, 4 g/day) versus placebo (soy oil) on low-density lipoprotein cholesterol (LDL-C) and other aspects of the fasting lipid profile in 31 men and women with primary, isolated hypercholesterolemia (LDL-C 130-220 mg/dL and triglycerides less than 150 mg/dL while free of lipid-altering therapies). Mean ± standard error of the mean baseline concentrations of total cholesterol, LDL-C, high-density lipoprotein cholesterol (HDL-C), very-low-density lipoprotein cholesterol, and triglycerides were 229 ± 3, 146 ± 3, 60 ± 2, 23 ± 2, and 113 ± 8 mg/dL, respectively. POM3 produced a modest increase from baseline in LDL-C (3.4%) versus the placebo response (-0.7%, P = 0.010). Significant changes (P < 0.05) for POM3 (placebo-corrected) were observed for very-low-density lipoprotein cholesterol (-18.8%), triglycerides (-18.7%), and HDL-C (3.3%). Nuclear magnetic resonance-determined very-low-density lipoprotein particle concentration and size and HDL particle concentration decreased significantly more with POM3 versus placebo, whereas LDL and HDL particle sizes increased significantly more with POM3 versus placebo. Total cholesterol, non-HDL-C, apolipoproteins A1 and B, and LDL particle concentration responses did not differ between treatments. These results did not confirm the hypothesis that POM3 treatment would lower LDL-C in primary, isolated hypercholesterolemia. Effects on other variables were consistent with prior results in mixed dyslipidemia.