Changes in Athletic Performance in Children Attending a Secondary School with a Physical Activity Profile

The longitudinal and multidisciplinary research project Malmö Youth Sport Study measured the sports results achieved by two cohorts of pupils using a variable named ACHIEVE, dividing the pupils into three categories (an elite group competing at the national or international level, a group competing at the district level, and a third group either not competing at all or below district level). This was assessed three and six years after baseline at age 13. An additional hypothetical measure, based on information from the athletes’ trainers, predicted the category the pupils were expected to belong to after twelve years (age 25). Social variables related to the ACHIEVE variable are sex, socio-economic position of the parents, ethnicity, completed secondary sports school, sports capital, and quartile of birth. After three years, 28% of the pupils belonged to the elite group and after six years, 26%. Thirty-two and 48%, respectively, had abandoned their elite efforts. The elite group remained fairly stable over time but fewer girls than boys advanced to the elite group. The pupils at the school have a homogenous middle-class background. We found little evidence that socio-economic factors affected ACHIEVE. Nearly all parents had been engaged in sports, either competing or as coaches. On admission to the school, there was a pronounced relative age effect (RAE). This remained after three years as the age was significantly different between the three groups but was reduced after six years. According to the prognosis made by the coaches, the elite group would be considerably smaller when the subjects reached the age of 25. The RAE was again significant in the prognosis. A further follow-up when the subjects are 25 years old will reveal not only what proportion of subjects are actively competing, but also if they are engaged in recreational sports, to what extent the RAE is present, and how accurately coaches can predict success.

Physical activity spectrum discriminant analysis-A method to compare detailed patterns between groups

Investigating physical activity (PA) patterns as a detailed intensity spectrum instead of crude intensity categories have improved the ability to analyze the relationship between measured PA and health variables. The aim of this methodological study was to introduce and investigate the utility of using detailed PA intensity spectrum compared to crude PA intensity categories for comparison of PA between groups and between repeated measures. The study sample consisted of two groups of children, where one group was scheduled for extended physical education (PE) by daily classes while the other group followed usual PE schedule. Accelerometer data was processed into traditional crude PA intensity categories and into detailed PA intensity spectrum. Multivariate partial least squares regression for discriminant analysis (PLS-DA) was applied for PA intensity spectrum group comparison and compared to traditional univariate statistical analysis. Repeated measures were investigated using independent PLS-DA as well as multilevel PLS-DA for paired analysis. While traditional analysis of crude PA intensity categories was unable to find any group differences, multivariate analysis of the PA intensity spectrum identified statistically significant differences. By the extension of multilevel PLS-DA for paired comparison, a clear difference in the PA intensity spectrum was demonstrated between repeated measures. In conclusion, analysis of detailed PA intensity spectrum demonstrates utility for comparing detailed PA data between groups and between repeated measures in interventional and observational research.

Lung function is associated with tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) levels in school-aged children

BACKGROUND

Tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) is a cytokine with inflammatory and apoptotic properties. A complex relationship exists between TRAIL and the lung where both elevated TRAIL and TRAIL deficiency are associated with lung impairment. In neonatal mice, TRAIL is thought to translate respiratory infections into chronic lung disease but the association between TRAIL and lung function in childhood has not been assessed.

AIM

To assess the cross-sectional relationship between TRAIL levels and lung function in school-aged children.

METHODS

The study cohort consisted of 170 school-aged children attending four schools in Malmö, Sweden. Lung volumes, impulse oscillometry (IOS) and serum TRAIL were measured for all children. Linear regression was used to assess changes in lung function per 1-SD increase in TRAIL. General linear models were used to assess mean lung function by tertiles (T) of TRAIL.

RESULTS

Mean age was 9.9 years (±0.6). A 1-SD increase in TRAIL was associated with lower values of FEV₁ and FEV₁/VC (change in FEV₁ (L) and FEV₁/VC ratio: -0.047, p-value 0.002, and -0.011, p-value 0.020, respectively) and higher values of lung resistance (change in R₅ and R₂₀ (kPa/(L/s)): 0.035, p-value <0.001 and 0.027, p-value 0.004, respectively). These associations remained significant after excluding children with pre-existing lung disease. Higher TRAIL levels were associated with more negative values for X₅ in general linear models (Mean X₅ (kPa/(L/s)) in T1 (low TRAIL): -0.193 vs T3 (high TRAIL): -0.216, p-value 0.026).

CONCLUSIONS

High TRAIL levels are significantly associated with markers of pulmonary airflow obstruction in school-aged children.

School-based study found that physical activity and aerobic fitness predicted increases in total body fat and abdominal fat at a mean age of 9.8 years

AIM

We assessed whether baseline measurements of physical activity, aerobic fitness, body fat and abdominal fat were predictors of changes in body fat measurements over a two-year period.

METHODS

The study comprised of 204 children aged 9.8 ± 0.6 years with a normal body mass distribution, who recruited from four schools in middle-class areas of Malmö, Sweden, from 2001 to 2004. Peak oxygen uptake and physical activity were measured at baseline. Body fat was measured by dual-energy X-ray absorptiometry at baseline and two years later.

RESULTS

Physical activity, aerobic fitness and total body fat or abdominal fat were predictors of change in total body fat or abdominal fat over a period of two years. Changes in the percentage of body fat were not related to any of the baseline measurements.

CONCLUSION

Our two-year follow-up of children with a mean age of 9.8 years at baseline showed that physical activity, aerobic fitness and body fat or abdominal fat predicted changes in total body fat or abdominal fat, but not the percentage of body fat.

