Normal weight for length in newborn infants in whom growth hormone deficiency was later diagnosed. Swedish Paediatric Study Group for GH Treatment.

A new model for evaluating leanness/fatness (LeanSDS) in the newborn infant has been used to examine body weight for length in a group of Swedish infants in whom idiopathic growth hormone deficiency (GHD n = 220) was later diagnosed. These infants have earlier been reported to be significantly shorter (median = -0.87 SDS; SDS; standard deviation scores) and lighter (median = -0.60 SDS) in relation to gestational age, than the most recent reference. A group of infants who later developed GHD due to organic etiologies (n = 92) had normal weight and length for gestational age at birth. Using the LeanSDS model (with intercept 0.0 and regression coefficient 0.7) revealed that these idiopathic GHD infants have weight that is normal for their length (mean LeanSDS = 0.11 +/- 0.08 (SEM); n.s.) why the abnormality is a reduced linear growth. These findings also indicate that birth length (linear growth) should be given increased attention when size at birth is evaluated.

Weight-for-length model in newborn Swedish infants.

A new methodology for evaluation of weight in relation to length normalized for sex and gestational age (leanness/fatness) in the newborn infant is presented. Using standard deviation scores (SDS) for weight and length in a linear regression model, a new continuous variable called LEANSDS has been constructed with intercept = zero, regression coefficient = 0.7152, SD = 0.6988 and r2 = 0.51, irrespective of gender and gestational age within the range 34-43 weeks' gestation. The model is based on the Swedish 1986 Medical Birth Register and was tested on the 1985 year cohort. The reference material consisted of live-born, singleton infants considered "healthy". This new variable is independent of length. A chart is presented which simplifies visual evaluation. Using -2 SD as the cut-off limit, approximately one-third of light-for-dates infants are also lean, while two-thirds of the lean infants are not light for dates. Proportions of "not healthy" live-born infants and still births are given. Using another method, based on weight and length, and with some approximations needed for calculation of a comparable BW/BLSDS, the correlation was 0.9974, but this calculation is more elaborate and the comparable chart more complex. This method reveals the influence of gestational age on the relationship between weight and length, indicating a "prenatal puberty". Empirically, the logarithmic relationship found between weight and length indicates a ponderal index exponent of 2.4-2.5 instead of 3. LEANSDS, with its continuous nature, also gives the degree of deviation in each individual and in groups of infants, and can be added together and further analysed with improved sensitivity.

An update of the Swedish reference standards for weight, length and head circumference at birth for given gestational age (1977-1981).

An update of the Swedish reference standards for weight, length, and head circumference at birth, for each week of gestational age, is presented. It is based on the total Swedish cohorts of infants born 1977-1981 (n = 475,588). A "healthy population" (79%) was extracted, using prospectively collected data. Weekly (28-42 weeks) grouped data for length and head circumference were well approximated by the normal distribution, but the distributions for birthweight were positively skewed. The original skewed distributions for birthweight were transformed, using the square root, resulting in distributions close to the Gaussian. For smoothing purposes, the weakly values for the mean and the standard deviation were both fitted by a third degree polynomial function. These functions also make possible the calculation of the continuous variable, standard deviation score, for individual newborn infants as well as a comparison of distributions between groups of infants. The reference values and charts presented here have two major advantages over the current Swedish ones: the sample size used is now sufficiently large at the lower gestational ages, so that empirically found variations can be used, and the skewness of the birth weight distribution has been taken into account. The use of the reference standards presented here improves and facilitates evaluation of size deviation at birth.

Birth data for patients who later develop growth hormone deficiency: preliminary analysis of a national register. The Executive Scientific Committee of the Kabi International Growth Study and the Swedish Paediatric Study Group for Growth Hormone Treatment.

This study analyses gestational age, mode of delivery and size at birth in children who later developed idiopathic or organic growth hormone deficiency (GHD). A data register of children on growth hormone (GH) treatment in Sweden was compared with the Swedish Medical Birth Register during a 14-year period (1973-1986) comprising 1.4 million newborn children. Size at birth was evaluated using a new Swedish reference standard based on data from around 500,000 newborn children. It was found that the children who later develop idiopathic GHD (IGHD) were born with a normal distribution of gestational age. They were more often born with breech delivery (7.1% versus 2.8%) or caesarean section (16.6% versus 10.4%) compared with normal children. The children's condition at birth was poorer than normal, as shown by the frequency of Apgar scores below 7 at 5 minutes (5.2% versus 1.2%). Finally, it was found that children who later develop IGHD (n = 220) had a median birth length of 0.87 SDS below the mean and a median birth weight of 0.60 SDS below the mean of the standard. In contrast, both the birth length and weight of the children who later develop organic GHD (OGHD) (n = 92) did not differ from that of the reference.

