Improved Blood Lipid Profile Research Articles

Blood lipid responses to consumption of two different very low carbohydrate diets versus a lower fat diet

Low carbohydrate diets lower fasting serum concentrations of triglycerides (TG), while increasing HDL-cholesterol (HDL-C) and LDL-cholesterol (LDL-C) in comparison to lower fat diets; however, few studies have actually fed participants and none have evaluated the potential role of the type of food consumed in these fat-rich diets. Eighteen subjects (BMI=30–38) consumed three diets in a randomized, balanced cross-over design for 4 weeks separated by 4-week washout periods. Diets provided 1600 kcals for women (n=14) and 2200 kcals for men (n=4) to promote weight loss. The diets included 61% of kcals from carbohydrate (CHO), 18% protein (PRO), and 21% fat for the low fat (LF) diet and 10% CHO, 30% PRO, and 60% fat for the very low carbohydrate (VLC) diets. One of the VLC diets was primarily plant and mushroom (170 g/d) based (VLCPM) and the other provided more fat and protein from animal foods (VLCA). Serum TG was higher for the LF trial after 4 weeks (122.1 ± 46.4 mg/dl) than the VLCA (89.9 ± 29.6) and VLCPM (93.3 ± 39.3 mg/dl) diets. TC decreased by 6.1%, 13.5%, and 15.6% for the LF, VLCA, and VLCPM diets, respectively. HDL-C decreased by 10.9% during the LF trial and remained unchanged for the other trials. No differences in LDL-C were detected at the end of the trials. These results support previous research suggesting that a VLC diets can improve blood lipid profiles during weight loss in comparison to a lower fat diet. Research is needed to determine if similar effects occur during weight maintenance. Supported by a grant from the Mushroom Council.

Viscosity rather than quantity determines lipid lowering effects of dietary fiber in individuals consuming typical North American diet

Objective To investigate the role of low (wheat), medium (psyllium), and high (viscous fiber blend PGXTM) viscosity fibers on serum lipid profile. Methods Using a randomized, single blind, crossover design, 22 healthy participants (12M:10F, 34±11 years) on a typical North American diet (50% carbohydrates, 35% fat and 15% protein) and dietary fiber intake 15±5 g/day received addition of either Wheat Bran (WB), Bran Buds with Psyllium (BBP), or PGX (4.7 g/day) cereals, or low-fiber wheat flour cereal (control) for three weeks separated by one-week washout periods. Results Comparison between PGX and the control showed that the addition of PGX to the diet significantly lowered serum levels of cholesterol (6.5%, p=0.008), triglycerides (24.0%, p=0.02), ApoB (3.8%, p=0.048), LDL (7.1%, p=0.047), cholesterol/HDL (9.3%, p=0.004), and LDL/HDL (8.4%, p=0.045). Compared to the baseline, PGX significantly decreased serum levels of cholesterol (10.4%, p<0.0001), ApoB (5.7%, p=0.0005), LDL (13.3%, p=0.0007), cholesterol/HDL (9.6%, p=0.001), and LDL/HDL (11.1%, p=0.002) at the end of the 3-week study period. Other diets (WB, BBP) did not induce significant changes in lipid levels except elevation in ApoB and cholesterol at week 3 on the AB diet. Comparison between diets showed superior lipid-lowering effect of PGX. Conclusion The addition of a high viscous fiber PGX, but not wheat bran or psyllium, to a metabolically controlled typical North American diet significantly improves blood lipid profile in healthy subjects. Viscosity rather than quantity determines lipid lowering effects of dietary fiber. Research Support: Inovobiologic Inc, Calgary

Physical activity, sport, and pediatric diabetes

The benefits derived from regular physical activity include improved cardiovascular fitness, increased lean mass, improved blood lipid profile, enhanced psychosocial well-being, and decreased body adiposity. The benefits for children with diabetes may also include blood glucose control and enhanced insulin sensitivity. However, for these children, engagement in vigorous physical activity and sport must be properly controlled through modifications in insulin therapy and nutritional intake so that the benefits of exercise outweigh the risks. The following review describes the various physiological and metabolic factors which occur both during exercise and during sport while describing specific recommendations to control glucose excursions by proper insulin management and diet.

