Arie Laor

BIRTH WEIGHT, CURRENT BODY WEIGHT, AND BLOOD PRESSURE IN LATE ADOLESCENCE

Objective--To study the effect of birth weight and body weight on blood pressure in late adolescence. Design--Analysis of data on weight, height, and blood pressure at age 17 of subjects from the Jerusalem perinatal study, according to their birth weight. Data for men and women were analysed separately. Setting--Jerusalem, Israel. Subjects--32,580 subjects (19,734 men and 12,846 women) born in the three major hospitals in Jerusalem during 1964-71 and subsequently drafted in to the army. MAIN OUTCOME MEASURES--Correlations between birth weight and blood pressure at age 17 and weight and height at age 17 and blood pressure. Results--Diastolic and systolic blood pressures were associated with birth weight in both young men and young women, but the correlation coefficients were low. A high body weight at age 17 (greater than 66 kg for women, greater than 75 kg for men) rather than a low birth weight (less than 2500 g) was linked with higher systolic and diastolic blood pressures in both men and women (p less than 0.01). Conclusions--Intrauterine environment, as reflected by birth weight, has little effect on blood pressure in young men and women. Modification of factors which lead to excess weight during adolescence may have a major role in preventing hypertension in adults.

The cognitive outcome of full-term small for gestational age infants at late adolescence

Objective To assess the cognitive and academic performance of adolescents who were born small for gestational age (SGA) at term. Methods A 17-year historical prospective study was done by matching neonatal data of 1758 infants to the results of the medical and intelligence assessment performed at age 17 years at the army draft board medical examination in Israel. The results of children born SGA (weight at term birth below the third percentile) were compared to those of children who were born appropriate for gestational age (AGA). Results After adjustment by a multiple linear regression analysis, the mean (± standard error of the mean) intelligence test scores were 103.1 ± 2.9 versus 105.8 ± 1.5 (P = 0.3) for the males and 100.3 ± 2.5 versus 104.7 ± 1.6 (P < .03) for the females. Males born SGA at term were found to have lower educational achievements (having less than 12 years of schooling or attending a vocational school) compared with the AGA group. The odds ratio for this finding after adjustment by a logistic regression analysis was 2.40 (95% confidence interval 1.07–5.39; P < .03). Intranatal events were not found to have an effect on the measured neurodevelopmental outcome. Conclusion Infants born SGA at term have an increased risk for lower cognitive performance and schooling achievements than those born AGA; this result seems to be unrelated to their intranatal course.

Is low birth weight a risk factor for asthma during adolescence

The effect of low birth weight on the incidence of asthma by 17 years of age was investigated by studying medical draft examination records of 20,312 male subjects born in Jerusalem between January 1967 and December 1971. Additional information on birth weight and other demographic factors was abstracted from the Jerusalem Perinatal Study computerised database. A stepwise multiple logistic regression was used to estimate the odds ratios for developing asthma by 17 years of age in 500 g birthweight categories from less than 2000 g to 4500 g. The odds ratios were adjusted for the confounding effects of ethnic origin, social class (determined by area of residence), paternal education, maternal age, and birth order. The group with low birth weights (less than 2500 g, n = 1004) had a significantly increased risk of developing asthma by 17 years of age, with an adjusted odds ratio of 1.44 (95% confidence interval (CI) 0.79 to 2.66) for birthweight group less than 2000 g and 1.49 (95% CI 1.05 to 2.12) for birthweight group 2000-2499 g compared with the reference group of 3000-3499 g. We conclude that infants with birth weights of less than 2500 g may have a higher risk of asthma during childhood and adolescence than infants who were heavier at birth.

Size at birth, maternal nutritional status in pregnancy, and blood pressure at age 17: population based analysis

Abstract Objective: To assess the effect of size at birth, maternal nutrition, and body mass index on blood pressure in late adolescence. Design: Population based analysis of birth weight corrected for gestational age, mothers weight before pregnancy and weight gain in pregnancy, obtained from the Jerusalem perinatal study, and blood pressure and body mass index at age 17, available from military draft records. Setting: Jerusalem, Israel. Subjects: 10 883 subjects (6684 men and 4199 women) born in Jerusalem during 1974-6 and subsequently drafted to the army. Main outcome measures: Systolic and diastolic blood pressures measured at age 17 and their correlation with birth weight, size at birth, mothers body mass index and weight gain during pregnancy, and height and weight at age 17. Results: Systolic and diastolic blood pressures were significantly and positively correlated with body weight, height, body mass index at age 17, and with mothers body weight and body mass index before pregnancy, but not with birth weight or mothers weight gain in pregnancy. Conclusion: Variables reflecting poor intrauterine nutrition, including low maternal body mass index before pregnancy, poor maternal weight gain in pregnancy, and being born small for gestational age, were not associated with a higher blood pressure in late adolescence. Key messages Several studies have shown a significant inverse relation between blood pressure and birth weight, though the finding is not consistent In 10 883 Israelis blood pressure measured at age 17 was related to their birth weight adjusted for gestational age, their current body mass index, and their mothers weight before pregnancy and weight gain during pregnancy Blood pressure was significantly and positively correlated with body mass index at age 17 and with mothers weight before pregnancy but not with birth weight or mothers weight gain during pregnancy Variables reflecting poor intrauterine nutrition were therefore not associated with higher blood pressures in late adolescence

