Effects of moderate intensity exercise on serum lipids in African-American men with severe systemic hypertension

Tracking Biomarker Responses to Exercise in Hypertension

PURPOSE OF REVIEW

Strong evidence is evolving that physical exercise prevents hypertension and reduces blood pressure in patients with pre- and manifest HTN. Yet, identifying and confirming the effectiveness of exercise are challenging. Herein, we discuss conventional and novel biomarkers such as extracellular vesicles (EVs) which may track responses to HTN before and after exercise.

RECENT FINDINGS

Evolving data shows that improved aerobic fitness and vascular function as well as lowered oxidative stress, inflammation, and gluco-lipid toxicity are leading biomarkers considered to promote HTN, but they explain only about a half of the pathophysiology. Novel biomarkers such as EVs or microRNA are providing additional input to understand the complex mechanisms involved in exercise therapy for HTN patients. Conventional and novel biomarkers are needed to fully understand the integrative "cross-talk" between tissues to regulate vasculature physiology for blood pressure control. These biomarker studies will lead to more specific disease markers and the development of even more personalized therapy in this field. However, more systematic approaches and randomized controlled trials in larger cohorts are needed to assess exercise effectiveness across the day and with different exercise types.

The effect of endurance and endurance-strength training on body composition and cardiometabolic markers in abdominally obese women: a randomised trial

Studies comparing the effect of endurance and endurance-strength training on cardiometabolic markers provided inconsistent results. Therefore, the study aimed to compare the effect of endurance and endurance-strength training on body composition and cardiometabolic parameters in abdominally obese women. In this randomised trial, 101 subjects were included and divided into endurance (n = 52) and endurance-strength (n = 49) training. During the 12-week intervention, participants performed supervised one-hour training three times a week. Body composition, blood pressure (BP), markers of glucose and lipid homeostasis, and myoglobin levels were measured before and after the intervention. In total, 85 subjects completed the trial. Both interventions decreased fat mass and visceral adipose tissue and increased free fat mass, appendicular lean mass index and lean mass index. Neither endurance training nor endurance-strength training affected glucose and lipid metabolism. However, only endurance training significantly decreased paraoxonase and myoglobin levels. Both training programmes significantly decreased BP, with a more reduction of diastolic BP noted in the endurance group. In conclusion, both training programmes had a favourable effect on body composition but did not improve glucose and lipid homeostasis. Besides, endurance training decreased paraoxonase activity and myoglobin levels and was more effective in reducing BP.The study was registered with the German Clinical Trials Register (DRKS) within the number: DRKS00019832 (retrospective registration), date of registration: 26/02/2020.

Resistance Training in Spontaneously Hypertensive Rats with Severe Hypertension

BACKGROUND

Resistance training (RT) has been recommended as a non-pharmacological treatment for moderate hypertension. In spite of the important role of exercise intensity on training prescription, there is still no data regarding the effects of RT intensity on severe hypertension (SH).

OBJECTIVE

This study examined the effects of two RT protocols (vertical ladder climbing), performed at different overloads of maximal weight carried (MWC), on blood pressure (BP) and muscle strength of spontaneously hypertensive rats (SHR) with SH.

METHODS

Fifteen male SHR ENT#091;206 ± 10 mmHg of systolic BP (SBP)ENT#093; and five Wistar Kyoto rats (WKY; 119 ± 10 mmHg of SBP) were divided into 4 groups: sedentary (SED-WKY) and SHR (SED-SHR); RT1-SHR training relative to body weight (~40% of MWC); and RT2-SHR training relative to MWC test (~70% of MWC). Systolic BP and heart rate (HR) were measured weekly using the tail-cuff method. The progression of muscle strength was determined once every fifteen days. The RT consisted of 3 weekly sessions on non-consecutive days for 12-weeks.

RESULTS

Both RT protocols prevented the increase in SBP (delta - 5 and -7 mmHg, respectively; p > 0.05), whereas SBP of the SED-SHR group increased by 19 mmHg (p < 0.05). There was a decrease in HR only for the RT1 group (p < 0.05). There was a higher increase in strength in the RT2 (140%; p < 0.05) group as compared with RT1 (11%; p > 0.05).