Galectin-3 levels relate in children to total body fat, abdominal fat, body fat distribution, and cardiac size

Galectin-3 has recently been proposed as a novel biomarker for cardiovascular disease in adults. The purpose of this investigation was to assess relationships between galectin-3 levels and total body fat, abdominal fat, body fat distribution, aerobic fitness, blood pressure, left ventricular mass, left atrial size, and increase in body fat over a 2-year period in a population-based sample of children. Our study included 170 children aged 8-11 years. Total fat mass and abdominal fat were measured by dual-energy x-ray absorptiometry (DXA). Body fat distribution was expressed as abdominal fat/total fat mass. Maximal oxygen uptake was assessed by indirect calorimetry during a maximal exercise test and scaled to body mass. Systolic and diastolic blood pressure and pulse pressure were measured. Left atrial size, left ventricular mass, and relative wall thickness were measured by echocardiography. Frozen serum samples were analyzed for galectin-3 by the Proximity Extension Assay technique. A follow-up DXA scan was performed in 152 children 2 years after the baseline exam. Partial correlations, with adjustment for sex and age, between galectin-3 versus body fat measurements indicated weak to moderate relationships. Moreover, left atrial size, left ventricular mass, and relative wall thickness and pulse pressure were also correlated with galectin-3. Neither systolic blood pressure nor maximal oxygen uptake was correlated with galectin-3. There was also a correlation between galectin-3 and increase in total body fat over 2 years, while no such correlations were found for the other fat measurements.

CONCLUSION

More body fat and abdominal fat, more abdominal body fat distribution, more left ventricular mass, and increased left atrial size were all associated with higher levels of galectin-3. Increase in total body fat over 2 years was also associated with higher levels of galectin-3. What is Known: • Galectin-3 has been linked to obesity and been proposed to be a novel biomarker for cardiovascular disease in adults. • Information on this subject in children is very scarce. What is New: • The present study demonstrates a relationship between galectin-3 levels and total body fat, abdominal fat, body fat distribution, cardiac size and geometry, and increase in total body fat over 2 years in young children.

Cystatin B, cathepsin L and D related to surrogate markers for cardiovascular disease in children

OBJECTIVE

This study investigated potential associations between novel biomarkers for cardiovascular disease and other surrogate markers for health.

METHODS

Community sample of 170 (92 boys and 78 girls) children aged 8-11 years. Total fat mass (TBF) and abdominal fat (AFM) were measured by Dual-energy x-ray absorptiometry (DXA). Total body fat was also expressed as percentage of total body mass (BF%), and body fat distribution was calculated as AFM/TBF. Maximal oxygen uptake (VO2PEAK), systolic and diastolic blood pressure (SBP and DBP) and pulse pressure (PP) were measured. Echocardiography was performed. Left atrial size (LA) and left ventricular mass (LVM) were measured. A follow-up DXA scan was available in 152 children (84 boys and 68 girls). Frozen serum samples were analyzed for cystatin B, cathepsin L and cathepsin D.

RESULTS

Partial correlations between cystatin B versus lnTBF, lnBF%, lnAFM, AFM/TBF, VO2PEAK and PP were; r = 0.38, 0.36, 0.38, 0.29, -0.25 and 0.25, P = 0.001 or less for all. Weaker predominantly non-significant correlations were found for cathepsin L, whereas cathepsin D was not related to any surrogate markers for health. No significant correlations were found between biomarkers and change in body fat over 2 years.

CONCLUSION

Findings from this community-based cohort of young children show that surrogate markers for cardiovascular disease such as total fat mass, percent body fat, abdominal fat, body fat distribution, maximal oxygen uptake and pulse pressure were all associated with cystatin B. This was not found for cathepsin L or cathepsin D.

Total body fat, abdominal fat, body fat distribution and surrogate markers for health related to adipocyte fatty acid-binding protein (FABP4) in children

BACKGROUND

The aim of the study was to assess possible relationships between adipocyte fatty acid-binding protein (FABP4) and total body fat (TBF), abdominal fat, body fat distribution, aerobic fitness, blood pressure, cardiac dimensions and the increase in body fat over 2 years in a community sample of children.

METHODS

A cross-sectional study was used in a community sample of 170 (92 boys and 78 girls) children aged 8-11 years. TBF and abdominal fat (AFM) were measured by dual-energy X-ray absorptiometry (DXA). TBF was also expressed as percentage of total body mass (BF%), and body fat distribution was calculated as AFM/TBF. Maximal oxygen uptake (VO2PEAK) was assessed by indirect calorimetry during a maximal exercise test and scaled to body mass. Systolic and diastolic blood pressure (SBP and DBP) and pulse pressure (PP) were measured. Echocardiography was performed. Left atrial (LA) size was measured, and left ventricular mass (LVM) was calculated. A follow-up DXA scan was available in 152 children (84 boys and 68 girls). Frozen serum samples were analyzed for FABP4.

RESULTS

Partial correlations, with adjustment for sex, between FABP4 vs. ln TBF, ln BF%, ln AFM, AFM/TBF and VO2PEAK were (r=0.69, 0.68, 0.69, 0.49 and -0.39, p<0.05 for all). Moreover, SBP, PP, LVM and LA were also weakly correlated with FABP4 (r=0.23, 0.22, 0.28 and 0.21, p<0.05 for all). Correlations between FABP4 vs. increase in TBF and AFM over 2 years were 0.29 and 0.26, p<0.05, for both. (Increase in percent body fat or change in fat distribution were not correlated.) Conclusions: Findings from this community-based cohort of young children show that increased body fat and abdominal fat, more abdominal body fat distribution, low fitness, more LVM and increased LA, increased SBP and PP were all associated with increased levels of FABP4. Increase in TBF and abdominal fat over 2 years were also associated with increased levels of FABP4.

Cognitive abnormalities and cerebral perfusion defects in a community-dwelling cohort of elderly men with MMSE within the normal range

OBJECTIVES

Mini Mental State Examination's (MMSE's) sensitivity in its upper level is questioned, hence we investigated cognitive abnormalities and defects in regional cerebral blood flow (rCBF) in elderly with MMSE scores ≥24.

METHODS

One hundred and four men at age 81 with MMSE scores ≥24 (mean 28.4 ± 1.7), no dementia or stroke, were examined with neuropsychological test battery, and their rCBF was estimated using ^99mTc-HMPAO SPECT.

