Effects of endurance exercise training on plasma HDL cholesterol levels depend on levels of triglycerides: evidence from men of the Health, Risk Factors, Exercise Training and Genetics (HERITAGE) Family Study

The effects of exercise on C-reactive protein, insulin, leptin and some cardiometabolic risk factors in Egyptian children with or without metabolic syndrome

BACKGROUND

The prevalence and magnitude of obesity in the children and the adolescents have increased dramatically in the developing countries over the last 20-30 years. The prevalence of metabolic syndrome (MS) in children is increasing.

AIM

This study aimed to investigate the changes of C-reactive protein (CRP), leptin, insulin, and blood lipids before and after the exercise therapy in normal and obese children (with or without metabolic syndrome).

METHODS

The study covered 49 normal children (control), 32 obese children without metabolic syndrome and 12 obese children with metabolic syndrome. We examined the influence of exercise (3 times/week) for 12 weeks on the levels of serum CRP, leptin, insulin, homeostatic model assessment insulin resistance (HOMA-IR), triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) in all groups.

RESULTS

There were significant correlations between HOMA-IR and the individual components of the metabolic syndrome. After 12 weeks of exercise, both of the obese children groups, with and without metabolic syndrome, showed reduced body weight, body mass index (BMI), and CRP level, and increased HDL-C level. The percentage of metabolic syndrome decreased from 12.9% before the exercise training to 7.5% after training. Also, there was a significant reduction in BMI (from 47.3 to 32.6%), in systolic blood pressure (from 18.3 to 15.1%) and in HDL-C level (from 18.3 to 9.7%).

CONCLUSION

Overweight children have multiple risk factors associated with the metabolic syndrome. 12-week exercise may have a positive effect on reducing risk factors for the metabolic syndrome.

Residual cardiovascular risk despite optimal LDL cholesterol reduction with statins: the evidence, etiology, and therapeutic challenges

This review captures the existence, cause, and treatment challenges of residual cardiovascular risk (CVR) after aggressive low-density lipoprotein cholesterol (LDL-C) reduction. Scientific evidence implicates low high-density lipoprotein cholesterol (HDL-C) and high triglycerides (TG) in the CVR observed after LDL-C lowering. However, the Action to Control Cardiovascular Risk in Diabetes (ACCORD) lipid trial with fenofibrate, the Investigation of Lipid Level Management to Understand its Impact in Atherosclerotic Events (ILLUMINATE) study with torcetrapib, and the recently terminated Atherothrombosis Intervention in Metabolic Syndrome with Low HDL Cholesterol/High Triglyceride and Impact on Global Health Outcomes (AIM-HIGH) study with niacin, do not clearly attribute risk reduction value to HDL-C/TG modulation. The optimum approach to long-term lipid-modifying therapies for CVR reduction remains uncertain. Consequently, absolute risk modulation via lifestyle changes remains the centerpiece of a strategy addressing the physiologic drivers of CVR associated with HDL-C/TG, especially in the context of diabetes/metabolic syndrome.

Fatness, fitness, and cardiometabolic risk factors in middle-aged white men

The objective was to test the hypothesis that traditional and novel cardiometabolic risk factors would be significantly different in groups of men of different fatness and fitness. Total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, glucose, insulin, high-sensitivity C-reactive protein, alanine aminotransferase, aspartate aminotransferase, γ-glutamyltransferase, leptin, adiponectin, tumor necrosis factor-α, interleukin-6, interleukin-10, fibrinogen, and insulin resistance were assessed in 183 nonsmoking white men aged 35 to 53 years, including 62 who were slim and fit (waist girth ≤90 cm and maximal oxygen consumption [VO(2)max] above average), 24 who were slim and unfit (waist girth ≤90 cm and VO(2)max average or below), 39 who were fat and fit (waist girth ≥100 cm and VO(2)max above average), and 19 who were fat and unfit (waist girth ≥100 cm and VO(2)max average or below). Seventy-six percent gave blood on 2 occasions, and the average of 1 or 2 blood tests was used in statistical tests. Waist girth (centimeters) and fitness (milliliters of oxygen per kilogram of fat-free mass) were associated with high-density lipoprotein cholesterol, leptin, and insulin resistance after adjustment for age, saturated fat intake, and total energy intake. High-density lipoprotein cholesterol, triglycerides, alanine aminotransferase, and insulin resistance were significantly different in men who were fat and fit and those who were fat and unfit. These data suggest that differences in lipid and lipoprotein concentrations, liver function, and insulin resistance may explain why the risks of chronic disease are lower in men who are fat and fit than those who are fat and unfit.

Randomized controlled study of the effect of a butter naturally enriched in trans fatty acids on blood lipids in healthy women

BACKGROUND

Whereas the negative effect of consuming trans fatty acids found in partially hydrogenated vegetable oils on cardiovascular disease (CVD) risk is well established, the effect of trans fatty acids from ruminant sources (rTFAs) on CVD risk factors has not yet been established, particularly among women.

OBJECTIVE

We investigated the effects of a butter naturally enriched in rTFAs, of which vaccenic acid is the predominant isomer, on plasma lipid concentrations among healthy women.

DESIGN

In a double-blind, randomized, crossover controlled study, 61 healthy women aged 19-70 y were fed 2 isoenergetic diets lasting 4 wk each. The 2 diets were defined as moderately high in rTFAs (3.7 g/d, 1.5% of daily energy) and control (0.9 g/d, 0.3% of daily energy).

RESULTS

No significant effect of the rTFA diet was found on total plasma cholesterol, LDL cholesterol, apolipoprotein B, apolipoprotein A-I, and triglyceride concentrations compared with the control diet. There was a small yet statistically significant reduction in plasma HDL-cholesterol concentrations with the rTFA diet (-2.8%; P = 0.004), which was significant (P for the BMI × treatment interaction = 0.006) among women with a BMI (in kg/m(2)) ≥25 (-5.2%; P = 0.004; n = 18) but not among women with a BMI <25 (-1.2%; P = 0.13; n = 43).

CONCLUSIONS

These results suggest that an increase in dietary rTFAs equivalent to ∼1% of daily energy has no significant effect on LDL but may be associated with a reduction in plasma HDL-cholesterol concentrations, particularly in overweight women. This trial is registered at clinicaltrials.gov as NCT00930137.

Effect of the Mediterranean diet with and without weight loss on cardiovascular risk factors in men with the metabolic syndrome

BACKGROUND AND AIMS

No study has yet examined how weight loss modifies the impact of the Mediterranean diet (MedDiet) on cardiovascular risk factors in men with the metabolic syndrome (MetS). The objective of the study was to assess the efficacy of MedDiet, with and without weight loss, to modify the cardiometabolic risk profile of male patients with MetS.

METHODS AND RESULTS

Twenty-six men aged between 24 and 62 years with the MetS consumed a North American control diet for 5 weeks followed by a 5-week MedDiet, both under weight-maintaining conditions. Participants then underwent a 20-week weight loss period, after which they consumed the MedDiet for five weeks under weight stable conditions. Body weight was reduced by 10.2% ± 2.9% after the weight loss period (p < 0.001). All foods were provided to participants during the weight stable phases of the study. The MedDiet in the absence of weight loss decreased total plasma cholesterol (C) (-7.1%), LDL-C (-9.3%) and the total/HDL-C ratio (-6.5%) compared to the control diet (all p < 0.04). The MedDiet combined with weight loss led to reductions in systolic blood pressure (-4.7%), diastolic blood pressure (-7.7%), triglycerides (-18.2%), ApoB (-10.7%), fasting glucose (-4.2%) and insulin (-29.9%) compared to the control diet (all p < 0.001).

CONCLUSION

The MedDiet in the absence of weight loss leads to significant changes in plasma cholesterol concentrations but has little effects on other cardiometabolic risk factors associated with the MetS in men.

