Increased serum levels of fibroblast growth factor 23 after an ultradistance run

OBJECTIVES

Healthy bones need to be loaded on a regular basis. However, overstrenuous exercise causes uncoupling of bone metabolism. Thus, it is important to be aware of exercise-induced alterations in bone metabolism. The aim of this observational study was to determine whether participation in an ultradistance run has an impact on the phosphaturic hormone fibroblast growth factor 23 (FGF23), which is produced by osteocytes and suppresses osteoblast differentiation as well as matix mineralization.

DESIGN

Observational study.

METHODS

Nine participants of the Spartathlon (246km) had venous blood samples taken before and within 15min after finishing the race as well as during recovery. Serum levels of FGF23, phosphate, and blood urea nitrogen were determined.

RESULTS

FGF23 increased 6.5-fold from pre-race to post-race (2.2pmol/L [IQR: 0.4; 3.2pmol/L] to 14.4pmol/L [IQR: 4.7; 20.0pmol/L]; p=0.001). Thereafter, serum levels of FGF23 fell to 1.4pmol/L [IQR: 0.5; 1.7pmol/L] (p<0.0001). The differences in FGF23 levels between pre-race and recovery (3 days after the start) did not achieve statistical significance (p=0.614). Serum levels of phosphate and blood urea nitrogen also did not change significantly.

CONCLUSIONS

Since FGF23 plays a central role in mineral homeostasis, the transient overexpression of FGF23 may be an important contributor to the short-term uncoupling of bone metabolism induced by overstrenuous exercise.

Effects of a hops (Humulus lupulus L.) dry extract supplement on self-reported depression, anxiety and stress levels in apparently healthy young adults: a randomized, placebo-controlled, double-blind, crossover pilot study

OBJECTIVE

The Humulus lupulus L. plant (hops) is used as a herbal medicinal product for anxiety/mood disorders. Our aim was to study the effects of a hops dry extract on self-reported depression, anxiety and stress levels in young adults.

DESIGN

Apparently healthy young adults from our university completed the Depression Anxiety Stress Scale-21 (DASS-21) and those reporting at least mild depression, anxiety and stress were invited to complete the study intervention. This followed a randomized (1:1), placebo-controlled, double-blind, crossover design with two 4-week intervention periods (Melcalin hops or placebo; two 0.2 gr capsules once daily) separated by a 2-week wash-out. Anthropometric measurements, DASS-21 assessments and measurements of morning cortisol plasma levels were performed at the beginning and the end of the 4-week treatment periods.

RESULTS

36 participants (Females/Males: 31/5; age: 24.7±0.5 years) completed the study intervention (attrition: 6/42). No significant changes in body weight and composition or morning circulating cortisol were noted with the hops or placebo. Significantly decreased DASS-21 anxiety, depression and stress scores were documented with hops (9.2±7.3 vs. 5.1±5.9, 11.9±7.9 vs. 9.2±7.4, and 19.1±8.1 vs. 11.6±8.1; all p values <0.05), which were significantly greater compared to those caused by the placebo (all p values <0.05).

CONCLUSION

In otherwise healthy young adults reporting at least mild depression, anxietyand stress symptoms, daily supplementation with a hops dry extract can significantly improve all these symptoms over a 4-week period. These beneficial effects agree with the indication of hops for anxiety/mood disorders and restlessness, as approved by the German Commission E.

Changes in Serum Levels of Myokines and Wnt-Antagonists after an Ultramarathon Race

BACKGROUND

Regular physical activities have a positive effect on the muscular skeletal system but overstrenuous exercise may be different. Transiently suppressed bone formation and increased bone resorption after participation in a 246-km ultradistance race has been demonstrated.

PURPOSE

The aim of this study was to analyze effects of the Spartathlon race on novel musculoskeletal markers.

METHODS

Venous blood samples were obtained before and immediately after the race from 19 participants of the Spartathlon. From 9 runners who were available 3 days after the start blood was drawn for a third time. Serum levels of myostatin, an inhibitor of myogenic differentiation, and its opponent follistatin as well as sclerostin and dickkopf-1, both of them inhibitors of the wnt signaling pathway, and markers of bone turnover were determined.

