Central corneal thickness - Z-ring corneal confocal microscopy versus ultrasound pachymetry

Abstract PURPOSE: To compare the repeatability and validity of corneal pachymetry by a corneal confocal microscope with a z-axis adapter (Confoscan 4.0 with z-ring adapter: z-CS4) versus ultrasound (US) pachymetry in the measurement of central corneal thickness (CCT). METHODS: CCT in 44 eyes of 44 subjects was determined with z-CS4. Z-CS4 exams were used to estimate the repeatability of thickness measurement by z-ring adapter for this confocal microscope. Intraclass Correlation Coefficient (ICC) between two different z-CS4 users was also determined. CCT in the same 44 eyes was determined with US pachymetry and measurements were compared with z-CS4 CCT. RESULTS: Z-CS4 CCT showed high intrainstrument reproducibility (ICC = 0.989; 95%CI 0.982-0.993; P < 0.0001). Mean difference among three CCT consecutive measures, in the same eye, was 0.8 +/- 11.1 microm. High correlation was found between two users (ICC = 0.896; 95%IC 0.830-0.937; P < 0.0001). Z-CS4 CCT showed high correlation with US pachymetry (ICC = 0.921; 95%CI 0.851-0.958; P < 0.0001). Mean corneal thickness determined was statistically different with the two methods (US: 512.6 +/- 65.8 microm; z-CS4: 487.8 +/- 60.1 microm; P < 0.0001). CONCLUSION: Z-CS4 seems an accurate, noninvasive and reproducible technique for CCT evaluation and confirms that central cornea is thinner when measured with confocal microscopy compared to ultrasounds. PMID: 17413957 [PubMed - indexed for MEDLINE

Energy Expenditure Measure By Portable Accelerometer During A High Altitude Trekking

Abstract: In the last years an ever increasing number of people participate in pleasure or work activities at high altitude. In this framework, the assessment of individual energy expenditure during ascent would be of great interest for adapting physical strain and personalizing food intake and equipment. However, environmental conditions prevent from obtaining a simple measure of energy expenditure by traditional methods. Recently, accelerometers have been introduced in clinical practice and scientific research, allowing to measure subjects energy expenditure during daily activities and different physical exercises. PURPOSE: aim of this study was to measure the total and single stage energy expenditure of healthy adults, during a trekking at high altitude, using an arm accelerometer. METHODS: fourteen healthy subjects (mean age 29.8\ub112.3 years, range 22-59 years) wore anAccelerometer SenseWear Pro Armband (Body Media, Inc., USA) during a 7-day trekking from Lukla airport (2851m) to the Pyramid Laboratory (5050 m, Nepal), for a total ascent of 2199 meters, divided into 5 stages. Daily subjects physical activity have been recorded and relative energy expenditure calculated. RESULTS: total energy expenditure related to physical activity ranged from 5987.4 and 10744.8 kcal (from 89.5 to 141.4 kcal/kg). Per kilogram average energy expenditure for the entire trekking was 116.8\ub114.8kcal/kg (mean\ub1SD), while the average energy expenditure for each 100 meters of ascent was 5.15\ub11.06 kcal/kg. Evaluating single stages, inter-individual per kilogram variability ranged from 16.3\ub13.7 and 29.2\ub14.8kcal/kg (from 16.1 to 26.5% of the single stage total energy expenditure). CONCLUSION: Our study confirms that the portable Accelerometer SenseWear Pro Armband is a useful and practical tool to assess energy expenditure during a trekking at high altitude. However, despite a similar track, we demonstrate a moderate inter-individual variability of measured energy expenditure. This variability could possibly be ascribed to different arm movements during walking and to different body composition