Colchicine Prevents Kidney Transplant Amyloidosis in Familial Mediterranean Fever

Twenty-one familial Mediterranean fever (FMF) patients who received a kidney transplant for terminal renal failure due to amyloidosis were studied retrospectively to evaluate the prophylactic effect of colchicine on graft amyloidosis. Proteinuria, highly suggestive of kidney transplant amyloidosis, developed in 11 patients within a median of 3 years after transplantation (range 0.5-10 years). In 10 patients, repeated urinalyses for protein were negative during a median of 5 years after transplantation (range 1-13). Patients who developed proteinuria or transplant amyloidosis received smaller colchicine doses than patients without proteinuria--mean 0.69 (range 0-1) versus 1.53 (range 1-2) milligrams per day (p = 0.0002), suggesting that colchicine prevents or delays development of transplant amyloidosis. This prophylactic effect of colchicine was complete at a dose of 1.5 mg/day or more and absent at a daily dose of 0.5 mg or less. In patients who received 1 mg/day, individual variability in the response to colchicine was observed. We conclude that the development of amyloidosis of the kidney transplant in FMF is inevitable at a colchicine dose lower than 1 mg/day, unpredictable at 1 mg/day and usually preventable with 1.5 mg/day or more.

Can gender differences during exercise-heat stress be assessed by the physiological strain index?

A physiological strain index (PSI) based on rectal temperature (Tre) and heart rate (HR) was recently suggested to evaluate exercise-heat stress. The purpose of this study was to evaluate PSI for gender differences under various combinations of exercise intensity and climate. Two groups of eight men each were formed according to maximal rate of O2 consumption (VO2 max). The first group of men (M) was matched to a group of nine women (W) with similar (P > 0.001) VO2 max (46.1 +/- 2.0 and 43.6 +/- 2.9 ml. kg-1. min-1, respectively). The second group of men (MF) was significantly (P < 0. 001) more fit than M or W with VO2 max of 59.1 +/- 1.8 ml. kg-1. min-1. Subjects completed a matrix of nine experimental combinations consisting of three different exercise intensities for 60 min [low, moderate, and high (300, 500, and 650 W, respectively)] each at three climates (comfortable, hot wet, and hot dry [20 degrees C 50% relative humidity (RH), 35 degrees C 70% RH, and 40 degrees C 35% RH, respectively]). No significant differences (P > 0.05) were found between matched genders (M and W) at the same exposure for sweat rate, relative VO2 max (%VO2 max), and PSI. However, MF had significantly (P < 0.05) lower strain than M and W as reflected by %VO2 max and PSI. In summary, PSI applicability was extended for exercise-heat stress and gender. This index continues to show potential for wide acceptance and application.A physiological strain index (PSI) based on rectal temperature (Tre) and heart rate (HR) was recently suggested to evaluate exercise-heat stress. The purpose of this study was to evaluate PSI for gender differences under various combinations of exercise intensity and climate. Two groups of eight men each were formed according to maximal rate of O2 consumption (V˙o 2 max). The first group of men (M) was matched to a group of nine women (W) with similar ( P > 0.001)V˙o 2 max (46.1 ± 2.0 and 43.6 ± 2.9 ml ⋅ kg-1 ⋅ min-1, respectively). The second group of men (MF) was significantly ( P < 0.001) more fit than M or W with V˙o 2 max of 59.1 ± 1.8 ml ⋅ kg-1 ⋅ min-1. Subjects completed a matrix of nine experimental combinations consisting of three different exercise intensities for 60 min [low, moderate, and high (300, 500, and 650 W, respectively)] each at three climates {comfortable, hot wet, and hot dry [20°C 50% relative humidity (RH), 35°C 70% RH, and 40°C 35% RH, respectively]}. No significant differences ( P > 0.05) were found between matched genders (M and W) at the same exposure for sweat rate, relativeV˙o 2 max(%V˙o 2 max), and PSI. However, MF had significantly ( P < 0.05) lower strain than M and W as reflected by %V˙o 2 max and PSI. In summary, PSI applicability was extended for exercise-heat stress and gender. This index continues to show potential for wide acceptance and application.

Evaluation of the environmental stress index for physiological variables

Abstract A new environmental stress index (ESI), based on ambient temperature ( T a ), relative humidity (RH) and solar radiation (SR), was recently suggested as a potential substitute for the wet-bulb globe temperature (WBGT) index. The purpose of this study was to evaluate and validate ESI for three different physiological variables including rectal temperature ( T re ), heart rate (HR), and sweat rate ( m sw ). A database was taken from a previous study where 12 young men (21±1 y) served as subjects exposed to 120 min of 12 different combinations consisting of three metabolic rates (rest and treadmill walking at 5 km·h −1 at 0% and 5% grades), two clothing ensembles (BDU and protective MOPP gear) and two outdoor solar radiation levels (shade and open sky). ESI was calculated as follows: ESI=0.63 T a -0.03RH+0.002SR+0.0054( T a RH)-0.073(0.1+SR) −1 . Significant differences of about 2 units ( p p m sw , HR and T re when measured in the sun and in the shade during all the exercise exposures. Thus, very high correlations ( R 2 >0.838) were found between ESI and T re , HR, or m sw . These results indicate that ESI is strongly correlated to the physiological strain, whereby higher stress is reflected in higher strain. Therefore, evaluating heat stress by ESI, which uses the more common, fast response and accurate climatic measures, becomes more predominant.