Exercise and diet, independent of weight loss, improve cardiometabolic risk profile in overweight and obese individuals

Diet and/or exercise are routinely advised as methods for weight loss in overweight/obese individuals, particularly those who are at high risk for cardiovascular disease and type 2 diabetes mellitus. However, physical activity and structured exercise programs rarely result in significant loss of body weight or body fat, and weight-loss diets have extraordinarily high recidivism rates. Despite only modest effects on body weight, exercise and ad libitum nutrient-dense diets for overweight/obese individuals have many health benefits, including skeletal muscle adaptations that improve fat and glucose metabolism, and insulin action; enhance endothelial function; have favorable changes in blood lipids, lipoproteins, and hemostatic factors; and reduce blood pressure, postprandial lipemia and glycemia, and proinflammatory markers. These lifestyle-induced adaptations occur independently of changes in body weight or body fat. Thus, overweight/obese men and women who are at increased risk for cardiovascular disease and type 2 diabetes as a result of sedentary lifestyle, poor diet, and excess body weight should be encouraged to engage in regular physical activity and improve their diet, regardless of whether the healthier lifestyle leads to weight loss.

Aerobic exercise improves reverse cholesterol transport in cholesteryl ester transfer protein transgenic mice

We analyzed the effect of a 6-week aerobic exercise training program on the in vivo macrophage reverse cholesterol transport (RCT) in human cholesteryl ester transfer protein (CETP) transgenic (CETP-tg) mice. Male CETP-tg mice were randomly assigned to a sedentary group or a carefully supervised exercise training group (treadmill 15 m/min, 30 min sessions, five sessions per week). The levels of plasma lipids were determined by enzymatic methods, and the lipoprotein profile was determined by fast protein liquid chromatography (FPLC). CETP activity was determined by measuring the transfer rate of ¹⁴C-cholesterol from HDL to apo-B containing lipoproteins, using plasma from CETP-tg mice as a source of CETP. The reverse cholesterol transport was determined in vivo by measuring the [³H]-cholesterol recovery in plasma and feces (24 and 48 h) and in the liver (48 h) following a peritoneal injection of [³H]-cholesterol labeled J774-macrophages into both sedentary and exercise trained mice. The protein levels of liver receptors were determined by immunoblot, and the mRNA levels for liver enzymes were measured using RT-PCR. Exercise training did not significantly affect the levels of plasma lipids or CETP activity. The HDL fraction assessed by FPLC was higher in exercise-trained compared to sedentary mice. In comparison to the sedentary group, a greater recovery of [³H]-cholesterol from the injected macrophages was found in the plasma, liver and feces of exercise-trained animals. The latter occurred even with a reduction in the liver CYP7A1 mRNA level in exercised trained animals. Exercise training increased the liver LDL receptor and ABCA-1 protein levels, although the SR-BI protein content was unchanged. The RCT benefit in CETP-tg mice elicited by exercise training helps to elucidate the role of exercise in the prevention of atherosclerosis in humans.

Low high density lipoprotein cholesterol: prevalence and associated risk-factors in a large French population

PURPOSE

High density lipoprotein-cholesterol (HDL-C) is a strong predictor of cardiovascular risk. We investigated the distribution of HDL-C in a French general population according to age, sex, and the risk factors associated with low HDL-C values.

METHODS

A group of 18,483 men and 22,047 women 16-79 years of age were investigated during a medical check-up. Relevant parameters were studied in three groups according to age and gender-specific percentile classes (≤5th [HDL₅] median and >95th). Gender-specific logistic regression models selected variables associated with HDL₅.

RESULTS

Using the National Cholesterol Education Program Adult Treatment Panel III criteria (threshold: 40 mg/dL in men, 50 mg/dL in women) the prevalence of low HDL-C was 11.1% and 26.4% in men and women and it decreased with age. Mean HDL-C levels increased with age. HDL₅ was positively associated with a sedentary lifestyle and deprivation (p < 0.00001) even after adjustment on alcohol consumption and smoking. Abdominal obesity, smoking, hypertriglyceridemia, hyperleucocytosis, and low alcohol consumption were associated with HDL₅ for both genders.

CONCLUSIONS

The prevalence of low HDL-C was similar to that observed in other Europeans but lower than in the United States. HDL₅ was associated with cardiovascular risk factors, metabolic syndrome, and social deprivation. A prevention policy to increase HDL-C levels should focus on reducing smoking and abdominal obesity, particularly in deprived subjects.

Visceral adipose tissue accumulation and cardiovascular disease risk profile in postmenopausal women with impaired glucose tolerance or type 2 diabetes

OBJECTIVE

Women with impaired glucose tolerance (IGT) and type 2 diabetes (T2D) are more at risk of cardiovascular disease. The aim of this study was to test the hypothesis that increased visceral adipose tissue (VAT) could explain to a large extent alterations in the cardiovascular disease risk profile of postmenopausal women with IGT or T2D.

DESIGN, PATIENTS AND MEASUREMENTS

Sixty-two women with normal glucose tolerance (NGT), 33 with IGT and 18 with de novo diagnosed T2D were tested. The sample was further divided into five groups: (i) NGT-low VAT (<130 cm(2) ); (ii) NGT-high VAT (≥130 cm(2)); (iii) IGT-low VAT (<130 cm(2) ); (iv) IGT-high VAT (≥130 cm(2) ) and (v) T2D.

RESULTS

Women with T2D, women with IGT-high VAT and those with NGT-high VAT all had lower insulin sensitivity as determined by the euglycaemic-hyperinsulinaemic clamp (M_I), higher triglyceride (TG), lower HDL(2)-cholesterol (chol) levels and higher levels of high-sensitivity C-reactive protein than women with NGT-low VAT. Only differences in M_I and early insulin response (EIR) were observed between women with IGT-high VAT and those with NGT-high VAT (lower values in IGT-high VAT). Women with T2D had lower M_I and EIR as well as higher plasma TG and lower plasma Apo A1 and HDL-chol concentrations than women with NGT-high VAT.

CONCLUSIONS

Our results suggest that increase in VAT accumulation usually found in women with IGT explains to a large extent the deterioration in their plasma lipid-lipoprotein and inflammatory profile. However, factors other than VAT are involved in explaining the high TG-low HDL dyslipidaemia observed in women with T2D.

[Cardiac rehabilitation after acute myocardial infarction]

At the time of evidence-based medicine, while the proofs of the benefits of cardiac rehabilitation to the coronary multiply, a large number of patients are still managed without any form of rehabilitation. In particular, younger patients with myocardial infarction treated by early reperfusion and older subjects. The objective of in-hospital or ambulatory cardiac rehabilitation is a global coverage of the patient and his/her risk factors, that the short duration of hospitalization in the acute phase does not allow. Several randomized studies, metaanalyses, and registers show a decrease from 20 to 30% of the mortality after cardiac rehabilitation. The benefits of physical training on risk factors modification are demonstrated by numerous works: improvement of lipid parameters and arterial pressure, prevention of diabetes, increased smoking cessation, loss of weight, better overall well-being; besides the management of risk factors, physical training improves exercise capacity, a recognised prognostic factor. The efficiency of cardiac rehabilitation may be comparable with that of the key treatments of coronary artery disease, such as beta-blockers or coronary angioplasty. All these proofs give to the cardiac rehabilitation in post-myocardial infarction a high-level recommendation, grade IA.

Dose-response relationship between physical activity and dyslipidemia in youth

BACKGROUND

The minimal and optimal amount of physical activity associated with cardiovascular health benefits in young people is unknown.

OBJECTIVE

To determine the dose-response relationship between moderate-to-vigorous physical activity (MVPA) with high-risk low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol and triglyceride values in youth.