RESULTS

Serum levels of myostatin were significantly higher after the race. Serum follistatin only showed a transient increase. Sclerostin levels did not significantly differ before and after the race, whereas dickkopf-1 levels were significantly decreased. At follow-up a decrement of sclerostin and dickkopf-1 levels was seen. Serum cathepsin K levels did not change.

CONCLUSION

The increase of serum levels of myostatin appears to reflect muscle catabolic processes induced by overstrenuous exercise. After the short-term uncoupling of bone turnover participation in an ultradistance race seems to initiate a long-term positive effect on bone indicated by the low-level inhibition of the Wnt/β-catenin signaling pathway.

A Mediterranean-like breakfast affects energy intake and appetite-related feelings

Energy intake and appetite feelings after the consumption of two different types of breakfast, a high-fiber, traditional, Mediterranean-type breakfast and a low-fiber, Western-type breakfast were compared. Sixteen non-obese young men received the two treatments on separate days: the Mediterranean- and the Western-type breakfasts were isocaloric, similar in volume and macronutrient content, but different in fiber content. Following a 4-hour fast, subjects offered an ad libitum lunch. Food consumed and subjective feelings of hunger, fullness, and desire to eat were evaluated. Energy intake in the ad libitum lunch was significantly lower after the Mediterranean-type, compared to the Western-type breakfast, adjusting for previous day's energy intake (1488 ± 468 versus 1674 ± 416 kcal, respectively), whereas no energy compensation was made throughout the day. Furthermore, those who had the Mediterranean-type breakfast reported lower values in the desire to eat during study's course. These findings propose a fulfilling effect of a traditional, Mediterranean, high in fiber breakfast.

Metabolic profiles of adult Wistar rats in relation to prenatal and postnatal nutritional manipulation: the role of birthweight

OBJECTIVE

This experimental study aimed to prospectively investigate the impact of combinations of prenatal and postnatal food manipulations on the metabolic profile of adult offspring.

DESIGN

On day 12 of gestation, 67 timed pregnant rats were randomized into three nutritional groups, control: standard laboratory food; starved: 50% food restricted, FR; fat-fed: fat-rich diet, FF. Seven hundred and seventy-four (774) pups were born on day 21 and culled to 8 (4 males, 4 females) per litter to normalize rearing. Rats born to starved mothers were later subdivided, based on birthweight (BiW), into fetal growth restricted (FGR) and non-FGR. The pups were then weaned to the diet of their fostered mother until one year old. Thus, 12 groups were studied: 1.

CONTROL/CONTROL

14 rats, 2.

CONTROL/FR

12 rats, 3.

CONTROL/FF

15 rats, 4.

FGR/CONTROL

16 rats, 5.

FGR/FR

10 rats, 6.

FGR/FF

15 rats, 7. non-

FGR/CONTROL

10 rats, 8. non-

FGR/FR

17 rats, 9. non-

FGR/FF

10 rats, 10.

FF/CONTROL

15 rats, 11.

FF/FR

14 rats, and 12.

FF/FF

13 rats. During sacrifice, body weight (BW) and liver weight (LW) were measured (expressed in grams) and concentrations of serum glucose, triglycerides, HDL and NEFA were determined.

RESULTS

Postnatal food restriction, compared to control diet significantly reduced BW (p=0.004, p=0.036, p<0.001, p=0.008) and LW (p<0.001) in all study groups. Postnatal control diet significantly increased BW in non-FGR compared to FGR rats (p=0.027). No significant differences were detected in biochemical parameters (excluding NEFA) between FGR and non-FGR, regardless of the postnatal diet.

CONCLUSIONS

Interaction between prenatal and postnatal nutrition produces distinct metabolic profiles. Apart from BiW, prenatal diet had an important impact on the metabolic profile of the adult offspring, implying that intrauterine events should be considered in the estimation of the metabolic risk of an individual, independently of BiW.