CONCLUSIONS

Our data indicated that both RT protocols were effective in preventing chronic elevation of SBP in SH. Additionally, a higher RT overload induced a greater increase in muscle strength.

Effects of Exercise Training on Cardiorespiratory Fitness and Biomarkers of Cardiometabolic Health: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Guidelines recommend exercise for cardiovascular health, although evidence from trials linking exercise to cardiovascular health through intermediate biomarkers remains inconsistent. We performed a meta-analysis of randomized controlled trials to quantify the impact of exercise on cardiorespiratory fitness and a variety of conventional and novel cardiometabolic biomarkers in adults without cardiovascular disease.

METHODS AND RESULTS

Two researchers selected 160 randomized controlled trials (7487 participants) based on literature searches of Medline, Embase, and Cochrane Central (January 1965 to March 2014). Data were extracted using a standardized protocol. A random-effects meta-analysis and systematic review was conducted to evaluate the effects of exercise interventions on cardiorespiratory fitness and circulating biomarkers. Exercise significantly raised absolute and relative cardiorespiratory fitness. Lipid profiles were improved in exercise groups, with lower levels of triglycerides and higher levels of high-density lipoprotein cholesterol and apolipoprotein A1. Lower levels of fasting insulin, homeostatic model assessment-insulin resistance, and glycosylated hemoglobin A1c were found in exercise groups. Compared with controls, exercise groups had higher levels of interleukin-18 and lower levels of leptin, fibrinogen, and angiotensin II. In addition, we found that the exercise effects were modified by age, sex, and health status such that people aged <50 years, men, and people with type 2 diabetes, hypertension, dyslipidemia, or metabolic syndrome appeared to benefit more.

CONCLUSIONS

This meta-analysis showed that exercise significantly improved cardiorespiratory fitness and some cardiometabolic biomarkers. The effects of exercise were modified by age, sex, and health status. Findings from this study have significant implications for future design of targeted lifestyle interventions.

A systematic review of weight loss, physical activity and dietary interventions involving African American men

When compared with men of other racial or ethnic groups, African American men are more likely to experience adverse health conditions. The systematic review objectives were to (i) determine the current evidence base concerning African American men's response to lifestyle behavioural interventions designed to promote weight loss, increase physical activity, and/or improve healthy eating and (ii) determine the next steps for research in these areas. The PubMed, Web of Science, Psych Info and Cochrane databases were searched to identify papers published before January 1, 2013 that reported change in weight, physical activity and/or dietary patterns in African American men aged 18 and older, as a result of behavioural change strategies. The titles and abstracts of 1,403 papers were screened; after removing duplicates, 141 papers were read to determine their eligibility. Seventeen publications from 14 studies reported outcomes for African American men. Eight large multi-centre trials and six community-based studies were identified. African American men were an exclusive sample in only four studies. Five studies showed statistically significant improvements. Although the available evidence appears to show that these interventions produce positive results, the relative and the long-term effectiveness of weight loss, dietary and/or physical activity interventions for this population are unknown.

Exploring the feasibility of a physical activity intervention for midlife African American men

BACKGROUND

This study tested the initial efficacy of implementing a physical activity (PA) behavior change intervention for midlife African American (AA) men.

METHODS

Intervention components were based on information gathered during formative research preceding the intervention. Eligible participants were underactive AA men ages 45-66 years. In a quasi-experimental pre-post design, participants attended 90-min program sessions twice weekly for 8 weeks. Session topics specific to PA included overcoming barriers, gaining social support, setting goals, tracking progress and integrating into one's lifestyle. Participants were assigned to teams to facilitate group discussion, problem solving, accountability and camaraderie.

