Cardiorespiratory Fitness and Risk of Sudden Cardiac Death in Men and Women in the United States: A Prospective Evaluation From the Aerobics Center Longitudinal Study

OBJECTIVES

To examine the relation between cardiorespiratory fitness (CRF) and sudden cardiac death (SCD) in a large US adult population and to study the effects of hypertension, obesity, and health status on the relation of CRF with SCD.

PATIENTS AND METHODS

A total of 55,456 individuals (mean age, 44.2 years; 13,507 women) from the Aerobics Center Longitudinal Study, a prospective observational investigation (from January 2, 1974, through December 31, 2002), were included. Cardiorespiratory fitness was assessed by a maximal treadmill test, and baseline assessment included an extensive set of measurements.

RESULTS

There were 109 SCDs. An inverse risk of SCD was found across incremental CRF levels after adjusting for potential confounders. Participants with moderate and high CRF levels had 44% (hazard ratio, 0.56; 95% CI, 0.35-0.90) and 48% (hazard ratio, 0.52; 95% CI, 0.30-0.92) significantly lower risk of SCD, respectively, than did those with low CRF levels (P<.001). The risk of SCD decreased by 14% (hazard ratio, 0.86; 95% CI, 0.77-0.96) per 1-metabolic equivalent increase in the fully adjusted model. Hypertensive, overweight, or unhealthy individuals with moderate to high CRF levels had lower risks of SCD (ranging from 58% to 72% of lower risk) than did those with the same medical conditions and low CRF levels.

CONCLUSION

The risk of SCD in US men and women could be partially reduced by ensuring moderate to high levels of CRF independently of other risk factors and especially in those who are hypertensive, overweight, or unhealthy.

A Fit-Fat Index for Predicting Incident Diabetes in Apparently Healthy Men: A Prospective Cohort Study

Background

The purpose of this study was to examine the impact of combined cardiorespiratory fitness and waist-to-height ratio in the form of a fit-fat index on incident diabetes risk. Additionally, the independent predictive performance of cardiorespiratory fitness, waist-to-height ratio, and body mass index also were estimated and compared.

Methods

This was a prospective cohort study of 10,381 men who had a normal electrocardiogram and no history of major chronic disease at baseline from 1979 to 2005. Random survival forest models and traditional Cox proportional hazards models were used to predict diabetes at 5-, 10-, and 15-year incidence horizons.

Results

Overall, 4.8% of the participants developed diabetes. Receiver operating characteristic curve analyses for incidence risk demonstrated good discrimination using random survival forest models across fitness and fatness measures; Cox models were poor to fair. The differences between fitness and fatness measures across horizons were clinically negligible. Smoothed random survival forest estimates demonstrated the impact of each fitness and fatness measure on incident diabetes was intuitive and graded.

Conclusions

Although fitness and fatness measures showed a similar discriminative ability in predicting incident diabetes, unique to the study was the ability of the fit-fat index to demonstrate a better indication of incident risk when compared to fitness or fatness alone. A single index combining cardiorespiratory fitness and waist-to-height ratio may be more useful because it can indicate improvements in either or both of the measures.

MiR-18a upregulation decreases Dicer expression and confers paclitaxel resistance in triple negative breast cancer

OBJECTIVE

MiR-18a is a miRNA that is aberrantly overexpressed in triple-negative breast cancer (TNBC). However, its biophysical function in TNBC is still not clear. In this study, we investigated the association among miR-18a dysregulation, Dicer dysregulation and paclitaxel (PTX) resistance in TNBC cells.

PATIENTS AND METHODS

20 TNBC patients who received neoadjuvant chemotherapy before surgery were recruited. MiR-18a expression was quantified using QRT-PCR. The effects of miR-18a overexpression or knockdown on cell viability and apoptosis of PTX sensitive MDA-MB-231 cells and PTX resistant MDA-MB-231 cells after PTX treatment were studied. The influence of miR-18a overexpression on Dicer expression was measured by qRT-PCR and Western blot analysis.