A proteomic study of plasma protein changes under extreme physical stress

The Spartathlon race (brisk walking a distance of 246km in less than 36h) was employed as a model of severe physical stress to investigate proteomic alterations in the plasma of athletes at the start (Athens) and finish (Sparta) of the race, as well as 48h after the race (Post). The athletes' plasma was analyzed by 2D gel electrophoresis (2-DE) and the differentially expressed proteins were identified by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry (MS). The ProteoSeek™ Albumin/IgG removal kit and the ProteoMiner™ enrichment kit were utilized to detect medium- and low-abundance proteins, whose expression may be masked due to high-abundance proteins. Our results were confirmed by Western blot and biochemical analyses. Overall fifty-two proteins were differentially expressed between the starting point, the finishing line and two days after the end of the race. Of these, thirty proteins were involved in inflammation, while the rest concerned anti-oxidation, anti-coagulation and iron and vitamin D transport. These results indicate that prolonged physical stress affects circulating stress-related proteins, which might be employed as biomarkers of stress-related diseases.

BIOLOGICAL SIGNIFICANCE

The current study employed the Spartathlon, as a model of prolonged endurance exercise, to identify and isolate putative biomarkers of inflammation under extreme physical stress conditions. These protein quantitative variations may pave the way to exploration and understanding of stress-related physiological processes, the stress response itself and diseases whose onset appears to be linked to stress.

The IL-6 Gene G-174C Polymorphism Related to Health Indices in Greek Primary School Children

Interleukin-6 (IL-6) is a pleiotropic cytokine expressed in many tissues. A polymorphism in the IL-6 gene, associated with differences in IL-6 transcription rate, has been recently described. Subjects with the -174GG genotype are prone to lipid abnormalities. We investigated the effect of the G-174C IL-6 polymorphism on health indices and lipid values of 184 Greek primary school children. The genotype distribution of the polymorphism was 37.5% for GG and 52.2% and 10.3% for GC and CC, respectively. No differences were observed between genotype distribution and gender (p = 0.37). Boys homozygous for the G allele showed higher triglyceride levels than boys carrying the C allele (86 +/- 28 vs. 74 +/- 20 mg/dL, p = 0.02) and lower mid-upper arm muscle circumference (17.46 +/- 1.86 vs. 18.91 +/- 2.53 cm, p = 0.013). In addition, girls homozygous for the G allele had higher values for suprailiac skinfolds compared with those bearing the C allele (21.28 +/- 12.56 vs. 17.09 +/- 13.36 mm, p = 0.06). These findings were confirmed by multiple linear regression analysis, after controlling for age, sex, BMI, energy and total fat intake, and weekly physical activity. From the results of the present study, we concluded that individuals homozygous for G allele on the IL-6 gene have higher values in some parameters associated with obesity.

A 246-km continuous running race causes significant changes in bone metabolism

BACKGROUND

Regular physical exercise exerts a favorable effect on the skeleton. However, excessive physical exercise may have detrimental effects. A low bone mineral density (BMD) has been registered in highly trained runners. The aim of the present study was to evaluate potential effects of the Spartathlon, an annual ultramarathon race of 246 km, on bone metabolism.

METHODS

Venous blood samples were taken before and within 15 min after the end of the race as well as three days after the start of the race. The following variables of bone metabolism were studied: osteocalcin (Oc), cross-linked-C-telopeptide of type I collagen (CTX), osteoprotegerin (OPG), and its ligand, receptor activator of nuclear factor kappaB ligand (RANKL).

RESULTS

Blood samples were taken from 18 runners (16 men and 2 women) at the three time points. The median time taken by the runners to complete the race was 32 h and 52 min. Serum levels of CTX were significantly increased immediately after the race as well as three days after the start of the race compared with the time prior to the race. Oc was transiently suppressed after the race. Serum levels of RANKL and OPG were increased three days after the start of the race compared to the time before the start of the race.

CONCLUSIONS

This study showed that an ultra-distance run of nearly 250 km induced changes in RANK/RANKL/OPG interaction, which suggests a transient uncoupling of bone metabolism, increased bone resorption, and suppressed bone formation.

Dramatic reduction of erythrocyte glucose‐6‐phosphate dehydrogenase activity in athletes participating in the ultradistance foot race “Spartathlon”

OBJECTIVE

To investigate the effect of a long-distance endurance exercise "Spartathlon" on erythrocyte glucose-6-phosphate dehydrogenase (G(6)PD) activity.