RESULTS

MMSE was very sparsely correlated with rCBF. Instead, visuo-spatial tests were correlated with rCBF in parietal and occipital lobe, verbal tests with rCBF in frontal and temporal-parietal lobes, and most of all between Digit Symbol and all rCBF regions, especially in subcortical gray and white matter. In a cluster of low achievers, test of Synonyms, followed by Digit Symbol and Benton test, had highest discriminatory importance. Low achievers had generalized rCBF changes especially in subcortical areas. Only lower scores on two MMSE items, figure drawing and calculation, could discriminate the clusters.

CONCLUSION

A substantial number of octogenarian men with MMSE ≥ 24p have widespread rCBF changes corresponding to a decreased speeded performance and verbal capacity.

Clinical value of wireless pH-monitoring of gastro-esophageal reflux in children before and after proton pump inhibitors

Background

Wireless pH-monitoring is an accurate method for diagnosing adults with gastroesophageal reflux disease (GERD). The aim of this study was to evaluate the use of the Bravo capsule on children investigated for GERD in terms of safety, tolerability and feasibility before and after administration of proton pump inhibitors.

Methods

A Bravo capsule was inserted during upper endoscopy under general anaesthesia or deep sedation with propofol. 48-hour pH-metry was performed in 106 children (50 males, 56 females) at the median age of 11 years (range 17 months-18 years). On the second day of investigation, proton pump inhibitor (PPI) was given at a mean dose of 1.6 mg/kg (SD ±0.6 mg). The definition of GERD was set to a reflux index (RI) of ≥5% and DeMeester score (DMS) ≥14.7.

Results

Application of the capsule was successful in 103 of the 106 children (97.2%) and interpretable in 99 of these 103 (96.1%). 49 of the children with interpretable results (49.5%) had GERD according to RI, while 51 (56.7%) had GERD according to DMS. After PPI was given on day 2, RI decreased from a median of 4.9% (range 0.3-63.4%) to 2.2% (0–58.0%), while DMS decreased from a median of 17.6 (range 2.2-207.6) to 8.2 (0.3-178.6), respectively (p < 0.0001). No severe adverse events were reported.

Conclusion

Wireless pH-metry is a safe and tolerable method when investigating children for GERD. PPI given on the second day of assessment provides additional information on response to treatment suggesting that pH-metry preferably should be extended to 48 hours.

Posterior laryngitis: a disease with different aetiologies affecting health-related quality of life: a prospective case-control study

BACKGROUND

Laryngo-pharyngeal reflux (LPR) is assumed to be the most common cause of posterior laryngitis (PL). Since LPR is found in healthy subjects, and PL patients are not improved by acid-reducing therapy, other aetiologies to PL must be considered. The aims of this study in PL were to investigate the prevalence of acid reflux in the proximal oesophagus and functional gastrointestinal symptoms, to analyse motilin levels in plasma, and to assess health-related quality of life (HRQOL) before and after treatment.

METHODS

Forty-six patients (26 women), with verified PL, median age 55 (IQR 41-68) years, were referred to oesophago-gastro-duodenoscopy and 24-h pH monitoring. Plasma motilin was analysed. The 36-item Short-Form questionnaire was completed at inclusion and at follow-up after 43±14 months, when also the Visual Analogue Scale for Irritable Bowel Syndrome was completed. Values were compared to controls. Treatment and relief of symptoms were noted from medical records.

RESULTS

Thirty-four percent had proximal acid reflux and 40% showed signs of distal reflux. Ninety-four percent received acid-reducing treatment, with total relief of symptoms in 17%. Patients with reflux symptoms had lower plasma motilin levels compared to patients without reflux symptoms (p = 0.021). The HRQOL was impaired at inclusion, but improved over time. Patients, especially men, had more functional gastrointestinal symptoms than controls.

CONCLUSIONS

This study indicates that a minority of patients with PL has LPR and is cured by acid-reducing therapy. Disturbed plasma motilin levels and presence of functional gastrointestinal symptoms are found in PL. The impaired HRQOL improves over time.

Aerobic capacity related to cardiac size in young children

AIM

Aerobic capacity, defined as peak oxygen uptake (VO2PEAK), is generally considered to be the best single marker for aerobic fitness. We assessed if VO2PEAK is related to different cardiac dimensions in healthy young children on a population base.

METHODS

In a cross-sectional study, 245 children (137 boys and 108 girls) aged 8-11 years, were recruited from a population based cohort. VO2PEAK (ml/min-1/kg-1) was assessed by indirect calorimetry during a maximal exercise test. DXA-scan was used to measure lean body mass (LBM) and total fat mass (TBF). Echocardiography, with 2-dimensional guided M-mode, was performed in accordance with current guidelines. Left ventricular end-diastolic diameter (LVDD) and left atrial end-systolic diameter (LA) were measured, and left ventricular mass (LVM) was calculated.

RESULTS

Univariate correlations were found between VO2PEAK versus LVDD r=0.44 and LA r=0.27 (both P<0.05) and LVM r=-0.06 (NS) in boys. Corresponding values for girls were; 0.55, 0.34 (both P<0.05) and 0.11 (NS). Multiple regression analysis with VO2PEAK as dependent variable and inclusion of LBM, TBF, sex, age, Tanner stage, and maximal heart rate as independent variables showed that 67% of the total variance of VO2PEAK could be explained by these variables. Including LVDD or LA in the model, added 1% additional explained variance.

CONCLUSION

Findings from this population based cohort of young healthy children show that multiple cardiac dimensions at rest are related to VO2PEAK. However, the different cardiac dimensions contributed very little to the added explained variance of VO2PEAK.

Evaluation of image reconstruction methods for (123)I-MIBG-SPECT: a rank-order study

BACKGROUND

There is an opportunity to improve the image quality and lesion detectability in single photon emission computed tomography (SPECT) by choosing an appropriate reconstruction method and optimal parameters for the reconstruction.

PURPOSE

To optimize the use of the Flash 3D reconstruction algorithm in terms of equivalent iteration (EI) number (number of subsets times the number of iterations) and to compare with two recently developed reconstruction algorithms ReSPECT and orthogonal polynomial expansion on disc (OPED) for application on (123)I-metaiodobenzylguanidine (MIBG)-SPECT.

