The effect of endurance training on lipoprotein(a) [Lp(a)] levels in middle-aged males

Non-genetic influences on lipoprotein(a) concentrations

An elevated level of lipoprotein(a) [Lp(a)] is a genetically regulated, independent, causal risk factor for cardiovascular disease. However, the extensive variability in Lp(a) levels between individuals and population groups cannot be fully explained by genetic factors, emphasizing a potential role for non-genetic factors. In this review, we provide an overview of current evidence on non-genetic factors influencing Lp(a) levels with a particular focus on diet, physical activity, hormones and certain pathological conditions. Findings from randomized controlled clinical trials show that diets lower in saturated fats modestly influence Lp(a) levels and often in the opposing direction to LDL cholesterol. Results from studies on physical activity/exercise have been inconsistent, ranging from no to minimal or moderate change in Lp(a) levels, potentially modulated by age and the type, intensity, and duration of exercise modality. Hormone replacement therapy (HRT) in postmenopausal women lowers Lp(a) levels with oral being more effective than transdermal estradiol; the type of HRT, dose of estrogen and addition of progestogen do not modify the Lp(a)-lowering effect of HRT. Kidney diseases result in marked elevations in Lp(a) levels, albeit dependent on disease stages, dialysis modalities and apolipoprotein(a) phenotypes. In contrast, Lp(a) levels are reduced in liver diseases in parallel with the disease progression, although population studies have yielded conflicting results on the associations between Lp(a) levels and nonalcoholic fatty liver disease. Overall, current evidence supports a role for diet, hormones and related conditions, and liver and kidney diseases in modifying Lp(a) levels.

Lipoprotein(a) and Cardiovascular Disease Prevention across Diverse Populations

Lipoprotein(a) (Lp(a)) is a highly proatherogenic lipid fraction that is genetically determined and minimally responsive to lifestyle or behavior changes. Mendelian randomization studies have suggested a causal link between elevated Lp(a) and heart disease, stroke, and aortic stenosis. There is substantial inter-ethnic variation in Lp(a) levels, with persons of African descent having the highest median values. Monitoring of Lp(a) has historically been limited by lack of standardization of assays. With the advent of novel therapeutic modalities to lower Lp(a) levels including proprotein convertase subtilisin/kexin 9 (PCSK9) inhibitors and targeted antisense oligonucleotides, it is increasingly important to screen patients who have family or personal history of atherosclerotic cardiovascular disease for elevations in Lp(a). Further study is needed to establish a causal relationship between elevated Lp(a) and cardiovascular disease across diverse ethnic populations.

The association between physical activity, cardiorespiratory fitness, and lipoprotein(a) concentrations in a tri-ethnic sample of women: The Cross-Cultural Activity Participation Study

The purpose of this cross-sectional study was threefold: (1) to examine ethnic differences in plasma lipoprotein(a) [Lp(a)] concentrations; (2) to examine the relationship between physical activity levels (moderate, moderate-vigorous, and total MET-min/day) and Lp(a) concentrations; and (3) to determine the relationship between maximal treadmill time and Lp(a) concentrations among African-American, Native American, and Caucasian women (n = 140, ages 40-70 years: 54.5610.7). Physical activity records were kept for two 4-day periods, scheduled 1 month apart, a total of 8 days, and each activity was assigned a code from the `Compendium of physical activity'. Subjects completed a graded exercise test to determine maximal treadmill time, and a fasted blood sample was collected to quantify Lp(a) concentration. Lp(a) concentrations were negatively skewed with a geometric mean of 28.3 mg/dl (25-75%: 10.4- 43.1 mg/dl) in African-Americans (n = 47), 2.9 mg/dl (25-75%: 1.2-7.4 mg/dl) in Native Americans (n = 45), and 9.4 mg/dl (25-75%: 2.6-22.4 mg/dl) in Caucasians (n = 48). African-American women had significantly higher (p,0.05) Lp(a) concentrations than either Native Americans or Caucasians. No relationships were observed among moderate, moderate-vigorous, and total MET-min/day of physical activity, maximal treadmill time, and Lp(a) concentrations. Significant ethnic differences in Lp(a) concentrations were found, with African-American women having higher Lp(a) concentrations than Native American and Caucasian women. Lp(a) concentrations were not associated with any physical activity variables. Therefore, physical activity and maximal treadmill time did not influence Lp(a) concentrations in this tri-ethnic population of women.