METHODS

The study sample consisted of 1235 adolescents (12 to 19 years of age) from the 20032004 and 20052006 cycles of the United States National Health and Nutrition Examination Survey. Objective measures of MVPA were obtained over seven days with accelerometers. LDL cholesterol, HDL cholesterol and triglycerides were measured from a fasting blood sample. High-risk values for these lipidslipoproteins were determined using age- and sex-specific thresholds. Logistic regression models were used to determine the dose-response relationships between MVPA and high-risk lipid levels.

RESULTS

ORs for high-risk HDL cholesterol and triglyceride values decreased in a curvilinear manner with increasing minutes of MVPA. Compared with no MVPA (0 min), the ORs for high-risk HDL cholesterol values at 15 min, 30 min and 60 min per day of MVPA were 0.29 (95% CI 0.13 to 0.67), 0.24 (95% CI 0.10 to 0.64) and 0.21 (95% CI 0.07 to 0.61), respectively. The corresponding ORs for high-risk triglyceride values were 0.40 (95% CI 0.18 to 0.76), 0.22 (95% CI 0.06 to 0.66) and 0.10 (95% CI 0.01 to 0.51). There was no discernible dose-response relationship between MVPA and LDL cholesterol.

CONCLUSIONS

Small amounts of MVPA were associated with a large reduction in the likelihood of having high-risk HDL cholesterol and triglyceride values in this representative sample of adolescents.

Cardiorespiratory fitness and metabolic risk factors in obesity

PURPOSE OF REVIEW

An increase in cardiorespiratory fitness (CRF) through exercise training appears to partly ameliorate the health hazards of obesity and a number of mechanisms might explain the potential benefits. We review recent evidence about the relationships between CRF, exercise training and metabolic risk factors in obesity.

RECENT FINDINGS

Epidemiological data have shown that the anti-inflammatory effects of exercise could be an important mechanism in explaining cardio-protective effects of physical activity. Emerging evidence suggests that exercise training reduces markers of inflammation and improves glucose control in obesity, independent of weight loss. Novel mechanisms appear to involve exercise-induced changes in CD14+CD16+ cell populations, expression of toll-like receptors, and key changes in the metabolic regulation of visceral white adipose tissue. Other promising recent research has focused on exercise-induced signalling pathways governing glucose metabolism, such as insulin receptor substrate and Akt substrate. Using novel imaging techniques, studies have demonstrated exercise-induced improvements in lipoprotein subfraction particle size, and reduction in visceral adipose tissue and liver fat, independent of weight loss. These effects appear to be mostly restricted to interventions consisting of relatively high doses of exercise or exercise combined with calorie restriction, although further work is required to elucidate the dose-response relationships.

SUMMARY

Physical activity and the pursuit of physical fitness are important in the treatment of obesity because exercise training can improve a number of metabolic risk factors independent of weight loss. Thus exercise can provide important health benefits irrespective of weight loss in obese and overweight individuals.

The utility of physical activity in the management of global cardiometabolic risk

Major health organizations promote the adoption of a healthy lifestyle, composed of sufficient daily physical activity and a balanced diet for the prevention and management of type 2 diabetes (T2D) and cardiovascular disease risk. In particular, it is recommended that adults accumulate 30 min of moderate-intensity aerobic physical activity on most days of the week. Despite these recommendations, a physically active lifestyle is seldom adopted, and the majority of the North American population remains sedentary. Although the optimal strategy for promoting physical activity in today's environment remains elusive, the evidence for the utility of physical activity in the management of risk factors for T2D and cardiovascular disease is overwhelming. This review examines the influence of aerobic-type physical activity on components of global cardiometabolic risk, that is, the traditional and emerging risk factors for cardiovascular disease and T2D, including visceral obesity, insulin resistance, hypertension, atherogenic dyslipidemia, thrombosis, inflammation, and cardiorespiratory fitness. Where possible, specific consideration is given to the independent effects of an acute bout of physical activity vs. chronic physical activity with weight loss vs. chronic physical activity without weight loss.

Discordances among different tools used to estimate cardiovascular risk in postmenopausal women

BACKGROUND

New cardiovascular disease (CVD) risk factors are being recognized and suggested to be included in CVD risk stratification. High-sensitivity C-reactive protein (hs-CRP) and the metabolic syndrome (MetS) are among these risk factors. However, CVD risk classification may be divergent when using different approaches.

OBJECTIVES

To compare differences in CVD risk estimation using the Framingham risk score (FRS), hs-CRP and the presence of the MetS in a group of 109 postmenopausal women in primary CVD prevention.

METHODS

The FRS and presence of the MetS were determined. CVD risk was evaluated with a cardiovascular point scoring system based on Framingham covariables and hs-CRP values (Women's Health Study [WHS] model). The estimated CVD risks based on hs-CRP levels and the WHS model were compared with the FRS.

RESULTS

Using the FRS, 99% of women (n=108) were determined to have a low CVD risk. The MetS was identified in 39.4% (n=43) of the women. When hs-CRP was used alone to estimate CVD risk, 37.6% (n=41) of women were classified as being at low, 33.9% (n=37) at moderate and 28.4% (n=31) at high CVD risk. With the WHS model, 83.5% (n=91), 14.7% (n=16) and 1.8 % (n=2) of women were classified as being at low, moderate and high CVD risk, respectively.

CONCLUSIONS

A substantial number of postmenopausal women showing evidence of the MetS were not identified by the FRS, even though women with the MetS are at higher risk of CVD. Estimation of risk by hs-CRP is significantly divergent when using conventional hs-CRP cutoff values compared with an integrated use in the WHS model.

Endurance exercise training effects on body fatness, VO2max, HDL-C subfractions, and glucose tolerance are influenced by a PLIN haplotype in older Caucasians

Perilipins are lipid droplet-coating proteins that regulate intracellular lipolysis in adipocytes. A haplotype of two perilipin gene (PLIN) single nucleotide polymorphisms, 13041A>G and 14995A>T, has been previously associated with obesity risk. Furthermore, the available data indicate that this association may be modified by sex. We hypothesized that this haplotype would associate with body fatness, aerobic fitness, and a number of cardiovascular (CV) risk factor phenotypes before and after a 6-mo endurance exercise training program in sedentary older Caucasians. The major haplotype group (13041A/14995A; n = 57) had significantly lower body mass index (BMI) and body fatness compared with noncarriers of the AA haplotype (n = 44) before the training intervention. Training improved body composition in both groups, but fatness remained higher in noncarriers than AA carriers after training. This fat retention in noncarriers blunted their maximal oxygen uptake (Vo(2 max)) adaptation to training. Female noncarriers had substantially higher concentrations of several conventionally and NMR-measured HDL-C subfractions than male noncarriers before and after training, but only minimal differences were found between the sexes in the AA haplotype group. Haplotype group differences in baseline and after-training responses to an oral glucose tolerance test (OGTT) also differed by sex, as noncarrier men had the highest baseline area under the insulin curve (insulin AUC), but were the only group to significantly improve insulin AUC with training. The insulin sensitivity index and plasma glucose responses to the OGTT were more favorable in AA carriers than noncarriers before and after training. Overall, our findings suggest that PLIN variation explains some of the interindividual differences in the response of obesity and CV phenotypes to exercise training. Furthermore, these data contribute to the growing understanding of PLIN as a candidate gene for human obesity and the cardiometabolic consequences of excess adiposity.

Validation of reported physical activity for cholesterol control using two different physical activity instruments

The National Cholesterol Education Program recommends increasing physical activity to improve cholesterol levels and overall cardiovascular health. We examined whether US adults who reported increasing their physical activity to control or lower blood cholesterol following physician’s advice or on their own efforts had higher levels of physical activity than those who reported that they did not. We used data from the National Health and Nutrition Examination Survey 2003–2004, which implemented two physical activity assessment instruments. The physical activity questionnaire (PAQ) assessed self-reported frequency, intensity, and duration of leisure-time, household, and transportation-related physical activity in the past month. Physical movement was objectively monitored using a waist accelerometer that assessed minute-by-minute intensity (counts of movement/minute) during waking time over a 7-day period. We adjusted our analysis for age, gender, race/ethnicity, educational attainment, and body mass index. Participants who reported increasing physical activity to control blood cholesterol had more PAQ-assessed physical activity and more accelerometer-assessed active days per week compared to those who did not. However, there were no significant differences in cholesterol levels between comparison groups. These findings suggest that self-report of exercising more to control or lower cholesterol levels among US adults might be valid.