MATERIAL AND METHODS

Eleven adult patients underwent SPECT 4 h and 14 patients 24 h after injection of approximately 200 MBq (123)I-MIBG using a Siemens Symbia T6 SPECT/CT. Images were reconstructed from raw data using the Flash 3D algorithm at eight different EI numbers. The images were ranked by three experienced nuclear medicine physicians according to their overall impression of the image quality. The obtained optimal images were then compared in one further visual comparison with images reconstructed using the ReSPECT and OPED algorithms.

RESULTS

The optimal EI number for Flash 3D was determined to be 32 for acquisition 4 h and 24 h after injection. The average rank order (best first) for the different reconstructions for acquisition after 4 h was: Flash 3D(32) > ReSPECT > Flash 3D(64) > OPED, and after 24 h: Flash 3D(16) > ReSPECT > Flash 3D(32) > OPED. A fair level of inter-observer agreement concerning optimal EI number and reconstruction algorithm was obtained, which may be explained by the different individual preferences of what is appropriate image quality.

CONCLUSION

Using Siemens Symbia T6 SPECT/CT and specified acquisition parameters, Flash 3D(32) (4 h) and Flash 3D(16) (24 h), followed by ReSPECT, were assessed to be the preferable reconstruction algorithms in visual assessment of (123)I-MIBG images.

Body fat, abdominal fat and body fat distribution related to cardiovascular risk factors in prepubertal children

AIM

We analysed whether total body fat (TBF), abdominal fat and body fat distribution are associated with higher composite risk factor scores for cardiovascular disease (CVD) in young children.

METHODS

Cross-sectional study of 238 children aged 8-11 years. TBF and abdominal fat mass (AFM) were measured by Dual-Energy X-Ray Absorptiometry. TBF was expressed as a percentage of body weight (BF%). Body fat distribution was calculated as AFM/TBF. Maximal oxygen uptake (VO(2PEAK) ), systolic and diastolic blood pressure (SBP, DBP), and resting heart rate (RHR) were measured. Mean arterial pressure (MAP) and pulse pressure (PP) were calculated. Left atrial diameter (LA) was measured, and left ventricular mass (LVM) and relative wall thickness (RWT) were calculated. Z-scores were calculated. Sum of z-scores for SBP, DBP, MAP, PP, RHR, LVM, LA, RWT and -VO(2PEAK) was calculated in boys and girls, separately, and used as composite risk factor score.

RESULTS

Pearson correlations between ln BF%, ln AFM and AFM/TBF versus composite risk factor score for boys were r = 0.56, r = 0.59 and r = 0.48, all p < 0.001, and for girls r = 0.45, r = 0.50 and r = 0.48, all p < 0.001.

CONCLUSION

Total body fat, abdominal fat and body fat distribution were all associated with higher composite risk factor scores for CVD in young children.

Body fat, abdominal fat, and body fat distribution is related to left atrial diameter in young children

In adults, the size of the left atria (LA) has important prognostic information. In obese adults, adolescents and children enlargement of LA have been observed. This has not been investigated on a population-based level in young children. We therefore assessed if total body fat mass (TBF), abdominal fat, and body fat distribution were related to LA diameter. Cross-sectional study of 244 children (boys = 137 and girls n = 107) aged 8-11 years, recruited from an urban population-based cohort. Dual-energy X-ray absorptiometry (DXA) measured total lean body mass, TBF, and abdominal fat mass (AFM). Body fat was also calculated as a percentage of body mass (BF%). Body fat distribution (AFM/TBF) was calculated. Echocardiography was performed with two-dimensional guided M-mode. LA diameter was measured and left ventricular mass (LVM) was calculated. Systolic blood pressure and diastolic blood pressure were measured and maturity assessed according to Tanner. There were significant (P < 0.05) univariate correlations for all children between TBF (r = 0.40), BF% (r = 0.32), AFM (r = 0.41), and AFM/TBF (r = 0.41) vs. LA diameter. Multiple regression analyses with the inclusion of possible confounders such as lean body mass, blood pressure, gender, age, and Tanner stage revealed that TBF, AFM, and AFM/TBF were all independently related to LA diameter. Differences in the different body fat measurements explained 6-9% of the variance in LA size. These results demonstrated that both total body fat, AFM, and body fat distribution are already at a young age negatively and independently associated to LA diameter.

Aerobic fitness related to cardiovascular risk factors in young children

Low aerobic fitness (maximum oxygen uptake (VO(2 PEAK))) is predictive for poor health in adults. In a cross-sectional study, we assessed if VO(2 PEAK) is related to a composite risk factor score for cardiovascular disease (CVD) in 243 children (136 boys and 107 girls) aged 8 to 11 years. VO(2 PEAK) was assessed by indirect calorimetry during a maximal exercise test and scaled by body mass (milliliters per minute per kilogram). Total body fat mass (TBF) and abdominal fat mass (AFM) were measured by Dual-energy X-ray absorptiometry. Total body fat was expressed as a percentage of total body mass (BF%) and body fat distribution as AFM/TBF. Systolic and diastolic blood pressure (SDP and DBP) and resting heart rate (RHR) were measured. The mean artery pressure (MAP) and pulse pressure (PP) were calculated. Echocardiography, 2D-guided M-mode, was performed. Left atrial diameter (LA) was measured and left ventricular mass (LVM) and relative wall thickness (RWT) were calculated. Z scores (value for the individual - mean value for group)/SD were calculated by sex. The sum of z scores for DBP, SDP, PP, MAP, RHR, LVM, LA, RWT, BF%, AFM and AFM/TBF were calculated in boys and girls, separately, and used as composite risk factor score for CVD. Pearson correlation revealed significant associations between VO(2 PEAK) and composite risk factor score in both boys (r = -0.48 P < 0.05) and in girls (r = -0.42, P < 0.05). One-way ANOVA analysis indicated significant differences in composite risk factor score between the different quartiles of VO(2 PEAK) (P < 0.001); thus, higher VO(2 PEAK) was associated with lower composite risk factor score for CVD. In conclusion, low VO(2 PEAK) is associated with an elevated composite risk factor score for CVD in both young boys and girls.