Meta-Analyses of the Effects of Habitual Running on Indices of Health in Physically Inactive Adults

Background

In order to implement running to promote physical activity, it is essential to quantify the extent to which running improves health.

Objective

The aim was to summarise the literature on the effects of endurance running on biomedical indices of health in physically inactive adults.

Data Sources

Electronic searches were conducted in October 2014 on PubMed, Embase, CINAHL, SPORTDiscus, PEDro, the Cochrane Library and LILACS, with no limits of date and language of publication.

Study Selection

Randomised controlled trials (with a minimum of 8 weeks of running training) that included physically inactive but healthy adults (18–65 years) were selected. The studies needed to compare intervention (i.e. endurance running) and control (i.e. no intervention) groups.

Study Appraisal and Synthesis Methods

Two authors evaluated study eligibility, extracted data, and assessed risk of bias; a third author resolved any uncertainties. Random-effects meta-analyses were performed to summarise the estimates for length of training and sex. A dose-response analysis was performed with random-effects meta-regression in order to investigate the relationship between running characteristics and effect sizes.

Results

After screening 22,380 records, 49 articles were included, of which 35 were used to combine data on ten biomedical indices of health. On average the running programs were composed of 3.7 ± 0.9 sessions/week, 2.3 ± 1.0 h/week, 14.4 ± 5.4 km/week, at 60–90 % of the maximum heart rate, and lasted 21.5 ± 16.8 weeks. After 1 year of training, running was effective in reducing body mass by 3.3 kg [95 % confidence interval (CI) 4.1–2.5], body fat by 2.7 % (95 % CI 5.1–0.2), resting heart rate by 6.7 min⁻¹ (95 % CI 10.3–3.0) and triglycerides by 16.9 mg dl⁻¹ (95 % CI 28.1–5.6). Also, running significantly increased maximal oxygen uptake (VO_2max) by 7.1 ml min⁻¹ kg⁻¹ (95 % CI 5.0–9.1) and high-density lipoprotein (HDL) cholesterol by 3.3 mg dl⁻¹ (95 % CI 1.2–5.4). No significant effect was found for lean body mass, body mass index, total cholesterol and low-density lipoprotein cholesterol after 1 year of training. In the dose-response analysis, larger effect sizes were found for longer length of training.

Limitations

It was only possible to combine the data of ten out the 161 outcome measures identified. Lack of information on training characteristics precluded a multivariate model in the dose-response analysis.

Conclusions

Endurance running was effective in providing substantial beneficial effects on body mass, body fat, resting heart rate, VO_2max, triglycerides and HDL cholesterol in physically inactive adults. The longer the length of training, the larger the achieved health benefits. Clinicians and health authorities can use this information to advise individuals to run, and to support policies towards investing in running programs.

Electronic supplementary material

The online version of this article (doi:10.1007/s40279-015-0359-y) contains supplementary material, which is available to authorized users.

Lipoprotein (a): impact by ethnicity and environmental and medical conditions

Levels of lipoprotein (a) [Lp(a)], a complex between an LDL-like lipid moiety containing one copy of apoB, and apo(a), a plasminogen-derived carbohydrate-rich hydrophilic protein, are primarily genetically regulated. Although stable intra-individually, Lp(a) levels have a skewed distribution inter-individually and are strongly impacted by a size polymorphism of the LPA gene, resulting in a variable number of kringle IV (KIV) units, a key motif of apo(a). The variation in KIV units is a strong predictor of plasma Lp(a) levels resulting in stable plasma levels across the lifespan. Studies have demonstrated pronounced differences across ethnicities with regard to Lp(a) levels and some of this difference, but not all of it, can be explained by genetic variations across ethnic groups. Increasing evidence suggests that age, sex, and hormonal impact may have a modest modulatory influence on Lp(a) levels. Among clinical conditions, Lp(a) levels are reported to be affected by kidney and liver diseases.