Corneal diabetic neuropathy: A confocal microscopy study

Abstract PURPOSE: To evaluate the role of corneal confocal microscopy in the diagnosis of morphologic damage of the corneal sub-basal nerve plexus in diabetic patients and to correlate corneal confocal microscopy findings with peripheral diabetic neuropathy. METHODS: Corneal sub-basal nerve plexus parameters were quantified by corneal confocal microscopy in 42 diabetic patients and 27 age-matched controls. The parameters quantified were the number of fibers, the tortuosity of fibers, the number of beadings, and the branching pattern of the fibers. Peripheral neuropathy was also quantified using the Michigan Neuropathy Screening Instrument. RESULTS: The number of fibers, number of beadings, and branching pattern of fibers significantly decreases in diabetic patients versus control subjects (P<.0001; P<.0001; P=.0006, respectively), whereas nerve tortuosity significantly increases (P<.0001). The same corneal sub-basal nerve plexus parameters show a statistical trend, suggesting progression of corneal neuropathy with peripheral diabetic neuropathy. CONCLUSIONS: Corneal confocal microscopy represents a new tool in the diagnosis, clinical evaluation, and follow-up of peripheral diabetic neuropathy. This study found that diabetes damages corneal nerves, particularly the corneal sub-basal nerve plexus. This damage may be easily and accurately documented using corneal confocal microscopy. PMID: 17444092 [PubMed - indexed for MEDLINE

Cardiovascular Screening In Young Italian Athletes: A Comparison Between Different Exercise Test For Arrhythmia Detection.

Abstract: In 1982 a pre-participation screening of athletes was launched in Italy. For younger athletes (<35y.o.). The protocol included a resting 12-lead ECG together with two more ECG recorded during the recovery phase of a submaximal test (Harvard step test, HST). More recently (2006), Veneto Region established the ECG monitoring throughout the Harvard step test. In our Sports Medicine Unit since 1998 we independently decided to use a maximal treadmill test with ECG monitoring for the same screening puposes. PURPOSE: Aim of this study was to compare the ability of three different exercise test modalities to detect arrhythmias, and whether they were associated with structural heart abnormalities. METHODS: 1500 athletes, mean age 14.7\ub10.6 (range 8-15yo) were evaluated (500 each) in three Sports Medicine Centers differentiating one from each other by three different test modalities: HST without ECG monitoring (HST), HST with ECG monitoring (HSTM), and maximal treadmill test with ECG monitoring (MTT). Before the exercise test, each athlete underwent a history and clinical evaluation, and a resting ECG. Athletes underwent additional ecocardiography and 24-hour ECG monitoring when required. RESULTS: the maximal heart rate achieved was 74,7% (HST), 85,6% (HSTM) and 92,1% (MTT) of the maximal predicted. Arrhythmias (VEB and/or SVEB) were observed in 1%, 2,6%, and 8.6% of the subjects for HST, HSTM, and MTT, respectively. Considering only the monitored exercise phase, arrhythmias were recorded in 0,6% of HSTM subjects (23,1% of total arrhythmias) and in 2,4% of MTT subjects (27,9%). The positive predictive value of generic arrhythmias recorded during the MTT for any echocardiographic structural heart abnormality was 0,35, while was 0,6 when both VEB and SVEB were present. CONCLUSION: Exercise monitoring increased the sensitivity in detecting arrhythmias and structural heart defects respect to the non monitored exercise test. The MTT induced a greater number of arrhythmias, which were associated with cardiac abnormalities (mainly mitral valve prolapse, PFO, aortic and mitral regurgitation) in 35-60% of subjects, depending on the type of arrhythmias. In athletes screening, ECG monitoring during exercise should be considered to improve the sensitivity of the exercise test

Clogging potential evaluation of porous mixture surfaces used in permeable pavement systems