One-month administration of hydroxytyrosol, a phenolic antioxidant present in olive oil, to hyperlipemic rabbits improves blood lipid profile, antioxidant status and reduces atherosclerosis development

The present study analysed the effects of hydroxytyrosol (HT) on blood lipids, antioxidant status and the progression of aortic lesions in hyperlipemic rabbits. Sixty-four rabbits were distributed into eight groups of animals ( n = 8). Animal groups C, A and H were fed for 1-month with a control diet containing sunflower oil (C), an atherogenic diet (A) high in saturated fat and cholesterol or the A diet together with HT, respectively. The other five groups were fed for 2-months with diets C or A (groups CC or AA, respectively), or for 1-month with the A-diet followed by a further month with diet C, extra virgin olive oil diet (O) or diet C with HT (groups AC, AO and AH, respectively). Four milligram of HT/kg body weight were used in the study. Fifty and 42% decrease in total cholesterol and triacylglycerols, respectively, and a 2.3-fold increase in HDL-cholesterol were observed in the AH group but not in the H group. The HT-supplemented groups improved their antioxidant status and reduced the size of atherosclerotic lesions measured as intimal layer areas of the aortic arch when compared with control animals. We conclude that HT supplementation may have cardioprotective effects in vivo.

Effects of conjugated linoleic acid supplementation on blood lipids and adiposity of rats fed diets rich in saturated versus unsaturated fat

Conjugated linoleic acid (CLA) may decrease adiposity and improve blood lipid profiles under some conditions. The goal of this study was to determine the effects of CLA supplementation on blood lipid profiles and adiposity of rats fed a diet containing a primarily saturated fat versus a diet containing a primarily unsaturated fat. Twenty-eight male Sprague–Dawley rats were randomly assigned to one of four diets containing coconut oil, coconut oil with CLA, corn oil or corn oil with CLA. After 28 days, blood was collected and serum concentrations of total cholesterol (TC), HDL-cholesterol (HDL-C), and triacylglycerols (TG) were assessed. Food intake, body weights, and epididymal fat pads were measured. No significant differences ( p > 0.05) were noted among groups for amount of food consumed, weight gained, food efficiency ratio or serum TG concentrations. TC concentrations were lower ( p < 0.05) in the CLA-supplemented rats that were fed coconut oil but not those consuming corn oil. Serum HDL-C was lower ( p < 0.05) in rats consuming corn oil but was not significantly different ( p > 0.05) for CLA supplemented groups. Epididymal fat pads weighed significantly more ( p < 0.05) in the coconut oil fed group compared to the corn oil fed group, but there was no significant difference ( p > 0.05) between the corn oil and coconut oil + CLA group. Overall, this study suggests that CLA is more beneficial for control of blood lipids and adiposity when supplemented to a diet rich in saturated versus unsaturated fat.

The Effect of Garlic on Nitric Oxide Level in Diabetic Rats

The increase in number of diabetic patients motivated scientists to find new methods to control such disease. In the present study, the action of Garlic [Allium sativum] was studied on normal and sterptozocin [STZ]-induced diabetic rats. Experimental group included 60 male albino rats divided equally into control group, control group given oral daily dose of garlic [100 mg/kg B.wt] for 16 weeks, STZ-induced diabetic untreated group, and diabetic garlic-treated group included STZ-induced diabetic rats given the daily oral dose of the garlic for 16 weeks. Blood samples were collected for determination of blood glucose, nitric oxide [NO], malondialdehyde [MDA], and lipid profile [triglycerides [TG], cholesterol [C], high density lipoprotein-cholesterol [HDL-C], and low density lipoprotein-cholesterol [LDL-C]].Supplementation of garlic to non-diabetic rats had produced no significant differences as regards any of the parameters including glucose, lipid profile, nitric oxide, and lipid peroxidation end product malondialdehyde [MDA] levels when compared with the control group. The diabetic rats showed significant elevation in serum glucose, NO, MDA, TG, C, and LDL-C. Concomitantly significant decrease in HDL-C was detected when compared with their corresponding values of controls. However, supplementation of garlic to the diabetic rats had shown a significant decrease in serum glucose, TG, C, LDL-C, NO, [and MDA] levels, while elevation in HDL-C level was detected. Thus, from the present study it is assumed that garlic treatment decrease the blood glucose level. Antioxidant garlic may protect B cells against toxic effect of ROS [reactive oxygen species] provoked due to hyperglycemia. This was indicated by the significant decrease of oxidative stress after garlic treatment in the studied group. It is concluded that garlic supplementation improves blood lipid profiles, strengthens blood oxidant potential, and causes significant reduction in blood glucose; NO; and MDA levels. These results suggest that garlic exerted antioxidant and antihyperglycemic effects.

