From adolescence to parenthood: a multi-decade study of preconception mental health problems and postpartum parent-infant bonds.

PURPOSE: To examine associations between anxiety and depressive symptoms across adolescence and young adulthood with subsequent maternal- and paternal-infant bonding at 1 year postpartum. METHODS: The data were from a prospective, intergenerational cohort study. Participants (381 mothers of 648 infants; 277 fathers of 421 infants) self-reported depression and anxiety at three adolescent waves (ages 13, 15 and 17 years) and three young adult waves (ages 19, 23 and 27 years). Subsequent parent-infant bonds with infants were reported at 1 year postpartum (parent age 29-35 years). Generalised estimating equations (GEE) separately assessed associations for mothers and fathers. RESULTS: Mean postpartum bonding scores were approximately half a standard deviation lower in parents with a history of persistent adolescent and young adult depressive symptoms (maternal ßadj = - 0.45, 95% CI - 0.69, - 0.21; paternal ßadj = - 0.55, 95% CI - 0.90, 0.20) or anxiety (maternal ßadj = - 0.42, 95% CI - 0.66, - 0.18; paternal ßadj = - 0.49, 95% CI - 0.95, 0.03). Associations were still mostly evident, but attenuated after further adjustment for postpartum mental health concurrent with measurement of bonding. CONCLUSIONS: Persistent symptoms of depression or anxiety spanning adolescence and young adulthood predict poorer emotional bonding with infants 1-year postbirth for both mothers and fathers.

Childhood disadvantage and adolescent socioemotional wellbeing as predictors of future parenting behaviour.

INTRODUCTION: In extending work on early life antecedents of parenting, we investigate associations between childhood family history of disadvantage, adolescent socioemotional wellbeing, and age at first parenthood and subsequent parenting behaviour. METHODS: Parent-child interactions were recorded when participants in the longitudinal Dunedin Multidisciplinary Health and Development Study (New Zealand) had a three-year-old child. Data were available for 358 mothers and 321 fathers, aged between 17.7 and 41.5 at the time of their child's birth. Associations between parenting and antecedent data on socioeconomic disadvantage, adolescent wellbeing and mental health, as well as current adult mental health and age at parenting, were tested for using structural equation modelling. RESULTS: Family disadvantage in childhood and lower adolescent wellbeing was associated with less positive future parenting, but only adult (not adolescent) anxiety/depression symptoms were directly associated with parenting behaviour. Childhood family disadvantage was associated with further disadvantage across the life course that included less positive parenting of the next generation. In contrast, socioemotional wellbeing during adolescence and later age of onset of parenting were associated with more positive parenting. CONCLUSIONS: Reducing childhood disadvantage and improving socioemotional wellbeing during childhood and adolescence is likely to have intergenerational benefits through better parenting of the next generation.

Obesity, underweight and BMI distribution characteristics of children by gross national income and income inequality: results from an international survey.

BACKGROUND: Economic wealth and income inequality may impact on childhood BMI distribution by affecting overconsumption of food and sedentary forms of transportation and entertainment across the whole or some of the population. OBJECTIVES: To determine whether BMI distribution of children differs by gross national income (GNI) per capita and Gini index derived from World Bank data. METHODS: Secondary analysis of largely self-reported height and weight data from a multi-country, cross-sectional study (ISAAC), of 77,963 children aged 6-7 (from 19 countries) and 205,388 adolescents aged 13-14 (from 36 countries), were used to examine underweight vs obesity prevalence and BMI distribution skewness, median and dispersion. RESULTS: Children and adolescents from 'lower' GNI countries had higher prevalence of underweight than those from 'higher' GNI countries (6% vs 3%, p = 0.03; 2% vs 1%, p = 0.05 respectively), but the prevalence of obesity was not different (2% vs 5%, p = 0.29; 2% vs 2%, p = 0.66). BMI distribution of participants from 'higher' GNI countries had higher median, without significant difference in skewness or dispersion compared to 'lower' GNI countries (higher medians +1.1 kg/m2 for 6-7 year olds, and + 0.7 kg/m2, +1.2 kg/m2 for 13-14 year old girls and boys respectively). Gini index was not associated with underweight or obesity prevalence in either children or adolescents, nor with any BMI distribution characteristics with one exception. Adolescent girls from higher income inequality countries had a greater median BMI (+0.7 kg/m2) and a less skewed BMI distribution. CONCLUSIONS: It appears that the obesogenic impact of economic prosperity affects all children similarly. Income inequality may have a gender specific effect affecting BMI distribution in adolescent girls.