RESULTS

25 AA men (mean age = 54.7 ± 4.8 years) completed the intervention. After 8 weeks, significant (P < 0.05) positive changes were observed for moderate to vigorous-intensity PA (+7.3 hour week(-1)) and overall PA (+9.4 hour week(-1)), self-efficacy for PA (+12%), social support for PA from family (+28%) and friends (+53%), self-regulation for planning (+33%) and goal setting (+48%) and each fitness component (+9 to +144%). Based on a post-intervention satisfaction survey, participants rated the program very positively.

CONCLUSION

These positive results attest to the feasibility of successfully engaging midlife AA men in a tailored PA behavior change program.

Systematic Review of Interventions to Increase Physical Activity and Physical Fitness in African-Americans

Objective.

To identify characteristics of effective interventions designed to increase physical activity (PA) or fitness among African-Americans.

Data Sources.

Articles published between 1985 and 2006.

Study Inclusion Criteria.

Studies reporting PA or fitness change data in African-American participants were included.

Data Extraction.

Information on study design, intervention, data collection methods, and outcomes was extracted using a standardized form.

Data Synthesis.

Studies were ranked on quality and were summarized separately for adults and children.

Results.

We identified 29 studies in adults and 14 studies in children. Most were randomized controlled trials. All but six specifically targeted African-Americans; comparisons of effectiveness in African-Americans vs. others were not possible. Methodological heterogeneity limited comparisons of findings across studies. In adults, most studies showed significant within-group pre-post improvements in PA, but only 10 studies found differences between intervention and comparison groups. Most studies in children were null.

Conclusions.

Effective programs in adults were from randomized controlled trials and involved structured exercise programs. Studies with explicit cultural adaptations did not necessarily result in better PA outcomes. Additional studies are needed with larger sample sizes, longer follow-up, attention controls, strategies informed by proven behavior change theories, and objective PA assessment.

Physical Activity and Fitness in African Americans: Implications for Cardiovascular Health

The prevalence of cardiovascular disease (CVD), obesity, diabetes mellitus, hypertension, and physical inactivity is significantly higher in African Americans. The higher prevalence of these important risk factors is thought to be largely responsible for the higher CVD mortality rate in blacks. Limited evidence suggests that the aerobic power of African Americans may be inherently lower than that of whites. This apparent deficiency may be explained, in part, by differences in muscle oxidative capacity but is poorly understood. Studies have shown a lower prevalence of overweight/obesity, the metabolic syndrome, and insulin resistance with higher levels of physical activity/fitness. Training studies have shown that increasing physical activity and/or fitness positively affects metabolic risk factors, body composition, and insulin sensitivity. The few studies of African Americans suggest that they respond to exercise training in a manner similar to whites. Controlling blood pressure of hypertensive blacks at levels comparable with that of whites could result in more than 7000 fewer deaths from CVD. Physical fitness has been shown to be negatively associated with blood pressure in African Americans, but results from interventional studies have been equivocal. Some evidence suggests that increased physical activity and/or fitness may reduce the blood pressure response to submaximal exercise and other stressors in African Americans. Blacks have higher levels of high-density lipoprotein cholesterol (HDL-C) and lower levels of total cholesterol, triglycerides, and small dense low-density lipoprotein particles. Studies suggest that the blood lipid response to exercise training is similar between African Americans and whites. There may be an intensity threshold of 75% of age-predicted maximal heart rate to elicit significant changes in HDL-C. More research is needed to explore the association between physical activity/fitness and CVD risk factors in this population.

A meta-analysis of psycho-behavioral obesity interventions among US multiethnic and minority adults

OBJECTIVE

The present review examines efficacious psycho-behavioral interventions in preventing weight gains or reducing weight among US multiethnic and minority adults as few studies were conducted to review such interventions to date.

METHODS

Data were examined from 24 controlled intervention studies, representing 23 programs and involving 13,326 adults. Studies were identified through manual and online search of databases that include MEDLINE, Academic Search Premier, ERIC, PsycARTICLES, SPORTDiscus, and CINAHL Plus.