Associations of Low-Intensity Resistance Training with Body Composition and Lipid Profile in Obese Patients with Type 2 Diabetes

Resistance training to increase muscle mass and functional capacity is an integral part of diet and exercise programs for the management of obesity and type 2 diabetes. Low-intensity resistance training with slow movement and tonic force generation (LST) may be a practical and safe regimen for elderly obese individuals but the health benefits are uncertain. This study investigated the effects of LST on body composition and metabolic parameters in obese patients with type 2 diabetes. Twenty-six obese patients with type 2 diabetes engaged in LST training during hospitalization and were advised to maintain this regimen for 12 weeks after discharge. We compared lipid profile, arterial stiffness, and body composition before and after LST training. After 12 weeks of LST training, the ratio of lower extremity muscle mass to body weight increased significantly (0.176 ± 0.028 to 0.184 ± 0.023, mean ± SD), while body fat mass and body fat percentage decreased significantly (36.2 ± 10.9 kg to 34.3 ± 9.4 kg and 41.2 ± 8.6% to 40.1 ± 7.7%, respectively). Moreover, high-density lipoprotein cholesterol was significantly increased (42.2 ± 14 mg/dl to 46.3 ± 12.4 mg/dl) and both free fatty acids and lipoprotein(a) were decreased (665.2 ± 212.1 μEq/l to 525.4 ± 231.3 μEq/l and 15.4 ± 18 mg/dl to 13.8 ± 18 mg/dl, respectively). No significant change was observed in arterial stiffness. Although this study was a non-controlled investigation and some confounding factors including dietary intake, medication and compliance with training might affect the study result, a brief (12-week) LST training program may be a safe and effective strategy for the management of obesity and type 2 diabetes.

An elevated level of physical activity is associated with normal lipoprotein(a) levels in individuals from Maracaibo, Venezuela

Coronary artery disease is the main cause of death worldwide. Lipoprotein(a) [Lp(a)], is an independent risk factor for coronary artery disease in which concentrations are genetically regulated. Contradictory results have been published about physical activity influence on Lp(a) concentration. This research aimed to determine associations between different physical activity levels and Lp(a) concentration. A descriptive and cross-sectional study was made in 1340 randomly selected subjects (males = 598; females = 712) to whom a complete clinical history, the International Physical Activity Questionnaire, and Lp(a) level determination were made. Statistical analysis was carried out to assess qualitative variables relationship by chi2 and differences between means by one-way analysis of variance considering a P value <0.05 as statistically significant. Results are shown as absolute frequencies, percentages, and mean +/- standard deviation according to case. Physical activity levels were ordinal classified as follows: low activity with 24.3% (n = 318), moderate activity with 35.0% (n = 458), and high physical activity with 40.8% (n = 534). Lp(a) concentration in the studied sample was 26.28 +/- 12.64 (IC: 25.59-26.96) mg/dL. Lp(a) concentration according to low, moderate, and high physical activity levels were 29.22 +/- 13.74, 26.27 +/- 12.91, and 24.53 +/- 11.35 mg/dL, respectively, observing statistically significant differences between low and moderate level (P = 0.004) and low and high level (P < 0.001). A strong association (chi2 = 9.771; P = 0.002) was observed among a high physical activity level and a normal concentration of Lp(a) (less than 30 mg/dL). A lifestyle characterized by high physical activity is associated with normal Lp(a) levels.