Abnormalities of growth in 7- to 18-year-old psychiatric patients.

The growth curves of all nonimmigrant school-age children living in one district of Malmö, Sweden and treated at the Department of Child and Youth Psychiatry during 1983 were investigated. The study group consisted of 40 children. Twenty-five of these children (63%) showed abnormal growth compared to 6 children (15%) with abnormal growth in an age-and sex-matched nonpsychiatric control population (p less than 0.001). A majority of the children with abnormal growth exhibited deviant growth within the first 4 years of life, usually several years before showing any psychiatric symptoms. These results, if borne out by additional studies, may have important clinical applications in the fields of developmental medicine and child psychiatry.

Modelling of reference values for size at birth.

Data from the Swedish Medical Birth Registration, 1977-1981 were used to apply methods of constructing reference standards for size at birth. Using clinical information a 'healthy' sub-population was extracted. The conditional distributions of birthweight (BW) and birthlength (BL) for each week of Gestational age, and the conditional distribution of birthweight given birthlength were modelled using truncated Normal distributions, after making use of Box-Cox power transformations. Spline functions were then used in conjunction with a multiplicative method to obtain appropriate percentage point curves. Examples of this analysis are given.

Early affective antecedents of adult type A behavior.

The early affective, apparently temperamental antecedents of Type A behavior were investigated in a Swedish longitudinal sample (N = 149). Four clusters of Type A items (describing irritability, hurried behavior, work achievement, and competitiveness) were regressed on maternal ratings of the child's poor appetite, sleep disturbances, liveliness, anger, and shyness, collected annually from infancy to adolescence. The child's liveliness, sociability, and poor appetite during infancy and childhood were positively related to the adult Type A irritability and hurried behavior clusters, as were the mother's liveliness, orderliness, and intelligence as rated by psychologists during the child's first 6 years. The two work-involvement clusters were predicted by interactive effects among shyness, poor appetite, and anger during adolescence but were unrelated to mother attributes. Sleep disturbances were only related to competitiveness and only in late adolescence. These findings indicate that the interrelated components of adult Type A behavior have contrasting developmental histories and that temperament-related constructs are important antecedents to the adult syndrome.

The epidemiology of sudden infant death syndrome and attacks of lifelessness in Sweden.

Infants who died showing the syndrome of sudden infant death (SIDS) and infants who survived attacks of lifelessness (AL) were examined in a prospective epidemiological multicentre study over 24 months covering close to 40% of all births in Sweden. Seventy SIDS cases and 34 cases of AL were observed, giving an incidence for SIDS of 0.94/1000 and for AL of 0.46/1000. This SIDS incidence is higher than that observed during the seventies. The boy/girl ratio was 1.4:1 for SIDS and 1.6:1 for AL. The age distribution for AL resembled that for SIDS. Similarities were also seen with regard to place of occurrence. Sixty per cent of the SIDS cases occurred during the daytime/evening. Twenty-nine per cent of the infants with AL had more than one apneic spell during the three-day-period around the attack, indicating a period of respiratory instability, but only 12% had such spells later on. None of the infants who had had AL died from SIDS. The possible relationship between AL and SIDS is discussed.

Analysis of linear growth using a mathematical model. I. From birth to three years.

According to the "ICP-growth model" (ICP = Infancy, Childhood and Puberty components), linear growth during the first three years of life can be represented mathematically by a combination of a sharply decelerating Infancy component and a slowly decelerating Childhood component. Growth as measured by supine length is analysed for 191 longitudinally followed healthy infants using this model. The main aim is to devise ICP-based methods for biological and clinical applications. The onset of the Childhood component, which occurs some time between 6 and 12 months of age and is typically abrupt, can be detected on an individual basis. Its starting point probably defines the as yet unknown age at which growth hormone begins to exert a significant influence. The analyses have also revealed some new facets of linear growth. Most infants are found to have a non-linear decelerating Infancy component, free from seasonal influence. Age at onset of the Childhood component is earlier for girls than for boys and is positively related to the magnitude of the Infancy component. During the second year of life the variation in growth rate of the cohort increases. This fluctuation is found to be seasonal and greater for those with late onset of the Childhood component. During the third year of life the growth pattern is stabilized.

The relation of stress hormone excretion to type A behavior and to health.

