The double burden of obesity and iron deficiency on children and adolescents in Greece: the Healthy Growth Study.

BACKGROUND: Some small cohort studies have noted that obesity co-exists with lower serum iron levels. The present study aimed to examine the association between being overweight and iron deficiency (ID) in a large cohort of Greek children and adolescents. METHODS: A representative sample of 2492 primary schoolchildren aged 9-13 years old was examined. Anthropometric, biochemical, clinical, dietary intake and physical activity data were collected. RESULTS: The prevalence of ID and iron deficiency anaemia (IDA) was higher in obese boys and girls compared to their normal-weight peers (P < 0.05). Serum ferritin was higher in obese compared to normal-weight boys (P = 0.024) and higher in obese compared to normal-weight and overweight girls (P = 0.001). By contrast, a negative association was found between transferrin saturation and adiposity in both boys and girls (P = 0.001 and P = 0.005). Furthermore, obese girls had significantly higher fibre intake than normal-weight girls (P = 0.048) and also overweight and obese boys and girls recorded significantly fewer pedometer steps than their normal-weight peers (P < 0.001). Finally, obesity more than doubled the likelihood of ID in both boys (odds ratio = 2.83; 95% confidence inteval = 1.65-4.85) and girls (odds ratio = 2.03; 95% confidence interval = 1.08-3.81) after controlling for certain lifestyle and clinical indices as potential confounders. CONCLUSIONS: The present study shows that obese children and adolescents were at greater risk for ID and IDA than their normal-weight peers. Low grade inflammation induced by excessive adiposity may be a reason for the observed low iron levels. This is also strengthened by the elevated serum ferritin levels, comprising an acute phase protein that is plausibly increased in inflammation.

Dairy intake associates with the IGF rs680 polymorphism to height variation in periadolescent children.

BACKGROUND/OBJECTIVES: Height is a classic polygenic trait, with a number of genes underlying its variation. We evaluated the prospect of gene-to-diet interactions in a children's cohort, for the insulin-like growth factor II (IGF) rs680 polymorphism and height variation. SUBJECTS/METHODS: We screened 795 periadolescent children (424 girls) aged 10-11 years old from the Gene and Diet Attica Investigation (GENDAI) pediatric cohort for the IGF rs680 polymorphism (rs680). RESULTS: Children homozygous for the common allele (GG) were taller (148.9+/-7.9 cm) compared with those with the A allele (148.1+/-7.9 cm), after adjusting for age, sex and dairy intake (beta+/-s.e.: 2.1+/-0.95, P=0.026). A trend for rs680 x dairy intake interaction was also revealed (P=0.09). Stratification by IGF rs680 genotype revealed positive significant (P=0.014) association between dairy product intake and height in A-allele children adjusted for the same confounders. A daily increase of four dairy servings was associated with a 0.4 cm increase in height. On grouping dairy intake into low (1.9+/-0.7 servings per day) and high dairy product consumption (4.4+/-1.5 servings per day), children with the A allele who were high dairy product consumers were taller compared with the low dairy product consumers (148.8+/-7.9 vs 147.4+/-7.7 cm, respectively, P=0.05). CONCLUSIONS: A higher consumption of dairy products is associated with increased height depending on the rs680 IGF2 genotype.

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.

Changes in free radical generation and antioxidant capacity during ultramarathon foot race.

BACKGROUND: Exhaustive exercise has been implicated in the generation of reactive oxygen species, resulting in oxidative stress. We studied the effect of a long-distance, endurance exercise on oxidative stress parameters in athletes who participated in the ultramarathon race Spartathlon (246 km). MATERIALS AND METHODS: This study included 18 runners (16 men and 2 women) aged 42.8 +/- 1.4 years. Blood samples were obtained 24 h before (prerace), at the end (postrace) and 48 h after the end of the race (48 h postrace). We measured oxidative stress indices, including red cell glutathione, malonyldialdehyde and 8-iso-prostaglandin F(2a), as well as the total antioxidant capacity. RESULTS: 8-Iso-prostaglandin F(2a) level increased significantly at the end of the race, compared to prerace levels (up to 914.7 +/- 61.4 pg mL(-1) from 197.6 +/- 8.4 pg mL(-1)), and remained 2.5-fold increased over the baseline 48 h after the race (532.0 +/- 54.2 pg mL(-1), P < 0.000). The total antioxidant capacity of the athletes increased from a baseline of 289.6 +/- 9.0 micromol L(-1) to 358.7 +/- 11.0 micromol L(-1) immediately after the race and remained elevated 48 h later (350.6 +/- 7.6 micromol L(-1)) (P < 0.001). CONCLUSIONS: Prolonged exercise induces a marked response of oxidative stress biomarkers, which in part is compensated by serum ability to scavenge free radicals. Whether these changes have long-term negative effects in the organism needs further investigation.

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.

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.

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.

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.

Clinical evaluation of plasma high-density lipoprotein subfractions (HDL2, HDL3) in non-insulin-dependent diabetics with coronary artery disease.

STATEMENT OF THE PROBLEM: Low levels of high-density lipoprotein cholesterol (HDL-C) have a strong association with coronary artery disease (CAD) in patients with non-insulin-dependent diabetes mellitus (NIDDM). In this study, we tried to evaluate whether one or both of the major HDL subclasses (HDL2, HDL3) is strongly associated with the risk of CAD in NIDDM subjects. METHODS: The separation of HDL subclasses was carried out by ultracentrifugation in a Beckman Airfuge. HDL2 subclass was isolated from the supernatant and its cholesterol content was measured enzymatically. Plasma HDL3 cholesterol was calculated as the difference between results for total HDL cholesterol and HDL2 cholesterol. RESULTS: NIDDM patients with CAD had significantly higher triglyceride levels compared to either control (217.09+/-55.04 versus 89.62+/-31.29 mg/dl, P=.001) or CAD patients without NIDDM (217.09+/-55.04 versus 156.28+/-46.39 mg/dl, P<.05). However, in the diabetic patients with CAD, there was a statistically significant decrease in HDL cholesterol (39.63+/-8.59 versus 55.86+/-13.49 mg/dl, P<.01), HDL2 cholesterol (8.74+/-3.28 versus 16.95+/-5.73 mg/dl, P<.001), and HDL3 cholesterol (31.23+/-7.41 versus 38.91+/-8.93 mg/dl, P<.05) in comparison to nondiabetic controls. Moreover, in the comparison between non-insulin-dependent diabetics with CAD and CAD subjects without NIDDM, HDL cholesterol (39.63+/-8.59 versus 46.13+/-6.33 mg/dl, P<.05) and HDL2 cholesterol (8.74+/-3.28 versus 11.84+/-4.01 mg/dl, P<.02) were significantly reduced, while HDL3 cholesterol levels were (31.23+/-7.41 versus 34.29+/-7.94 mg/dl, P=.92) unaltered. Additionally, the percentage reduction of cholesterol in HDL2 fraction was proportionately greater than the decrease in HDL3 subclass in both comparisons. Moreover, in NIDDM with CAD, HDL cholesterol was reduced by 29% and 14%, HDL2 cholesterol by 48% and 26%, and HDL3 cholesterol by 20% and 9%, compared relatively to controls and CAD subjects without NIDDM. CONCLUSIONS: In conclusion, HDL2 is the more variable subclass and reflects changes in HDL. This suggests that the protective role of total HDL against CAD is mainly mediated through HDL2 fraction. Therefore, HDL2 might be a better predictor of coronary heart disease than total HDL, in non-insulin-dependent diabetes mellitus.