Exercise capacity in relation to body fat distribution and muscle fibre distribution in elderly male subjects with impaired glucose tolerance, type 2 diabetes and matched controls

BACKGROUND

The aim of this study was to examine the impact of insulin sensitivity and muscle fibre composition to exercise capacity in individuals with type 2 diabetes (T2D), impaired glucose tolerance (IGT) and normal glucose tolerance (NGT).

METHODS

Thirty-nine male patients with T2D, 44 male subjects with IGT and 58 subjects with NGT matched for age, weight and body mass index (BMI) participated in the study. Insulin sensitivity was obtained with hyperinsulinemic-euglycemic clamps, muscle fibre distribution with a biopsy and exercise capacity from an incremental exercise test. Anthropometric measurements as height, weight, waist and hip circumference were performed.

RESULTS

There were small differences between groups in waist hip ratio (WHR) with significance attained between NGT and T2D. There was a progressive reduction in exercise capacity, both expressed as VO(2peak) and work rate from subjects with NGT to IGT to T2D. Multiple regression analysis with VO(2peak) as dependent variable showed insulin sensitivity to be the most important factor followed by Type I fibres. WHR and capillary density also influenced the variance of VO(2peak).

CONCLUSION

Exercise capacity is independently related to insulin sensitivity, muscle fibre composition and WHR in subjects with NGT, IGT and T2D who are matched for age and BMI.

Esophageal dysmotility is more common than gastroparesis in diabetes mellitus and is associated with retinopathy

OBJECTIVES

Gastroparesis is a well-known complication of diabetes mellitus, both in symptomatic and asymptomatic patients. Esophageal dysmotility has also been described, but is not as well-characterized. The etiology and effect of these complications need to be clarified. The aim of the present study was to evaluate esophageal and gastric motility, complications, gastrointestinal symptoms, and plasma biomarkers in a cross-sectional study comprising patients with diabetes mellitus.

METHODS

Patients with diabetes were consecutively asked to participate, and eventually 84 volunteers were included in the study. Esophageal manometry and the gastric emptying test were performed in all patients. Type of diabetes, symptoms, diabetic complications, body mass index (BMI), and biomarkers were recorded. Patients were interviewed about gastrointestinal symptoms.

RESULTS

Esophageal dysmotility was present in 63% of patients and gastroparesis in 13% of patients. There was no difference in dysmotility between patients with type 1 and type 2 diabetes or between genders. Gastrointestinal symptoms did not correlate to objective findings. Age correlated negatively with gastric emptying rate (p = 0.004). Patients with esophageal dysmotility had longer duration of diabetes compared to those without dysmotility (p = 0.043). In logistic regression analysis, retinopathy was strongly associated with esophageal dysmotility, independent of duration (p = 0.003).

CONCLUSIONS

Esophageal dysmotility is more common than gastroparesis in diabetes mellitus independent of gender, symptoms, and type of diabetes. There is a strong association between retinopathy and esophageal dysmotility.

Relation between cycling exercise capacity, fiber-type composition, and lower extremity muscle strength and muscle endurance

The aim of the study was to determine the relation between peak oxygen uptake V(O2)peak), peak work rate (WRpeak), fiber-type composition, and lower extremity strength and endurance during a maximal incremental cycle test. Thirty-nine healthy sedentary men, aged 30-46, participated in the study. Subjects performed a maximal incremental cycle test and isokinetic knee extension (KE) and flexion (KF) strength and endurance tests at velocities of 60 and 180° · s(-1). Muscle biopsies were taken from m. vastus lateralis and analyzed for fiber-type composition. A significant correlation existed between KE strength and V(O2)peak and WRpeak. Also, KF endurance correlated significantly to V(O2)peak and WRpeak. The KE endurance correlated significantly to WRpeak (rp = 0.32, p < 0.05) and almost significantly to V(O2)peak (rp = 0.28, p = 0.06). Stepwise multiple regression analyses showed that KE strength, KF endurance, and the percentage of type I fibers could explain up to 40% of the variation in V(O2) and WRpeak. The performance of sedentary subjects in a maximal incremental cycle test is highly affected by knee muscle strength and endurance. Fiber-type composition also contributes but to a smaller extent.

Lack of physical activity in young children is related to higher composite risk factor score for cardiovascular disease

AIM

This study evaluates whether accelerometer-measured physical activity is related to higher composite risk factor scores for cardiovascular disease (CVD) in children.

METHODS

Cross-sectional study that included 223 children aged 7.9-11.1 years (boys n = 123, girls n = 100). Daily physical activity was assessed by accelerometers for 4 days. Body fat was quantified by dual X-ray absorptiometry. Maximal oxygen uptake was measured during a maximal exercise test. Resting heart rate and blood pressure were measured. Z-scores [(value for the individual - mean value for group)/SD] were calculated for each variable, and the sum of different risk factor z-scores used as an index of composite risk factors score for CVD.

RESULTS

Partial correlations, from General Linear Model, between moderate to vigorous physical activity (MVPA), vigorous physical activity (VPA) and general physical activity versus index of composite risk factor score were in boys 0.29, 0.33 and 0.30 (all p < 0.05), respectively. The corresponding correlations in girls were -0.28, -0.32 (both p < 0.05) and -0.18 (NS), respectively.

CONCLUSION

Low amounts of MVPA and VPA were related to higher composite risk factor scores for CVD in children aged 8-11 years.

Impact of exercise intensity and duration on insulin sensitivity in women with T2D

BACKGROUND

Clinical guidelines seldom provide in depth information about the most suitable type and intensity of exercise to obtain optimal benefit in different subgroups of T2D individuals. The aim of this study was to examine the effect of group exercise training on exercise capacity, insulin sensitivity and HbA1c in women with diabetes.

