Martijn F.H. Maessen

Entering a new era of body indices: the feasibility of a body shape index and body roundness index to identify cardiovascular health status

Background The Body Mass Index (BMI) and Waist Circumference (WC) are well-used anthropometric predictors for cardiovascular diseases (CVD), but their validity is regularly questioned. Recently, A Body Shape Index (ABSI) and Body Roundness Index (BRI) were introduced as alternative anthropometric indices that may better reflect health status. Objective This study assessed the capacity of ABSI and BRI in identifying cardiovascular diseases and cardiovascular disease risk factors and determined whether they are superior to BMI and WC. Design and Methods 4627 Participants (54±12 years) of the Nijmegen Exercise Study completed an online questionnaire concerning CVD health status (defined as history of CVD or CVD risk factors) and anthropometric characteristics. Quintiles of ABSI, BRI, BMI, and WC were used regarding CVD prevalence. Odds ratios (OR), adjusted for age, sex, and smoking, were calculated per anthropometric index. Results 1332 participants (27.7%) reported presence of CVD or CVD risk factors. The prevalence of CVD increased across quintiles for BMI, ABSI, BRI, and WC. Comparing the lowest with the highest quintile, adjusted OR (95% CI) for CVD were significantly different for BRI 3.2 (1.4–7.2), BMI 2.4 (1.9–3.1), and WC 3.0 (1.6–5.6). The adjusted OR (95% CI) for CVD risk factors was for BRI 2.5 (2.0–3.3), BMI 3.3 (1.6–6.8), and WC 2.0 (1.6–2.5). No association was observed for ABSI in both groups. Conclusions BRI, BMI, and WC are able to determine CVD presence, while ABSI is not capable. Nevertheless, the capacity of BRI as a novel body index to identify CVD was not superior compared to established anthropometric indices like BMI and WC.

Predictors of cardiac troponin release after a marathon

OBJECTIVES Exercise leads to an increase in cardiac troponin I in healthy, asymptomatic athletes after a marathon. Previous studies revealed single factors to relate to post-race cardiac troponin I levels. Integrating these factors into our study, we aimed to identify independent predictors for the exercise-induced cardiac troponin I release. DESIGN Observational study. METHODS Ninety-two participants participated in a marathon at a self-selected speed. Demographic data, health status, physical activity levels and marathon experience were obtained. Before and immediately after the marathon fluid intake was recorded, body mass changes were measured to determine fluid balance and venous blood was drawn for analysis of high-sensitive cardiac troponin I. Exercise intensity was examined by recording heart rate. We included age, participation in previous marathons, exercise duration, exercise intensity and hydration status (relative weight change) in our model as potential determinants to predict post-exercise cardiac troponin I level. RESULTS Cardiac troponin I increased significantly from 14±12 ng/L at baseline to 94±102 ng/L post-race, with 69% of the participants demonstrating cardiac troponin I levels above the clinical cut-off value (40 ng/L) for an acute myocardial infarction. Linear backward regression analysis identified younger age (β=-0.27) and longer exercise duration (β=0.23) as significant predictors of higher post-race cardiac troponin I levels (total r=0.31, p<0.05), but not participation in previous marathons, relative weight change and exercise intensity. CONCLUSIONS We found that cardiac troponin I levels significantly increased in a large heterogeneous group of athletes after completing a marathon. The magnitude of this response could only be partially explained, with a lower age and longer exercise duration being related to higher post-race cardiac troponin I levels.

A systematic review and meta‐analysis on the effects of exercise training versus hypocaloric diet: distinct effects on body weight and visceral adipose tissue

Exercise training (‘exercise’) and hypocaloric diet (‘diet’) are frequently prescribed for weight loss in obesity. Whilst body weight changes are commonly used to evaluate lifestyle interventions, visceral adiposity (VAT) is a more relevant and stronger predictor for morbidity and mortality. A meta‐analysis was performed to assess the effects of exercise or diet on VAT (quantified by radiographic imaging). Relevant databases were searched through May 2014. One hundred seventeen studies (n = 4,815) were included. We found that both exercise and diet cause VAT loss (P < 0.0001). When comparing diet versus training, diet caused a larger weight loss (P = 0.04). In contrast, a trend was observed towards a larger VAT decrease in exercise (P = 0.08). Changes in weight and VAT showed a strong correlation after diet (R2 = 0.737, P < 0.001), and a modest correlation after exercise (R2 = 0.451, P < 0.001). In the absence of weight loss, exercise is related to 6.1% decrease in VAT, whilst diet showed virtually no change (1.1%). In conclusion, both exercise and diet reduce VAT. Despite a larger effect of diet on total body weight loss, exercise tends to have superior effects in reducing VAT. Finally, total body weight loss does not necessarily reflect changes in VAT and may represent a poor marker when evaluating benefits of lifestyle‐interventions.

