M Eriksson

Breastfeeding: physiological, endocrine and behavioural adaptations caused by oxytocin and local neurogenic activity in the nipple and mammary gland.

It is now well established that oxytocin, as well as stimulating uterine contractions and milk cjection, promotes the development of maternal behaviour and also bonding between mother and offspring. In addition, oxytocin exerts by way of peripheral, circulating as well as by central, neurogenic mechanisms multiple physiological, endocrine and behavioural effects in connection with milk ejection and lactation. Some effects of oxytocin in the nipple and mammary gland appear to be exerted in close collaboration with peptides released from axon collaterals of somatosensory nerves originating in this region. The distribution of peptides localized to the somatosensory afferents in the nipple and mammary gland as well as possible effects by oxytocin and/or local neurogenic peptides in connection with milk ejection and lactation are reviewed in this paper.

Population-based rates of severe respiratory syncytial virus infection in children with and without risk factors, and outcome in a tertiary care setting

The aim of this study was to make a population‐based estimate of the risk of hospitalization and complications during virologically confirmed respiratory syncytial virus (RSV) infection in relation to established risk factors, and an estimation of additional risk factors and outcome as seen in a tertiary care referral centre. During a period of 12 y, all children with virologically confirmed RSV infection were included. Recorded complications were: admission to the intensive care unit, mechanical ventilation, death and later hospitalization for wheezing. In total, 1503 cases were identified, 1354 of which originated from the population defined by the catchment area. There was a biannual seasonal variation with late small outbreaks alternating with early large ones. The hospitalization rates for infants without risk factors were 0.8 and 1.4% during the 2 epidemic types. They were 1.6–3.2% for infants born preterm (>33 gestational wk), 2.9–7.0% for children under 2 y old with chronic lung disease of prematurity and 2.8–6.4% for infants with congenital heart disease. The presence of siblings in the family more than doubled the risk of hospitalization. Later hospitalization for wheezing occurred in 8.4 and 4.9% of children without risk factors over and under the age of 2 mo, respectively (p > 0.001).

Incidence and estimates of the diease burden of rotavirus in Sweden

Laboratory and hospitalization data from two childrens hospitals with large primary catchment areas and national laboratory and hospitalization data for children under 4 y of age with acute diarrhoea were compiled to estimate the number of hospitalizations and the cost burden associated with rotavirus diarrhoea in Sweden. According to our estimates 1500‐1700 rotavirus‐associated hospitalizations occur annually in Sweden in children under 4 y of age (3.7 hospitalizations/lOOO children/y). This number represents 2.3% of admissions for all diagnoses in children of this age group. The cost of these hospitalizations is 13.5–15 million Swedish crowns (US

Birth Weight in Relation to Leisure Time Physical Activity in Adolescence and Adulthood: Meta-Analysis of Results from 13 Nordic Cohorts

1.8–2 million). Serotyping by PCR for two years revealed that serotype 1 (GI) was the most common (49% and 58%, respectively) identified. Serotypes 2‐4 were identified in the following proportions G2 (23% and 5%), G3 (21% and 0%) and G4 (7% and 16%). The national laboratory report data for 1993‐96 show that as much as 7‐13% of rotavirus infections occur in elderly people. □G‐typing, incidence, rotavirus

Associations of birthweight and infant growth with body composition at age 15 – the COMPASS study

Background Prenatal life exposures, potentially manifested as altered birth size, may influence the later risk of major chronic diseases through direct biologic effects on disease processes, but also by modifying adult behaviors such as physical activity that may influence later disease risk. Methods/Principal Findings We investigated the association between birth weight and leisure time physical activity (LTPA) in 43,482 adolescents and adults from 13 Nordic cohorts. Random effects meta-analyses were performed on categorical estimates from cohort-, age-, sex- and birth weight specific analyses. Birth weight showed a reverse U-shaped association with later LTPA; within the range of normal weight the association was negligible but weights below and above this range were associated with a lower probability of undertaking LTPA. Compared with the reference category (3.26–3.75 kg), the birth weight categories of 1.26–1.75, 1.76–2.25, 2.26–2.75, and 4.76–5.25 kg, had odds ratios of 0.67 (95% confidence interval: 0.47, 0.94), 0.72 (0.59, 0.88), 0.89 (0.79, 0.99), and 0.65 (0.50, 0.86), respectively. The shape and strength of the birth weight-LTPA association was virtually independent of sex, age, gestational age, educational level, concurrent body mass index, and smoking. Conclusions/Significance The association between birth weight and undertaking LTPA is very weak within the normal birth weight range, but both low and high birth weights are associated with a lower probability of undertaking LTPA, which hence may be a mediator between prenatal influences and later disease risk.

Bias in height and weight reported by Swedish adolescents and relations to body dissatisfaction: the COMPASS study.

