Effect of milk protein intake and casein-to-whey ratio in breakfast meals on postprandial glucose, satiety ratings, and subsequent meal intake.

Whey and casein proteins differentially affect postprandial blood glucose and satiety mechanisms, with relevance for type 2 diabetes and obesity. Therefore, the purpose of this work was to investigate the effect of the casein-to-whey protein ratio and total protein concentration of milks consumed with cereal on postprandial blood glucose, appetite ratings, and subsequent food intake in a randomized, controlled, double-blinded study with healthy young adults (n = 32, 23.4 ± 3.1 yr, body mass index = 22.2 ± 2.5 kg/m2). Fasted participants consumed milk (250 mL) with either 80:20 or 40:60 (modified) casein-to-whey protein ratios at commercially normal (3.1%, wt) or high protein (9.3%, wt) concentration, or control (water with whey permeate), each along with 2 servings of oat-based breakfast cereal. Blood glucose concentrations were determined from finger prick blood samples and appetite was assessed using visual analog scales. Participants consumed a measured ad libitum pizza lunch at 120 min and blood glucose determination and appetite assessment continued following the lunch meal (140-200 min) to observe the second meal effect. Pre-lunch (0-120 min) incremental area under the curve (iAUC) and mean change from baseline blood glucose were reduced with consumption of all milk treatments relative to control. However, we found no differences between all treatments on pre-lunch appetite change from baseline and total area under the curve (tAUC) or lunch meal food intake. In terms of protein concentration results, high protein (9.3%, wt) treatments contrasted to normal protein (3.1%, wt) treatments lowered blood glucose change from baseline and iAUC, and post-lunch appetite change from baseline and tAUC. Protein ratio showed a modest effect in that modified (40:60) protein ratio lowered pre-lunch blood glucose change from baseline but not iAUC, and normal (80:20) protein ratio lowered pre-lunch appetite change from baseline but not tAUC. Therefore, high-carbohydrate breakfast meals with increased protein concentration (9.3%, wt) could be a dietary strategy for the attenuation of blood glucose and improved satiety ratings after the second meal.

The role of alginates in regulation of food intake and glycemia: a gastroenterological perspective.

Regulation of food intake through modulation of gastrointestinal responses to ingested foods is an ever-growing component of the therapeutic approaches targeting the obesity epidemic. Alginates, viscous and gel-forming soluble fibers isolated from the cell wall of brown seaweeds and some bacteria, are recently receiving considerable attention because of their potential role in satiation, satiety, and food intake regulation in the short term. Enhancement of gastric distension, delay of gastric emptying, and attenuation of postprandial glucose responses may constitute the basis of their physiological benefits. Offering physical, chemical, sensorial, and physiological advantages over other viscous and gel-forming fibers, alginates constitute promising functional food ingredients for the food industry. Therefore, the current review explores the role of alginates in food intake and glycemic regulation, their underlying modes of action and their potential in food applications.

Obesogenic phenotype of offspring of dams fed a high multivitamin diet is prevented by a post-weaning high multivitamin or high folate diet.

BACKGROUND: High multivitamin (10-fold AIN-93G, HV) diets fed during pregnancy to Wistar rats increase characteristics of metabolic syndrome in offspring when weaned to the recommended vitamin (RV) diet. OBJECTIVE: To determine whether the effects of HV gestational diets on obesogenic phenotypes in the offspring arise as a consequence of altered hypothalamic control of feeding behavior and if their increased food intake could be prevented by feeding them HV or high folate (10-fold folate, HFol) diets. METHODS: Male offspring of dams fed HV diet during pregnancy weaned to RV, HV or HFol diets were compared with those born to RV dams and weaned to RV diet for 29 weeks. Food intake over 72 h and body weight were measured bi-weekly and weekly, respectively. Glucose response to a glucose load was measured at 18 weeks post weaning. Hypothalamic gene expression of feeding-related neuropeptides including neuropeptide Y, pro-opiomelanocortin (POMC), insulin receptor, leptin receptor, brain-derived neurotrophic factor (BDNF), receptors for dopamine (DopaR1/2/5) and serotonin (SeroR1A/2A/2C), as well as global DNA methylation and brain and plasma folate concentrations were measured at 29 weeks post weaning. RESULTS: HV or HFol pup diets increased brain and plasma folate concentrations and prevented the increase in food intake (5%, P=0.03), body weight (8%, P=0.0006) and glucose response to a glucose load (36%, P=0.02) found in those fed the RV diet. Expression of anorexigenic POMC (P=0.004) and BDNF (P=0.02) was higher, and DopaR1 was lower (P=0.06) in pups fed the HV diet. The HFol pup diet partially brought BDNF to the control level (P=0.02) and lowered SeroR2A (P=0.008). Expression of other genes was unaffected. Global DNA methylation was similar among the diet groups. CONCLUSION: The obesogenic phenotype in offspring from HV-fed dams is prevented by feeding HV or HFol pup diets, possibly due to post-weaning modulation of food intake regulatory mechanisms.