RESULTS

Whereas one-component (n=5, d=0.08, 90% CI=-0.04, 0.35) and two-component interventions (n=13, d=0.22, 90% CI=0.05, 0.40) showed a low mean effect size, three-component interventions (n=6, d=0.52, 90% CI=0.39, 0.65) showed a moderate effect size. Interventions conducted in individual sessions (n=15, d=0.40, 90% CI=0.24, 0.56) showed a higher mean effect size than group interventions (n=9, d=0.08, 90% CI=-0.04, 0.30) although the confidence intervals overlapped.

CONCLUSIONS

The study results indicate that future obesity prevention interventions targeting multiethnic and minority adults might benefit from incorporating individual sessions, family involvement, and problem solving strategies into multi-component programs that focus on lifestyle changes.

Cardiovascular health disparities: a systematic review of health care interventions

Racial and ethnic disparities in cardiovascular health care are well documented. Promising approaches to disparity reduction are increasingly described in literature published since 1995, but reports are fragmented by risk, condition, population, and setting. The authors conducted a systematic review of clinically oriented studies in communities of color that addressed hypertension, hyperlipidemia, physical inactivity, tobacco, and two major cardiovascular conditions, coronary artery disease and heart failure. Virtually no literature specifically addressed disparity reduction. The greatest focus has been African American populations, with relatively little work in Hispanic, Asian, and Native American populations. The authors found 62 interventions, 27 addressing hypertension, 9 lipids, 18 tobacco use, 8 physical inactivity, and 7 heart failure. Only 1 study specifically addressed postmyocardial infarction care. Data supporting the value of registries, multidisciplinary teams, and community outreach were found across several conditions. Interventions addressing care transitions, using telephonic outreach, and promoting medication access and adherence merit further exploration.

Aerobic exercise and HDL2-C: a meta-analysis of randomized controlled trials

PURPOSE

Use the meta-analytic approach to examine the effects of aerobic exercise on high-density lipoprotein two cholesterol (HDL2-C) in adults. STUDY SOURCES: (1) Computerized literature searches; (2) cross-referencing from retrieved articles; (3) hand-searching; and (4) expert review of our reference list.

STUDY SELECTION

(1) Randomized controlled trials; (2) aerobic exercise > or = 8 weeks; (3) adults > or = 18 years of age; (4) studies published in journal, dissertation, or master's thesis format; (5) studies published in the English-language between January 1, 1955 and January 1, 2003; and (6) assessment of HDL2-C in the fasting state.

DATA ABSTRACTION

All coding conducted by both authors, independent of each other. Discrepancies were resolved by consensus.

RESULTS

Nineteen randomized controlled trials representing 20 HDL2-C outcomes from 984 males and females (516 exercise, 468 control) were pooled for analysis. Using random-effects modeling and bootstrap confidence intervals (BCI), a statistically significant increase of approximately 11% was observed for HDL2-C (X +/- S.E.M., 2.6 +/- 0.9 mg/dl, 95% BCI, 1.0-4.4 mg/dl). With each study deleted from the model once, results remained statistically significant. Increases in HDL2-C were independent of decreases in body weight, body mass index (kg/m2), and percent body fat.

CONCLUSION

Aerobic exercise increases HDL2-C in adults.

Obesity and lipids

Obesity increases cardiovascular risk through multiple mechanisms. Abdominal (visceral) adiposity is metabolically active and is largely responsible for the atherogenic dyslipidemia, hyperinsulinemia, hypertension, chronic inflammatory state, and prothrombotic state that constitute the metabolic syndrome, and the subsequent increased risk for cardiovascular disease and acute coronary events. Cholesterol guidelines for assessing cardiovascular risk have traditionally focused on low-density lipoprotein (LDL) levels, and reduction of plasma LDL has been shown to reduce cardiovascular events and total mortality. However, the cardiovascular risks associated with the dyslipidemia of obesity--characterized by low levels of high-density lipoprotein; increased triglycerides; increased subfractions of small, dense LDL; and increased levels of apolipoprotein B-100--are also now well recognized.