Birth weight and subsequent body mass index in children: an international cross-sectional study.

BACKGROUND: The reported association between birth weight and subsequent body mass index (BMI) is conflicting. OBJECTIVES: To examine the relationship between birth weight and BMI in children aged 6-7 years. METHODS: Secondary analysis of data from a multi-centre, multi-country, cross-sectional study (International Study of Asthma and Allergies in Childhood (ISAAC) Phase Three). Parents/guardians of children aged 6-7 years completed questionnaires about their children's birth weight, current height and weight and whether their mother smoked in the first year of the child's life. A general linear mixed model was used to determine the association between BMI and birth weight. RESULTS: A total of 72 111 children (17 countries) were included in the analysis. There was a positive association of birth weight with BMI (for each kg increase in birth weight the BMI at 6-7 increased by 0.47 (SE 0.02) kg/m2 ; p < 0.0001) with a clear gradient by birth weight category. There was no statistically significant interaction between birth weight and Gross National Income (GNI). CONCLUSIONS: There is a positive linear relationship between birth weight and BMI in 6-7 year old children, which is present in both high and low income countries.

Association between breastfeeding and body mass index at age 6-7 years in an international survey.

BACKGROUND: Breastfeeding is believed to reduce children's risk for obesity but data are conflicting. It is also uncertain if breastfeeding has different effects on obesity in high- and low-income countries. OBJECTIVES: This study aimed to investigate the association between having been breastfed and body mass index (BMI) in 6- to 7-year-old children in a large international survey. METHODS: Parents/guardians reported whether their child had been breastfed and their current height and weight. Some centres measured height and weight directly. Analyses adjusted for whether height and weight were reported or measured, child's age, sex, country gross national income and centre. RESULTS: Data were available for 76,635 participants from 31 centres in 18 countries. Reported breastfeeding rates varied from 27 to 98%. After adjusting for potential confounders, the estimated BMI difference was 0.04 kg m(-2) lower among those who had been breastfed (P = 0.07). The risk for being overweight or obese was slightly lower among breastfed children (odds ratio = 0.95, P = 0.012). There was no evidence that the association between breastfeeding and BMI was different in lower income countries compared with higher income countries. CONCLUSIONS: The findings suggest that breastfeeding has little impact on children's BMI. Increasing breastfeeding is unlikely to reduce the global epidemic of childhood obesity.

Antibiotic treatment during infancy and increased body mass index in boys: an international cross-sectional study.

OBJECTIVE: To investigate whether antibiotic exposure during the first year of life is associated with increased childhood body mass index (BMI). DESIGN: Secondary analysis from a multi-centre, multi-country, cross-sectional study (The International Study of Asthma and Allergies in Childhood Phase Three). SUBJECTS: A total of 74 946 children from 31 centres in 18 countries contributed data on antibiotic use in the first 12 months of life and current BMI. METHODS: Parents/guardians of children aged 5-8 years completed questionnaires that included questions about their children's current height and weight, and whether in the child's first 12 months of life, they had received any antibiotics, paracetamol, were breastfed or the mother/female guardian smoked cigarettes, and whether the child had wheezed in the past 12 months. A general linear mixed model was used to determine the association of antibiotic exposure with BMI, adjusting for age, sex, centre, BMI measurement type (self-reported or measured), maternal smoking, breastfeeding, paracetamol use, gross national income and current wheeze. RESULTS: There was a significant interaction between sex and early-life antibiotic exposure. Early-life antibiotic exposure was associated with increased childhood BMI in boys (+0.107 kg m(-2), P<0.0001), but not in girls (-0.008 kg m(-2), P=0.75) after controlling for age, centre and BMI measurement type. The association remained in boys (+0.104 kg m(-2), P<0.0007), after adjustment for maternal smoking, breastfeeding, paracetamol use and current wheeze. There was no interaction between age, maternal smoking, breastfeeding, paracetamol use, gross national income and current wheeze in the association between early antibiotic exposure and BMI. CONCLUSIONS: Exposure to antibiotics during the first 12 months of life is associated with a small increase in BMI in boys aged 5-8 years in this large international cross-sectional survey. By inference this provides additional support for the importance of gut microbiota in modulating the risk of obesity, with a sex-specific effect.