The relation between catecholamine and cortisol excretion and Type A behavior, assessed using an 11-item self-report questionnaire based on the Jenkins Activity Survey, is examined in a Swedish sample of young adults (N = 149). Cluster analysis indicates that the items measure four aspects of Type A behavior: irritability, hurried behavior, work achievement, and competitiveness. These clusters are not correlated with measures of recent health care utilization. In both sexes, a higher total Type A behavior score is related to decreased daytime urine concentrations of norepinephrine and day and night concentrations of cortisol. In males, increased hurried behavior is related to lower night levels of norepinephrine; higher irritability and competitiveness predict lower night levels of epinephrine and cortisol and increased urine excretion rate. In females, higher irritability and lower competitiveness scores are related to increases in daytime urine excretion and slightly lower levels of cortisol. These results indicate that only certain aspects of the Type A syndrome are related to stress processes and imply that the behaviors serve to lower stress responses in early adulthood.

Analysis of linear growth using a mathematical model. II. From 3 to 21 years of age.

The 'ICP growth model' (ICP = Infancy, Childhood and Puberty components) represents linear growth from 3 years of age to maturity by a combination of a slowly decelerating childhood component together with a sigmoid puberty component, the latter acting only during adolescence. Linear growth is analysed for 157 longitudinally followed healthy infants using this model. The main aim is to assess the ability of the ICP model to describe and evaluate individual growth patterns in healthy children with particular emphasis on the considerable individual variation in the timing of puberty and the shape of the pubertal growth spurt. The use of the model to evaluate growth longitudinally over both short and long periods is also outlined. Reference values based on the ICP approach, the ICP Standard, seem to have a number of advantages in comparison with cross-sectional standards. In the 'Prepubertal ICP Standard', the contribution of the puberty component is omitted. The standard can be applied on an individual basis to evaluate prepubertal growth and pubertal onset, independently of the timing of puberty. By using the 'Pubertal ICP Standard' both the difference in pubertal maturation and the negative relationship between the size of the pubertal gain and the timing of puberty are taken into account. The fact that the gain in the puberty component is time-invariant, and can thus be aligned with the timing of puberty for an individual child, forms the basis of this approach. The analyses have also revealed a new predictor for final height, which is termed HAPO (height adjusted for pubertal onset). This predictor is based on age and attained size at onset of puberty--the 'onset' regression line.

A methodology for evaluating size at birth.

Data from the Swedish Medical Birth Registration, 1977-78, were utilized to develop methods of calculating reference standards for evaluating size at birth. Using the clinical information available, a 'healthy' sub-group was extracted. The individual distributions of birthweight (BW), birth length (BL) and birth headcircumference (BHc) at each week of gestational age (GA) were modelled following some truncation of their ranges. Application of the Box-Cox power family of transformations was generally found to improve the normality of the data. Certain percentages (such as 2.28, 50 and 97.72) were linked through a smoothing device. Features of the results include a positively skewed BW distribution in most GA weeks, a normal positively skewed BW distribution in most GA weeks, a normal distribution of BL and BHc at term, a larger relative variation in BW at lower GA than at term, and a distinct sigmoid shape of the median and other BW curves. Compared with five commonly quoted standards, the present data show the least deceleration in the fullterm region. Disregarding the clinical information, 'primary' sub-groups were also extracted using decomposing techniques. These gave rise to similar BW/GA relationships. Using data from the WHO comparative study, the method just mentioned was applied to standardize BW and BW-specific early neonatal mortality rates. This resulted in an improved description of biological events.

Estimation of the "normal" growth of Swedish infants at term. Preliminary report.

Using the Swedish Medical Birth Registry for 1983 the birthweights were studied from the 38th to the 42nd week of gestation. Several criteria were used in order to retain a "normal" population of infants without signs of pathology. The mothers all negated smoking. Of about 93 000 livebirths roughly 10% fulfilled the criteria. Both in the infants who were the first-born child (n = 5.640) and in those who were the second-born child (n = 3.599) there was a successively higher mean birthweight for each completed week until 41 weeks. After that a graph connecting the mean values showed a significant flattening.

Clinical application of evoked EEG responses in infants. III: congenital hypothyroidism.