Service life of permeable pavements is strongly influenced by the infiltration capacity reduction produced due to the progressive clogging of the interconnected pores. This study focused on the effect of rainfall intensity and duration as well as the pavement slope, on the clogging and de-clogging processes of permeable pavements. For this purpose, a rainfall simulator was used in order to test porous asphalt and pervious concrete samples with void contents of 15, 20 and 25%. In order to simulate the permeability reduction in permeable pavements during their service life, test samples were clogged using three different sediment concentrations: 0.5, 1.0 and 2.0 kg/m2. Three different rainfall intensities (50, 100 and 150 mm/h) and two different rainfall durations (15 and 30 min) were tested over the test samples. The infiltration capacity of the test samples was assessed in newly built conditions, and for each clogging scenario before and after rainfall simulations. Results showed that rainfall patterns as well as pavement slope significantly affect the infiltration capacity of clogged permeable materials, being higher after longer and intense rainfall events and for lower pavement slopes. Overall, PC mixture showed a best performance in terms of infiltration capacity and self-cleaning capabilities

Delayed Nocturnal Hypoglycemia In Type 1 Diabetic Patients: Effect Of Two Different Exercise Modalities

Abstract: Exercise is a cornerstone of diabetes management as it aids in glycemic control in type 1 diabetic patients (DMT1). The type of exercise is important in determining the propensity to experience hypoglycaemia. PURPOSE: To assess, by continuous glucose monitoring (CGM), the glucose variability and the possible hypoglycemic episodes before, during and in the following 24 hours after a session of two different types of exercise. METHODS: Eight healthy, physically active, non-trained, male volunteers with well-controlled DMT1 were studied [age 34\ub17 yr, body mass index (BMI) 24.0\ub12.2 kg/m2, HbA1c 7.14\ub10.6, insulin dosage 0.6\ub10.2 U/kg/day, VO2max 33.7\ub1 6.1 ml\ub7kg-1\ub7min-1, duration of diabetes 14.3\ub18yr (mean\ub1SD)]. They underwent to 30 min. of both intermittent high intensity exercise (IHE) and moderate intensity exercise (MOD) in random order. Expired air was recorded during the exercise, while metabolic and hormonal determinations were performed before and for 120 min after exercises. CGM system and activity monitor were applied for the subsequent 19 hours. RESULTS: Blood glucose declined during both type of exercise. At 150 min following the start of exercise, plasma glucose tended to be higher, although not significantly, after IHE. No changes were observed in plasma insulin concentration. A significant increase of norepinephrine concentration was noticed during IHE respect to MOD (peak values: 1016.3\ub1154 vs 680.0\ub184.5pg/mL; p<0.05) while no differences were observed in epinephrine levels. During nighttime glucose levels were significantly lower after IHE than those observed after MOD exercise (147\ub117 vs 225\ub131mg/dl at 3:00AM, p<0.05). Moreover, the number of hypoglycemic episodes after IHE was significantly higher than that observed after MOD (2 in MOD vs 7 and IHE). CONCLUSIONS: We demonstrate a previously unrecognized phenomenon: despite slightly higher plasma glucose values in the early post-exercise, IHE is associated with a higher risk of delayed nocturnal hypoglycemia respect to MOD. These data suggest that CGM can be a useful approach in Type 1 diabetic patients who undergo to an exercise program

Continuous glucose monitoring reveals delayed nocturnal hypoglycemia after intermittent high-intensity exercise in nontrained patients with type 1 Diabetes

Objective: Exercise is a cornerstone of diabetes therapy in type 1 diabetes mellitus (DMT1) patients. The type of exercise is important in determining the propensity to hypoglycemia. We assessed, by continuous glucose monitoring (CGM), the glucose profiles during and in the following 20\u2009h after a session of two different types of exercise. Research Design and Methods: Eight male volunteers with well-controlled DMT1 were studied. They underwent 30\u2009min of both intermittent high-intensity exercise (IHE) and moderate-intensity exercise (MOD) in random order. Expired air was recorded during exercise, while metabolic and hormonal determinations were performed before and for 120\u2009min after exercises. The CGM system and activity monitor were applied for the subsequent 20\u2009h. Results: Blood glucose level declined during both type of exercise. At 150\u2009min following the start of exercise, plasma glucose content was slightly higher after IHE. No changes were observed in plasma insulin concentration. A significant increase of norepinephrine concentration was noticed during IHE. Between midnight and 6:00 a.m. the glucose levels were significantly lower after IHE than those observed after MOD (area under the curve, 23.3\u2009\ub1\u20093 vs. 16\u2009\ub1\u20093\u2009mg/dL/420\u2009min [P\u2009=\u20090.04]; mean glycemia at 3 a.m., 225\u2009\ub1\u200931 vs. 147\u2009\ub1\u200917\u2009mg/dL [P\u2009<\u20090.05]). The number of hypoglycemic episodes after IHE was higher than that observed after MOD (seven vs. two [P\u2009<\u20090.05]). Conclusions: We demonstrate that (1) CGM is a useful approach in DMT1 patients who undergo an exercise program and (2) IHE is associated with delayed nocturnal hypoglycemia