Cardiac dysfunction and N-terminal pro-B-type natriuretic peptide in exacerbations of chronic obstructive pulmonary disease.

Elevated levels of B-type natriuretic peptides among patients with exacerbations of chronic obstructive pulmonary disease (COPD) are associated with higher mortality. The pathophysiology is unclear. To establish if elevated levels of N-terminal pro-B-type natriuretic peptide (NT-proBNP) are due to right or left heart dysfunction, we performed echocardiograms in 18 patients admitted to hospital with COPD. Elevated levels of NT-proBNP were associated with both right and left heart dysfunction and indicate that these patients have biventricular dysfunction rather than isolated right ventricular compromise.

Forceps birth delivery, allergic sensitisation and asthma: a population-based cohort study.

BACKGROUND: Studies indicate an increased risk of allergies among children born by caesarean section, possibly because immune development is altered by avoiding exposure to maternal vaginal flora. It is unknown if other obstetric interventions are associated with allergies. OBJECTIVE: To assess associations between delivery with forceps assistance and development of atopy and asthma. METHODS: In a population-based cohort of 1037 individuals born in 1972/73, atopy was assessed by skin-prick tests for common allergens at ages 13 and 32 years. A history of asthma was obtained at the same ages. Associations between birth with forceps assistance, atopy and asthma were assessed with adjustments for sex, head circumference at birth, parental atopy disease, birth order and socio-economic status. RESULTS: Children born using forceps were more likely to have atopy at ages 13 (53% vs. 44%) and 32 (68% vs 59%). They were also more likely to have asthma (21% vs. 11% and 23% vs. 16% at ages 13 and 32 respectively). Except for asthma at age 13, these associations were not statistically significant after adjustment for multiple confounding factors. CONCLUSIONS & CLINICAL RELEVANCE: Delivery with forceps assistance is associated with an increased risk of atopy and asthma, but the associations were weaker after adjustment for confounding factors. The previously reported association between caesarean birth and atopic disease may be due to confounding rather than altered exposure to maternal flora, although other factors associated with a difficult labour cannot be ruled out.

Cardio-selective and non-selective beta-blockers in chronic obstructive pulmonary disease: effects on bronchodilator response and exercise.

BACKGROUND: Patients with chronic obstructive pulmonary disease (COPD) often have co-existing cardiovascular disease and may require beta-blocker treatment. There are limited data on the effects of beta-blockers on the response to inhaled beta2-agonists and exercise capacity in patients with COPD. OBJECTIVE: To determine the effects of different doses of cardio-selective and non-selective beta-blockers on the acute bronchodilator response to beta-agonists in COPD, and to assess their effects on exercise capacity. METHODS: A double-blind, randomized, three-way cross-over (metoprolol 95 mg, propranolol 80 mg, placebo) study with a final open-label high-dose arm (metoprolol 190 mg). After 1 week of each treatment, the bronchodilator response to salbutamol was measured after first inducing bronchoconstriction using methacholine. Exercise capacity was assessed using the incremental shuttle walk test. RESULTS: Eleven patients with moderate COPD were recruited. Treatments were well-tolerated although two did not participate in the high-dose metoprolol phase. The area under the salbutamol-response curve was lower after propranolol compared with placebo (P=0.0006). The area under the curve also tended to be lower after high-dose metoprolol (P=0.076). The per cent recovery of the methacholine-induced fall was also lower after high-dose metoprolol (P=0.0018). Low-dose metoprolol did not alter the bronchodilator response. Oxygen saturation at peak exercise was lower with all beta-blocker treatments (P=0.046). CONCLUSION: Non-selective beta-blockers and high doses of cardio-selective beta-blockers may inhibit the bronchodilator response to beta2-agonists in patients with COPD. Beta-blockers were also associated with lower oxygen saturation during exercise. The clinical significance of these adverse effects is uncertain in view of the benefits of beta-blocker treatment for cardiovascular disease.

Effects of cannabis on lung function: a population-based cohort study.