Regular consumption of pulses for 8 weeks reduces metabolic syndrome risk factors in overweight and obese adults.

Pulses are low in energy density, supporting their inclusion in the diet for the management of risk factors of the metabolic syndrome (MetSyn). The aim of the present study was to describe the effects of frequent consumption (five cups/week over 8 weeks) of pulses (yellow peas, chickpeas, navy beans and lentils), compared with counselling to reduce energy intake by 2093 kJ/d (500 kcal/d), on risk factors of the MetSyn in two groups (nineteen and twenty-one subjects, respectively) of overweight or obese (mean BMI 32·8 kg/m2) adults. Body weight, waist circumference, blood pressure, fasting blood parameters and 24 h food intakes were measured at weeks 1, 4 and 8. Blood glucose, insulin, C-peptide, glucagon-like peptide-1 (GLP-1) and ghrelin were measured after a 75 g oral glucose load at weeks 1 and 8. At week 8, both groups reported reductions in energy intake, waist circumference, systolic blood pressure, glycosylated Hb (HbA1c) and glucose AUC and homeostasis model of insulin resistance (HOMA-IR) following the glucose load (P < 0·05). However, HDL, fasting C-peptide and insulin AUC responses were dependent on diet (P < 0·05). HDL and C-peptide increased by 4·5 and 12·3 %, respectively, in the pulse group, but decreased by 0·8 and 7·6 %, respectively, in the energy-restricted group. Insulin AUC decreased in both females and males on the energy-restricted diet by 24·2 and 4·8 %, respectively, but on the pulse diet it decreased by 13·9 % in females and increased by 27·3 % in males (P < 0·05). In conclusion, frequent consumption of pulses in an ad libitum diet reduced risk factors of the MetSyn and these effects were equivalent, and in some instances stronger, than counselling for dietary energy reduction.

The acute effects of a pulse-containing meal on glycaemic responses and measures of satiety and satiation within and at a later meal.

Pulses are low glycaemic foods; however, their effect on satiation is unknown. The objective was to determine the effects of an ad libitum pulse meal on food intake (FI), appetite and blood glucose (BG) before and after a test meal (4 h later) and on FI at the test meal. Males (n 24, 22·8 kg/m2) received one of four treatments or control. The pulse treatments contained pasta and tomato sauce and 44 % of energy from: (1) chickpeas, (2) lentils, (3) navy beans or (4) yellow peas. The control was pasta and tomato sauce (pasta and sauce). FI (satiation) was measured at the treatment meal (0-20 min) and at an ad libitum pizza meal 4 h later. BG and appetite were measured from 0 to 340 min. At the treatment meal, lentils led to lower FI compared to chickpeas and pasta and sauce, whereas navy beans led to lower FI compared to chickpeas. Also, lentils led to lower cumulative FI compared to pasta and sauce. All pulses led to lower BG peak and cumulative area under the curve (AUC; 0-340 min); however, only chickpeas, lentils and navy beans reduced pre-pizza meal BG AUC (0-260 min) relative to pasta and sauce. Chickpeas led to lower post-pizza meal BG AUC (260-340 min) compared to navy beans and yellow peas. Consumption of pulses in a high-glycaemic meal contributes to earlier satiation, lower BG following the meal and after a later meal, but these effects are specific to pulse type and cannot be explained by their glycaemic properties alone.