Aerobic exercise and lipids and lipoproteins in men: a meta-analysis of randomized controlled trials

BACKGROUND: Aerobic exercise is recommended for improving lipoprotein and lipid levels which at less than their optimal levels are risk factors for cardiovascular disease. Evidence seems lacking for the effectiveness of exercise in reducing these levels, possibly due to small sizes in studies. We concluded a meta-analysis of the studies to examine the effects of aerobic exercise on lipids and lipoproteins in adult men. METHODS: Studies were retrieved via computerized literature searches, cross-referencing from retrieved articles, hand-searching, and expert review of our reference list. Inclusion criteria were randomized controlled trials, aerobic exercise ≥8 weeks, adult men ≥18 years of age, studies published in journal, dissertation, or master's thesis format, studies published in the English-language between January 1, 1955 and January 1, 2003, and assessment of one or more of the following lipids and lipoproteins: total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDLC), and triglycerides (TG). All coding was conducted by both authors, independent of each other. Discrepancies were resolved by consensus. RESULTS: Forty-nine randomized controlled trials representing up to 67 outcomes from 2,990 men (1,741 exercise, 1,249 control) were pooled for analysis. Using random-effects modeling, statistically significant improvements were observed for TC, HDL-C and TG, and a trend for decreases was observed for LDL-C. Changes were equivalent to improvements of 2% for TC and HDL-C, 3% of LDL-C, and 9% for TG. CONCLUSIONS: Aerobic exercise reduces TC and TG and increases HDL-C in men 18 years of age and older.

What is the relationship between exercise and metabolic abnormalities? A review of the metabolic syndrome

Prevention of the metabolic syndrome and treatment of its main characteristics are now considered of utmost importance in order to combat the epidemic of type 2 diabetes mellitus and to reduce the increased risk of cardiovascular disease and all-cause mortality. Insulin resistance/hyperinsulinaemia are consistently linked with a clustering of multiple clinical and subclinical metabolic risk factors. It is now widely recognised that obesity (especially abdominal fat accumulation), hyperglycaemia, dyslipidaemia and hypertension are common metabolic traits that, concurrently, constitute the distinctive insulin resistance or metabolic syndrome. Cross-sectional and prospective data provide an emerging picture of associations of both physical activity habits and cardiorespiratory fitness with the metabolic syndrome. The metabolic syndrome, is a disorder that requires aggressive multi-factorial intervention. Recent treatment guidelines have emphasised the clinical utility of diagnosis and an important treatment role for 'therapeutic lifestyle change', incorporating moderate physical activity. Several previous narrative reviews have considered exercise training as an effective treatment for insulin resistance and other components of the syndrome. However, the evidence cited has been less consistent for exercise training effects on several metabolic syndrome variables, unless combined with appropriate dietary modifications to achieve weight loss. Recently published randomised controlled trial data concerning the effects of exercise training on separate metabolic syndrome traits are evaluated within this review. Novel systematic review and meta-analysis evidence is presented indicating that supervised, long-term, moderate to moderately vigorous intensity exercise training, in the absence of therapeutic weight loss, improves the dyslipidaemic profile by raising high density lipoprotein-cholesterol and lowering triglycerides in overweight and obese adults with characteristics of the metabolic syndrome. Lifestyle interventions, including exercise and dietary-induced weight loss may improve insulin resistance and glucose tolerance in obesity states and are highly effective in preventing or delaying the onset of type 2 diabetes in individuals with impaired glucose regulation. Randomised controlled trial evidence also indicates that exercise training decreases blood pressure in overweight/obese individuals with high normal blood pressure and hypertension. These evidence-based findings continue to support recommendations that supervised or partially supervised exercise training is an important initial adjunctive step in the treatment of individuals with the metabolic syndrome. Exercise training should be considered an essential part of 'therapeutic lifestyle change' and may concurrently improve insulin resistance and the entire cluster of metabolic risk factors.