RESULTS

Tissues from patients with stable disease (SD, n = 5) and progressive disease (PD, n = 2) to paclitaxel (PTX) containing neoadjuvant chemotherapy had significantly higher miR-18a expression than that from patients with partial response (PR, n = 13). MDA-MB-231/PTX cells had higher miR-18a expression than MDA-MB-231 cells. MiR-18a overexpression directly led to Dicer repression at mRNA and protein level. MiR-18a overexpression significantly increased PTX IC50 and reduced PTX induced cell apoptosis, while miR-18a suppression substantially decreased PTX IC50 and increased PTX induced cell apoptosis.

CONCLUSIONS

This study found that miR-18a is an important miRNA that suppresses Dicer expression and increases PTX resistance in TNBC cells.

Addition of Cardiorespiratory Fitness Within an Obesity Risk Classification Model Identifies Men at Increased Risk of All-Cause Mortality

OBJECTIVE

Guidelines for identification of obesity-related risk which stratify disease risk using specific combinations of body mass index and waist circumference. Whether the addition of cardiorespiratory fitness, an independent predictor of disease risk, provides better risk prediction of all-cause mortality within current body mass index and waist circumference categories is unknown. The study objective was to determine whether the addition of cardiorespiratory fitness improves prediction of all-cause mortality risk classified by the combination of body mass index and waist circumference.

METHODS

We performed a prospective observational study using data from the Aerobics Center Longitudinal Study. A total of 31,267 men (mean age, 43.9 years; standard deviation, 9.4 years) who completed a baseline medical examination between 1974 and 2002 were included. The main outcome measure was all-cause mortality. Participants were grouped using body mass index- and waist circumference-specific threshold combinations: normal body mass index: 18.5 to 24.9 kg/m(2), waist circumference threshold of 90 cm; overweight body mass index: 25.0 to 29.9 kg/m(2), waist circumference threshold of 100 cm, and obese body mass index: 30.0 to 34.9 kg/m(2), waist circumference threshold of 110 cm. Participants were classified using cardiorespiratory fitness as unfit or fit, where unfit was the lowest fifth of the age-specified distribution of maximal exercise test time on the treadmill among the entire Aerobics Center Longitudinal Study population.

RESULTS

A total of 1399 deaths occurred over a follow-up of 14.1 ± 7.4 years, for a total of 439,991 person-years of observation. Men who were unfit and had normal body mass index with waist circumference <90 cm and ≥90 cm had 95% (hazard ratio [HR], 1.95; 95% confidence interval [CI], 1.34-2.83) and 163% (HR, 2.63; 95% CI, 1.58-4.40) higher mortality risk than men who were fit, respectively (P <.05). Men who were unfit and overweight had 41% (HR, 1.41; 95% CI, 1.04-1.90) higher mortality risk with a waist circumference <100 cm (P <.05), but were at no greater risk (HR, 1.30; 95% CI, 0.92-1.84) if their waist circumference was ≥100 cm (P = .14). Men who were unfit and obese were not at increased mortality risk (HR, 1.37; 95% CI, 0.90-2.09) with a waist circumference <110 cm (P = .14), but were at 111% (HR, 2.11; 95% CI, 1.31-3.42) increased risk with a waist circumference ≥110 cm (P <.05).

CONCLUSIONS

For most of the body mass index and waist circumference categories, inclusion of cardiorespiratory fitness allowed for improved identification of men at increased mortality risk.

Body Mass Index, the Most Widely Used But Also Widely Criticized Index: Would a Criterion Standard Measure of Total Body Fat Be a Better Predictor of Cardiovascular Disease Mortality?

OBJECTIVES

To examine whether an accurate measure (using a criterion standard method) of total body fat would be a better predictor of cardiovascular disease (CVD) mortality than body mass index (BMI).