METHODS

Twenty-two women with T2D participated in a supervised group exercise program for six months. The program combined endurance and resistance exercise. The duration and intensity of exercise for each subject was recorded. The volume of exercise was calculated as the product of exercise duration and intensity. Exercise capacity, insulin sensitivity and HbA1c were measured at baseline and after six months of training. The subjects were dichotomized with respect to training volume in a high training volume group and a low training volume group.

RESULTS

Exercise capacity did not change significantly during the training period. Insulin sensitivity increased significantly and HbA1c decreased significantly from baseline in the high volume group but not in the low volume group. The increase in insulin sensitivity was explained with the intensity of exercise by 30%. The reduction in HbA1c was explained with exercise by 25%.

CONCLUSION

Improvement in insulin sensitivity after six months combined supervised group training in female diabetic subjects is related to exercise intensity, whereas the reduction in HbA1c is related mainly to training volume. Metabolic effects of training may be seen in the absence of improved exercise capacity.

Evaluation of the effects of exercise on insulin sensitivity in Arabian and Swedish women with type 2 diabetes

AIMS

The purpose of this study was to evaluate the effects of exercise on cardio-respiratory fitness and insulin sensitivity in sedentary, overweight Arabian and Swedish women with type 2 diabetes.

METHODS

Eighteen Arabian and 14 Swedish women participated in a supervised 6-month resistance training and aerobic program of moderate intensity. Insulin sensitivity and VO(2max) were measured at entry to the study and after 3 and 6 months training.

RESULTS

After 6 months exercise, insulin sensitivity (M-value) increased (2.7+/-1.4 mg kg(-1) min(-1) vs. 3.4+/-2 mg kg(-1) min(-1), p<0.05) in all patients and accounted for by an increase in non-oxidative glucose metabolism (0.3+/-1.1 mg kg(-1) min(-1) vs. 1.5+/-1.5 mg kg(-1) min(-1), p<0.005) with no significant difference between the ethnic groups. Notably, significant improvement in HbA1c was only seen in the Swedish patients who achieved greater exercise intensity (73.3+/-4.8% vs. 63.3+/-5.2% of maximum heart rate, p<0.005). No changes were observed regarding VO(2max) or lipid profile in either group.

CONCLUSIONS

Although a 6-month exercise intervention of moderate intensity in Arabian and Swedish patients with type 2 diabetes can improve insulin sensitivity it is hampered by the metabolic inflexibility of switching between oxidation of glucose or fat.

Quantitative detection of myocardial ischaemia by stress echocardiography; a comparison with SPECT

Aims

Real-time perfusion (RTP) adenosine stress echocardiography (ASE) can be used to visually evaluate myocardial ischaemia. The RTP power modulation technique angio-mode (AM), provides images for off-line perfusion quantification using Qontrast^® software, generating values of peak signal intensity (A), myocardial blood flow velocity (β) and myocardial blood flow (Axβ). By comparing rest and stress values, their respective reserve values (A-r, β-r, Axβ-r) are generated. We evaluated myocardial ischaemia by RTP-ASE Qontrast^® quantification, compared to visual perfusion evaluation with ^99mTc-tetrofosmin single-photon emission computed tomography (SPECT).

Methods and Results

Patients admitted to SPECT underwent RTP-ASE (SONOS 5500) using AM during Sonovue^® infusion, before and throughout adenosine stress, also used for SPECT. Visual myocardial perfusion and wall motion analysis, and Qontrast^® quantification, were blindly compared to one another and to SPECT, at different time points off-line.

We analyzed 201 coronary territories (left anterior descendent [LAD], left circumflex [LCx] and right coronary [RCA] artery territories) in 67 patients. SPECT showed ischaemia in 18 patients and 19 territories. Receiver operator characteristics and kappa values showed significant agreement with SPECT only for β-r and Axβ-r in all segments: area under the curve 0.678 and 0.665; P < 0.001 and < 0.01, respectively. The closest agreements were seen in the LAD territory: kappa 0.442 for both β-r and Axβ-r; P < 0.01. Visual evaluation of ischaemia showed good agreement with SPECT: accuracy 93%; kappa 0.67; P < 0.001; without non-interpretable territories.

Conclusion

In this agreement study with SPECT, RTP-ASE Qontrast^® quantification of myocardial ischaemia was less accurate and less feasible than visual evaluation and needs further development to be clinically useful.

Head to head comparisons of two modalities of perfusion adenosine stress echocardiography with simultaneous SPECT

BACKGROUND

Real-time perfusion (RTP) contrast echocardiography can be used during adenosine stress echocardiography (ASE) to evaluate myocardial ischemia. We compared two different types of RTP power modulation techniques, angiomode (AM) and high-resolution grayscale (HR), with 99mTc-tetrofosmin single-photon emission computed tomography (SPECT) for the detection of myocardial ischemia.

METHODS

Patients with known or suspected coronary artery disease (CAD), admitted to SPECT, were prospectively invited to participate. Patients underwent RTP imaging (SONOS 5500) using AM and HR during Sonovue(R) infusion, before and throughout the adenosine stress, also used for SPECT. Analysis of myocardial perfusion and wall motion by RTP-ASE were done for AM and HR at different time points, blinded to one another and to SPECT. Each segment was attributed to one of the three main coronary vessel areas of interest.

RESULTS

In 50 patients, 150 coronary areas were analyzed by SPECT and RTP-ASE AM and HR. SPECT showed evidence of ischemia in 13 out of 50 patients. There was no significant difference between AM and HR in detecting ischemia (p = 0.08). The agreement for AM and HR, compared to SPECT, was 93% and 96%, with Kappa values of 0.67 and 0.75, respectively (p < 0.001).

CONCLUSION

There was no significant difference between AM and HR in correctly detecting myocardial ischemia as judged by SPECT. This suggests that different types of RTP modalities give comparable data during RTP-ASE in patients with known or suspected CAD.