Regular exercise and plasma lipid levels associated with the risk of coronary heart disease: a 20-year longitudinal study

We investigated the effects of regular exercise on the plasma lipid levels that contribute to coronary heart disease (CHD), of 20 sedentary men who participated in an exercise program over 20 consecutive years. The men, whose initial ages ranged from 30-51 years, participated in the University of Nevada-based exercise program for an average of 45 min/day, 3.5 days/week. The study examined plasma levels of low-density lipoprotein (LDL) cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), total cholesterol (TC), triglycerides (TG), and TC to HDL-C (TC/HDL-C) ratios. All lipid values improved significantly during the study (p < .05). The largest changes occurred during the first year of participation and slow, gradual improvements continued in the subsequent years. We concluded that regular exercise has positive effects on plasma lipid levels, which results in reducing the risk of CHD in middle-aged and older adults.

Associations between circulating free fatty acids, visceral adipose tissue accumulation, and insulin sensitivity in postmenopausal women

The aims of the study were to evaluate the contribution of visceral adipose tissue (AT) accumulation and insulin sensitivity to the determination of circulating free fatty acid (FFA) concentrations measured during a 2-hour euglycemic-hyperinsulinemic clamp and to verify whether elevated FFAs are associated with other components of the metabolic syndrome in postmenopausal women. This cross-sectional study included 115 postmenopausal women (46-68 years old). Visceral AT was estimated by computed tomography. Insulin sensitivity was assessed by a 2-hour euglycemic-hyperinsulinemic clamp. Free fatty acid concentration was measured in the fasting state and every 30 minutes during the clamp. Fasting plasma glucose and 2-hour plasma glucose were measured by an oral glucose tolerance test. Visceral AT was associated positively and insulin sensitivity negatively with FFA area under the curve (AUC) measured during the clamp. Women with high visceral AT accumulation and low insulin sensitivity had higher FFA AUC than women with high visceral AT accumulation and high insulin sensitivity or women with low visceral AT combined with either low or high insulin sensitivity. Free fatty acid AUC was positively associated with triglyceride (r = 0.25, P < .05), fasting plasma glucose (r = 0.26, P < .01), 2-hour plasma glucose (r = 0.27, P < .01), and diastolic blood pressure (r = 0.21, P < .05) independently of visceral AT and insulin sensitivity. In postmenopausal women, the presence of both high visceral AT and low insulin sensitivity is needed to observe an elevated FFA AUC. Moreover, FFA AUC is associated with some components of the metabolic syndrome, independently of visceral AT and insulin sensitivity.

Cardiorespiratory fitness and components of the metabolic syndrome in sedentary men

OBJECTIVE

To investigate the relationships between fitness and components of the metabolic syndrome in sedentary men.

SUBJECTS AND METHODS

39 subjects (34-53 years) were evaluated for fitness (VO(2max)) and anthropometric, metabolic, and skeletal muscle phenotypes. VO(2max) was assessed on a bicycle ergometer whereas other variables were obtained from an oral glucose tolerance test (OGTT), hydrostatic weighing, and a muscle biopsy.

RESULTS

Pearson and partial correlations adjusted for fat mass (FM), waist circumference (WC), muscle enzyme activities (citrate synthase (CS), cytochrome c oxidase (COX)), and capillary density were used to investigate the independent relationships be tween variables. Negative correlations between VO(2max) and WC as well as blood pressure and OGTT test were observed. When adjusted for FM, correlations remained between VO(2max) and WC (r = -0.46, p < 0.01) and systolic blood pressure (r = -0.35, p < 0.05). When adjusted for WC and CS activity, all correlations were lost except for high-sensitivity C-reactive protein (hs-CRP) (r = -0.34, p < 0.05) which remained when adjusted for CS activity. Adjustment for COX activity failed to remove correlations with hs-CRP (r = -0.36, p < 0.05), age (r = 0.34, p < 0.05), WC (r = -0.35, p < 0.05), and blood pressure. Negative correlations persisted when fitness was adjusted for the mean number of capillaries.

CONCLUSION

The effects of fitness on components of the metabolic syndrome in sedentary men are explained by abdominal obesity and muscle phenotypes.

Prevalence of metabolic syndrome and associated risk factors in Illinois

PURPOSE

To examine the prevalence of metabolic syndrome (MS) in Illinois and associated risk factors to document emerging problems as a basis for preventive and/or therapeutic interventions.

DESIGN

The 2005 Illinois Behavioral Risk Factor Surveillance System data were analyzed for prevalence rates and relative risk (RR) of risk factors for MS.

SETTING

Illinois.

SUBJECTS

Representative sample of 5077 noninstitutionalized Illinoisans aged > or = 18.

MEASURES

Presence of diabetes, hypertension, hypercholesterolemia, angina, and obesity; adequate fruit/vegetable intake; adequate daily physical activity; routine consumption of calcium-rich foods; smoking; and demographic variables.

ANALYSIS

Prevalence, chi-square, RR, and analyses of variance.

RESULTS

MS prevalence was 16.2%. The RR for MS was 8 for those having diabetes; 20 for those with hypertension; 14 for those with hypercholesterolemia; 6 for those with angina; and 7 for those with obesity. Fruit/vegetable intake did not significantly influence the RR (RR = 1.01), but RR was greater when calcium-rich foods were not routinely consumed (RR = 1.61) and with inadequate physical activity (RR = 1.85). MS prevalence was highest in those over 65 years; with incomes < $15,000; and among Blacks. Differences among those with one through five indicators of MS were not significant for fruit/vegetable intake, but were for physical activity, age group, income, and education level (p < .001).

CONCLUSION

These findings reveal that MS prevention should be emphasized for lower-income, older Blacks. Increasing physical activity and calcium-rich foods are areas for community-based education.

Dietary cod protein reduces plasma C-reactive protein in insulin-resistant men and women

Chronic low-grade inflammation has been associated with insulin resistance and type 2 diabetes. Recently, we showed that cod protein (CP) improved insulin sensitivity in insulin-resistant subjects. In this study, we investigated the effects of dietary CP compared with those of other animal proteins on plasma concentrations of inflammatory markers, lipids, and lipoproteins in insulin-resistant subjects. Nineteen Caucasian men and women aged 40-65 y, overweight or obese (BMI > 25 kg/m(2)), and insulin resistant, rotated in a crossover design and consumed a CP diet and a similar diet containing lean beef, pork, veal, eggs, milk, and milk products (BPVEM) for 4 wk each. Diets differed only in protein source and thus provided equivalent amounts of dietary fibers, monounsaturated fat, PUFA [including (n-3) fatty acids], and SFA. Blood samples were collected before and after each experimental diet. Notably, the CP diet decreased high-sensitivity C-reactive protein (hsCRP; P = 0.021), whereas the BPVEM diet tended to increase it (P = 0.063), leading to a significant difference between diets (P = 0.041). Changes in plasma interleukin-6, tumor necrosis factor-alpha, and adiponectin concentrations did not differ between diets. Plasma total cholesterol (P = 0.0007), LDL cholesterol (P = 0.014), and apolipoprotein B (P = 0.005) were reduced only by the BPVEM diet. Thus, changes in total cholesterol differed between diets (P = 0.040), whereas changes in LDL cholesterol (P = 0.052) and apolipoprotein B (P = 0.075) tended to differ. Changes in all other lipids and lipoproteins did not differ between diets. Therefore, these results show that CP can lower hsCRP, a marker of inflammation associated with insulin resistance and type 2 diabetes.