Heart Rate Recovery And Its Determinants In Young Athletes

Abstract: Heart rate recovery (HRR) is the reduction of heart rate immediately after exercise, and it\u2019s the consequence of vagal reactivation and sympathetic withdrawal that normally occur in this phase. HRR is also considered a valid index of training level and cardiovascular system health. A recent study (Singh, MSSE, 2008) demonstrates an association of attenuated 1-min HRR with higher BMI in a children population, suggesting a possible link between healthy body weight and faster HRR. However, this hypothesis is not supported by data about HRR values in healthy young athletes. PURPOSE: Our aim was to evaluate HRR in young athletes (age range 10 - 20 yr) and to analyze the relationships between HRR and other parameters, such as age, gender, BMI, heart rate at rest, maximal heart rate and workload achieved, sports practice. We also evaluated the effect of two different post-exercise protocols on HRR. METHODS: 1000 persons (606 male, 394 female) gave their informed consent to participate in the study. Each athlete completed a questionnaire and a maximal treadmill test using a ramp protocol. Heart rate was monitored before, during, and after the exercise, until the third minute of the recovery phase. Athletes were divided into two groups characterised by a different recovery modality (supine position right after exercise vs supine position after measuring blood pressure in standing position). RESULTS: The plot of HRR values yielded a sigmoidal curve showing a larger recovery between 30 and 90 seconds. An early supine position significantly increased HRR in the first minute (43,0 \ub115,6 vs 52,6\ub116,0 bpm, p<0,001), while no differences were present after the second minute. Mean HRR was faster among male and younger athletes, while HRR and BMI appeared weakly related. CONCLUSION: Our data are at variance, but complete Singh\u2019s data, confirming the hypothesis that a higher BMI is related to a reduced HRR only when it\u2019s expression of overweight due to excess of fat mass and lower fitness level. Further, HRR values are significantly different depending on the position in the recovery post-exercise. As suggested by the American Heart Association, we recommend placing instantly patients in supine position after treadmill test in order to obtain the maximal heart rate recovery and standardize this parameter

Clogging potential evaluation of porous mixture surfaces used in permeable pavement systems

Service life of permeable pavements is strongly influenced by the infiltration capacity reduction produced due to the progressive clogging of the interconnected pores. This study focused on the effect of rainfall intensity and duration as well as the pavement slope, on the clogging and de-clogging processes of permeable pavements. For this purpose, a rainfall simulator was used in order to test porous asphalt and pervious concrete samples with void contents of 15, 20 and 25%. In order to simulate the permeability reduction in permeable pavements during their service life, test samples were clogged using three different sediment concentrations: 0.5, 1.0 and 2.0&nbsp;kg/m2. Three different rainfall intensities (50, 100 and 150&nbsp;mm/h) and two different rainfall durations (15 and 30 min) were tested over the test samples. The infiltration capacity of the test samples was assessed in newly built conditions, and for each clogging scenario before and after rainfall simulations. Results showed that rainfall patterns as well as pavement slope significantly affect the infiltration capacity of clogged permeable materials, being higher after longer and intense rainfall events and for lower pavement slopes. Overall, PC mixture showed a best performance in terms of infiltration capacity and self-cleaning capabilities