PARTICIPANTS AND METHODS

A total of 60,335 participants were examined between January 1, 1979, and December 31, 2003, and then followed-up for a mean follow-up period of 15.2 years. Body mass index was estimated using standard procedures. Body composition indices (ie, body fat percentage [BF%], fat mass index [FMI], fat-free mass [FFM], and FFM index [FFMI]) were derived from either skinfold thicknesses or hydrostatic weighing. For exact comparisons, the indices studied were categorized identically using sex-specific percentiles.

RESULTS

Compared with a medium BMI, a very high BMI was associated with a hazard ratio (HR) of 2.7 (95% CI, 2.1-3.3) for CVD mortality, which was a stronger association than for BF% or FMI (ie, HR, 1.6; 95% CI, 1.3-1.9 and HR, 2.2; 95% CI, 1.8-2.7, respectively). Compared with a medium FFMI, a very high FFMI was associated with an HR of 2.2 (95% CI, 1.7-2.7) for CVD mortality, with these estimates being markedly smaller for FFM (ie, HR, 1.2; 95% CI, 0.9-1.6). When the analyses were restricted only to the sample assessed with hydrostatic weighing (N=29,959, 51.7%), the results were similar, with even slightly larger differences in favor of BMI (ie, HR, 3.0; 95% CI, 2.2-4.0) compared with BF% and FMI (ie, HR, 1.5; 95% CI, 1.2-1.9 and HR, 2.1; 95% CI, 1.6-2.7, respectively). We estimated Harrell's c-index as an indicator of discriminating/predictive ability of these models and observed that the c-index for models including BMI was significantly higher than that for models including BF% or FMI (P<.005 for all).

CONCLUSION

The simple and inexpensive measure of BMI can be as clinically important as, or even more than, total adiposity measures assessed using accurate, complex, and expensive methods. Physiological explanations for these findings are discussed.

Decline in cardiorespiratory fitness and odds of incident sleep complaints

PURPOSE

To examine longitudinal change in cardiorespiratory fitness and odds of incident sleep problems.

METHODS

A cohort of 7368 men and 1155 women, age 20-85 yr, was recruited from the Aerobics Center Longitudinal Study. The cohort did not complain of sleep problems, depression, or anxiety at their first clinic visit. Cardiorespiratory fitness assessed at four clinic visits between 1971 and 2006, each separated by an average of 2-3 yr, was used as a proxy measure of cumulative physical activity exposure. Sleep complaints were made to a physician during follow-up.

RESULTS

Across visits, there were 784 incident cases of sleep complaints in men and 207 cases in women. After adjusting for age, time between visits, body mass index, smoking, alcohol use, chronic medical conditions, complaints of depression or anxiety at each visit, and fitness at visit 1, each minute of decline in treadmill endurance (i.e., a decline in cardiorespiratory fitness of approximately 0.5 MET) between the ages of 51 and 56 yr increased the odds of incident sleep complaints by 1.7% (range = 1.0%-2.4%) in men and by 1.3% (range = 0.0%-2.8%) in women. Odds were ∼8% higher per minute decline in people with sleep complaints at visits 2 and 3.

CONCLUSIONS

The results indicate that maintenance of cardiorespiratory fitness during middle age, when decline in fitness typically accelerates and risk of sleep problems is elevated, helps protect against the onset of sleep complaints made to a physician.

Relation of Body's Lean Mass, Fat Mass, and Body Mass Index With Submaximal Systolic Blood Pressure in Young Adult Men

We examined the association of body composition and body mass index (BMI) with submaximal systolic blood pressure (SSBP) among young adult men. The analysis included 211 men with BMI between 20 and 35 kg/m(2). Total lean mass and fat mass were measured using dual x-ray absorptiometry and lean mass percentage was calculated from the total lean mass. Fat mass index (FMI) and BMI were calculated using height and weight (total fat mass and total weight, respectively) measurements. SSBP was measured at each stage of a graded exercise test. Quintiles of lean mass percentage, FMI, and BMI were created with quintile 1 the lowest and quintile 5 the highest lean mass percentage, FMI, and BMI. Compared with men in lean mass percentage quintile 1, those in quintiles 2, 3, and 4 had significantly lower SSBP, whereas there was no significant difference in SSBP between quintile 1 and 5 at 6, 8, and 10 minutes. Compared with men in FMI quintile 5, those in quintiles 2, 3, and 4 had significantly lower SSBP, whereas there was no significant difference in SSBP between quintile 1 and 5. SSBP among men in lean mass percentage quintile 5 and FMI quintile 1 were still less than lean mass percentage quintile 1 and FMI quintile 5, respectively. There were no significant differences in SSBP across BMI quintiles 1 to 4 but a significantly higher SSBP in quintile 5 compared with quintiles 1 to 4. In conclusion, there was a J-curve pattern between SSBP and components of body composition, whereas, a linear relation between SSBP and BMI.