Minor changes in blood lipids after 6 weeks of high-volume low- intensity physical activity with strict energy balance control

Physical activity has been shown to favorably affect metabolic risk markers, including blood lipids. The impact of high-energy turnover, without influencing the traditionally used markers of exercise training effects, on blood lipids is still unclear. The aim was to study the effect of high-volume low-intensity physical activity on the blood lipid pattern, with a tight control of diet and energy balance. Eight untrained men [42.5 (12.1) years, body mass index 24.2 (2.8) kg m(-2)] were tested in two different 6-week protocols. In the sedentary protocol, the subjects were instructed to limit their everyday physical activity. In the activity protocol, a 2-h physical activity bout was performed 5 days week(-1) (approximately 40% of VO(2max); equivalent of an additional 21 MJ week(-1) in energy expenditure). The diet for both protocols comprised approximately 40 energy percent (E%) fat, approximately 50 E% carbohydrates (CHO). The polyunsaturated fatty acids to saturated fatty acids ratio of the diet was approximately 0.12. There were no changes during each 6-week period or differences between the two protocols in body weight, body composition or aerobic capacity. Low-intensity physical activity did not affect lipid parameters substantially, except for a slightly lower Apo-B/Apo-A1 ratio with the activity protocol (P < 0.05). Total and low-density lipoprotein cholesterol, as well as Apo-B and Apo-A1, were increased during the beginning of each 6-week period (P < 0.05), but returned to basal levels by the sixth week. In conclusion, 6 weeks of high-volume low-intensity physical activity did not affect blood lipids substantially.

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.

Response of Blood Lipids to Physical Exercise in Elderly Subjects

Regular physical activity plays an important role in nonpharmacologic management of hyperlipidemia, in both the primary and secondary prevention of coronary heart disease. Training intensity and duration, health status (especially the presence of cardiovascular disease), and concomitant changes in body mass and dietary habits are the most important factors that can modify the physical activity-blood lipid profile relationship in the elderly. The benefit of regular exercise goes beyond direct influence on blood lipids; it aids in reducing weight, decreasing fat mass, increasing lean body mass, reducing elevated blood pressure, and increasing insulin sensitivity. Regular physical activity has become widely recommended as an important element of healthy and successful aging and should be encouraged in individuals without contraindications. (c)2001 CHF, Inc.

Effects of short-duration and long-duration exercise on lipoprotein(a)

PURPOSE

Most studies that use either a single exercise session, exercise training, or a cross-sectional design have failed to find a relationship between exercise and plasma lipoprotein(a) [Lp(a)] concentrations. However, a few studies investigating the effects of longer and/or more strenuous exercise have shown elevated Lp(a) concentrations, possibly as an acute-phase reactant to muscle damage. Based on the assumption that greater muscle damage would occur with exercise of longer duration, the purpose of the present study was to determine whether exercise of longer duration would increase Lp(a) concentration and creatine kinase (CK) activity more than exercise of shorter duration.

METHODS

Ten endurance-trained men (mean +/- SD: age, 27 +/- 6 yr; maximal oxygen consumption [VO(2max)], 57 +/- 7 mL x kg(-1) x min(-1)) completed two separate exercise sessions at 70% VO(2max). One session required 800 kcal of energy expenditure (60 +/- 6 min), and the other required 1500 kcal (112 +/- 12 min). Fasted blood samples were taken immediately before (0-pre), immediately after (0-post), 1 d after (1-post), and 2 d after (2-post) each exercise session.

RESULTS

CK activity increased after both exercise sessions (mean +/- SE; 800 kcal: 0-pre 55 +/- 11, 1-post 168 +/- 64 U x L(-1) x min(-1); 1500 kcal: 0-pre 51 +/- 5, 1-post 187 +/- 30, 2-post 123 +/- 19 U x L(-1) x min(-1); P < 0.05). However, median Lp(a) concentrations were not altered by either exercise session (800 kcal: 0-pre 5.0 mg x dL(-1), 0-post 3.2 mg x dL(-1), 1-post 4.0 mg x dL(-1), 2-post 3.4 mg x dL(-1); 1500 kcal: 0-pre 5.8 mg x dL(-1), 0-post 4.3 mg x dL(-1), 1-post 3.2 mg x dL(-1), 2-post 5.3 mg x dL(-1)). In addition, no relationship existed between exercise-induced changes in CK activity and Lp(a) concentration (800 kcal: r = -0.26; 1500 kcal: r = -0.02).