Bone turnover markers are correlated with total skeletal uptake of 99mTc-methylene diphosphonate (99mTc-MDP)

Background

Skeletal uptake of ^99mTc labelled methylene diphosphonate (^99mTc-MDP) is used for producing images of pathological bone uptake due to its incorporation to the sites of active bone turnover. This study was done to validate bone turnover markers using total skeletal uptake (TSU) of ^99mTc-MDP.

Methods

22 postmenopausal women (52–80 years) volunteered to participate. Scintigraphy was performed by injecting 520 MBq of ^99mTc-MDP and taking whole body images after 3 minutes, and 5 hours. TSU was calculated from these two images by taking into account the urinary loss and soft tissue uptake. Bone turnover markers used were bone specific alkaline phosphatase (S-Bone ALP), three different assays for serum osteocalcin (OC), tartrate resistant acid phosphatase 5b (S-TRACP5b), serum C-terminal cross-linked telopeptides of type I collagen (S-CTX-I) and three assays for urinary osteocalcin (U-OC).

Results

The median TSU of ^99mTc-MDP was 23% of the administered activity. All bone turnover markers were significantly correlated with TSU with r-values from 0.52 (p = 0.013) to 0.90 (p < 0.001). The two resorption markers had numerically higher correlations (S-TRACP5b r = 0.90, S-CTX-I r = 0.80) than the formation markers (S-Total OC r = 0.72, S-Bone ALP r = 0.66), but the difference was not statistically significant. TSU did not correlate with age, weight, body mass index or bone mineral density.

Conclusion

In conclusion, bone turnover markers are strongly correlated with total skeletal uptake of ^99mTc-MDP. There were no significant differences in correlations for bone formation and resorption markers. This should be due to the coupling between formation and resorption.

Long-term biokinetics and radiation exposure of patients undergoing 14C-glycocholic acid and 14C-xylose breath tests

The (14)C-glycocholic acid and (14)C-xylose breath tests are clinically used for the diagnosis of intestinal diseases, such as bacterial overgrowth in the small intestine. The two tests have in earlier studies been thoroughly evaluated regarding their clinical value, but due to the long physical half-life of (14)C and the limited biokinetic and dosimetric data, which are available for humans, several hospitals have been restrictive in their use. The aim of this study was to investigate the long-term biokinetics and dosimetry of the two (14)C compounds in patients and volunteers, using the highly sensitive accelerator mass spectrometry (AMS) technique. Eighteen (18) subjects were included, 9 for each compound. The (14)C content in samples from exhaled air, urine, and, for some subjects, also feces were analyzed with both liquid scintillation counting (LSC) and AMS. The results from the glycocholic acid study showed that, up to 1 year after the administration, 67%+/-6% (mean+/-standard deviation) of the administered activity was recovered in exhaled air, 2.4%+/-0.4% was found in urine, and 7.6% (1 subject) in feces. In the xylose study, the major part was found in the urine (66%+/-2%). A significant part was exhaled (28%+/-5%), and the result from an initial 72-hour stool collection from 2 of the subjects showed that the excretion by feces was insignificant. The absorbed dose to various organs and tissues and the effective dose were calculated by using biokinetic models, based on a combination of experimental data from the present study and from earlier reports. In the glycocholic acid study, the highest absorbed dose was received by the colon (1.2 mGy/MBq). In the xylose study, the adipose tissue received 0.8 mGy/MBq. The effective dose was estimated to 0.5 (glycocholic acid) and 0.07 mSv/MBq (xylose). Thus, from a radiation protection point of view, we see no need for restrictions in using the two (14)C-labeled radiopharmaceuticals on adults with the activities normally administered (0.07-0.4 MBq).

Oesophageal dysmotility, delayed gastric emptying and gastrointestinal symptoms in patients with diabetes mellitus

AIMS

Gastroparesis is a common gastrointestinal complication in diabetes mellitus, whereas dysfunction in the other gastrointestinal organs has been less thoroughly investigated. Furthermore, it is not known whether there is any relationship between motility and dysmotility between these organs. The aim of this study was to examine whether diabetic patients with gastrointestinal symptoms also have motility disturbances in the oesophagus and stomach and, if so, whether there are any associations between these disturbances.

METHODS

Thirty-one patients with diabetes mellitus who complained of gastrointestinal symptoms were asked to complete a questionnaire about their symptoms. They were further investigated with oesophageal manometry and gastric emptying scintigraphy.

RESULTS

Fifty-eight per cent of the patients had abnormal oesophageal function, and 68% had delayed gastric emptying. Abdominal fullness was the only symptom that related to any dysfunction, and it was associated with delayed gastric emptying (P = 0.02). We did not find any relationship in motility or dysmotility between the oesophagus and the stomach.

CONCLUSION

Oesophageal dysmotility, as well as gastroparesis, are common in patients with diabetes who have gastrointestinal symptoms. It is important to investigate these patients further, to be able to reach an accurate diagnosis and instigate appropriate treatment. Our findings indicate that the oesophagus and the stomach function as separate organs and that pathology in one does not necessarily mean pathology in the other.

Prediction of fat-free body mass from bioelectrical impedance among 9- to 11-year-old Swedish children

AIM

Predictive equations for estimating body composition from bioelectrical impedance analysis (BIA) among Scandinavian children are lacking. In the present study, equations for estimation of fat-free body mass (FFM) and lean tissue mass (LTM) were developed and cross-validated from BIA using dual-energy X-ray absorptiometry (DXA) as the reference measurement of body composition.

METHODS

The study population consisted of 49 girls and 52 boys aged 9-11 years from Malmö, Sweden. Bioelectrical impedance was measured between hand and foot at 50 kHz. Predictive equations were developed by multiple linear regression and cross-validated against DXA measurements of body composition.

RESULTS

FFM was predicted from BIA and anthropometric variables with an adjusted R(2)= 0.95 and root mean square error (RMSE) = 0.84 kg, and LTM was predicted with an adjusted R(2)= 0.95 and RMSE = 0.87 kg. Cross-validation revealed a mean RMSE = 0.95 kg FFM and a mean RMSE = 0.96 kg LTM. Prediction of body composition from equations developed in previous literature was mixed when applied to the present cohort of children.