Cardiorespiratory Fitness, Body Fatness, and Submaximal Systolic Blood Pressure Among Young Adult Women

OBJECTIVES

We examined the independent and combined associations of cardiorespiratory fitness (CRF), body fat (BF) percentage (BF%), and body mass index (BMI) with submaximal systolic blood pressure (SSBP) among young adult women.

MATERIALS AND METHODS

Analyses included a sample of 211 normotensive women with a BMI between 20 and 35 kg/m(2); BF% was calculated using total BF measured from dual X-ray absorptiometry, CRF was assessed using a graded exercise test, and SSBP was measured at each stage.

RESULTS

There was a significant direct association of SSBP with BF% and BMI, whereas an inverse association between SSBP and CRF when adjusted for the covariates. There was no significant association between SSBP and BF% across the stages 1-3 with a borderline significant association at stage 4 when further adjusted for CRF, whereas no association at any of the stages when adjusted for BMI. A borderline significant association between SSBP and BMI was found at stage 1 and significant association at stages 2-4 when additionally adjusted for CRF, whereas the association disappeared at stages 1-2 when adjusted for BF%. The inverse association between SSBP and CRF was eliminated at stages 3-4 when further adjusted for BF% with borderline significant association at stages 1-2. The associations remained significant at the stages 1-2 but not at stages 3-4 after adjusting for BMI.

CONCLUSION

CRF, BF%, and BMI seem to have critical roles in determining SSBP with CRF and BF% being more potent at lower intensity exercise, whereas BMI was more strongly associated at higher intensity exercise.

Objectively Measured Daily Steps and Subsequent Long Term All-Cause Mortality: The Tasped Prospective Cohort Study

Background

Self–reported physical activity has been inversely associated with mortality but the effect of objectively measured step activity on mortality has never been evaluated. The objective is to determine the prospective association of daily step activity on mortality among free-living adults.

Methods and Findings

Cohort study of free-living adults residing in Tasmania, Australia between 2000 and 2005 who participated in one of three cohort studies (n = 2 576 total participants). Daily step activity by pedometer at baseline at a mean of 58.8 years of age, and for a subset, repeated monitoring was available 3.7 (SD 1.3) years later (n = 1 679). All-cause mortality (n = 219 deaths) was ascertained by record-linkage to the Australian National Death Index; 90% of participants were followed-up over ten years, until June 2011. Higher daily step count at baseline was linearly associated with lower all-cause mortality (adjusted hazard ratio AHR, 0.94; 95% CI, 0.90 to 0.98 per 1 000 steps; P = 0.004). Risk was altered little by removing deaths occurring in the first two years. Increasing baseline daily steps from sedentary to 10 000 steps a day was associated with a 46% (95% CI, 18% to 65%; P = 0.004) lower risk of mortality in the decade of follow-up. In addition, those who increased their daily steps over the monitoring period had a substantial reduction in mortality risk, after adjusting for baseline daily step count (AHR, 0.39; 95% CI, 0.22 to 0.72; P = 0.002), or other factors (AHR, 0.38; 95% CI, 0.21–0.70; P = 0.002).

Conclusions

Higher daily step count was linearly associated with subsequent long term mortality among free living adults. These data are the first to quantify mortality reductions using an objective measure of physical activity in a free living population. They strongly underscore the importance of physical inactivity as a major public health problem.