Children are fit and active – fact or fiction?

This paper focuses on the importance of appropriate physical activity during childhood and adolescence. It notes that the effect of regular physical activity in improving blood lipid profile, reducing high blood pressure, facilitating blood glucose control, countering obesity, retarding osteoporosis and promoting psychological well‐being is evidence‐based and has been extensively documented. It also asserts that the successful promotion of physical activity requires a contribution from environmental, behavioural, social, cultural, legislative and financial factors, and notes that health care professionals have a high credibility among children and adolescents, and that they are well placed to help meet this challenge.

Effects of garlic extract consumption on blood lipid and oxidant/antioxidant parameters in humans with high blood cholesterol

Effects of garlic extract supplementation on blood lipid profile and oxidant/antioxidant status were investigated in volunteer subjects with high blood cholesterol. A total of 23 volunteer subjects with high blood cholesterol (>5.98 mmol/L) participated in the study. Of them, 13 patients were evaluated as a hypertensive group and the others a normotensive group. Before (first sample) and after (second sample) garlic extract consumption for 4 months, routine blood analyses including lipid parameters and liver and kidney function tests were performed. Additionally, blood oxidant (malondialdehyde [MDA], oxidation resistance [OR]), and antioxidant (antioxidant potential [AOP], nonenzymatic superoxide radical scavenger activity [NSSA]) parameters were measured. Serum total cholesterol, low-density lipoprotein (LDL) and very–low-density lipoprotein (VLDL) cholesterols, and triglyceride levels were found to be significantly lowered, but HDL high-density lipoprotein cholesterol level increased after the extract use. The total:HDL cholesterol ratio was also found to be significantly decreased after the extract use. There were no meaningful differences with regard to other routine biochemical parameters. Additionally, blood AOP, OR, and NSSA values were found increased and MDA level decreased in the second samples relative to the first ones. Systolic and diastolic blood pressure values were also found to be significantly lowered after extract supplementation in the hypertensive group, but no similar changes were observed in the normotensive group. We conclude that garlic extract supplementation improves blood lipid profile, strengthens blood antioxidant potential, and causes significant reductions in systolic and diastolic blood pressures. It also leads to a decrease in the level of oxidation product (MDA) in the blood samples, which demonstrates reduced oxidation reactions in the body.

Resistance training for health and performance.

Resistance training is recommended by national health organizations for incorporation into a comprehensive fitness program that includes aerobic and flexibility exercise. Its potential benefits on health and performance are numerous; it has been shown to reduce body fat, increase basal metabolic rate, decrease blood pressure and the cardiovascular demands to exercise, improve blood lipid profiles, glucose tolerance, and insulin sensitivity, increase muscle and connective tissue cross-sectional area, improve functional capacity, and relieve low back pain. Many improvements in physical function and athletic performance are associated with the increases in muscle strength, power, endurance, and hypertrophy observed during resistance training. The key element to effective resistance training is supervision by a qualified professional and the proper prescription of the program variables. Proper program design, ie, that which uses progressive overload, variation, and specificity, is essential to maximize the benefits associated with resistance training.

The impact of improved phosphorus control: use of sevelamer hydrochloride in patients with chronic renal failure.