MATERIAL AND METHODS

The study comprised 15 male runners, median age 36.5 years. Blood samples were obtained in the 15 min before the race and again within 15 min after the end of the race. Erythrocyte glutathione (GSH and GSSG) and plasma malonyldialdehyde were measured with HPLC methods, and total antioxidant capacity (TAC), total hyperoxides and G(6)PD activity with commercial kits. Lipids, uric acid and total bilirubin were determined with a clinical chemistry analyser.

RESULTS

Total hyperoxides were found statistically reduced, whereas total bilirubin was measured elevated post-race. Interestingly, GSSG levels were found increased (167.3+/-12.0 versus 219.5+/-20.3 micromol/L; p<0.005) as well as GSSG/GSH ratio (16.0+/-1.3 versus 20.60+/-1.65; p<0.05) post-race. In contrast, G(6)PD activity was found remarkably decreased (8.72+/-3.10 versus 3.8+/-2.5 U/g Hb; p<0.0001) pre versus post the event.

CONCLUSION

Red blood cell G(6)PD activity in athletes may be reduced post-race as a consequence of the modulation of NADP/NADPH levels and elevation of the erythrocyte GSSG, and especially GSSG/GSH ratio, resulting in an impairment of the hexose monophosphate shunt.

Beneficial effects of raloxifene and atorvastatin on serum lipids and HDL phospholipids levels of postmenopausal women

Selective oestrogen receptor modulators (raloxifene) and statins (atorvastatin) have been shown to reduce the risk of cardiovascular disease associated with the postmenopausal status. Their beneficial effects may be mediated partly by favourable changes in serum lipids and particular on HDL phospholipid composition. In the present study, individual administration of either raloxifene (Group A) or atorvastatin (Group B) or both (Group C) was compared for a period of 3 months and their effects on total lipids and HDL phospholipids were evaluated. The combined treatment of raloxifene and atorvastatin resulted in profound changes in the majority of serum lipids, including a significant reduction in total cholesterol and triglycerides (P<0.001), a rise in total phospholipids (P<0.01) and a reduction in LDL-C and Apo B levels (P<0.001). Furthermore, Apo A-I was elevated (P<0.001) whereas total HDL phospholipids were significantly increased (P<0.05). Specifically, HDL phosphatidylcholine levels were markedly increased (P<0.001) and HDL lysophosphatidylcholine, sphingomyelin and phosphatidylinositol levels were reduced (P<0.05). A further attempt to evaluate each treatment group was performed and the significance of these results is discussed.

Evidence of improved serum fatty acid profile of postmenopausal women receiving atorvastatin and raloxifene

Raloxifene and atorvastatin have been shown to reduce the risk of cardiovascular disease associated with postmenopausal status and it has been postulated that their effects may be partly mediated by favourable changes in serum lipids and fatty acid composition. In the present study, individual administration of either raloxifene (Group A) or atorvastatin (Group B) or both (Group C) was compared for a period of 3 months and their effects on total lipids and fatty acids composition was evaluated. Postmenopausal women receiving both raloxifene and atorvastatin showed significant changes in the majority of serum lipids with important reductions in total cholesterol (p < 0.001), triglycerides (p < 0.001), LDL-C (p < 0.001) and Apo B levels (p < 0.001). Phospholipids concentrations (p < 0.01) as well as Apo A-I were also significantly raised (p < 0.001). Furthermore, oleic acid (18:1) and linoleic acid (18:2) levels were significantly increased (p < 0.01 and p < 0.001 respectively) followed by a marked reduction in palmitic acid (16:0) and arachidonic acid (20:4) concentrations (p < 0.01 and p < 0.001 respectively). The results of the study indicate that the serum lipid and fatty acid composition in postmenopausal women is influenced by the combined treatment of raloxifene and atorvastatin and a further attempt to evaluate the significance of these results is discussed.