Effects of Running on Chronic Diseases and Cardiovascular and All-Cause Mortality

Considerable evidence has established the link between high levels of physical activity (PA) and all-cause and cardiovascular disease (CVD)-specific mortality. Running is a popular form of vigorous PA that has been associated with better overall survival, but there is debate about the dose-response relationship between running and CVD and all-cause survival. In this review, we specifically reviewed studies published in PubMed since 2000 that included at least 500 runners and 5-year follow-up so as to analyze the relationship between vigorous aerobic PA, specifically running, and major health consequences, especially CVD and all-cause mortality. We also made recommendations on the optimal dose of running associated with protection against CVD and premature mortality, as well as briefly discuss the potential cardiotoxicity of a high dose of aerobic exercise, including running (eg, marathons).

Genistein-loaded nanoparticles of star-shaped diblock copolymer mannitol-core PLGA-TPGS for the treatment of liver cancer

The purpose of this research is to develop nanoparticles (NPs) of star-shaped copolymer mannitol-functionalized PLGA-TPGS for Genistein delivery for liver cancer treatment, and evaluate their therapeutic effects in liver cancer cell line and hepatoma-tumor-bearing nude mice in comparison with the linear PLGA nanoparticles and PLGA-TPGS nanoparticles. The Genistein-loaded M-PLGA-TPGS nanoparticles (MPTN), prepared by a modified nanoprecipitation method, were observed by FESEM and TEM to be near-spherical shape with narrow size distribution. The nanoparticles were further characterized in terms of their size, size distribution, surface charge, drug-loading content, encapsulation efficiency and in vitro drug release profiles. The data showed that the M-PLGA-TPGS nanoparticles were found to be stable, showing almost no change in particle size and surface charge during 3-month storage of their aqueous solution. In vitro Genistein release from the nanoparticles exhibited biphasic pattern with burst release at the initial 4days and sustained release afterwards. The cellular uptake efficiency of fluorescent M-PLGA-TPGS nanoparticles was 1.25-, 1.22-, and 1.29-fold higher than that of the PLGA-TPGS nanoparticles at the nanoparticle concentrations of 100, 250, and 500μg/mL, respectively. In the MPTN group, the ratio of apoptotic cells increased with the drug dose increased, which exhibited dose-dependent effect and a significant difference compared with Genistein solution group (p<0.05). The data also showed that the Genistein-loaded M-PLGA-TPGS nanoparticles have higher antitumor efficacy than that of linear PLGA-TPGS nanoparticles and PLGA nanoparticles in vitro and in vivo. In conclusion, the star-shaped copolymer M-PLGA-TPGS could be used as a potential and promising bioactive material for nanomedicine development for liver cancer treatment.

The role of cardiorespiratory fitness on plasma lipid levels

Dyslipidemia is a treatable risk factor for cardiovascular disease. Epidemiological studies have demonstrated the importance of treatment for abnormalities in total cholesterol, LDL-cholesterol, HDL-cholesterol and triglycerides. Aside from pharmacotherapy, exercise and cardio-respiratory fitness have been shown to have beneficial effects on decreasing cardiovascular disease risk. Even though previous data regarding the benefits of exercise on plasma lipids have been somewhat conflicting, numerous studies have demonstrated that exercise increases HDL-cholesterol and reduces the triglyceride levels. Also, smaller, more atherogenic LDL particles seem to decrease with increases in cardio-respiratory fitness and exercise, and favorable blood lipid profiles seem to persist longer through the adult life span.

Association of Cardiorespiratory Fitness With Coronary Heart Disease in Asymptomatic Men

OBJECTIVE

To examine the association of cardiorespiratory fitness (CRF) with risk of coronary heart disease (CHD) while controlling for an individual's Framingham Risk Score (FRS)-predicted CHD risk.