CONCLUSIONS

FFM and LTM are predicted with sufficient accuracy at the population level. We recommend that the predictive equations developed in the present study are used in prepubescent European children aged 9-11 years only in order to minimize confounding of results because of possible differences in population samples.

BMI and objectively measured body fat and body fat distribution in prepubertal children

BACKGROUND

Body Mass Index (BMI) is often used as a surrogate estimate of body fat in epidemiological studies. This study explores the association between BMI, body fat and body fat distribution assessed by Dual-Energy X-Ray Absorptiometry (DXA) in younger children.

METHODS

Cross-sectional study of 246 children (138 boys and 108 girls) aged 8-11 years. DXA was used to quantify abdominal fat mass (AFM), total body fat (TBF) and also total body fat as percentage of total body mass (BF%). Body fat distribution was calculated as AFM/TBF.

RESULTS

We found close correlations between BMI vs. TBF, BF% and AFM (r = 0.94, r = 0.92 and r = 0.93) for boys and (r = 0.95, r = 0.92 and r = 0.95) for girls, respectively (P<0.05 for all r-values). However, significantly lower correlation (P<0.001 for difference between the r-values) existed for body fat distribution (r = 0.64 for boys and 0.73 for girls).

CONCLUSION

Percentage body fat, TBF and AFM were all closely associated with BMI, suggesting that BMI serves as a good surrogate marker for obesity in population studies. However, a significantly lower correlation existed for BMI vs. body fat distribution, which may be a limitation when BMI is used to study cardiovascular risk factors in epidemiological studies.

Reference values for respiratory system impedance by using impulse oscillometry in children aged 2-11 years

The forced oscillation technique makes it possible to evaluate the mechanical properties of the respiratory system with a minimum of cooperation. The method is therefore especially useful in children. Impulse oscillometry (IOS) is a commercially available version of this technique. There is, as yet, limited information on reference values for IOS in children. The aim of this study was to extend the reference values for IOS variables and to study their correlation with height, weight and age in healthy children. A sample (n = 360) of children (age 2.1-11.1 years) was measured by using impulse oscillometry (IOS; Jaeger, Würzburg, Germany). The sample was based on children attending kindergarten in Finland and children attending primary school in Sweden. Measurements of respiratory resistance (Rrs) and reactance (Xrs) at 5, 10, 15 and 20 Hz, total respiratory impedance (Zrs) and the resonance frequency (Fr) were made. All variables were related to body height. Most of them were also weakly related to weight. Reference equations for children (height 90-160 cm) are presented.

Gender differences and determinants of aerobic fitness in children aged 8–11 years

Previous studies of gender differences in maximum oxygen uptake have come to different conclusions. Limited data exists where the determinants of maximum oxygen uptake have been evaluated in a comprehensive manner. Thus, we examined 248 children (140 boys and 108 girls), aged 7.9-11.1 years. Body composition was determined by dual-energy X-ray absorptiometry, measured variables were total body fat (TBF) and lean body mass (LBM). Maximal oxygen uptake (VO2peak) was measured by indirect calorimetry during a maximal cycle exercise test. Daily physical activity was assessed by accelerometers and duration of vigorous activity per day (VPA) was calculated. Left ventricular inner diastolic diameter (LVDD) was measured by echocardiography. Lung function was evaluated with spirometric testing and whole body plethysmography. Boys had between 8 and 18% higher values than girls for VO2peak, dependent upon whether VO2peak was expressed in absolute values or scaled to body mass, LBM or if allometric scaling was used. In multiple regression analysis absolute values of aerobic fitness were independently related to LBM, maximal heart rate (Max HR), gender, LVDD, and VPA. Furthermore, when VO2peak was scaled to body mass it was independently related to ln TBF, Max HR, gender, VPA, and LVDD. Lung function had no relation to VO2peak. Our study concludes that body composition is the main predictor for VO2peak, in children aged 8-11 years, whereas VPA or LVDD has only a modest impact. Existing gender differences in VO2peak cannot be explained only by differences in body composition, physical activity, or heart size.

Oesophageal dysmotility, delayed gastric emptying and autonomic neuropathy correlate to disturbed glucose homeostasis

AIMS/HYPOTHESIS

Among diabetic patients, glucose homeostasis may be affected by abnormal gastrointestinal motility and autonomic neuropathy. This study analysed whether oesophageal dysmotility, delayed gastric emptying or autonomic neuropathy affect glucose homeostasis.

MATERIALS AND METHODS

Oesophageal manometry and gastric emptying scintigraphy were performed in 20 diabetic patients. Heart-rate variation during deep breathing (expiration/inspiration [E/I] ratio) and continuous subcutaneous glucose concentrations for a period of 72 h were also monitored in the same patients.

RESULTS

Oesophageal dysmotility was found in eight of 14 patients. Eleven of 20 patients had delayed gastric emptying (abnormal gastric emptying half-time [T (50)]) and nine of 18 had an abnormal E/I ratio. Complaints of abdominal fullness were predictive of delayed gastric emptying. A low peristaltic speed of the oesophagus was associated with impaired T (50) (r ( s )=-0.67; p=0.02). One hour after breakfast, subcutaneous glucose levels decreased in patients with delayed gastric emptying but continued to rise in those with normal emptying. Consequently, the median glucose level 2.5 h after breakfast was lower in the former (9.1 [4.2-12.5] vs 14.3 [11.2-17.7] mmol/l; p<0.05). Glucose fluctuations during the 72 h were significantly higher in patients with an abnormal E/I ratio than in those with a normal E/I ratio (coefficient of variation: 41 [46-49] vs 28 [27-34]%; p=0.008).

CONCLUSIONS/INTERPRETATION

Abdominal fullness predicted delayed gastric emptying that was associated with diminished glucose uptake after breakfast. Low oesophageal peristaltic speed was associated with slow gastric emptying whereas parasympathetic neuropathy was associated with increased glucose variations.