Phosphorus control is a primary goal in the care of patients with end-stage renal disease (ESRD). Sevelamer hydrochloride, a novel calcium-free, aluminum-free phosphate binder, allows physicians to control serum phosphorus in patients with ESRD without increasing serum calcium levels or contributing an excess calcium load. Clinical studies have shown that sevelamer provides sustained reduction in markers of soft-tissue and cardiac calcification, specifically serum phosphorus, calciumxphosphorus product, parathyroid hormone and also improves blood lipid profiles. Thus, sevelamer hydrochloride offers the promise of impacting cardiac calcification and thereby reducing patient morbidity and mortality. Long-term studies are underway to evaluate these potential benefits. This paper reviews sevelamer studies to date and addresses ongoing strategies for improving clinical management of phosphorus in ESRD.

BLOOD LIPID RESPONSES TO A SINGLE BOUT OF EXERCISE IN AFRICAN-AMERICAN WOMEN

Since very little is known about exercise-induced blood lipid changes in African-Americans, our purpose was to characterize the effect of a single bout of aerobic exercise on blood lipids in 14 sedentary, premenopausal African-American females (Age = 32 ± 5, BMI = 29.4 ± 5.6, %FAT = 36 ± 8). Subjects expended 350 kcals of energy on a motor driven treadmill at 60% to 70% of VO2peak. Fasting blood samples were obtained during the early follicular phase of the menstrual cycle, 24 hr before, immediately, 24 and 48 hr after exercise. All blood samples were analyzed for serum concentrations of total cholesterol, triglyceride, lowdensity lipoprotein cholesterol, high-density lipoprotein cholesterol (HDL-C), and HDL-C2 & 3 subfractions. Significant differences over time were determined using a 1 × 4 repeated measures ANOVA (p < 0.05 for all). Relative to baseline, HDL-C and HDL3-C were elevated immediately after exercise and remained elevated 48 hr after the exercise bout. Exercise did not alter any other serum lipid or lipoprotein variable. These results demonstrate that a single bout of aerobic exercise can improve blood lipid profiles in sedentary African-American women by increasing HDL-C.

MULTIPLE SHORT BOUTS OF EXERCISE AND IMPROVED QUALITY OF DIET

Twenty sedentary, overweight women [age = 45.5 (2.5) yr; ht = 162.8 (0.7) cm; wt = 80.2 (5.2) kg] underwent a 3-week exercise and nutrition program to determine if multiple short bouts of aerobic, strength, and flexibility exercise, combined with relatively modest changes in diet, could improve overall fitness and CVD risk profile. Subjects were instructed to perform 15 10-min exercise sessions/week: 7–10 aerobic (brisk walking), 2–4 strength (mostly dumbbell exercises), 2–4 flexibility (general stretching), with the recommendation to spread them out as evenly as possible throughout the week. Subjects were encouraged to increase consumption of fiber-rich foods and reduce total and saturated fat intake, with no emphasis on restricting total calories. After 3 weeks, significant (P < 0.05) improvements [Mean (SEM) pre, post] were observed in mile walk time [16.7 (0.6) min, 15.6 (0.5) min], biceps curls (8-lb dumbbells) [13 (1), 19 (1)] and chair stands (“squats” with 10-lb dumbbells) [12 (1), 17 (1)] in 30 sec, push-ups [10 (2), 22 (3)] and sit-ups [13 (2), 21 (3)] in 60 sec, and sit-and-reach [1.0 (1.2) inches, 3.8 (0.8) inches]. Significant (P < 0.05) reductions (mg/dl) were observed for total cholesterol [226 (7), 210 (6)], LDL-cholesterol [149 (6), 138 (4)], and TG [131 (20), 109 (16)]; and in cholesterol/HDL-C (4.3 (0.4), 4.0 (0.2)] and LDL-C/HDL-C [2.9 (0.2), 2.6 (0.2)]. We conclude that multiple short (10 min) bouts of aerobic, strength, and flexibility exercise interspersed throughout the week, coupled with increasing dietary fiber and reducing total and saturated fat intake, can significantly enhance overall fitness and improve blood lipid profiles in sedentary overweight women. This multiple short-bout approach to “total” fitness, combined with relatively modest dietary changes, may have considerable appeal for sedentary, overweight persons who claim they don't have time to exercise and who would like a viable nutritional alternative to calorie restriction.