PATIENTS AND METHODS

The study included 29,854 men from the Aerobics Center Longitudinal Study, who received a baseline examination from January 1, 1979, to December 31, 2002. Coronary heart disease events included self-reported myocardial infarction or revascularization or CHD death. Multivariable survival analysis investigated the association between CRF, FRS, and CHD. Cardiorespiratory fitness was analyzed as both a continuous and a categorical variable. The population was stratified by "low" and "moderate or high" risk of CHD to test for differences in the FRS stratified by CRF.

RESULTS

Compared with men without incident CHD, men with incident CHD were older (mean age, 51.6 years vs 44.6 years), had lower average maximally achieved fitness (10.9 metabolic equivalent of tasks vs 12.0 metabolic equivalent of tasks [METs]), and were more likely to have moderate or high 10-year CHD risk (P<.001). Cardiorespiratory fitness, defined as maximal METs, exhibited a 20% lower risk of CHD (hazard ratio, 0.80; 95% CI, 0.77-0.83) for each 1-unit MET increase. Among men in the low CRF strata, individuals with moderate or high 10-year CHD risk, according to the FRS, had a higher CHD risk (hazard ratio, 6.55; 95% CI, 3.64-11.82) than men with low CHD risk according to the FRS.

CONCLUSION

Clinicians should promote physical activity to improve CRF so as to reduce CHD risk, even to patients with otherwise low CHD risk.

The effect of cardiorespiratory fitness on age-related lipids and lipoproteins

BACKGROUND

Evidence on the effect of cardiorespiratory fitness (CRF) on age-related longitudinal changes of lipids and lipoproteins is scarce.

OBJECTIVES

This study sought to assess the longitudinal aging trajectory of lipids and lipoproteins for the life course in adults and to determine whether CRF modifies the age-associated trajectory of lipids and lipoproteins.

METHODS

Data came from 11,418 men, 20 to 90 years of age, without known high cholesterol, high triglycerides, cardiovascular disease, and cancer at baseline and during follow-up from the Aerobics Center Longitudinal Study. There were 43,821 observations spanning 2 to 25 health examinations (mean 3.5 examinations) between 1970 and 2006. CRF was quantified by a maximal treadmill exercise test. Marginal models using generalized estimating equations were applied.

RESULTS

Total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), triglycerides, and non-high-density lipoprotein cholesterol (non-HDL-C) presented similar inverted U-shaped quadratic trajectories with aging: gradual increases were noted until age mid-40s to early 50s, with subsequent declines (all p < 0.0001). Compared with men with higher CRF, those with lower CRF developed abnormal values earlier in life: TC (≥200 mg/dl), LDL-C (≥130 mg/dl), non-HDL-C (≥160 mg/dl), and triglycerides/HDL-C ratio (≥3.0). Notably, abnormal values for TC and LDL-C in men with low CRF were observed around 15 years earlier than in those with high CRF. After adjusting for time-varying covariates, a significant interaction was found between age and CRF in each trajectory, indicating that CRF was more strongly associated with the aging trajectories of lipids and lipoproteins in young to middle-age men than in older men.

CONCLUSIONS

Our investigation reveals a differential trajectory of lipids and lipoproteins with aging according to CRF in healthy men and suggests that promoting increased CRF levels may help delay the development of dyslipidemia.

Exercise and the cardiovascular system: clinical science and cardiovascular outcomes

Substantial evidence has established the value of high levels of physical activity, exercise training (ET), and overall cardiorespiratory fitness in the prevention and treatment of cardiovascular diseases. This article reviews some basics of exercise physiology and the acute and chronic responses of ET, as well as the effect of physical activity and cardiorespiratory fitness on cardiovascular diseases. This review also surveys data from epidemiological and ET studies in the primary and secondary prevention of cardiovascular diseases, particularly coronary heart disease and heart failure. These data strongly support the routine prescription of ET to all patients and referrals for patients with cardiovascular diseases, especially coronary heart disease and heart failure, to specific cardiac rehabilitation and ET programs.

Influence of the Source of Social Support and Size of Social Network on All-Cause Mortality

OBJECTIVE

To examine associations between relative, friend, and partner support, as well as size and source of weekly social network, and mortality risk in the Aerobics Center Longitudinal Study.