Therapies to increase high-density lipoprotein cholesterol and their effect on cardiovascular outcomes and regression of atherosclerosis

Epidemiological studies have shown that decreased level of high-density lipoprotein (HDL) cholesterol (C) is an independent inverse predictor of coronary artery disease (CAD) even in patients with normal levels of low-density lipoprotein (LDL)-C. There is an abundance of evidence in favor of statins and aggressive LDL-C lowering therapy for both primary and secondary prevention of CAD. In contrast, the evidence for reduction of CAD risk with HDL-C raising therapy is relatively thin, partly due to the paucity of effective and safe drugs for increasing HDL-C level. However, there are emerging new therapies for raising HDL-C level and growing evidence in favor of pharmacologic therapies to raise HDL-C level. We present in this article a review of pharmacologic therapies that are currently available to increase HDL-C level, their safety and efficacy in relation to cardiovascular endpoints.

Efeito do exercício físico aeróbio sobre o perfil lipídico de pacientes idosas, portadoras de Diabetes Mellitus tipo 2, atendidas em Unidade Básica de Saúde, Maringá, Estado do Paraná

RESUMO Este estudo tem por objetivo verificar a influência de um programa de exercícios físicos aeróbios sobre o perfil lipídico de pacientes idosas, portadoras de Diabetes Mellitus (DM) tipo 2. Foram selecionados 40 pacientes do gênero feminino com idade maior ou igual a 60 anos. A amostra foi distribuída em dois grupos de 20 pacientes cada: Grupo Treinado, que recebeu orientação nutricional e participou das sessões supervisionadas de exercício físico aeróbio, e Grupo Controle, que recebeu somente orientação nutricional. A intervenção teve a duração de 12 semanas. O protocolo de exercício foi aplicado três vezes por semana, tendo cada sessão 1 h de duração. Os dados obtidos mostraram que o protocolo desenvolvido promoveu redução significativa nos triglicerídeos séricos (pré-teste= 190 ± 76,67 e pós-teste= 125,33 ± 45,82 mg/dL, p<0,05) e no LDL-colesterol (pré-teste= 147,98 ± 29,98 e pós-teste= 122,24 ± 17,61 mg/dL, p<0,05) no Grupo Treinado. Os resultados permitiram concluir que o programa de exercícios adotado promoveu melhora no perfil lipídico de pacientes idosas portadoras de DM tipo 2, demonstrando a importância da prática de atividade física orientada em Unidades Básicas de Saúde.

A practical "ABCDE" approach to the metabolic syndrome

The metabolic syndrome comprises a cluster of risk factors for cardiovascular disease and type 2 diabetes mellitus that are due to abdominal obesity and insulin resistance. This increasingly important proinflammatory condition remains both underrecognized and undertreated. To aid physicians in their approach to the metabolic syndrome, we assessed and synthesized the literature on cardiovascular risk assessment and early intervention for risk reduction. We performed a comprehensive search of MEDLINE and the Cochrane database for peer-reviewed clinical studies published from January 1, 1988, to December 31, 2007, augmented by consultation with content experts. We used the search terms metabolic syndrome, abdominal obesity, waist circumference, insulin resistance, cardiovascular disease, prediabetes, diabetes, treatment, prevention, aspirin, hypertension, cholesterol, atherogenic dyslipidemia, lifestyle therapy, diet, and exercise. Criteria used for study review were controlled study design, English language, relevance to clinicians, and validity based on experimental design and appropriateness of conclusions. Although growing evidence supports early intervention in patients with the metabolic syndrome, many physicians do not recognize the risk associated with this condition and fail to initiate early treatment. A comprehensive management plan can be assembled through an "ABCDE" approach: "A" for assessment of cardiovascular risk and aspirin therapy, "B" for blood pressure control, "C" for cholesterol management, "D" for diabetes prevention and diet therapy, and "E" for exercise therapy. This ABCDE approach provides a practical and systematic framework for encouraging metabolic syndrome recognition and for implementing a comprehensive, evidence-based management plan for the reduction of cardiovascular risk.

Habitual consumption of eggs does not alter the beneficial effects of endurance training on plasma lipids and lipoprotein metabolism in untrained men and women

Changes in plasma lipid and apolipoprotein profiles were evaluated in 12 healthy, unfit subjects (VO(2peak) 39.1+/-2.8 ml.kg(-1).min(-1); 5 women, 7 men) at baseline and following endurance exercise training. The exercise protocol consisted of a 6-week endurance exercise training program (4-5 days week(-1); 60 min.session(-1); > or =65% HR(max)). Subjects were randomly assigned to consume an egg- (n=6; 12 eggs.week(-1)) or no-egg (n=6; 0 eggs.week(-1))-based, eucaloric, standardized diet for 8 weeks. Both diets were macronutrient balanced [60% carbohydrate, 30% fat, 10% protein (0.8 g.kg(-1).day(-1))] and individually designed for weight maintenance. Plasma lipids were measured twice within the same week at baseline and following exercise training. At baseline, subjects were normolipidemic with values of 163.9+/-41.8, 84.8+/-36.7, 60.6+/-15.4 and 93.1+/-52 mg dl(-1) for total cholesterol, LDL cholesterol and HDL cholesterol and triglyceride concentrations, respectively. A two-way ANOVA was used to analyze diet and exercise effects and interactions. In both groups, endurance exercise training resulted in a significant 10% increase in HDL-C (P<.05), a 19% decrease in Apo B concentrations (P<.05) and reductions in plasma CETP activity (P<.05). Plasma LDL-C decreased by 21% (P=.06). No main effects of diet or interactions with plasma lipids or Apo B concentrations were observed. These data demonstrate that endurance training improved the plasma lipid profiles of previously unfit, normolipidemic subjects independent of dietary cholesterol intake from eggs.

Low high-density lipoprotein cholesterol: an important consideration in coronary heart disease risk assessment

PURPOSE OF REVIEW

One aim is to summarize evidence from observational studies and clinical trials evaluating the inverse relationship between high-density lipoprotein and coronary heart disease. Other aims are to explore the mechanisms underlying the reported cardioprotective effects of high-density lipoprotein and to evaluate therapeutic modalities to increase high-density lipoprotein levels and functionality.

RECENT FINDINGS

In addition to reverse cholesterol transport, recent data suggest that high-density lipoprotein possesses antioxidant, anti-inflammatory and fibrinolytic properties and the inverse relationship between high-density lipoprotein cholesterol and coronary heart disease is most evident with associated elevations in low-density lipoprotein cholesterol and triglyceride. Recent data suggest, however, that even after low-density lipoprotein cholesterol is sufficiently reduced, residual coronary heart disease risk persists with low high-density lipoprotein cholesterol. The excess death rate reported with the high-density lipoprotein cholesterol raising drug torcetrapib appears to have been the result of an off-target effect of the drug, rather than an effect attributable to cholesteryl ester transfer protein inhibition.

SUMMARY

Low high-density lipoprotein cholesterol remains an important consideration in coronary heart disease risk assessment, however several issues remain unresolved. They include the extent to which low high-density lipoprotein cholesterol in the absence of other risk factors augments risk, the relationship between high-density lipoprotein functionality and levels of high-density lipoprotein cholesterol and whether and to what extent improving these parameters independently offsets coronary heart disease risk.

Study of the effect of trans fatty acids from ruminants on blood lipids and other risk factors for cardiovascular disease

BACKGROUND

The intake of trans fatty acids (TFA) from industrially hydrogenated vegetable oils (iTFA) is known to have a deleterious effect on cardiovascular health, the effects of TFA from ruminants (rTFA) are virtually unknown.