Impact of lifelong exercise training on endothelial ischemia-reperfusion and ischemic preconditioning in humans

Reperfusion is essential for ischemic tissue survival, but causes additional damage to the endothelium [i.e., ischemia-reperfusion (I/R) injury]. Ischemic preconditioning (IPC) refers to short repetitive episodes of ischemia that can protect against I/R. However, IPC efficacy attenuates with older age. Whether physical inactivity contributes to the attenuated efficacy of IPC to protect against I/R injury in older humans is unclear. We tested the hypotheses that lifelong exercise training relates to 1) attenuated endothelial I/R and 2) maintained IPC efficacy that protects veteran athletes against endothelial I/R. In 18 sedentary male individuals (SED, <1 exercise h/wk for >20 yr, 63 ± 7 yr) and 20 veteran male athletes (ATH, >5 exercise h/wk for >20 yr, 63 ± 6 yr), we measured brachial artery endothelial function with flow-mediated dilation (FMD) before and after I/R. We induced I/R by 20 min of ischemia followed by 20 min of reperfusion. Randomized over 2 days, participants underwent either 35-min rest or IPC (3 cycles of 5-min cuff inflation to 220 mmHg with 5 min of rest) before I/R. In SED, FMD decreased after I/R [median (interquartile range)]: [3.0% (2.0-4.7) to 2.1% (1.5-3.9), P = 0.046] and IPC did not prevent this decline [4.1% (2.6-5.2) to 2.8% (2.2-3.6), P = 0.012]. In ATH, FMD was preserved after I/R [3.0% (1.7-5.4) to 3.0% (1.9-4.1), P = 0.82] and when IPC preceded I/R [3.2% (1.9-4.2) to 2.8% (1.4-4.6), P = 0.18]. These findings indicate that lifelong exercise training is associated with increased tolerance against endothelial I/R. These protective, preconditioning effects of lifelong exercise against endothelial I/R may contribute to the cardioprotective effects of exercise training.

Benefits of lifelong exercise training on left ventricular function after myocardial infarction.

Background Endurance exercise training induces cardio-protective effects, but athletes are not exempted from a myocardial infarction. Evidence from animal studies suggests that exercise training attenuates pathological left ventricular remodelling following myocardial infarction. We tested the hypothesis that lifelong exercise training is related to attenuated pathological left ventricular remodelling after myocardial infarction as evidenced by better left ventricular systolic function in veteran athletes compared to sedentary peers. Design This was a cross-sectional study. Methods Sixty-five males (60 ± 6 years) were included and allocated to four groups based on lifelong exercise training volumes: (a) athletes (n = 18), (b) post-myocardial infarction athletes (athletes + myocardial infarction, n = 20), (c) sedentary controls (n = 13), and (d) post-myocardial infarction controls (sedentary controls + myocardial infarction, n = 14). Athletes were lifelong (≥20 years) highly physically active (≥30 metabolic equivalent of task (MET)-h/week), whereas sedentary controls did not meet the exercise guidelines (<10 MET-h/week) for the past 20 years. left ventricular systolic function, diastolic function and wall strain were measured using echocardiography. Results Cardiac enzyme markers (creatine-kinase, creatinine, aspartate transaminase and lactate dehydrogenase) following myocardial infarction and infarct location did not differ between athletes + myocardial infarction and sedentary controls + myocardial infarction. Left ventricular ejection fraction was significantly higher in athletes (61% ± 4), athletes + myocardial infarction (58% ± 4) and sedentary controls (57% ± 6) compared to sedentary controls + myocardial infarction (51% ± 7; p < 0.01). Left ventricular circumferential strain was superior in athletes (–19% (–21% to –17%), athletes + myocardial infarction (–16% (–20% to –12%)), and sedentary controls (–15% (–18% to –14%) compared to sedentary controls + myocardial infarction (–13% (–15% to –8%), p < 0.01). Diastolic function parameters did not differ across groups. Conclusion These findings suggest that lifelong exercise training may preserve left ventricular systolic function and possibly attenuates or minimises the deleterious effects of pathological post-myocardial infarction left ventricular remodelling in veteran athletes.

Exercise for Coronary Heart Disease Patients: Little Is Good, More Is Better, Vigorous Is Best.

T he cardiovascular health benefits of a physically active lifestyle are well recognized and frequently described (1,2). Nevertheless, physical inactivity remains a global problem, particularly in clinical populations such as coronary heart disease (CHD) patients. A recent meta-analysis including >1,000,000 individuals found that individuals who are inactive and sit the most have the highest risk for mortality (3). The typical CHD patient fits this description as she or he usually performs little regular exercise and sits much of the time. Strategies to increase physical activity (PA) and decrease sitting in high-risk populations such as CHD patients are therefore needed. Current guidelines prescribe similar PA recommendations for primary (4) and secondary prevention (5,6): 150 min/week of exercise at a moderate intensity. Most evidence for the health benefits of exercise in CHD patients are derived from cardiac rehab studies (7). Although these findings support the benefits of regular PA, these studies do not inform on the minimal dose, optimal dose, and potential upper limit of PA to reduce cardiovascular morbidity and mortality.