CONCLUSION

These results suggest that plasma Lp(a) concentration will not increase in response to minor exercise-induced muscle damage in endurance-trained runners.

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.

Effect of physical exercise on lipoprotein(a) and low-density lipoprotein modifications in type 1 and type 2 diabetic patients

To evaluate the effect of physical exercise on blood pressure, the lipid profile, lipoprotein(a) (Lp(a)), and low-density lipoprotein (LDL) modifications in untrained diabetics, 27 diabetic patients (14 type 1 and 13 type 2) under acceptable and stable glycemic control were studied before and after a supervised 3-month physical exercise program. Anthropometric parameters, insulin requirements, blood pressure, the lipid profile, Lp(a), LDL composition, size, and susceptibility to oxidation, and the proportion of electronegative LDL (LDL(-)) were measured. After 3 months of physical exercise, physical fitness improved (maximal O2 consumption [VO2max], 29.6 +/- 6.8 v 33.0 +/- 8.4 mL/kg/min, P < .01). The body mass index (BMI) did not change, but the waist circumference (83.2 +/- 11.8 to 81.4 +/- 11.2 cm, P < .05) decreased significantly. An increase in the subscapular to triceps skinfold ratio (0.91 +/- 0.37 v 1.12 +/- 0.47 cm, P < .01) and midarm muscle circumference ([MMC], 23.1 +/- 3.4 v 24.4 +/- 3.7 cm, P < .001) were observed after exercise. Insulin requirements (0.40 +/- 0.18 v 0.31 +/- 0.19 U/kg/d, P < .05) and diastolic blood pressure (80.2 +/- 10 v 73.8 +/- 5 mm Hg, P < .01) decreased in type 2 diabetic patients. High-density lipoprotein cholesterol (HDL-C) increased in type 1 patients (1.48 +/- 0.45 v1.66 +/- 0.6 mmol/L, P < .05), while LDL cholesterol (LDL-C) decreased in type 2 patients (3.6 +/- 1.0 v3.4 +/- 0.9 mmol/L, P < .01). Although Lp(a) levels did not vary in the whole group, a significant decrease was noted in patients with baseline Lp(a) above 300 mg/L (mean decrease, -13%). A relationship between baseline Lp(a) and the change in Lp(a) (r = -.718, P < .0001) was also observed. After the exercise program, 3 of 4 patients with LDL phenotype B changed to LDL phenotype A, and the proportion of LDL(-) tended to decrease (16.5% +/- 7.4% v 14.0% +/- 5.1%, P = .06). No changes were observed for LDL composition or susceptibility to oxidation. In addition to its known beneficial effects on the classic cardiovascular risk factors, regular physical exercise may reduce the risk of cardiovascular disease in diabetic patients by reducing Lp(a) levels in those with elevated Lp(a) and producing favorable qualitative LDL modifications.

The relation between bone mineral density, insulin-like growth factor I, lipoprotein (a), body composition, and muscle strength in adolescent males

Osteoporosis is the most common metabolic bone disease. A low peak bone mass is regarded a risk factor for osteoporosis. Heredity, physical activity, and nutrition are regarded important measures for the observed variance in peak bone mass. Lp(a) lipoprotein is a well-known risk factor for atherosclerosis. Serum insulin-like growth factor I (IGF-I) has been found to be increased in males with early cardiovascular disease. In this study, we evaluated the association between bone mass, body constitution, muscle strength, Lp(a), and IGF-I in 47 Caucasian male adolescents (mean age, 16.9 yr). Bone mineral density (BMD) and body composition were measured by dual x-ray absorptiometry, muscle strength of thigh using an isokinetic dynamometer, IGF-I by RIA, and Lp(a) by enzyme-linked immunosorbent assay. IGF-I was only associated with Lp(a) (r = 0.38, P < 0.01). Lp(a) was related to total body (r = 0.40, P < 0.01), skull (r = 0.45, P < 0.01), and femoral neck BMD (r = 0.44, P < 0.01). Lp(a) was also related to fat mass (r = 0.34, P < 0.05) and muscle strength (r = 0.30-0.42, P < 0.05). After multiple regression and principal component (PC) analysis, the so-called PC body size (weight, fat mass, lean body mass, and muscle strength) was the most significant predictor of BMD (beta = 0.28-0.51, P < 0.05-0.01), followed by the so-called PC physical activity (beta = 0.28-0.38, P < 0.05-0.01, weight-bearing locations). However, the PC analysis confirmed that Lp(a) was an independent predictor of total body, skull, and femoral neck BMD (beta = 0.33-0.36, P < 0.01). The present investigation confirms that BMD, body size, and muscle strength are closely related and that the level of physical activity is a major determinant of BMD. However, the positive relation of Lp(a), a major risk factor for cardiovascular disease, to BMD has not previously been described. The importance of this observation has to be further investigated.