Previous studies have shown a close relationship between maturation of the central nervous system and development of evoked EEG responses. In this study, 13 infants with congenital hyperthyroidism were examined between the ages of one week and 17 weeks in an attempt to evaluate the degree of developmental retardation and the influence of hormonal treatment. It was found that visual evoked responses were abnormal in 12 of the patients, the most common abnormality being an immature abnormal response pattern. Latency was increased significantly in 10 of the 11 patients who were diagnosed before the age of six months, but was normal in the remaining two who were diagnosed later. A significant reduction of photic driving occurred in only two patients; it was the sole abnormality in one of them. Both the response pattern and latency became normal during treatment. The authors conclude that recording visual evoked responses is a simple and useful method of evaluating cerebral function in congenital hypothyroidism, both before and during treatment.

Effects of injected lipid emulsion on oxygen consumption, RQ, triglyceride, free-fatty-acid and beta-hydroxybutyrate levels in small-for-gestational-age (SGA) infants.

UNLABELLED: Ten SGA infants were studied from 4 hours after birth (day l) and again at 28 hours (day 2) before and for 4 hours after single injections of 0.5 g of Intralipid fat/kg b.w. (IL-group). Eight other SGA infants were given 9-10 ml/kg of breast milk (BM-group). After lipid injection the elimination of triglycerides (TG) from plasma was markedly delayed. On day 2 lipolysis had improved but was still slower than in previously studied AGA infants. The initial FFA plasma level was higher on day 1 than on day 2. Oxidation of released fatty acids was confirmed by a significant increase of VO2 and a decrease of RQ on day 1 and 2. In all infants the beta-hydroxybutyrate level in plasma increased and was still elevated 4 hours after injection of fat. A negative correlation was found between beta-hydroxybutyrate levels and RQ. In the BM-group changes in TG and beta-hydroxybutyrate levels were small and insignificant. FFA had decreased 60 min after breast milk on day 1. IN CONCLUSION: TG elimination from plasma was impaired on day 1 and had slightly improved on day 2. The fatty acids released by lipolysis were oxidized as seen by increasing VO2, falling RQ and increasing beta-hydroxybutyrate plasma levels both on day 1 and day 2.

Characteristics of active sodium and potassium transport in erythrocytes of healthy infants and children.

Erythrocytes were analysed for adenosine triphosphatase (total and sodium-potassium activated) activities, concentrations of sodium and potassium ions and ATP in normal individuals from birth to adulthood age. A decrease of Na+, K+-ATPase activity and an increase of the sodium concentration was seen in infants aged 1-3 and 4-8 months. A decrease of Na+, K+-ATPase was seen during puberty. A correlation was seen between the Na+, K+-ATPase activity and the Na+-K+ ratio. Different influences which might lead to the observed changes in Na+, K+-ATPase activity and erythrocyte sodium concentration are discussed.

Perinatal mortality in Sweden. Analyses with international aspects.

The perinatal mortality in Sweden has been decreasing during the last four decades. From available vital statistics in 1976 Sweden's figures are the lowest internationally. The decline continues and in 1978 the figure was as low as 10.0 per thousand. The five-year period 1973--1977 has been specially analysed using medical birth records from all births. Data from an international perinatal study in 1973 coordinated by WHO have been treated in the same way. With birth weight (BW) specific mortality rates in groups of 250 g it is shown that late fetal deaths (LFD) are related to BW only for high BW and that early neonatal deaths (END) are inversly related to BW. There is no sex difference in LFD but a marked male dominance in END, with one third higher rate for the boys. BW specific mortality rates in BW groups of 250 g, separated in LFD and END can be used as a tool for evaluating the quality of perinatal care. The influence oof factors related to patterns and standards of living is emphasized. It is suggested that perinatal mortality should be given in its two components separately late fetal death rates (LFD) and early neonatal death rates (END).

Long-term effect of previous swimtraining in girls. A 10-year follow-up of the "girl swimmers".

Thirty girls, studied in 1961 after 2.5 years of intensive swimtraining, were the subject of a follow-up for ten years. When last examined, seven and ten years after the original study, all the girls had given up swimtraining. The increased values for vital capacity observed in 1961 remained unchanged, but residual volume, functional residual capacity and total lung capacity showed small increases even after corrections for body growth. Such increases are, however, normal in these years. Heart volume which was high originally, was found to be lower ten years later, although mean values were still higher than normal. The decreases seen from 1961 to 1971 could mainly be ascirbed to a decrease in the subjects with the larges hearts originally. Both total hemoglobin and blood volume decreased to normal values in relation to body size. Maximal oxygen uptake, though, fell from 2.80 l/min (51. 4 ml/kg X min) to 2.18 l/min (36.4 ml/kg X min) ten years later. It is suggested that the functional capacity of the cardiovascular system declined more markedly than its dimensions.