Effect of drinking compared with eating sugars or whey protein on short-term appetite and food intake.

BACKGROUND: It is hypothesized that a solid form of food or food components suppresses subjective appetite and short-term food intake (FI) more than a liquid form. OBJECTIVE: To compare the effect of eating solid vs drinking liquid forms of gelatin, sucrose and its component mixtures, and whey protein, on subjective appetite and FI in young men. DESIGN AND SUBJECTS: A randomized crossover design was used in three experiments in which the subjects were healthy males of normal weight. Solid and liquid forms of gelatin (6 g) (experiment 1, n=14), sucrose (75 g) and a mixture of 50% glucose/50% fructose (G50:F50) (experiment 2, n=15), and acid and sweet whey protein (50 g) (experiment 3, n=14) were compared. The controls were water (experiments 1 and 3) and calorie-free sweetened water with gelatin (sweet gelatin, experiment 1) or calorie-free sweetened water (sweet control, experiment 2). Subjective average appetite was measured by visual analog scales over 1 h and ad libitum FI was measured 1 h after treatment consumption. RESULTS: Average appetite area under the curve was not different between solid and liquid forms of sugars, but was larger, indicating greater satiety for solid compared with liquid forms of gelatin and sweet, but not acid whey protein. The FI was not different from that of control because of solid or liquid sugars or gelatin treatments. However, both solid and liquid forms of whey protein, with no difference among them, suppressed FI compared with control (P<0.05). CONCLUSION: Macronutrient composition is more important than physical state of foods in determining subjective appetite and FI.

Multivitamin supplementation of Wistar rats during pregnancy accelerates the development of obesity in offspring fed an obesogenic diet.

OBJECTIVE: The effect of gestational multivitamin supplementation on the development of obesity in rat offspring fed an obesogenic diet was investigated. DESIGN: Pregnant Wistar rats (n=10 per group) were fed the AIN-93G diet with the recommended vitamin (RV) content or a 10-fold increase (high vitamin, HV). At weaning, 10 males and 10 females, from separate dams, and from each gestational diet group were weaned to the liquid obesogenic diet for 48 weeks post-weaning. MEASUREMENTS: Body weight (BW) was measured weekly, and food intake over 24 h was measured once every 3 weeks for 24 weeks. Every 4 weeks, after an overnight fast, food intake over 1 h was measured 30 min after a gavage of water or glucose. An oral glucose tolerance test (OGTT) was carried out every 3-5 weeks. Post-weaning fasting glucose, insulin, ghrelin, glucagon-like peptide 1 (GLP-1), and systolic blood pressure (SBP) were measured. RESULTS: No difference in BW at birth or litter size was observed. Males and females from HV dams gained 17% (P<0.05) and 37% (P<0.001) more BW at 48 weeks post-weaning, and consumed 18% (P=0.07) and 20% (P<0.05) more food. One-hour food intake after water and glucose preloads was 27% (P<0.01) and 34% (P<0.05) higher in males from HV dams. Fasting ghrelin and GLP-1 were 27 and 32% higher in males from HV dams at weaning (P<0.05). Blood glucose response to the OGTT was greater in both males and females from HV dams at 13 weeks post-weaning (P<0.05), and the insulin resistance index was 76 and 43% higher in females from HV dams at 14 and 28 weeks post-weaning (P<0.05). SBP was 23 and 16% higher at 44 weeks post-weaning in male and females (P<0.01). CONCLUSION: High multivitamin intake during pregnancy increases the phenotypic expression of obesity and components of the metabolic syndrome in both female and male rats fed an obesogenic diet.

Normal and abnormal function of the hypothalamic-pituitary-adrenocortical system in man.