Spartathlon, a 246 kilometer foot race: effects of acute inflammation induced by prolonged exercise on circulating progenitor reparative cells

Endothelial progenitor cells (EPCs) and the recently described circulating fibrocytes (CFs) are strongly associated with tissue repair. We investigated the kinetics of both "repair" progenitor cells in healthy athletes who participated in the "Spartahlon" ultradistance foot race (246 km continuous running exercise), which provides a unique model of inducing dramatic systemic inflammatory changes. Peripheral blood mononuclear cells (PBMCs) were isolated from 10 volunteer athletes, who completed successfully the race, before, at the end, and at 48 h post-race. EPCs and CFs were detected as endothelial colony-forming units (CFU-ECs) and as the number of adherent with a spindle-shaped morphology Collagen I(+) cells detected after 6-day culture of PBMCs, respectively. The marked increase of plasma levels of CRP, IL-6, SAA, MCP-1, IL-8, sVCAM-1, sICAM-1, thrombomodulin (sTM) and NT-pro-BNP at the end of race established acute inflammation and tissue injury. EPCs increased by nearly eleven-fold in peripheral blood at the end of the race from 44.5+/-2.5/ml to 494.6+/-27.9/ml and remained increased 428.5+/-31.5/ml at 48 h post-race (p<0.0001). The number of the fibrocytes cultured from PBMCs obtained before, at the end, and 48 h post-race did not reveal any significant difference. These findings indicate that bone marrow responses to acute inflammatory damage, induced by exhausting exercise, with a rapid release of EPCs but not CFs into circulation. Given the ability of EPCs to promote angiogenesis and vascular regeneration, we may suggest that this kind of cell mobilization may serve as a physiologic repair mechanism in acute inflammatory tissue injury.

Severe aseptic inflammation caused by long distance running (246 km) does not increase procalcitonin

BACKGROUND

The Spartathlon ultra distance running race (246 kilometres) is an exhausting physical exercise leading to a state of systemic inflammation associated with dramatic elevation of interleukin-6 and acute-phase reactants to levels seen only in critically ill or patients near death. We sought to study the effect of this severe inflammatory response on the levels of serum procalcitonin.

MATERIALS AND METHODS

Fifteen healthy endurance-trained runners who participated in the 2006 Spartathlon were studied. Blood samples were taken the day before the race, within 15 min after the end of the race and 48 h after the end of the race. Serum interleukin-6, serum amyloid A protein, C-reactive protein, tumour necrosis factor-alpha and procalcitonin concentrations were determined.

RESULTS

Serum interleukin-6, serum amyloid A protein and C-reactive protein were dramatically increased after the end of the race (150-, 116- and 10,470- fold increase of the mean values, respectively). Procalcitonin levels remained within normal range (mean +/- standard error of mean, 0.27 +/- 0.02 microg L(-1), 0.26 +/- 0.02 microg L(-1) and 0.27 +/- 0.02 microg L(-1) before, at the end, and 48 h after the race, respectively). Tumour necrosis factor-alpha measurements revealed no significant changes.

CONCLUSIONS

This study provides strong evidence that Spartathlon, a prolonged endurance exercise resulting in severe stimulation of inflammatory mediators followed by muscle and liver damage, does not induce procalcitonin secretion. The findings cannot directly be applied to other causes of aseptic inflammation.

Circulating levels of adhesion molecules and markers of endothelial activation in acute inflammation induced by prolonged brisk exercise

OBJECTIVES

To investigate circulating levels of adhesion molecules and markers of endothelial activation in acute inflammation induced by prolonged brisk exercise.

DESIGN AND METHODS

The circulating levels of adhesion molecules E-, L- and P-selectins, intercellular and vascular adhesion molecule-1 (ICAM-1 and VCAM-1), along with those of thrombomodulin (TM), N-terminal pro-brain natriuretic peptide (NT-pro-BNP) and cardiac troponin T, were measured before, at the end of and at 48 h post-race, in athletes participating in this extreme physical stress paradigm.

RESULTS

Levels of L- and P-selectins remained the same before and at the end of the "Spartathlon" race, presenting a similar decline at 48 h post-race. E-Selectin, ICAM-1 and TM reached a maximum value at the end of the race and returned to normal 48 h after the race. A similar profile was observed for VCAM-1 and NT-pro-BNP, with a tendency for a decrease at 48 h post-race, while troponin T was not detected.

CONCLUSIONS

The indices of endothelial activation are strongly affected during "Spartathlon" race, suggesting that, although prolonged brisk exercise activates the endothelium, it rapidly recovers.