OBJECTIVE

The purpose of the present study was to compare the effects of rTFA and iTFA on plasma LDL concentrations and other cardiovascular disease risk factors in healthy subjects.

DESIGN

In a double-blind, randomized crossover controlled study, 38 healthy men were fed each of 4 experimental isoenergetic diets lasting 4 wk each. The 4 diets were high in rTFA (10.2 g/2500 kcal), moderate in rTFA (4.2 g/2500 kcal), high in iTFA (10.2 g/2500 kcal), and low in TFA from any source (2.2 g/2500 kcal) (control diet).

RESULTS

Plasma LDL-cholesterol concentrations were significantly higher after the high- rTFA diet than after the control (P = 0.03) or the moderate- rTFA (P = 0.002) diet. Plasma LDL-cholesterol concentrations also were significantly (P = 0.02) higher after the iTFA diet than after the moderate-rTFA diet. Plasma HDL-cholesterol concentrations were significantly (P = 0.02) lower after the high-rTFA diet than after the moderate-rTFA diet. Finally, all risk factors were comparable between the control and the moderate-rTFA diets.

CONCLUSIONS

These results suggest that, whereas a high dietary intake of TFA from ruminants may adversely affect cholesterol homeostasis, moderate intakes of rTFA that are well above the upper limit of current human consumption have neutral effects on plasma lipids and other cardiovascular disease risk factors.

Long-term cardiac rehabilitation and exercise training programs improve metabolic parameters in metabolic syndrome patients with and without coronary heart disease

BACKGROUND AND AIMS

The effectiveness of long-term cardiac rehabilitation and exercise training programs on metabolic parameters was evaluated in metabolic syndrome subjects with and without coronary heart disease (CHD).

METHODS AND RESULTS

Fifty-nine CHD and 81 non-coronary patients with metabolic syndrome (59+/-8 vs 56+/-9years) were identified retrospectively at entry into identical cardiac rehabilitation and exercise-training programs. Metabolic syndrome was defined using modified Adult Treatment Panel III criteria. Exercise training occurred approximately twice per week. Metabolic and exercise testing data were collected at baseline and after 12months during the course of the program. Mean duration of cardiac rehabilitation and exercise training programs was over one year in both coronary and non-coronary patients (366+/-111 vs 414+/-102days for CHD and non-coronary CHD cohorts respectively, p<0.01). Significant improvements in bodyweight, body mass index, blood lipids, triglyceride/HDL ratio and exercise tolerance were noted in both cohorts. At the end of follow-up, 31% of CHD and 20% of non-CHD subjects no longer possessed diagnostic criteria for metabolic syndrome (p<0.0001 and p<0.001 respectively).

CONCLUSIONS

A long-term cardiac rehabilitation program reduces metabolic syndrome prevalence in CHD patients and results in a similar improvement in risk factor control for metabolic syndrome patients without CHD.

Non-high-density lipoprotein cholesterol in secondary prevention of coronary artery disease: a unique risk factor or redundant information?

PURPOSE

The purpose of this study was to assess the changes in standard lipid measures such as total cholesterol, low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) in comparison with changes in non-HDL-C.

METHODS

Data from 100 participants in a phase II cardiac rehabilitation program at entry and 12 weeks were assessed for changes in lipid measures. Eighty-six percent of participants were on stable lipid therapy throughout the 12-week period. Participants were classified as meeting or not meeting optimal levels of LDL-C, HDL-C, and non-HDL-C. Differences in classification for each measure were compared using the Fisher exact tests.

RESULTS

Changes in total cholesterol and LDL-C were not significant (P = .24 and P = .23, respectively). There was a significant increase in HDL-C (2.22 +/- 0.97 mg/dL, P = .0243). Non-HDL-C and triglycerides tended to decrease but did not reach significance (P = .08 and P = .96, respectively). At baseline, non-HDL-C classified a significantly higher number of participants as none optimal than did LDL-C (P < .0001). At the 12-week follow-up, a significantly higher number of participants were classified as optimal by non-HDL-C measures than by LDL-C (P < .0001).

CONCLUSIONS

Non-HDL-C provides additional information to that of standard lipid measures in secondary prevention. Non-HDL-C independently classifies risk levels of participants and is responsive to traditional rehabilitation.

Management of antipsychotic-induced weight gain: prospective naturalistic study of the effectiveness of a supervised exercise programme

OBJECTIVE

To determine the potential effectiveness of a behavioural weight control programme including physical exercise in the prevention of antipsychotic-induced weight gain and associated comorbid conditions in outpatients with schizophrenia and mood disorders.

METHODS

A prospective, comparative, open and naturalistic study was carried out for a total of 110 patients with schizophrenia, schizoaffective or bipolar disorders (DSM-IV), on treatment with atypical antipsychotics. Of these, 59 patients participated in an 18 month weight control programme that included an educational activity about dietary and physical activity counselling as well as a structured, supervised, facility-based exercise programme. The control group consisted of 51 patients with the same baseline characteristics who did not receive the clinical programme. Anthropometric measurements, plasma lipid-lipoprotein profile, and fasting plasma glucose concentrations were assessed at 11 time-points over the study. In addition, serum concentrations of prolactin, thyrotropin-stimulating hormone (TSH), and glycated haemoglobin (HbA1c) were assessed at four time-points. Finally, the Clinical Global Impression scale (CGI), the Brief Psychiatric Rating Scale (BPRS) and the Short Form (SF)-36 Health Survey were used.

RESULTS

The adherence rate of patients was 85%, both in the active and in the control group. Whereas the control group experienced a significant increase in bodyweight (4.1%), body mass index (BMI; 5.5%) and waist circumference (WC; 4.2%), the active group significantly reduced their bodyweight (-3.5%), BMI (-4.4%), and WC (-4.6%) at the study end-point. In addition, a significant increase in low-density lipoprotein (LDL)-cholesterol (14.8%) and in triglyceride concentrations (12.3%) was observed at month 18 in the control group. In contrast, high-density lipoprotein-cholesterol (HDL) significantly increased (21.4%), and LDL cholesterol (-13.7%), triglycerides (-26.2%), total cholesterol (-12.1%), fasting glucose concentrations (-12.0%), and HbA1c (-11.4%) significantly decreased compared to baseline in the active group. No significant changes were observed regarding serum concentrations of prolactin and TSH during the study. In regard to the changes observed in psychological measures, no between-group differences were seen in the clinical ratings of CGI and BPRS. However, the SF-36 showed that physical health was improved only for subjects in the active group at months 12 and 18 compared to baseline (p<0.05), and mental health was significantly improved for both groups at months 12 and 18 compared to baseline.

CONCLUSION

Bodyweight and metabolic risk profile in patients receiving atypical antipsychotic medications can be effectively managed with a weight control programme including physical activity.

Metabolic syndrome management

Overweight, obesity and the metabolic syndrome occur in genetically susceptible individuals with environmental influences, and may be further compounded by other disorders of metabolism or pharmacological therapy that increase insulin resistance or promotes weight gain. Treatment of the metabolic syndrome should focus on treatment on [corrected] each individual component, but first, lifestyle modification, including diet and exercise with weight reduction, should be [corrected] the foundation of any successful treatment regimen for the metabolic syndrome. Pharmacological therapy should be individualized and targeted to normalize blood pressure, HDL cholesterol, triglycerides and glucose values. If successful, comprehensive management of the metabolic syndrome promises to delay or prevent the development of coronary heart disease and Type 2 diabetes mellitus.

Effect of l-Carnitine Supplementation on Endurance Exercise in Normobaric/Normoxic and Hypobaric/Hypoxic Conditions

OBJECTIVE

To evaluate the effect of L-carnitine supplementation on improving endurance exercise in normobaric/normoxic and hypobaric/hypoxic environments.