The first half of this manuscript is devoted to a review of the methods used and the results obtained in the published measurements of the normal responses to tests of the three main types of hypothalamic-pituitary-adrenocortical (HPA) activity in man. These are, I, basal, unstressed activity leading to appropriate levels of total daily production of cortisol in the characteristic circadian pattern; II, responses to feedback stimulation of HPA activity by metyrapone administration; and III, responses to tests of the effects of stress on the HPA system including the effects of hypoglycemia, induced fever, vasopressin administration, and ACTH injections and infusions. The advantages and shortcomings of each type of procedure are discussed. The second half of this paper describes the authors' attempts to establish the limits of normality of standard and modified methods of evaluating the HPA system. The defined limits of normality have been used to assess the HPA function in 158 patients with known or suspected disorders of the HPA system. In normal controls, halfhourly plasma cortisol determinations established the normality of circadian and postprandial fluctuations and of mean plasma cortisol concentration, 6.2 +/- 0.3 (SEM) micrograms/dl, which were closely approximated by determinations every 6 h. Metyrapone, given in a dose of 500 mg every 2 h for 24 h increased urinary 17-OHCS excretion to 10.5-32.6 mg/day or to 1.7-7.8 times basal excretion rate. Increasing rates of insulin infusion disclosed significant relationships between resulting plasma glucose and cortisol concentrations. The slopes of the delta cortisol/delta glucose responses were similar after insulin infusions (0.46 +/- 0.05) and after insulin injections, 0.15 U/kg (0.43 +/- 0.09), and were always greater than 0.20 micrograms/mg. This index provides a useful objective measure of the normality of responses to hypoglycemic stress, 0.20-0.87 micrograms/mg. Adrenocortical responses to iv infusions of ACTH (cosyntropin 0.25 mg) may be equivocal at 2 h but are clear cut at 4, 6 and 8 h. Of 158 patients in whom hypopituitarism was known or suspected because of the presence of a pituitary tumor, acromegaly, hyperprolactinemia, or clinical features, HPA function was found to be entirely normal in 88 patients and partially or severely abnormal in the remaining 70 patients.(ABSTRACT TRUNCATED AT 400 WORDS)

A comparison of short-term appetite and energy intakes in normal weight and obese boys following glucose and whey-protein drinks.

OBJECTIVE: To compare the effect of glucose and whey-protein preloads on satiety and food intake (FI) as affected by time to the next meal and body composition in normal weight (NW) and obese (OB) boys. DESIGN: Cross-sectional clinical intervention study of the effect of caloric preloads on FI control in boys. SUBJECTS: Seventeen NW (body mass index (BMI)=18.9+/-0.5 kg/m(2); age=12.2+/-0.3 years) and 17 OB boys (BMI=25.8+/-0.9 kg/m(2); age=11.4+/-0.3 years) (Experiment 1) and 12 NW boys (BMI=18.6+/-0.6 kg/m(2); age=12.1+/-0.3 years) (Experiment 2). MEASUREMENTS: On three separate mornings and in random order each of the boys consumed a noncaloric sweetened preload, glucose (837 kJ) or whey protein (837 kJ) (Experiment 1) or noncaloric preload, glucose (1.0 g/kg) or whey protein (1.0 g/kg) (Experiment 2) made up to 250 ml with water 2 h after the consumption of a fixed breakfast. Food intake from a pizza meal was measured 30 min (Experiment 1) or 60 min (Experiment 2) later. RESULTS: In Experiment 1, glucose suppressed FI (mean kJ+/-s.e.m.) in NW (3126+/-304) and OB boys (3116+/-286) compared with the control (NW, 4015+/-337 and OB, 3791+/-255). Whey protein suppressed FI in NW, but not in OB boys. Body weight, fat-mass and fat-free mass were positively associated with FI after all treatments in NW, but was not related to FI in OB boys. In Experiment 2, FI was suppressed by whey protein (2683+/-367) more than by glucose (3107+/-294) or the control (3585+/-361). CONCLUSION: NW and OB boys respond differently to whey-protein preloads, with time to next meal a factor in the response to both glucose and protein preloads.

Design and evaluation by nitrogen balance and blood aminograms of an amino acid mixture for total parenteral nutrition of adults with gastrointestinal disease.