Gender differences on the risk evaluation of acute coronary syndromes: the CARDIO2000 study

Coronary heart disease (CHD) is more common in men than women. Gender differences in CHD risk may be explained by a different impact that coronary risk factors may have for men and women, in the development of CHD. Thus, the authors aimed to analyze the extent to which cardiovascular risk factors can explain the gender difference in CHD risk, at population level. During 2000-2001, 848 hospitalized patients with a first event of acute coronary syndrome and 1078 controls, paired by gender, age, and region with no evidence of overt CHD, were randomly selected from all Greek regions. Data revealed that women experiencing their first acute coronary syndrome were significantly older than men (65.3+/-8 vs. 59.7+/-10 years old; p<0.01), and that acute coronary syndrome occurred more frequently in men than women (frequency ratio 4:1, men:women). When adjusting for age, multivariate analysis revealed that both family history of premature CHD and hypercholesterolemia were associated with higher coronary risk in men than women (odds ratio [OR]=5.11 vs. 3.14; p<0.05 for family history and OR=3.77 vs. 2.19; p<0.05 for hypercholesterolemia). The presence of hypertension however, had a significantly greater effect in women than men (OR=4.86 vs. 1.66; p<0.01). Also, higher education level and the adoption of a Mediterranean diet had a more protective effect in women than men (OR=0.53 vs. 0.87; p<0.001; and OR=0.80 vs. 0.96; p<0.05, respectively). There was also evidence of a greater association between depression and higher coronary risk in women than men (OR=1.93 vs. 1.58; p<0.07). The impact of other factors (i.e., smoking, diabetes, body mass index, physical activity, alcohol consumption, and financial status), on the coronary risk difference between genders was similar for men and women. In conclusion, our findings suggest that the contribution of certain coronary risk factors to the risk for CHD is different for men and women.

The association between physical activity and the development of acute coronary syndromes in treated and untreated hypertensive subjects

The objective of this study was to evaluate the effect of physical activity on the risk of coronary events in different groups of hypertensive patients. During 2000-2001, 848 patients hospitalized for a first event of coronary heart disease and 1078 hospitalized controls without any suspicion of coronary heart disease, paired by sex and age, were randomly selected from all Greek regions. A total of 418 (49%) of the patients and 303 (28%) of the controls were classified as hypertensives, while 88 (21%) of the hypertensive patients and 88 (29%) of the hypertensive controls, reported regular leisure-time physical activity. Compared to physical inactivity, the analysis showed that light to moderate physical activity was associated with a reduction by 12% of the coronary risk in controlled hypertensive subjects (p=0.03), by 9% (p=0.04) in hypertensives who were untreated or unaware of their condition, and by 5% (p=0.087) in uncontrolled hypertensives. The practice of regular physical activity seems to be associated with lower coronary risk in various groups of hypertensives. However, these data cannot prove causality, and prospective studies will be necessary to confirm or refute the authors findings.

Exercise considerations in hypertension, obesity, and dyslipidemia

Sports medicine practitioners who care for a wide array of athletes and active individuals will consistently face issues regarding chronic cardiovascular diseases and their associated risk factors. Among these, hypertension, obesity, and dyslipidemia are common clinical conditions that may be encountered even amongst elite caliber athletes. Consequently, those entrusted with the care of this active population must recognize the presence of these disorders and feel comfortable with their management in the face of continued sports or exercise participation. This article reviews the pathophysiology of these conditions as they relate to athletes and outlines the value of continued exercise in the management of each of these entities while addressing the specific and unique treatment needs of active individuals.

Lipids, lipoproteins, and exercise

PURPOSE

Dose-response relationships between exercise training volume and blood lipid changes suggest that exercise can favorably alter blood lipids at low training volumes, although the effects may not be observable until certain exercise thresholds are met.

METHODS AND RESULTS

Plasma triglyceride reductions are often observed after exercise training regimens requiring energy expenditures similar to those characterized to increase high-density lipoprotein cholesterol (HDL-C). Thresholds established from cross-sectional and longitudinal exercise training studies indicate that 15 to 20 miles/week of brisk walking or jogging, which elicit between 1,200 to 2,200 kcals of energy expenditure per week, is associated with triglyceride reductions of 5 to 38 mg/dL and HDL-C increases of 2 to 8 mg/dL. Exercise training seldom alters total cholesterol and low-density lipoprotein cholesterol (LDL-C) unless dietary fat intake is reduced and body weight loss is associated with the exercise training program, or both. Thus, for most individuals, the positive effects of regular exercise are exerted on blood lipids at low training volumes and accrue so that noticeable differences frequently occur with energy expenditures of 1,200 to 2,200 kcals/week.