METHODS

Six-week-endurance-trained male Sprague-Dawley rats (n = 24) were randomly divided into 2 groups: control and experimental; the latter group was supplemented with L-carnitine, administered orally in a dose of 100 mg x kg(-1) body weight. The animals were supplemented for 25 days under ambient normobaric/normoxic conditions and thereafter were exposed to 72 hours of hypobaric hypoxia equivalent to 6100 m. The supplementation was continued during the exposure. "Run to exhaustion" was recorded on day 1 (R1) (presupplementation) and on days 7 (R2), 14 (R3), 21 (R4), and 28 (R5, which followed the last 72 hours of hypoxic exposure) of supplementation. Food intake, body weight, and the biochemical measures of plasma glucose, total cholesterol, and high-density lipoprotein (HDL) cholesterol were recorded.

RESULTS

There was a significant improvement in endurance exercise, as indicated by an increase in run to exhaustion following L-carnitine supplementation under normobaric normoxia (36%-39%) and hypobaric hypoxia (50%). L-carnitine supplementation had no effect on plasma glucose levels either at sea level or after hypoxic exposure. Total cholesterol was decreased in normoxic and HDL cholesterol was increased in normoxic and hypoxic conditions, indicating a beneficial effect of exercise.

CONCLUSION

L-carnitine supplementation improved exercise endurance in rats exposed to normobaric normoxic and hypobaric hypoxic conditions. Such supplementation would be beneficial in delaying the onset of fatigue during prolonged exercise in both conditions, indicating its potentially beneficial use at high altitude.

Inactivity, exercise training and detraining, and plasma lipoproteins. STRRIDE: a randomized, controlled study of exercise intensity and amount

Exercise has beneficial effects on lipoproteins. Little is known about how long the effects persist with detraining or whether the duration of benefit is effected by training intensity or amount. Sedentary, overweight subjects ( n = 240) were randomized to 6-mo control or one of three exercise groups: 1) high-amount/vigorous-intensity exercise; 2) low-amount/vigorous-intensity exercise; or 3) low-amount/moderate-intensity exercise. Training consisted of a gradual increase in amount of exercise followed by 6 mo of exercise at the prescribed level. Exercise included treadmill, elliptical trainer, and stationary bicycle. The number of minutes necessary to expend the prescribed kilocalories per week (14 kcal·kg body wt−1·wk−1for both low-amount groups; 23 kcal·kg body wt−1·wk−1for high-amount group) was calculated for each subject. Average adherence was 83–92% for the three groups; minutes per week were 207, 125, and 203 and sessions per week were 3.6, 2.9, and 3.5 for high-amount/vigorous-intensity, low-amount/vigorous intensity, and low-amount/moderate-intensity groups, respectively. Plasma was obtained at baseline, 24 h, 5 days, and 15 days after exercise cessation. Continued inactivity resulted in significant increases in low-density lipoprotein (LDL) particle number, small dense LDL, and LDL-cholesterol. A modest amount of exercise training prevented this deterioration. Moderate-intensity but not vigorous-intensity exercise resulted in a sustained reduction in very-low-density lipoprotein (VLDL)-triglycerides over 15 days of detraining ( P < 0.05). The high-amount group had significant improvements in high-density lipoprotein (HDL)-cholesterol, HDL particle size, and large HDL levels that were sustained for 15 days after exercise stopped. In conclusion, physical inactivity has profound negative effects on lipoprotein metabolism. Modest exercise prevented this. Moderate-intensity but not vigorous-intensity exercise resulted in sustained VLDL-triglyceride lowering. Thirty minutes per day of vigorous exercise, like jogging, has sustained beneficial effects on HDL metabolism.

Oat-derived beta-glucan significantly improves HDLC and diminishes LDLC and non-HDL cholesterol in overweight individuals with mild hypercholesterolemia

OBJECTIVE

To investigate the effect of bread formulated with 6 g of beta-glucan (oat soluble fiber) on serum lipids in overweight normotensive subjects with mild to moderate hypercholesterolemia.

DESIGN

Thirty-eight male subjects [mean age 59.8 +/- 0.6 yr, mean body mass index (BMI) 28.3 +/- 0.6 kg/m(2)] who were eligible for the study ate an isocaloric diet for a 1-week period. They were then divided into 2 groups: group A (n = 19), who were maintained on American Heart Association (AHA) Step II diet, including whole wheat bread, and group B (n = 19), who were maintained on AHA Step II diet containing high levels of monounsaturated fatty acids plus bread containing 6 g of beta-glucan (Nutrim-OB) for 8 weeks. Plasma lipids and glucose were measured at baseline and after weeks 8 in all subjects. All subjects were advised to walk for 60 minutes every day.

RESULTS

There was a significant increase (upward arrow 27.8%) in plasma high density lipoprotein (HDL) cholesterol in the beta-glucan group (group A) from 39.4 +/- 2.0 to 49.5 +/- 2.1 mg/dL (P < 0.001), but there was no change in group B. There was a significant reduction in total cholesterol in the 2 groups to approximately the same extent: group A, from 232.8 +/- 2.7 mg/dL to 202.7 +/- 6.7 mg/dL; P < 0.001; and group B, from 231.8 +/- 4.3 mg/dL to 194.2 +/- 4.3 mg dL; P < 0.001. Plasma low density lipoprotein (LDL) cholesterol also decreased significantly in the two groups: group A, from 160.3 +/- 2.8 mg/dL to 133.2 +/- 5.4 mg/dL; P < 0.001; group B, from 167.9 +/- 4.3 mg/dL to 120.9 +/- 4.3 mg/dL; P < 0.001; however, the beta-glucan fortified diet was significantly more effective (downward arrow 27.3% vs. downward arrow 16.8%; P < 0.04). There was a small and insignificant reduction in plasma very LDL (VLDL) cholesterol and triglycerides in the two groups. Similarly, non-HDL cholesterol levels were also decreased, with beta-glucan diet producing significantly higher effect (downward arrow 24.5% vs. downward arrow 16.1%; P < 0.04). The beta-glucan diet also produced higher reduction in total cholesterol/HDL cholesterol ratio (downward arrow 33.3% vs. downward arrow 8.4%; P < 0.003) and LDL cholesterol/HDL cholesterol ratio (downward arrow 42.1% vs. downward arrow 13.3%; P < 0.001) than the diet without beta-glucan. The beta-glucan diet also decreased fasting plasma glucose (P < 0.4), whereas the other diet had no effect. Interestingly, both diets reduced body weight and BMI significantly, with beta-glucan diet having a greater effect.

CONCLUSIONS

Six grams of beta-glucan from oats added to the AHA Step II diet and moderate physical activity improved lipid profile and caused a decrease in weight and, thus, reduced the risk of cardiovascular events in overweight male individuals with mild to moderate hypercholesterolemia. The diet with added beta-glucan was well accepted and tolerated.

Efetividade de um programa de exercícios no condicionamento físico, perfil metabólico e pressão arterial de pacientes hipertensos

HISTÓRICO E OBJETIVO: Tem sido mostrado que exercícios aeróbios são úteis na redução da pressão arterial. Contudo, a efetividade de um programa de exercícios ainda é controversa e não foi bem analisada em populações de baixa renda. O objetivo do presente estudo foi estabelecer um programa de condicionamento físico individualizado - Projeto Hipertensão - focado em pessoas hipertensas, pacientes da Unidade Básica de Saúde (UBS) e, logo após, investigar os efeitos deste programa no condicionamento físico, perfil metabólico e níveis de pressão. MÉTODOS: Dezesseis mulheres hipertensas (56 ± 3 anos) sob tratamento farmacológico regular foram submetidas a 4 meses de um programa de exercícios aeróbios e de alongamento (3 sessões/semana, 90 min/sessão, 60% de VO2max.) Diversas variáveis físicas e metabólicas foram comparadas antes e depois de 4 meses de treinamento. RESULTADOS: O treinamento diminuiu significativamente a pressão arterial sistólica (PAS, -6%); melhorou o condicionamento cardiorrespiratório (+42% do VO2max), flexibilidade (+11%) e conteúdo de glicose plasmática (-4%). IMC e % de gordura não tiveram modificação. Além de modificar o perfil metabólico, observou-se que o treinamento apresentou correlações significativas entre os valores iniciais individuais de nível de colesterol total (CT), lipoproteína de alta densidade (HDL-C) e lipoproteína de baixa densidade (LDL-C) e suas respostas após exercício. CONCLUSÕES: O estudo mostra que programas de exercício podem ser personalizados para pacientes hipertensos da UBS e confirma a efetividade do exercício na PA, condicionamento físico, flexibilidade e perfil lipídico em pacientes hipertensos. A redução expressiva de PA em sujeitos hipertensos sugere que esta intervenção de exercícios deve ser enfatizada em outros centros que assistam populações de baixa renda.