Elevated total and central adiposity and low physical activity are associated with insulin resistance in children

The aim of this study was 2-fold: (1) to examine insulin resistance, blood lipid levels, and inflammatory markers in 9- to 11.5-year-old obese and lean children and (2) to identify factors that influence insulin resistance in this cohort of youths. Body mass index, skinfold thickness, waist circumference, physical activity (4-day triaxial accelerometer), cardiorespiratory fitness (submaximal bicycle ergometer test), and dietary intake (3-day food records) were evaluated in 27 obese and 27 lean boys and girls. Fasting blood samples were analyzed for insulin, glucose, lipids and lipoproteins, C-reactive protein (CRP), interleukin 6, soluble intercellular adhesion molecule, and soluble vascular cell adhesion molecule. Homeostasis model assessment (HOMA) was used to evaluate insulin resistance (HOMA-IR). Obese children presented higher HOMA-IR, CRP, and blood lipid levels (all P < .01) compared with lean children. Total body fat and waist circumference were positively associated with fasting insulin (r > or = 0.51), HOMA-IR (r > or = 0.56), CRP (r > or = 0.51), and blood triacylglycerol (r > or = 0.38), and were inversely correlated with high-density lipoprotein cholesterol (r > or = -0.39; all P < .01). Cardiorespiratory fitness was inversely associated with HOMA-IR (r = -0.24; P < .05), but this association disappeared when adjusted for age, sex, and fat mass. Waist circumference and total daily physical activity explained 49% of the variance in HOMA-IR in these children. In conclusion, these findings suggest that total and central adiposity are positively associated and physical activity is negatively associated with insulin resistance in children. Interventions to improve glucose metabolism in youth should target at reducing total body and abdominal fat and increasing physical activity. The lack of association between inflammatory markers and HOMA-IR suggests that obesity may precede the elevation of these markers in the evolution of insulin resistance in youth.

The Pro12Ala Polymorphism in PPARγ2 Gene Affects Lipid Parameters in Greek Primary School Children: A Case of Gene-to-Gender Interaction

BACKGROUND

In the present study we sought to evaluate the impact of the PPAR-gamma2 Pro12Ala polymorphism on blood lipid levels of primary school children.

METHODS

81 male and 92 female schoolchildren were genotyped. Biochemical, anthropometric, and lifestyle variables were assessed.

RESULTS

14.1% females and 14.8% males were heterozygotes, while the rest of the subjects were homozygotes for the Pro allele. A significant interaction between the PPARgamma-2 gene and gender on blood lipid levels was detected. In particular, Pro/Pro females exhibited higher values of total cholesterol (194 +/- 32 vs 180 +/- 28 mg/dL, P = 0.06) and triglycerides (94 +/- 31 vs 77 +/- 11 mg/dL, P = 0.045) compared to Pro/Ala individuals. The gene-to-gender interaction term was highly significant (P < 0.001). On the other hand, Pro/Pro males showed higher values of HDL cholesterol (47 +/- 8 vs 43 +/- 9 mg/dL, P = 0.001), lower total cholesterol/HDL ratio (4.04 +/- 0.59 vs 4.45 +/- 0.61, P = 0.031), lower values of apoB (59.8 +/- 11.3 vs 66.8 +/- 6.6 mg/dL, P = 0.007) and lower values of apoB/apoA1 ratio (0.41 +/- 0.09 vs 0.48 +/- 0.08, P = 0.019) compared with Pro/Ala. Even after adjusting for body mass index (BMI), total energy intake, total fat intake and saturated fat intake, differences in total cholesterol/high-density lipoprotein (HDL) cholesterol and the apoB/apoA1 ratios remained significant. Regarding females, no differences were observed among genotypes concerning total cholesterol/HDL levels (P for gene-to-gender interaction = 0.001) and the apoB/apoA1 levels (P for gene-to-gender interaction = 0.029).

CONCLUSION

We show for the first time a gene-to-gender interaction on total cholesterol/HDL and apoB/apoA1 ratios, in male schoolchildren genotyped for PPAR-gamma2 Pro12Ala.

Diet, blood lipid profile and physical activity patterns in primary school children from a semi-rural area of Greece

BACKGROUND

Risk factors for heart disease are becoming increasingly prevalent among young populations. The aim of this study was to assess the cardiovascular risk profile of young adolescents living in a semi-rural area of mainland Greece, Volos.