Predicting the Risk of Jaundice in Fullterm Healthy Newborns: A Prospective Population-Based Study

OBJECTIVE:The need to recognize infants that are at high risk for developing significant jaundice is apparent in the era of routine early discharge. The aim of the present study was to prospectively determine the ability to predict severe hyperbilirubinemia in term healthy newborns (defined as total serum bilirubin of >10.0 mg/dl at day 2, >14.0 mg/dl at day 3, and >17.0 mg/dl at days 4 and 5 of life).DESIGN:Prospective study of 1177 healthy term newborns.SETTING:Two university-affiliated community hospitals in Jerusalem.RESULTS:Using a multiple logistic regression analysis, neonatal jaundice was best predicted (p < 0.0001) by day 1 serum bilirubin (adjusted odds ratio of 3.1 [per mg/dl] [95% confidence limits of 2.4 to 4.1]) and by a change in serum bilirubin from the first to the second day of life (2.4 [per mg/dl] [1.9 to 3.0]). Maternal blood type O (2.9 [1.5 to 5.8]), age (1.1 [per year] [1.0 to 1.2]), schooling (0.8 [per year] [0.7 to 0.9]), and full breastfeeding (0.4 [0.2 to 0.9]) were also associated with jaundice (p < 0.005). Other factors considered in the regression model but not found to be significantly related to jaundice included maternal ethnic origin, smoking, hypertension, diabetes mellitus, intranatal administration of oxytocin, meperidine, anesthesia, premature rupture of the membranes, parity, newborn sex, birth weight, gestational age, presentation, Apgar scores, blood type, hematocrit, cephalohematoma, and history of jaundice in other siblings. A model for predicting neonatal jaundice based on the above factors had a sensitivity of 81.8%, a specificity of 82.9%, a false positive rate of 80.2%, and a false negative rate of 1.1%.CONCLUSION: Individual risk assessment on discharge in association with day 1 total serum bilirubin is of value in identifying infants at greater risk for neonatal jaundice.

Hydration status measurement by radio frequency absorptiometry in young athletes?a new method and preliminary results

A new method for non-invasive measurement of the human state of hydration is presented. This method is based on frequency-dependent absorptiometry of radio-waves passing through tissues. A device utilizing this method was constructed and applied to 12 young (24 +/- 1) male volunteers, who were dehydrated for 1-2.5% of their weight by performance of a physical effort (two 30 min bouts of treadmill walking/running at 2, 3, 4, 5, 6 and 7 mph, 5 min at each speed, separated by 10 min rest), under moderate heat stress (40 degrees C, 40% RH). Hypohydration level was determined by body weight measurements taken before each session, after 30 min and at the end of each session. Concomitantly, measurements of radio frequency (RF) absorption were taken. Each volunteer underwent the heat stress exercise twice: one in which no drinking was permitted, and another with free drinking. A correlation (R2 = 0.734) between weight loss and a change in the radio-waves absorption pattern was observed in most of the volunteers, in both hypo and euhydration sessions. Further work to establish the reproducibility and validity of the RF methodology in larger and different populations, i.e., females, other age groups and different health conditions, is already being researched.

Are psoriatic patients at risk of heat intolerance

Sixteen young male subjects with psoriasis (mean of 4.9% of skin surface area involvement) and 10 healthy controls underwent a heat exercise test (40 °C, 40% r.h.) for 2 h. Rectal temperature (Tr). mean skin temperature (Tsk), heart rate (HR) and heat storage (dS) were measured and calculated. A sharper rise was found for all parameters in the psoriatic patients as compared with controls. Statistically significant differences were found in Tr after 60 min (37.9 ± 0.1°C and 37.5 ± 0.1°C in patients and controls, respectively) and at termination of the exercise (38.3 ± 0.1°C and 37.5 ± 0.1°C). Heat storage at the end of the first hour was 78 ± 9 and 30 ± 7 kcal in patients and controls, respectively. At the end of 120 min. heat storage in the study group increased to 87 ± 14 kcal. while the control group stored only 30 ± 7 kcal. Sweat rate was lower in the psoriatic patients (590 ± 49 g/h) than in controls (691 ± 42 g/h). even when corrected for healthy skin area (337 ± 26 g/h/m2 compared with 370 ± 24 g/h/m2). It is suggested that psoriatic patients have a reduced ability to dissipate extra heat during exposure to exercise in the heat. Psoriasis should therefore be considered as a risk factor for heat intolerance.