This study was undertaken to assess the efficacy of an amino acid mixture formulated for intravenous use from estimates of requirements for essential amino acids of human adults, and from data previously derived from a study using casein hydrolysate as the amino acid source. This mixture contained 39.4% essential amino acids, with glycine, alanine, arginine, histidine, and proline selected to supply the nonessential nitrogen. Nitrogen balance and blood aminograms were measured in six adult patients with gastrointestinal disease, fed intravenously for 1 wk at each of three levels of amino acid intake, while all other nutrients were constant and adequate in relation to body weight. Four of the patients were then fed 1.0 g/kg of egg or meat protein orally for 1 wk at the end of the 3 wk study, while all nutrients other than the amino acids were fed intravenously. Average nitrogen balances of -0.8, 0.5, and 2.2 g/day were observed when the amounts of amino acids infused were 0.25, 0.5, and 1.0 g/kg, respectively. Fasting levels of threonine, glycine, cystine, methionine, isoleucine, tryptophan, and arginine, but not of the other amino acids, increased with the increment in input, although the levels were generally lower than normal. The increase in blood concentration observed during infusion was similar for each of the essential amino acids, indicating that the supply of each of the amino acids was much better balanced for utilization than casein hydrolysate. However the blood aminograms did suggest that some changes in composition of the mixture for the malnourished adult were desirable, such that the amino acid mixture resembled that needed by the normal growing child. Nitrogen balance in the four patients fed orally with high-quality protein averaged 2.0 g/day, showing that an amino acid mixture given intravenously, provided it is well-balanced, can be utilized as efficiently as protein given orally. It is concluded that the prediction of oral requirements for amino acids should be combined with observations on changes in blood aminograms during infusion over a range of amino acid input in the development of amino acid mixtures for intravenous feeding.

Metabolic studies in total parenteral nutrition with lipid in man. Comparison with glucose.

A study was undertaken of patients on a regimen of total parenteral nutrition comparing the nitrogen balance, energy substrates, blood amino acids, immunoreactive insulin, and immunoreactive glucagon levels during the sequential infusion of nonprotein calories as either glucose alone (glucose system) or 83% as Intralipid (Pharmacia Fine Chemicals, Montreal, Canada) and 17% glucose (lipid system). These nonprotein calories were administered with a constant background of amino acids (1 g/kg per day), vitamins, and minerals. Each system was infused for a week at a time and the order of infusion randomized. In some patients whole blood arteriovenous (A-V) levels of amino acids were measured across forearm muscle. During the glucose system there was a significantly higher level of pyruvate, lactate, alanine, and immunoreactive insulin, consistent with glucose being the principal source of energy. In contrast, during the lipid system there was a rise in free fatty acids and ketone bodies with a fall in insulin, suggesting that lipid was now the principal source of energy. Despite these two very diverse metabolic situations the nitrogen balance with both systems was positive to a comparable degree after the establishment of equilibrium. Correspondingly, A-V differences of whole blood amino acid nitrogen showed uptake by muscle to an equivalent degree with both systems. Clinical studies indicated that the lipid system as defined herein could be infused by peripheral vein for up to 43 days with resultant weight gain, elevation of serum proteins, and healing of fistulae. Our studies suggest that for both metabolic and clinical reasons exogenously infused lipid is a suitable source of nonprotein calories.

The effects of potatoes and other carbohydrate side dishes consumed with meat on food intake, glycemia and satiety response in children.