MATERIALS AND METHODS

A total of 198 children (106 females and 92 males) aged 11.6 +/- 0.4 years were randomly recruited.

RESULTS

Mean body mass index was 20.4 +/- 3.5 kg m(-2), while 30.3% of children were overweight and 6.7% were obese; no differences were observed between boys and girls. Mean plasma cholesterol (4.93 +/- 0.75 mmol L(-1)), low-density lipoprotein-cholesterol (3.29 +/- 0.64 mmol L(-1)) and triglyceride (0.97 +/- 0.31 mmol L(-1)) concentrations were above age-specific recommended values. On the other hand, mean high-density lipoprotein-cholesterol was acceptable for 92.3% of the children. Self-reported daily energy intake (8.37 +/- 3.06 MJ) was adequate for age, but intake of fat was high (42.0 +/- 9.2% of energy) and that of carbohydrate was relatively low (44.5 +/- 10.0% of energy). Saturated fat consumption was elevated (15.6 +/- 4.3% of energy), while polyunsaturated fat intake fell short (4.8 +/- 1.6% of energy). The study participants spent 9.60 +/- 6.44 h week(-1) on moderate to vigorous physical activities, while they devoted 16.60 +/- 8.81 h week(-1) to sedentary activities. Boys spent significantly more time than girls on both physical (P < 0.001) and sedentary (P = 0.001) activities. No major gender differences were observed in anthropometric, dietary and plasma lipid parameters.

CONCLUSION

The findings from the present study support the worrisome trends that have been documented in Greek youngsters elsewhere, and predict an unfavourable cardiovascular risk profile for the Greek population in the foreseeable future.

Proton pump inhibition prevents gastrointestinal bleeding in ultramarathon runners: a randomised, double blinded, placebo controlled study

BACKGROUND

Ultra-endurance running is emerging as a popular sport in Western industrialised countries. Gastrointestinal bleeding has been reported to be an adverse effect in these runners.

OBJECTIVE

To see if the oral administration of a proton pump inhibitor would reduce the incidence of gastrointestinal bleeding in an ultramarathon.

METHODS

In a randomised, double blinded, placebo controlled study, a prophylactic regimen of three days of an oral proton pump inhibitor (pantoprazole 20 mg) was tested in healthy athletes participating in the Spartathlon ultramarathon. The incidence of gastrointestinal bleeding was assessed by a stool guaiac test.

RESULTS

Results were obtained for 70 healthy volunteers. The data for 20 of 35 runners in the intervention group and 17 of 35 runners in the placebo group were entered into the final analysis. At the end of the ultramarathon, two subjects in the intervention group and 12 in the placebo group had positive stool guaiac tests (risk difference 0.86; 95% confidence interval 0.45 to 0.96; p = 0.001).

CONCLUSION

A short prophylactic regimen of oral proton pump inhibition can successfully decrease the incidence of gastrointestinal bleeding in participants in an ultramarathon.

Aerobic exercise training improves insulin sensitivity without changes in body weight, body fat, adiponectin, and inflammatory markers in overweight and obese girls