Associations between dietary intakes and blood cholesterol concentrations at 31 months.

The initial stages of atherosclerosis have been shown to occur in children as young as 3. Elevated total and LDL cholesterol concentrations and low HDL concentrations are a well-established risk factor for atherosclerosis. The objective of this study was to investigate the dietary determinants of blood lipid concentrations at 31 months of age. A randomly selected group of children (214 boys, 175 girls) in south-west England forming part of the Avon Longitudinal Study of Pregnancy and Childhood (ALSPAC) cohort. Three-day dietary records were obtained at 18 months. At 31 months a non-fasting blood sample was taken and analysed for total and HDL cholesterol and triglyceride, and measures of height and weight were taken. Among boys, total cholesterol concentrations were positively associated with the intake of total fat (r=0.209, P=0.002) and saturated fatty acids (r=0.211, P=0.002). Among girls, HDLC was positively associated with energy intake (r=0.204, P=0.018), and negatively associated with intakes of polyunsaturated fat, saturated fat and sugar in multivariate analysis. There were no associations between the intakes of non-starch polysaccharides (fibre) or dietary cholesterol and total or HDL cholesterol concentrations in either sex. Among boys, higher intakes of breakfast cereals were associated with lower total cholesterol (r=-0.187, P=0.008). Among girls, higher intakes of biscuits and meat and meat products were associated with higher HDLC concentrations. These data suggest that the dietary determinants of blood lipid concentrations differ between boys and girls. Reducing saturated fat intake in boys would be likely to lead to an improvement in blood lipid profiles. In this study there is no evidence to suggest that an increase in the intake of polyunsaturated fat by pre-school children would result in improved blood lipid profiles.

HDL-cholesterol-raising effect of orange juice in subjects with hypercholesterolemia

Orange juice-a rich source of vitamin C, folate, and flavonoids such as hesperidin-induces hypocholesterolemic responses in animals. We determined whether orange juice beneficially altered blood lipids in subjects with moderate hypercholesterolemia. The sample consisted of 16 healthy men and 9 healthy women with elevated plasma total and LDL-cholesterol and normal plasma triacylglycerol concentrations. Participants incorporated 1, 2, or 3 cups (250 mL each) of orange juice sequentially into their diets, each dose over a period of 4 wk. This was followed by a 5-wk washout period. Plasma lipid, folate, homocyst(e)ine, and vitamin C (a compliance marker) concentrations were measured at baseline, after each treatment, and after the washout period. Consumption of 750 mL but not of 250 or 500 mL orange juice daily increased HDL-cholesterol concentrations by 21% (P: < 0.001), triacylglycerol concentrations by 30% (from 1.56 +/- 0.72 to 2.03 +/- 0.91 mmol/L; P: < 0.02), and folate concentrations by 18% (P: < 0.01); decreased the LDL-HDL cholesterol ratio by 16% (P: < 0.005); and did not affect homocyst(e)ine concentrations. Plasma vitamin C concentrations increased significantly during each dietary period (2.1, 3.1, and 3.8 times, respectively). Orange juice (750 mL/d) improved blood lipid profiles in hypercholesterolemic subjects, confirming recommendations to consume >/=5-10 servings of fruit and vegetables daily.

Effects of dietary inulin on serum lipids, blood glucose and the gastrointestinal environment in hypercholesterolemic men