BACKGROUND: The effect of carbohydrate (CHO) foods on blood glucose (BG) is ranked by their glycemic index (GI). Boiled and mashed potatoes (BMPs) are ranked as high GI foods, whereas pasta and rice have moderate GI rankings. The objective of this study was to compare ad libitum consumption of common CHO dishes consumed with meat on meal-time food intake and post-meal satiety, BG, insulin and gut hormones in 11- to 13-year-old normal weight children. METHODS: Two randomized crossover studies were conducted. At weekly intervals, children (experiment 1: 12 males (M), 8 females (F); experiment 2: 6M, 6 F) received in random order 1 of 5 CHO side dishes of rice, pasta, BMP, fried French fries (FFF) or baked French fries (BFF) eaten freely together with a fixed amount of lean beef (100 g). In experiment-1, food intake over 30 min and subjective appetite were measured for 120 min. In experiment-2, the same outcomes were measured along with BG, plasma insulin and gut hormones. RESULTS: The results for boys and girls were pooled as sex was not a factor. In both experiments, children consumed 30-40% less calories at meals with BMP (P<0.0001) compared with all other treatments, which were similar. BMP increased satiety, expressed as a change in appetite per kilocalorie, more than all other treatments (P<0.0001). FFF resulted in the lowest (P<0.0001) glucose and insulin at meal end and post-meal and peptide YY (PYY) post-meal. Blood measures were similar among all other treatments. CONCLUSIONS: The physiological functions of CHO foods consumed ad libitum at meal time on food intake, appetite, BG, insulin and gut hormone responses in children is not predicted by the GI.

The renin-angiotensin-aldosterone system in diabetic patients with hyperkalemia.

Seven long-standing diabetic patients with spontaneous and intermittent hyperkalemia were studied in an effort to assess the normality of their renin-aldosterone axis. The administration of oral glucose, in the absence of insulin, caused a paradoxical rise in serum potassium with no significant change in plasma aldosterone concentration from controls. All displayed subnormal aldosterone-secreting capacity to known stimuli of aldosterone secretion such as low salt diet, angiotensin II infusion, and ACTH infusion. The paradoxical rise in serum potassium with hyperglycemia was corrected in all by concomitant administration of insulin or pretreatment with a mineralocorticoid. Our observations question the role of aldosterone deficiency in the phenomenon of glucose-induced hyperkalemia.

Delayed orthostatic intolerance.

In seven patients who presented with lightheadedness, fatigue, "weakness," and sometimes syncope, blood pressure was found not to fall after standing for 3 to 4 minutes but to fall severely, frequently with syncope or presyncopal symptoms, after 13 to 30 minutes when measured every minute with an automatic device. This delayed orthostatic hypotension could be corrected with inflation of a pressure suit to 45 mm Hg. Its mechanism was further investigated with measurements of plasma catecholamines, plasma cortisol and aldosterone responses to corticotropin, and the effects of norepinephrine infusions on blood pressure and venous contractility. There was normal or excessive orthostatic norepinephrine release in all patients, evidence of impaired venous innervation in the legs in some, and various disorders in the other patients. Since therapeutic improvement in the orthostatic hypotension greatly reduced the symptoms, we concluded that orthostatic hypotension occurring after more than 10 minutes of standing is a potentially debilitating and often correctable disorder.

Primary hyperepinephrinemia in patients without pheochromocytoma.

Clinical features of epinephrine release led to the finding of spontaneously elevated plasma epinephrine concentrations in five patients, in four of whom plasma norepinephrine concentrations were normal. Adrenal medullary hyperplasia was suspected in one patient, whose first cousin had multiple endocrine neoplasia type IIa, and in two others, all of whom have experienced relief from symptoms during propranolol or atenolol administration. The other two patients had unilateral adrenal cysts, with negative metaiodobenzylguanidine scans and no histological evidence of pheochromocytoma, but complete relief of symptoms by excision of the cysts. In one patient, Cushing's syndrome and associated hypertension, diabetes, and ischemic finger-tip ulceration all disappeared after surgery. It is concluded that spontaneous hyperepinephrinemic manifestations can be received by beta-blockers or, when an adrenal mass is present, by unilateral adrenalectomy even when the metalodobenzylguanidine test result is negative.

Role of angiotensin in lethal cerebral hypoperfusion during treatment of acute hypertension.

A 23-year-old man developed lethal cerebral hypoperfusion associated with angiographically demonstrable cerebral arterial spasm while being treated for acute angiotensinogenic hypertension due to a traumatic coarctation of the aorta. This complication occurred even though the treatment maintained his blood pressure at normotensive to mildly hypertensive levels, without producing more than rare and fleeting periods of hypotension. To explain this enigmatic development, we propose that the high concentration of angiotensin II in the blood constricted the cerebral arteries and thus prevented adequate cerebral autoregulation when his blood pressure was lowered by drug therapy.