Relationship of physical activity and fitness to lipid and lipoprotein (a) in elderly subjects

PURPOSE

To determine, both by a cross-sectional and longitudinal study design, the relationship of maximal oxygen consumption (VO2max) and physical activity (PA) to blood lipids and lipoprotein(a) [Lp(a)] in a population of healthy and weight-stable elderly volunteers aged 66-84 yr.

METHODS

In a cross-sectional study in 52 subjects (23 men and 29 women), all independent variables (age, anthropometric, VO2max, and PA indices) were used in a multiple stepwise regression analysis to select variables influencing lipid and lipoprotein parameters. In a prospective nonintervention study, 38 subjects (17 men and 21 women) were reexamined after 6 months.

RESULTS

In a cross-sectional study, sports activity index contributed significantly to total cholesterol (TC), low density lipoprotein (LDL) cholesterol (LDL-C), TC/high density lipoprotein (HDL) cholesterol (HDL-C) ratio, and LDL-C/HDL-C ratio variance in men, whereas VO2max accounted for 23% variance of apolipoprotein A-I in women. In a prospective study, there was no indication that any measured variable was correlated with absolute or relative changes in PA indices in the total group or when analyzed by gender.

CONCLUSIONS

These data confirm that favorable relationship between PA/fitness and blood lipid profile is visible in elderly people but spontaneous changes in habitual PA are not a sufficient stimulus to alter serum lipid and lipoprotein levels in this population. Furthermore, there is no direct association between Lp(a) levels and PA, fitness, or body composition in the elderly men and women.

Effects of exercise on lipoprotein(a)

Lipoprotein(a) [Lp(a)] is a unique lipoprotein complex in the blood. At high levels (> 30 mg/dl), Lp(a) is considered an independent risk factor for cardiovascular diseases. Serum Lp(a) levels are largely genetically determined, remain relatively constant within a given individual, and do not appear to be altered by factors known to influence other lipoproteins (e.g. lipid-lowering drugs, dietary modification and change in body mass). Since regular exercise is associated with favourable changes in lipoproteins in the blood, recent attention has focused on whether serum Lp(a) levels are also influenced by physical activity. Population and cross-sectional studies consistently show a lack of association between serum Lp(a) levels and regular moderate physical activity. Moreover, exercise intervention studies extending from 12 weeks to 4 years indicate that serum Lp(a) levels do not change in response to moderate exercise training, despite improvements in fitness level and other lipoprotein levels in the blood. However, recent studies suggest the possibility that serum Lp(a) levels may increase in response to intense load-bearing exercise training, such as distance running or weight lifting, over several months to years. Cross-sectional studies have reported abnormally high serum Lp(a) levels in experienced distance runners and body builders who train for 2 to 3 hours each day. However, the possible confounding influence of racial or ethnic factors in these studies cannot be discounted. Recent intervention studies also suggest that 9 to 12 months of intense exercise training may elevate serum Lp(a) levels. However, these changes are generally modest (10 to 15%) and, in most individuals, serum Lp(a) levels remain within the recommended range. It is unclear whether increased serum Lp(a) levels after intense exercise training are of clinical relevance, and whether certain Lp(a) isoforms are more sensitive to the effects of exercise training. Since elevation of both low density lipoprotein cholesterol (LDL-C) and Lp(a) levels in the blood exerts a synergistic effect on cardiovascular disease risk, attention should focus on changing lifestyle factors to decrease LDL-C (e.g. dietary intervention) and increase high density lipoprotein cholesterol (e.g. exercise) levels in the blood.