PATIENTS AND METHODS

In a mail-back survey completed between January 1, 1990, and December 31, 1990, adult participants in the Aerobics Center Longitudinal Study (N=12,709) answered questions on whether they received social support from relatives, friends, and spouse/partner (yes or no for each) and on the number of friends and relatives they had contact with at least once per week. Participants were followed until December 31, 2003, or until the date of death. Cox proportional hazards regression analyses evaluated the strength of the associations, controlling for covariates.

RESULTS

Participants (3220 [25%] women) averaged 53.0 ± 11.3 years of age at baseline. During a median follow-up of 13.5 years, 1139 deaths occurred. Receiving social support from relatives reduced mortality risk by 19% (hazard ratio [HR], 0.81; 95% CI, 0.68-0.95). Receiving spousal/partner support also reduced mortality risk by 19% (HR, 0.81; 95% CI, 0.66-0.99). Receiving social support from friends was not associated with mortality risk (HR, 0.90; 95% CI, 0.75-1.09); however, participants reporting social contact with 6 or 7 friends on a weekly basis had a 24% lower mortality risk than did those in contact with 0 or 1 friend (HR, 0.76; 95% CI, 0.58-0.98). Contact with 2 to 5 or 8 or more friends was not associated with mortality risk, nor was the number of weekly contacts with relatives.

CONCLUSION

Receiving social support from one's spouse/partner and relatives and maintaining weekly social interaction with 6 to 7 friends reduced mortality risk. Such data may inform interventions to improve long-term survival.

Role of Fitness in the Metabolically Healthy but Obese Phenotype: A Review and Update

Despite the strong and consistent evidence supporting that a high physical fitness (PF) level at any age is a major predictor of a healthier metabolic profile, major studies focused on the metabolically healthy but obese (MHO) phenotype have ignored the role of PF when examining this phenotype and its prognosis. Particularly, the role of its main health-related components such as higher cardiorespiratory fitness (CRF) and muscular fitness in the MHO phenotype needs to be reviewed in depth. The present review aimed to: 1) contribute to the characterization of the MHO phenotype by examining whether MHO individuals are fitter than metabolically abnormal obese (MAO) individuals in terms of CRF and other PF components; 2) review the role of CRF and other PF components in the prognosis of MHO. The studies reviewed suggest that a higher CRF level should be considered a characteristic of the MHO phenotype. Likewise, CRF seems to play a key role in the prognosis of the MHO individuals, yet this statement is based on a single study and future studies need to confirm or contrast these findings. Comparability of studies is difficult due to the different definitions used for MHO; consequently, the present review makes a proposal for harmonizing this definition in adults and in youth. Obesity is still related to an important number of comorbidities; therefore, the public health message remains to fight against both obesity and low CRF in both adult and pediatric populations.

Marsdenia tenacssima extract and its functional components inhibits proliferation and induces apoptosis of human Burkitt leukemia/lymphoma cells in vitro and in vivo

Burkitt lymphoma is a fast growing non-Hodgkin lymphoma that occurs primarily in young males. The causes of Burkitt lymphoma include chromosome rearrangement and virus infection, but accurate and complete reasons remain to be discovered. The available treatment for Burkitt lymphoma is chemotherapy and radiation therapy. It is a highly aggressive B-cell neoplasm with not all patients cured, in spite of current therapies. This study evaluated the effects of traditional Chinese medicine Marsdenia tenacssima (MTE) and its component compound Tenacigenoside A (TGTA) and 11α-O-benzoyl-12β-O-acetyltenacigenin B (TGTB) on human Burkitt lymphoma growth. It was observed that MTE, TGTA or TGTB inhibited cell growth and induced apoptosis of Burkitt lymphoma cells in culture. In lymphoma bearing NOD/SCID nude mice, both TGTA and TGTB inhibited tumor growth and improved animal survival. TGTA and TGTB significantly increased tumor cell apoptosis on lymphoma bearing mice, primarily through down-regulation of BCL2 and BCL-XL and up-regulation of BID.