Physical Activity and Cognitive Function of Long-Distance Walkers: Studying Four Days Marches Participants

Studies show physical activity to be beneficial for cognitive function. However, studies usually included individuals who were not particularly inclined to exercise. Following research among master athletes, we examined associations between physical activity and cognitive function in participants of the International Nijmegen Four Days Marches. These individuals are also inclined to exercise. On 4 consecutive days >40,000 participants walk a daily distance of 30-50 km (120-200 km or 75-125 miles in total). Four Days Marches participants and less active or inactive control participants from the Nijmegen Exercise Study were examined. Self-reported current and lifelong physical activities were quantified in Metabolic Equivalent of Task minutes/day, and training walking speed was estimated in km/h. Cognitive functioning in the domains of working memory, executive function, and visuospatial short-term memory was assessed using the validated Brain Aging Monitor. Data from 521 participants (mean age 54.7, standard deviation 12.9) showed neither positive associations between lifelong physical activity and working memory, executive function, and visuospatial short-term memory nor positive associations between current physical activity and cognitive functioning in these domains (p-values >0.05). However, a positive association between training walking speed and working memory was revealed (age adjusted β = 0.18, p-value <0.01). Walking speed as a surrogate marker of fitness, but not lifelong and current physical activity levels was associated with cognitive function. Therefore, walking speed deserves more attention in research aimed at unraveling associations between physical activity and cognitive function.

Vascular Function and Structure in Veteran Athletes after Myocardial Infarction.

Purpose Although athletes demonstrate lower cardiovascular risk and superior vascular function compared with sedentary peers, they are not exempted from cardiac events (i.e., myocardial infarction [MI]). The presence of an MI is associated with increased cardiovascular risk and impaired vascular function. We tested the hypothesis that lifelong exercise training in post-MI athletes, similar as in healthy controls, is associated with a superior peripheral vascular function and structure compared with a sedentary lifestyle in post-MI individuals. Methods We included 18 veteran athletes (ATH) (>20 yr) and 18 sedentary controls (SED). To understand the effect of lifelong exercise training after MI, we included 20 veteran post-MI athletes (ATH + MI) and 19 sedentary post-MI controls (SED + MI). Participants underwent comprehensive assessment using vascular ultrasound (vascular stiffness, intima-media thickness, and endothelium (in)dependent mediated dilatation). Lifetime risk score was calculated for a 30-yr risk prediction of cardiovascular disease mortality of the participants. Results ATH demonstrated a lower vascular stiffness and smaller femoral intima-media thickness compared with SED. Vascular function and structure did not differ between ATH + MI and SED + MI. ATH (4.0% ± 5.1%) and ATH + MI (6.1% ± 3.7%) had a significantly better lifetime risk score compared with their sedentary peers (SED: 6.9% ± 3.7% and SED + MI: 9.3% ± 4.8%). ATH + MI had no secondary events versus two recurrent MI and six elective percutaneous coronary interventions within SED + MI (P < 0.05). Conclusion Although veteran post-MI athletes did not have a superior peripheral vascular function and structure compared with their sedentary post-MI peers, benefits of lifelong exercise training in veteran post-MI athletes relate to a better cardiovascular risk profile and lower occurrence of secondary events.

A comparison of dicarbonyl stress and advanced glycation endproducts in lifelong endurance athletes vs. sedentary controls

OBJECTIVES Dicarbonyl stress and high concentrations of advanced glycation endproducts (AGEs) relate to an elevated risk for cardiovascular diseases (CVD). Exercise training lowers the risk for future CVD. We tested the hypothesis that lifelong endurance athletes have lower dicarbonyl stress and AGEs compared to sedentary controls and that these differences relate to a better cardiovascular health profile. DESIGN Cross-sectional study. METHODS We included 18 lifelong endurance athletes (ATH, 61±7years) and 18 sedentary controls (SED, 58±7years) and measured circulating glyoxal (GO), methylglyoxal (MGO) and 3-deoxyglucosone (3DG) as markers of dicarbonyl stress. Furthermore, we measured serum levels of protein-bound AGEs NƐ-(carboxymethyl)lysine (CML), NƐ-(carboxyethyl)lysine (CEL), methylglyoxal-derived hydroimidazolone-1 (MG-H1), and pentosidine. Additionally, we measured cardiorespiratory fitness (VO2peak) and cardiovascular health markers. RESULTS ATH had lower concentrations of MGO (196 [180-246] vs. 242 [207-292] nmol/mmol lysine, p=0.043) and 3DG (927 [868-972] vs. 1061 [982-1114] nmol/mmol lysine, p<0.01), but no GO compared to SED. ATH demonstrated higher concentrations CML and CEL compared to SED. Pentosidine did not differ across groups and MG-H1 was significantly lower in ATH compared to SED. Concentrations of MGO en 3DG were inversely correlated with cardiovascular health markers, whereas CML and CEL were positively correlated with VO2peak and cardiovascular health markers. CONCLUSION Lifelong exercise training relates to lower dicarbonyl stress (MGO and 3DG) and the AGE MG-H1. The underlying mechanism and (clinical) relevance of higher CML and CEL concentrations among lifelong athletes warrants future research, since it conflicts with the idea that higher AGE concentrations relate to poor cardiovascular health outcomes.