Effect of exercise training on in vitro LDL oxidation and free radical-induced hemolysis: the HERITAGE Family Study

Oxidant stress and overproduction of reactive oxygen species (ROS) contribute to the development of cardiovascular disease. Oxidative modifications of low-density lipoproteins (LDL) are thought to play an early and critical role in atherogenesis. LDL oxidation can be reproduced in vitro, but results usually show a large interindividual variation not entirely explained by the environment. Free radical-induced hemolysis is also proposed to reveal the overall antioxidant capacity. The roles of genetic factors and exercise on the variability of both measures were investigated. The study was conducted in 146 healthy individuals from 28 families participating in a 20-week exercise-training program. In addition to important biological and environmental influences on variation, significant familial aggregation was detected in all oxidation measures. Exercise did not significantly modify the LDL oxidation parameters, but significantly increased resistance was observed in the free radical-induced hemolysis, especially in women, this effect was not observed in smokers. In total, the findings suggest the presence of familial effects in the response to ex vivo oxidation. Further, smoking negates the beneficial effect of exercise training on erythrocyte resistance to free radical-induced hemolysis. These observations emphasize the importance of context in the evaluation of exercise and oxidant stress.

Short sleep duration is associated with reduced leptin levels and increased adiposity: Results from the Quebec family study

OBJECTIVE

To explore cross-sectional associations between short sleep duration and variations in body fat indices and leptin levels during adulthood in a sample of men and women involved in the Québec Family Study.

RESEARCH METHODS AND PROCEDURES

Anthropometric measurements, plasma lipid-lipoprotein profile, plasma leptin concentrations, and total sleep duration were determined in a sample of 323 men and 417 women ages 21 to 64 years.

RESULTS

When compared with adults reporting 7 to 8 hours of sleep per day, the adjusted odds ratio for overweight/obesity was 1.38 (95% confidence interval, 0.89 to 2.10) for those with 9 to 10 hours of sleep and 1.69 (95% confidence interval, 1.15 to 2.39) for those with 5 to 6 hours of sleep, after adjustment for age, sex, and physical activity level. In each sex, we observed lower adiposity indices in the 7- to 8-hour sleeping group than in the 5- to 6-hour sleeping group. However, all of these significant differences disappeared after statistical adjustment for plasma leptin levels. Finally, the well-documented regression of plasma leptin levels over body fat mass was used to predict leptin levels of short-duration sleepers (5 and 6 hours of sleep), which were then compared with their measured values. As expected, the measured leptin values were significantly lower than predicted values.

DISCUSSION

There may be optimal sleeping hours at which body weight regulation is facilitated. Indeed, short sleep duration predicts an increased risk of being overweight/obese in adults and is related to a reduced circulating leptin level relative to what is predicted by fat mass. Because sleep duration is a potentially modifiable risk factor, these findings might have important clinical implications for the prevention and treatment of obesity.

Walking decreased risk of cardiovascular disease mortality in older adults with diabetes

OBJECTIVE

This study examines the association of walking with mortality in persons with type 2 diabetes compared to those with normal glucose tolerance.

STUDY DESIGN AND SETTING

This prospective study included community-dwelling adults from the Rancho Bernardo Study aged 50-90 years in 1984-86 who had type 2 diabetes (n=347) or normal glucose tolerance (n=1,317). During the 10-year follow up, Cox proportional hazards modeling was used to model time until death from all causes (n=538), coronary heart disease (CHD, n=143), other cardiovascular disease (non-CHD CVD, n=138), and other causes (n=257) while adjusting for multiple potential confounders.

RESULTS

After adjusting for sex, age, smoking, body mass index, alcohol, exercise, history of CHD, and other covariates, adults with diabetes who walked > or =1 mile per day were half as likely to die from all causes combined (hazard ratio [HR]=0.54; 95% confidence interval [CI]: 0.33, 0.88), and less than one-fifth as likely to die from non-CHD CVD (HR=0.19; 95% CI: 0.04, 0.86) compared to adults with diabetes who did not walk. Walking was also protective among adults with normal glucose tolerance (HR=0.55; 95% CI: 0.32, 0.96).

CONCLUSION

Results suggest walking > or =1 mile per day may provide strong protection from all-cause and non-CHD CVD mortality in older adults with diabetes.

Prevalence of low HDL-cholesterol in patients with cardiovascular risk factors: The ECHOS (Etude du Cholesterol HDL en Observationnel) French Survey

A low concentration of high-density lipoprotein-cholesterol (HDL-C) is an independent risk factor for cardiovascular heart disease (CHD), but little is known about the distribution of HDL-C in France. This study evaluated the prevalence of low HDL-C among a large French population (5232 patients) with other cardiovascular risk factors. Depending on the guidelines used, the prevalence of low HDL-C varied from 8.7% (cutoff value of 35 mg/dl) to 26.9% (National Cholesterol Education Program metabolic syndrome cutoff values). The prevalence of low HDL-C gradually increased with the number of associated risk factors. We identified three independent risk predictors for low HDL-C: hypertriglyceridaemia (HTG), abdominal obesity and gender. Overall, the frequency of HDL-C assessment was very high (>85%) and it was highest in patients with hypercholesterolaemia or a history of CHD. Risk factors more frequently associated with low HDL-C (i.e. HTG, abdominal obesity and type 2 diabetes) were not associated with a more frequent assessment of HDL-C. Our findings indicate that in France, the prevalence of low HDL-C remains relatively high, particularly for patients with obesity and HTG.

Nicotinic acid and other therapies for raising high-density lipoprotein

PURPOSE OF REVIEW

The purpose of this review is to describe the high-density-lipoprotein-raising effect of nicotinic acid and the clinical effects of treatment on cardiovascular diseases, particularly in combination with statins. Other treatments for raising high-density lipoprotein, including changes in lifestyle, other drugs and infusions of 'synthetic' (reconstituted) high-density lipoprotein will be summarized.

RECENT FINDINGS

Treatment of atherosclerotic cardiovascular disease with nicotinic acid and statin results in a pronounced increase of protective high-density lipoprotein cholesterol and reduces morbidity/mortality. Addition of prolonged-release nicotinic acid to ongoing treatment with statin raises high-density lipoprotein cholesterol and induces regression of atherosclerosis that otherwise would progress during statin treatment. Several new high-density lipoprotein-raising drugs in clinical trials are reported. New proposed mechanisms for the broad-spectrum lipid effects of nicotinic acid are described.

SUMMARY

Low plasma concentration of high-density lipoprotein is an important risk factor for atherosclerotic cardiovascular disease. Nicotinic acid has the uncomfortable but harmless side effect of flush. Prolonged-release nicotinic acid gives rise to less flush than immediate-release nicotinic acid. Treatment with nicotinic acid and statin targets the two independent lipid risk factors of low high-density lipoprotein and high low-density lipoprotein and has clinical benefits in secondary prevention of atherosclerotic cardiovascular disease.