Ethnicity effect on the serum lipid profile in persons with spinal cord injury

OBJECTIVE

The potential effect of ethnicity on the serum lipid profile and lipoprotein(a) [Lp(a)] was studied in a population with chronic spinal cord injury (SCI).

STUDY DESIGN

The distribution and correlates of high density lipoprotein (HDL) cholesterol and Lp(a) were studied in a population of 600 subjects with chronic SCI.

RESULTS

Mean +/- SEM serum HDL cholesterol was significantly higher in the African American group than in the white and Latino groups (47 +/- 1 vs 40 +/- 1 and 38 +/- 1 mg/dL, p < .0001, respectively). The African American group had a lower serum total to HDL cholesterol ratio than white and Latino groups (4.46 +/- .153 vs 5.18 +/- .168 and 5.40 +/- .140 mg/dL, p < .01, respectively). Mean serum Lp(a) levels were significantly higher in the African American group than in Latino or white groups (29 +/- 2 vs 18 +/- 1 and 15 +/- 1 mg/dL, p < .0001, respectively). Age, duration of SCI, and level and completeness of lesion had no significant effect on serum Lp(a) level.

CONCLUSIONS

In a population with chronic SCI, those in the African American group had the highest serum HDL cholesterol concentrations, the lowest serum total to HDL cholesterol ratios, and elevated levels of serum Lp(a) compared with the Latino and white groups. In a population of individuals with chronic SCI, ethnicity was shown to have a major effect on serum lipids and may be used to assist in the determination of cardiovascular risk.

Effects of physical activity and diet on lipoprotein(a)

Lipoprotein(a) [Lp(a)] represents a class of lipoproteins with some structural similarity to low density lipoprotein (LDL), but containing a unique apoprotein, apoprotein(a). First reported in 1963, Lp(a) is now considered to have an independent role in the development of atherosclerotic lesions. The level of Lp(a) in the blood is under strong genetic influence and does not appear to be alterable by lifestyle factors known to influence other lipoproteins. Regular moderate exercise has been shown to favorably alter other lipoproteins, and recent attention has focused on whether Lp(a) level can be influenced by physical activity. Current data from cross-sectional and intervention studies show little effect of moderate exercise on serum Lp(a) concentration. One possible exception may be an elevation of serum Lp(a) concentration in adult endurance and power athletes who exercise intensely on a daily basis. However, not all studies have taken into account possible racial or ethnic differences in Lp(a) concentrations and the skewed distribution observed within most populations. Standard dietary intervention such as a low fat diet recommended for weight loss and control of other blood lipids has little effect on serum Lp(a) level. At present, serum Lp(a) concentration does not appear to be significantly altered by realistic dietary changes and moderate physical activity as recommended for health. The synergistic effect on cardiovascular disease risk when both LDL-cholesterol and Lp(a) are elevated highlight the importance of attending to those risk factors that can be modified by exercise and other lifestyle changes.

Influence of fitness status on very-low-density lipoprotein subfractions and lipoprotein(a) in men and women