CONCLUSIONS

It appears that weekly exercise caloric expenditures that meet or exceed the higher end of this range are more likely to produce the desired lipid changes. Regarding hyperlipidemic disorders, the primary means for intervention is pharmacologic, whereas diet modification, weight loss, and exercise, although important, are viewed as adjunctive therapies. Because much is known about the exercise training-induced plasma lipid and lipoprotein modifications as well as the mechanisms responsible for these changes, rehabilitation professionals can better develop a comprehensive medical management plan that optimizes pharmacologic, reduced dietary fat intake, weight loss, and exercise interventions.

The effect of the combination of Mediterranean diet and leisure time physical activity on the risk of developing acute coronary syndromes, in hypertensive subjects

The World Health Organization reports that the number of hypertensives, worldwide, is estimated to be 600 million people. In addition a considerable proportion of hypertensive subjects remains untreated or uncontrolled. In this work we investigated the combined effect of physical activity and Mediterranean diet on coronary risk, in hypertensives. Thus we randomly selected, from all Greek regions, 848 hospitalised patients (695 males, 58 +/- 10 years old and 153 females, 65 +/- 9 years old) with a first event of coronary heart disease (CHD) and 1078 paired, by sex, age, region controls, without any suspicions for CHD. Physically active were those who reported non-occupational physical activity more than once per week. Subjects 'closer' to the Mediterranean diet were assessed through a special nutrient questionnaire. A total of 418 (49%) of the patients and 303 (28%) of the controls were hypertensive. Of these, 115 (27%) patients and 70 (23%) controls were untreated, 148 (35%)-111 (36%) were uncontrolled and 155 (38%)-122 (41%) were controlled (P-value <0.01). One hundred and sixty-two (19%) of the patients and 265 (25%) of the controls (P < 0.01) were 'closer' to the combination of Mediterranean type of diet and physical activity. The analysis showed that the previous combination is related to a 25% reduction of the coronary risk in controlled hypertensive subjects (OR = 0.75, P < 0.01), a 11% reduction in untreated (OR = 0.89, P < 0.05) and 17% reduction (OR = 0.83, P < 0.05) in uncontrolled, after adjusting for age, sex, educational and financial level and the conventional cardiovascular risk factors. Consequently, the adoption of Mediterranean diet by physically active subjects seems to reduce significantly the coronary risk and prevent, approximately, the one-third of acute CHD, in controlled hypertensive subjects.

Exercise in the treatment of lipid disorders

As a result of scientific evaluation, we know that exercise has a positive impact on the lipid and lipoprotein profile, and we have a greater understanding for the necessary amount of exercise needed to cause these changes. In the case of hyperlipidemic disorders, we know the primary means for intervention is pharmacological, and that diet, weight loss, and exercise are viewed as adjunctive therapies. Because much is known about the exercise training-induced plasma lipid and lipoprotein modifications as well as the lipoprotein enzyme changes, future research should continue to focus on the molecular basis for these changes. For example by knowing a person's apo E genotype, we gain better comprehension as to why some individuals respond to exercise, while others do not. Another area for further investigation is the assessment of drug and exercise interaction. Presently, little is known regarding the use of lipid-lowering drugs and the impact of exercise. Finally, these investigations could provide new insights for better understanding the exercise CAD protective effects. The future challenge is to better understand the impact that regular exercise participation has in optimizing the lipid and lipoprotein profile with individuals with special lipid disorders.