Efficacy of the National Cholesterol Education Program Step I diet. A randomized trial incorporating quick-service foods.

OBJECTIVE: To determine the effect of incorporating quick-service meals into a Step I diet on the achievement of the National Cholesterol Education Program (NCEP) guidelines and on the blood lipid response of hyperlipidemic subjects (as possibly, the achievement of, and adherence to, dietary goals may be assisted by the inclusion of familiar foods, instead of their exclusion). METHODS: This was a randomized, parallel design study in free-living subjects. Hypercholesterolemic men and women (low-density lipoprotein cholesterol [LDL-C] level, 3.36 to 5.69 mmol/L [130 to 220 mg/dL]) who were consuming a high-fat diet (> 33% of total calories from fat) were randomly assigned to either a traditional NCEP Step I diet (n = 44) or an NCEP Step I diet with the incorporation of frequent quick-service meals (NCEP-QS, n = 45). RESULTS: After 8 weeks of treatment, both groups similarly reduced their reported dietary intakes of energy (approximately 30%), total percent fat (approximately 8%), percent saturated fat (approximately 3%), and cholesterol (approximately 38% to 28%). Both groups also experienced a decrease in the levels of total serum cholesterol (NCEP Step I diet, 8%; NCEP-QS Step I diet, 3%) and LDL-C (NCEP Step I diet, 10%; NCEP-QS Step I diet, 4%). However, compared with the group receiving the NCEP-QS Step I diet, the subjects who were consuming the NCEP Step I diet showed a significantly greater reduction in their total serum cholesterol and LDL-C levels over time (P < .05). Weight loss was significantly correlated (P < .001) with the decrease in the total serum cholesterol and LDL-C levels for all subjects combined. CONCLUSIONS: Hyperlipidemic subjects who were consuming an NCEP Step I diet, with or without the incorporation of quick-service meals, experienced a significant decrease in their total serum cholesterol and LDL-C levels, body weight, and reported fat intake. The beneficial responses in lipid levels were modestly mitigated in the quick-service diet group.

A comparison of effects of lard and hydrogenated vegetable shortening on the development of high-fat diet-induced obesity in rats.

BACKGROUND: Obesity is associated with increased consumption and preference for dietary fat. Experimental models of fat-induced obesity use either lard or vegetable shortening. Yet, there are no direct comparisons of these commonly used fat sources, or the influence of their fatty acid composition, on the development of diet-induced obesity. OBJECTIVE: To compare the effects of lard and hydrogenated vegetable-shortening diets, which differ in their fatty acid composition, on weight gain and the development of obesity and insulin resistance in rats. METHODS AND DESIGN: Male Wistar rats were fed ad libitum for 14 weeks high-fat diets containing either (1) high vegetable fat (HVF, 60 kcal% from vegetable shortening) or (2) high lard fat (HLF, 60 kcal% from lard). Rats fed normal-fat (NF, 16 kcal% from vegetable shortening) diet served as control. Body weight, food intake, adipose tissue mass, serum 25[OH]D3, glucose, insulin and fatty acid composition of diets were measured. RESULTS: Rats fed either of the two high-fat diets had higher energy intake, weight gain and fat accretion than rats fed normal-fat diet. However, rats fed the HLF diet consumed more calories and gained more weight and body fat with greater increases of 32% in total (158.5±8.2 vs 120.2±6.6 g, P<0.05), 30% in visceral (104.4±5.2 vs 80.3±4.2 g, P<0.05) and 36% in subcutaneous fat mass (54.1±3.6 vs 39.9±3.1 g, P<0.05), compared with rats fed the HVF diet. Higher visceral adiposity was positively correlated with serum insulin (r=0.376, P<0.05) and homeostatic model assessment insulin resistance (r=0.391, P<0.05). CONCLUSION: We conclude that lard-based high-fat diets accentuate the increase in weight gain and the development of obesity and insulin resistance more than hydrogenated vegetable-shortening diets. These results further point to the importance of standardizing fatty acid composition and type of fat used in determining outcomes of consuming high-fat diets.