Size at birth and postnatal growth have been positively associated with obesity in adulthood. However, associations between postnatal growth and body composition later in life have rarely been studied. The overall purpose was to explore the associations between birthweight, weight gain during first year of life and height, weight, body mass index, fat free mass index (FFMI), fat mass index, % fat mass (FM) and waist circumference in adolescence. The COMPASS study is a population-based study of adolescents from a well-defined area in Stockholm County, Sweden. Birth characteristics and weight during childhood were collected from registers and child health centre records, and body composition at age 15 years was measured by bioelectric impedance by trained nurses. Complete data were available for 2453 adolescents. Associations between predictor and outcome variables were assessed with linear regression modelling. Birthweight was positively associated with all outcome variables, except for %FM among girls. FFMI increased by 0.49 kg/m(2)[95% CI 0.34, 0.63] (boys) and 0.25 kg/m(2)[0.12, 0.38] (girls) per 1 SD increase in birthweight. Increased weight gain in infancy showed strong, positive associations with all measures of body composition. FFMI increased by 0.73 kg/m(2)[0.60, 0.87] (boys) and 0.63 kg/m(2)[0.50, 0.76] (girls) per unit increase in weight z-score during first year of life. The effect of increased weight gain in infancy was not modified by birthweight. Birthweight and postnatal growth were both positively related to body composition in adolescence. Increased weight gain during the first year of life had stronger effect than prenatal growth, suggesting infancy to be a more critical period.

Hospitalization in Sweden of children born to immigrants

Objective:To assess the size of biases in self-reported height, weight in a large sample of adolescents with special attention to possible effects of body dissatisfaction and to assess how such biases may influence estimates of overweight and obesity.Design:Cross-sectional study.Setting:Unselected population from Southwestern parts of Stockholm County, Sweden.Subjects:Two-thousand seven hundred and twenty-six boys and girls, 15 years of age.Methods:Data were collected by a questionnaire answered by adolescents and a physical examination made by trained study nurses. A validated physical appearance scale and body silhouettes were embedded into the questionnaire.Results:Obese boys under-reported their weight (5.2 kg) (95% confidence intervals (CI) 3.7; 6.6) more than obese girls (3.8 kg) (95% CI 1.8; 5.8). Agreement between self-reported and measured body mass index (BMI)-categories (obese, overweight and non-overweight/obese) as estimated by weighted kappa was 0.77 (95% CI 0.72; 0.82) for girls and 0.74 (95% CI 0.70; 0.79) for boys. For obese girls and boys sensitivity of self-reports were 0.65 (95% CI 0.47; 0.79) and 0.52 (95% CI 0.38; 0.66). Boys with low scores on the physical appearance scale under-reported their weight and BMI more than those with high scores. Boys and girls who wished to be leaner under-reported their weight and BMI more than subjects who were satisfied with their body size (P<0.05).Conclusion:Thirty-five percent of obese girls and 48% of obese boys would remain undetected from self-reported data. Boys and girls who were dissatisfied with their physical appearance or size under-reported their weight more than satisfied subjects.

Changes in shape and location of BMI distributions of Swedish children

Aim: Sexual orientation plays an important part in building identity during adolescence. The aim of this study was to describe patterns of sexual orientation, including sexual attraction, fantasies, affiliations and behaviour. Methods: The study was based on the analysis of data from computerized self‐administered questionnaires of a Swiss national survey on the sexual life of 16 to 20‐year‐old adolescents (n= 2075 girls and 2208 boys.). Results: Overall, 95.0% of girls and 96.2% of boys described themselves as predominantly heterosexual; 1.4% of girls and 1.7% of boys as predominantly homosexual or bisexual; and 2.8% of teenagers (girls: 3.6%; boys: 2.1%) were “unsure” of their sexual orientation. The reported prevalence of homosexual attraction (girls: 2.0%; boys: 2.9%) exceeded homosexual fantasies (girls: 0.4%; boys: 0.5%) and affiliations (girls: 0.3%; boys: 0.5%). Among the 4205 respondents, 31 girls (1.5% of girls) and 56 boys (2.5% of boys) reported sexual behaviour (experience or penetrative intercourse) with a person of the same sex. Among 1.5% of girls and 2.5% of boys who reported sexual behaviour with a person of the same sex, 65% of boys and 80% of girls nevertheless considered themselves as heterosexual.

Salicylate-Induced Fetal Death and Malformations in Two Mouse Strains

Aims: One aim was to disentangle how the shape and location of the BMI distribution changed among Swedish children over a 12 y period. Another aim was to identify the age during childhood when changes occurred or became manifest.

Pre‐school Children of Amphetamine‐addicted Mothers: I. Somatic and Psychomotor Development

Sodium salicylate was given i.m. in a single dose on one gestation day (9th, 11th, 13th, 15th or 17th) to pregnant primiparous mice of A/Jax and CBA strains and of their reciprocal crossings. The incidence of fetal death and resorption and of vessel and skeletal anomalies induced in the fetuses was estimated on the 18th day of pregnancy.