Health status of African Americans

The health status of African Americans identifies a higher prevalence of cardiovascular diseases, cancer, hypertension, diabetes, obesity, and sexually transmitted infections when compared with Whites. However, more research is needed to identify socioeconomic variables and to establish needed health programs. The vestiges of early 20th century traditions of substandard housing and inadequate nutrition for African Americans are still apparent in many communities today. Most health care professionals are not educated and trained to be culturally sensitive. The struggle against the prevalence of diseases in African Americans must incorporate cultural sensitivity, community organization and empowerment. The need for a universal system of health insurance coverage is of utmost importance. The elimination of health disparities among African Americans requires a national effort, the involvement of public and private sectors, individuals and communities.

Response of blood lipids to exercise training alone or combined with dietary intervention

PURPOSE

The purpose of this study is to review the effects of aerobic exercise training (AET) on blood lipids and assess dose-response relationships and diet interactions.

METHODS

We reviewed papers published over the past three decades pertaining to intervention trials on the effects of > or = 12 wk of AET on blood lipids and lipoprotein outcomes in adult men and women. Included were studies with simultaneous dietary and AET interventions, if they had appropriate comparison groups. Studies were classified by the participants' relative weights expressed as mean BMIs. Information was extracted on baseline characteristics of study subjects, including age, sex, and relative baseline cholesterol levels; details on the training programs; and the responses to training of body weight, VO(2max), and blood total cholesterol (TC) and low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein-cholesterol (HDL-C), and triglyceride (TG).

RESULTS

We identified 51 studies, 28 of which were randomized controlled trials. AET was generally performed at a moderate to hard intensity, with weekly energy expenditures ranging from 2,090 to >20,000 kJ. A marked inconsistency was observed in responsiveness of blood lipids. The most commonly observed change was an increase in HDL-C (with reductions in TC, LDL-C, and TG less frequently observed). Insufficient data are available to establish dose-response relationships between exercise intensity and volume with lipid changes. The increase in HDL-C with AET was inversely associated with its baseline level (r = -0.462), but no significant associations were found with age, sex, weekly volume of exercise, or with exercise-induced changes in body weight or VO(2max).

CONCLUSION

Moderate- to hard-intensity AET inconsistently results in an improvement in the blood lipid profile, with the data insufficient to establish dose-response relationships.

Physical activity and high density lipoprotein cholesterol levels: what is the relationship?

High density lipoprotein cholesterol (HDL-C) levels are strongly, inversely and independently associated with coronary heart disease (CHD). Increased physical activity is associated with reduced CHD mortality. This protection against CHD may partially be explained by the increase in HDL-C levels observed following aerobic exercise training. Many also agree that an exercise threshold needs to be met before such favourable changes in HDL-C metabolism can occur. Most likely, the exercise-induced changes in HDL-C are the result of the interaction amongst exercise intensity, frequency, duration of each exercise session and length of the exercise training period. Although a relative contribution of each exercise component (intensity, duration and frequency) is also likely, it has not been established. There is also substantial support for a dose-response relationship. Favourable changes in HDL-C appear to occur incrementally and reach statistical significance at approximately 7-10 miles per week or 1200 to 1600kcal. Exercise-induced changes in HDL-C may also be gender dependent. The volume of exercise required to increase HDL-C levels appears to be substantially more for women than men. This perhaps is due to higher HDL-C levels in women at baseline compared with men. However, the many other health benefits derived from increased physical activity should encourage women to participate in regular exercise regardless of the exercise effects on HDL-C levels. A practical approach in prescribing exercise for patients is to use moderate intensity exercises (70 to 80% of predicted maximal heart rate), 3 to 5 times per week, for a total of 7 to 14 miles per week. This is equivalent to approximately 1200 to 1600kcal per week. Moderate to low intensity exercise should be preferred because such exercise carries a lower risk for cardiac complications. In addition, patients are more likely to participate and sustain a lower than higher intensity exercise programme. It is also important to recognise that other modes of physical activity can also be encouraged for patients. Such activities should be associated with similar increases in HDL-C levels as long as they meet or exceed the caloric expenditure of 1200 to 1600kcal (7 to 14 miles per week of jogging).