Insulin-like growth factor-I and insulin have no differential effects on glucose production and utilization under conditions of hyperglycemia.

We have previously shown that in moderately hyperglycemic depancreatized dogs, a glucose-lowering infusion of insulin-like growth factor-I (IGF-I) increased glucose utilization and lactate more, and suppressed glucose production and lipolysis less, than an equipotent glucose-lowering dose of insulin. Similar differences have been observed by others in nondiabetic and diabetic rats. To determine whether the decline in glycemia was important in detecting differential effects of IGF-I and insulin on glucose turnover, IGF-I (0.43 micrograms/kg.min; n = 6) or insulin (0.9 mU/kg.min; n = 9) were infused for 180 min, while hyperglycemia (approximately 180 mg/dl) was maintained. The decline of plasma glucose specific activity was minimized by using the matched step tracer infusion ([6-3H]- and [2-3H]glucose) method. Our results confirmed the approximately 10% potency of IGF-I on glucose metabolism compared to insulin and the lack of effect of IGF-I on insulin clearance. Under conditions of hyperglycemia, the glucose turnover findings were unexpected; there was no difference in the inhibition of glucose production (difference from basal, 2.7 +/- 0.4 mg/kg.min with IGF-I and 2.4 +/- 0.2 with insulin) or the stimulation of glucose utilization (difference from basal, 4.5 +/- 0.8 mg/kg.min with IGF-I and 4.7 +/- 1.3 with insulin). However, lactate increased more (P < 0.01) with IGF-I (from 1230 +/- 163 to a peak of 1903 +/- 349 microM) than insulin (from 1209 +/- 291 to 1535 +/- 340 microM) despite the same increment in glucose utilization. FFA and glycerol declined more with insulin, but the difference was not significant. IGF-I and insulin suppressed plasma amino acids to an equivalent extent. We concluded that 1) the differential effects of IGF-I and insulin on glucose turnover are masked under conditions of hyperglycemia; and 2) because insulin and IGF-I induced the same increment in glucose utilization, but lactate increased more with IGF-I, IGF-I might affect intracellular glucose metabolism differently from insulin. The failure of IGF-I to induce greater glucose utilization than insulin during hyperglycemia, the greater rise in lactate with IGF-I treatment, and the absence of differential effects on proteolysis indicate that IGF-I might have only limited clinical application in the treatment of diabetes.

Effect of posture on plasma atrial natriuretic hormone and renal function during salt loading in patients with and without postural (idiopathic) edema.

The effect of posture on plasma atrial natriuretic hormone (ANH) and renal function was studied in subjects with idiopathic edema. Sixty-five subjects with edema but with no clinical evidence for cardiac, renal, or pulmonary diseases were studied after they had been off all medication for 1 week or more. They had nothing by mouth after midnight and were admitted to the Clinical Research Center at 0800 h. They voided, were weighed, and had their blood pressure and pulse measured in the recumbent and upright positions. A needle was inserted, and subjects were recumbent for 0.5 h, after which blood was drawn for measurement of plasma ANH, serum sodium, potassium, and (in 35 subjects) creatinine. They were then given 150 mL 0.14% sodium chloride solution to drink every 0.5 h for the next 6 h. Urine was collected every 0.5 h for measurement of sodium, potassium, and creatinine. After 4 h of recumbency repeat blood samples were drawn, subjects ambulated for 2 h, after which final repeat blood samples were drawn. Subjects were considered to have postural edema if their upright urinary sodium/previous 2-h urinary sodium was less than 33%, and to have a normal response if it was 33% or more. The clinical characteristics of the 34 patients with postural edema and 31 patients with a normal response were similar. Plasma ANH levels (initial, after oral saline, and after standing) were similar in the two groups, and there was no relationship between changes in ANH and urinary sodium with standing. In conclusion, under conditions of mild oral sodium chloride loading, changes in plasma ANH do not cause the abnormal sodium retention found in patients with postural edema.