Inulin is a complex carbohydrate that belongs to a class of compounds known as fructans. Inulin has been consumed in plant sources by mankind for centuries, and is most concentrated in chicory, Jerusalem artichoke, garlic, leek and onion. It can be extracted from purified concentrated sources such as chicory root, and used to enhance the technological and nutritional properties of foods. Inulin is thought to share many of the properties of soluble dietary fibers, such as the ability to lower blood lipids and stabilize blood glucose. Additionally, inulin has been shown to enhance the growth of bifidobacteria and lactobacilli and enhance the gut environment. The objective of this study was to examine the effect of a commercially available inulin from chicory root (degree of polymerization (DP) ranging between 2 and 60, modal DP=9) in men with hypercholesterolemia on serum parameters and fecal composition. The study was a randomized, double blind, crossover design with no washout period. Twelve men were randomly assigned to two controlled diets that differed only in that the control diet contained one pint of vanilla ice cream made with sucrose while the inulin containing diet was supplemented with one pint of vanilla ice cream made with 20 grams of inulin. Subjects consumed each controlled diet for three weeks. Daily intake of 20 g of inulin significantly reduced serum triglycerides by 40 mg/dL (p=0.05). A trend toward a reduction in serum cholesterol was observed. Trends toward short chain fatty acid (SCFA) profile changes were observed after inulin administration. Transit time did not differ significantly between treatments. These data suggest that dietary inulin supplementation may improve blood lipid profiles and alters the colonic environment in a manner that may be beneficial. Because inulin is easily incorporated into an acceptable food like low-fat vanilla ice cream, it shows promise as a functional ingredient in many processed foods.

Viscous and nonviscous fibres, nonabsorbable and low glycaemic index carbohydrates, blood lipids and coronary heart disease.

Viscous fibres such as guar, glucomannans, pectins, oat betaglucan and psyllium continue to be seen as hypocholesterolaemic. Nevertheless, in large cohort studies, ironically it is the insoluble cereal fibre that has been demonstrated to relate negatively to cardiovascular disease and diabetes, despite an absence of effect on fasting lipids or postprandial glycaemia. In general, resistant or nonabsorbable starch is lipid neutral, whereas some nonabsorbable sugars or oligosaccharides may raise serum cholesterol, possibly through providing more acetate after colonic fermentation by colonic microflora. On the other hand, fructo-oligosaccharides appear to reduce serum triglycerides for reasons that are not entirely clear. Of possibly greater recent interest have been the carbohydrates that are not so much resistant to absorption, but rather are slowly absorbed. They possess some of the features of dietary fibre in providing a substrate for colonic bacterial fermentation. In the small intestine, however, they form lente or sustained release carbohydrate. In the form of low glycaemic index foods, lente carbohydrate consumption has been shown to relate to improved blood lipid profiles in hyperlipidaemic individuals and improved glycaemic control in diabetes. In larger cohort studies, low glycaemic index foods or low glycaemic load diets have been associated with higher HDL-cholesterol levels and reduced incidence of diabetes and cardiovascular disease.

Effects of margarine compared with those of butter on blood lipid profiles related to cardiovascular disease risk factors in normolipemic adults fed controlled diets

Effects of butter and 2 types of margarine on blood lipid and lipoprotein concentrations were compared in a controlled diet study with 23 men and 23 women. Table spreads, added to a common basal diet, provided 8.3% of energy as fat. Diets averaged 34.6% of energy as fat and 15.5% as protein. Each diet was fed for 5 wk in a 3 × 3 Latin-square design. One margarine (TFA-M) approximated the average trans monoene content of trans fatty acid–containing margarines in the United States (17% trans fatty acids by dry wt). The other margarine (PUFA-M) was free of trans unsaturated fatty acids; it contained approximately twice the polyunsaturated fatty acid content of TFA-M (49% compared with 27% polyunsaturated fatty acids). The tub-type margarines had similar physical properties at ambient temperature. Fasting blood lipids and lipoproteins were determined in 2 samples taken from the subjects during the fifth week of each dietary treatment. Compared with butter, total cholesterol was 3.5% lower (P = 0.009) after consumption of TFA-M and 5.4% lower (P< 0.001) after consumption of PUFAM. Similarly, LDL cholesterol was 4.9% lower (P = 0.005) and 6.7% lower (P< 0.001) after consumption of TFA-M and PUFAM, respectively. Neither margarine differed from butter in its effect on HDL cholesterol or triacylglycerols. Thus, consumption of TFA-M or PUFA-M improved blood lipid profiles for the major lipoproteins associated with cardiovascular risk when compared with butter, with a greater improvement with PUFA-M than with TFA-M.