The purpose of this study was to examine the influence of the physical activity level of men and women on the very-low-density lipoprotein (VLDL) subfractions and lipoprotein(a) [Lp(a)]. Fifty-four men (n = 30) and women (n = 24) aged 30 to 53 years were recruited based on their level of activity over the past 2 years, and formed three groups: sedentary (S), no routine activity; recreational exercise (R), routine moderate exercise three to five times per week; and trained (T), competition-based, high-volume aerobic training five to seven times per week. Each subject underwent a maximal oxygen consumption (VO2max) test and was measured for body composition (skinfolds) and waist to hip ratio (WHR). Following a prescribed 24-hour diet and abstinence from activity, a blood sample was obtained from each subject and the plasma was analyzed for cholesterol and triglycerides (TGs) in VLDL1, VLDL2, and VLDL3 subfractions. High-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and Lp(a) also were analyzed. Total VLDL-C was higher in men than in women, but no gender differences were observed in VLDL subfractions. VLDL1-TG and VLDL2-TG were elevated in the S group compared with groups R and T, even though total VLDL-TG, LDL-C, and HDL-C values were not different among the groups. Values for Lp(a) were not significantly different between men and women or among the groups. The two exercising groups were not different on any lipoprotein variable or WHR. VLDL1-TG was inversely correlated with VO2max and HDL-C. These results suggest that life-style activity is associated with a favorable VLDL subfraction pattern and WHR, but not Lp(a). In addition, long-term recreational activity is associated with a lipoprotein profile and WHR similar to those obtained with higher-volume exercise training.

Acute effects of treadmill running on lipoprotein(a) levels in males and females

This investigation examined the acute response of serum lipoprotein(a) (Lp(a)) concentration immediately after, and during several days following, level and downhill motorized treadmill running. Eight males ran for 1 h on a level motorized treadmill at an intensity producing 90% maximum heart rate (MHR). On a separate occasion, three males and three females performed downhill (negative 13.4% incline) treadmill running at an intensity producing 75-80% MHR. For both protocols, serial blood samples were taken pre- and post-exercise and at the same time of day 1, 3, 5, and 7 days following exercise. Levels of Lp(a), creatine kinase (CK), C-reactive protein (CRP), and ferritin were measured. Repeated measures statistical analysis (Friedman ANOVA) showed no significant change in the median level of Lp(a) (level run, 5.0 mg.dl-1; downhill run, 7.45 mg.dl-1) across time following either protocol. After level running, ferritin levels 5 and 7 d post-exercise were significantly (P < 0.05) lower compared with immediately and 1 d post-exercise measures (Friedman ANOVA). Following level running, the Wilcoxon signed rank test showed significant (P < 0.05) elevations in CK levels immediately, 1 and 5 d post-exercise compared with pre-exercise values. Following downhill running. CK level was significantly elevated up to 3 d post-exercise (Wilcoxon signed rank). Calculated plasma volume did not change significantly following either protocol. These data suggest that Lp(a) does not change acutely in response to level or downhill treadmill running up to 60 min duration.

Effect of a single session of exercise on lipoprotein(a)

Lipoprotein(a) (Lp(a)) is bound to apolipoprotein B-100 by disulfide linkage and is associated in the upper density range of low density lipoprotein cholesterol. Persons with elevated concentrations of Lp(a) are regarded as having an increased risk for premature coronary artery disease. Although many studies exist evaluating the effects of a single session of exercise on lipids and lipoproteins, little information is available concerning the effects of exercise on Lp(a). Therefore, the purpose of this study was to determine the effects of a single exercise session on plasma Lp(a). Twelve physically active men completed two 30-min submaximal treadmill exercise sessions: low intensity (LI, 50% VO2max) and high intensity (HI, 80% VO2max). Blood samples were obtained immediately before and after exercise. Total cholesterol (LI: before 4.22 +/- 0.26, after 4.24 +/- 0.28; HI: before 4.24 +/- 0.31, after 4.11 +/- 0.28 mmol.l-1, mean +/- SE) and triglyceride (LI: before 1.14 +/- 0.16, after 1.06 +/- 0.16; HI: before 1.12 +/- 0.19, after 1.21 +/- 0.19 mmol.l-1) concentrations did not differ immediately after either exercise session, nor did Lp(a) concentrations differ immediately after either exercise session (LI: before 4.1 +/- 2.2, after 4.0 +/- 2.1: HI: before 3.9 +/- 2.2, after 3.7 +/- 2.0 mg.dl-1). These results suggest that neither a low nor a high intensity exercise session lasting 30 min in duration has an immediate effect on plasma Lp(a).