The aim of this study was to examine the effect of aerobic exercise training on insulin sensitivity in overweight and obese girls. Nineteen overweight and obese girls (mean +/- SD: age, 13.1+/-1.8 years; body mass index, 26.8+/-3.9 kg/m(2)) volunteered for this study. Body composition (dual-energy x-ray absorptiometry), insulin sensitivity (oral glucose tolerance test and homeostasis model assessment estimate of insulin resistance; n=15), adiponectin, C-reactive protein (CRP), interleukin (IL) 6, insulin-like growth factor-1, soluble intercellular adhesion molecule-1 and soluble vascular cell adhesion molecule-1 serum levels, and blood lipids and lipoproteins were assessed before and after 12 weeks of aerobic training. Cardiorespiratory fitness increased by 18.8% (P<.05) as a result of training. The area under the insulin concentration curve (insulin area under the curve) decreased by 23.3% (12781.7+/-7454.2 vs 9799.0+/-4918.6 microU.min/mL before and after intervention, respectively; P=.03). Insulin sensitivity was improved without changes in body weight (pre-intervention, 67.9+/-14.5 kg; post-intervention, 68.3+/-14.0 kg) or percent body fat (pre-intervention, 41.4% +/- 4.8%; post-intervention, 40.7%+/-5.2%). The lower limb fat-free mass increased by 6.2% (P<.01) as a result of training, and changes in lower limb fat-free mass were correlated with changes in the insulin area under the curve (r= -.68; P< .01). Serum adiponectin, IL-6, and CRP concentrations did not change (pre-intervention vs post-intervention: adiponectin, 9.57+/-3.01 vs 9.08+/-2.32 microg/mL; IL-6, 1.67+/-1.29 vs 1.65+/-1.25 pg/mL, CRP, 3.21+/-2.48 vs 2.73+/-1.88 mg/L) whereas insulin-like growth factor-1 was lower after training (pre-intervention, 453.8 +/- 159.3 ng/mL; post-intervention, 403.2+/- 155.1 ng/mL; P<.05). In conclusion, 12 weeks of aerobic training improved insulin sensitivity in overweight and obese girls without change in body weight, percent body fat, and circulating concentrations of adiponectin, IL-6, CRP, and other inflammatory markers. These findings suggest that increased physical activity may ameliorate the metabolic abnormalities associated with obesity in children with a mechanism other than the parameters cited earlier.

Dramatic elevations of interleukin-6 and acute-phase reactants in athletes participating in the ultradistance foot race spartathlon: severe systemic inflammation and lipid and lipoprotein changes in protracted exercise

CONTEXT AND OBJECTIVE

Plasma IL-6, the serum inflammatory markers C-reactive protein (CRP) and serum amyloid A (SAA), and the tissue destruction marker-free plasma DNA, as well as the circulating lipid profile, were examined in athletes participating in the ultradistance foot race of the 246-km Spartathlon. SETTING, DESIGN, AND PARTICIPANTS: This race consists of continuous, prolonged, brisk exercise. Blood samples were obtained from 15 male athletes, who finished the race in less than 36 h, taken before, at the end of, and 48 h after the end of the race.

RESULTS

IL-6, CRP, SAA, and free plasma DNA levels markedly increased (by 8000-, 152- 108-, and 10-fold, respectively) over the baseline at the end of the race. However, IL-6 levels returned to normal by 48 h, whereas CRP, SAA, and free plasma DNA remained elevated. The mean values of cholesterol, triglycerides, low-density lipoprotein, and apolipoprotein B decreased to a minimum value at the end of the race and remained low 48 h after the race. High-density lipoprotein levels, on the other hand, were mildly increased at the end of the race (P < 0.015) and decreased to normal 48 h after the race. Apolipoprotein AI levels decreased significantly during the time course of the exercise and remained low 48 h after the race (P < 0.001).

CONCLUSIONS

These observations suggest that continuous, prolonged, moderate-intensity exercise is associated with markedly elevated IL-6 and acute-phase reactant concentrations, peripheral tissue damage, and significant changes in serum lipid levels. The biochemical changes observed during the Spartathlon amount to a potent systemic inflammatory response, which might explain severe cardiovascular events that occur during prolonged exercise in compromised individuals.

Effect of Maltose-Containing Sports Drinks on Exercise Performance

This study examined the effect of maltose-containing sports drinks on exercise performance. Ten subjects completed 4 trials. Each trial consisted of a glycogen depletion protocol, followed by a 15-min refueling, after which subjects performed an 1-h performance test while consuming one of the experimental drinks (HGlu, glucose; HMal, maltose; MalMix, sucrose, maltose, and maltodextrin; Plac, placebo). Drinks provided 0.65 g/kg body weight carbohydrates during refueling and 0.2 g/kg every 15 min during the performance test. Although no significant differences were found in performance (HGlu: 67.2 ± 2.0; HMal: 68.6 ± 1.7; MalMix: 66.7 ± 2.0; Plac: 69.4 ± 3.0 min, P > 0.05), subjects completed the MalMix trial 3.9% faster than the Plac. Carbohydrate drinks caused comparable plasma glucose values that were significantly higher during refueling and at the end of exercise, compared to Plac. The data suggest that although carbohydrate drinks help to maintain plasma glucose at a higher level, no differences in performance could be detected after glycogen-depleting exercise.