Long-term intake of soy protein improves blood lipid profiles and increases mononuclear cell low-density-lipoprotein receptor messenger RNA in hypercholesterolemic, postmenopausal women

The long-term clinical effects of soy protein containing various amounts of isoflavones on lipoproteins, mononuclear cell LDL receptor messenger RNA concentrations, and other selected cardiovascular risk factors are not well known. Sixty-six hypercholesterolemic, free-living, postmenopausal women were investigated during a 6-mo parallel-group, double-blind trial with 3 interventions. After a control period of 14 d, all subjects were randomly assigned to 1 of 3 dietary groups (all with 40 g protein): a National Cholesterol Education Program (NCEP) Step 1 diet with protein from casein and nonfat dry milk (control), an NCEP Step 1 diet with protein from isolated soy protein containing moderate amounts of isoflavones (ISP56), or an NCEP Step 1 diet with protein from isolated soy protein containing high amounts of isoflavones (ISP90). Non-HDL cholesterol in both the ISP56 and ISP90 groups was reduced compared with the control group (P < 0.05), whereas total cholesterol was not changed. HDL cholesterol increased in both the ISP56 and ISP90 groups (P < 0.05), whereas the ratio of total to HDL cholesterol decreased significantly in both groups compared with the control (P < 0.05). Mononuclear cell LDL receptor messenger RNA concentrations increased in subjects consuming ISP56 or ISP90 compared with the control (P < 0.05). These results indicate that soy protein, with different amounts of isoflavones, may decrease the risk of cardiovascular disease via improved blood lipid profiles, and that the mechanism by which apolipoprotein B–containing lipoproteins were depressed may be via alterations in LDL receptor quantity or activity. Am J Clin Nutr 1998;68:545–51.

Effects of exercise training on abdominal obesity and related metabolic complications.

Excessive deposition of visceral adipose tissue is known to predispose to cardiovascular diseases. Considerable epidemiological and experimental evidence suggests that many physiological factors are involved in the aetiology of premature atherosclerosis associated with visceral obesity. Insulin resistance is frequently associated with abdominal obesity, and probably plays an important role in the pathophysiology of hypertriglyceridaemia, low levels of plasma high-density lipoprotein (HDL)-cholesterol, hypertension and reduced fibrinolytic activity. Exercise training may counteract the aberrant metabolic profile associated with abdominal obesity both directly and as a consequence of body fat loss. Exercise may increase insulin sensitivity, favourably alter the plasma lipoprotein profile and improve fibrinolytic activity. Changes in the activity of insulin-sensitive glucose transporters and of skeletal muscle lipoprotein lipase are some of the possible explanations for the increased insulin sensitivity and improved blood lipid profile associated with regular exercise. This review presents physical training as a relevant nonpharmacological tool in the treatment of abdominal obesity and associated metabolic disorders. The impact of regular exercise on the different aspects of the insulin resistance syndrome is discussed. The roles of gender, age and the state of insulin resistance on the metabolic effect of physical training are also considered.

Blood Lipid and Physiological Responses to Endurance Training in Adolescents

The purpose of this study was to determine the effects of an endurance training program on blood lipids and lipoproteins in adolescents. Fifteen males and 10 females, ages 13 to 18 years, underwent pretest evaluations, including physical measurements, nutritional intake, physical working capacity (PWC), and fasting serum lipid and lipoprotein levels. Physical conditioning consisted of a 16-week progressive endurance training (ET) program 40 min·day1 three times per week. Twenty-five males and females matched for age, sex, and race served as controls. Following the conditioning program, the ET group had a significant increase (p &lt; .05) in PWC and a significant decrease (p &lt; .05) in sum of skinfolds and resting heart rate. A significant decrease (p &lt; .05) was also noted for total cholesterol (TC) and the ratio of TC to high density lipoprotein cholesterol (HDL-C) with a significant increase (p &lt; .05) in HDL-C. No differences were found for the control group. The results suggest that 16 weeks of endurance training favorably improves blood lipid profiles in adolescents.