The effects of cannabis on lung function remain unclear and may be different from those of tobacco. We compared the associations between use of these substances and lung function in a population-based cohort (n = 1,037). Cannabis and tobacco use were reported at ages 18, 21, 26 and 32 yrs. Spirometry, plethysmography and carbon monoxide transfer factor were measured at 32 yrs. Associations between lung function and exposure to each substance were adjusted for exposure to the other substance. Cumulative cannabis use was associated with higher forced vital capacity, total lung capacity, functional residual capacity and residual volume. Cannabis was also associated with higher airway resistance but not with forced expiratory volume in 1 s, forced expiratory ratio or transfer factor. These findings were similar among those who did not smoke tobacco. In contrast, tobacco use was associated with lower forced expiratory volume in 1 s, lower forced expiratory ratio, lower transfer factor and higher static lung volumes, but not with airway resistance. Cannabis appears to have different effects on lung function from those of tobacco. Cannabis use was associated with higher lung volumes, suggesting hyperinflation and increased large-airways resistance, but there was little evidence for airflow obstruction or impairment of gas transfer.

High-sensitive C-reactive protein is associated with reduced lung function in young adults.

Systemic inflammation has been associated with reduced lung function. However, data on the interrelationships between lung function and inflammation are sparse, and it is not clear if low-grade inflammation leads to reduced lung function. Associations between high-sensitive C-reactive protein (CRP) and spirometric lung function were assessed in a population-based cohort of approximately 1,000 Danes aged 20 yrs. In males, the average decline in forced expiratory volume in one second (FEV(1)) in the highest CRP quintile was 23 mL.yr(-1) versus 1.6 mL.yr(-1) in the lowest quintile. In females, the average decline was 6.2 mL.yr(-1) in the highest CRP quintile versus an increase of 1.8 mL.yr(-1) in the lowest CRP quintile. In a multiple regression analysis adjusted for sex, body mass index, cardiorespiratory fitness, smoking, asthma, airway hyperresponsiveness and serum eosinophil cationic protein, higher levels of CRP at age 20 yrs were associated with a greater reduction in both FEV(1) and forced vital capacity between ages 20 and 29 yrs. The findings show that higher levels of C-reactive protein in young adults are associated with subsequent decline in lung function, suggesting that low-grade systemic inflammation in young adulthood may lead to impaired lung function independently of the effects of smoking, obesity, cardiorespiratory fitness, asthma and eosinophilic inflammation.

Associations between birth weight, early childhood weight gain and adult lung function.

BACKGROUND: Low birth weight is associated with lower values for spirometry in adults but it is not known if birth weight influences other measures of pulmonary function. It is also unclear whether postnatal growth affects adult lung function. The associations between birth weight, postnatal growth and adult lung function were assessed in an unselected birth cohort of 1037 children. METHODS: Birth weight, weight gain between birth and age 3 years, and lung function at age 32 years were measured. Analyses were adjusted for adult height and sex and further adjusted for multiple other potential confounding factors. RESULTS: Birth weight was positively correlated with spirometric (forced expiratory volume in 1 s and forced vital capacity) and plethysmographic (total lung capacity and functional residual capacity) lung function and with lung diffusing capacity. These associations persisted after adjustment for confounding factors including adult weight, exposure to cigarette smoke in utero and during childhood, personal smoking, socioeconomic status, asthma and gestational age. Weight gain between birth and age 3 years was also positively associated with lung diffusing capacity, and with higher values of lung volumes in men after adjustment for covariates. Neither birth weight nor postnatal weight gain was associated with airflow obstruction. CONCLUSIONS: Low birth weight and lower weight gain in early childhood are associated with modest reductions in adult lung function across a broad range of measures of lung volumes and with lower diffusing capacity. These findings are independent of a number of potential confounding factors and support the hypothesis that fetal and infant growth is a determinant of adult lung function.

Psychosocial correlates of 6-n-propylthiouracil (PROP) ratings in a birth cohort.

This study investigated the relation between ratings of 6-n-propylthiouracil (PROP) and two psychosocial constructs, socioeconomic status and IQ, which are related to health outcomes. A 3.2mM solution of PROP was rated by 922 32-year-old members of a birth cohort (450 women) relative to the strongest imaginable sensation of any kind using the generalised Labelled Magnitude Scale. Women had higher PROP ratings than men. Following normalisation of PROP ratings, multiple linear regression showed that higher ratings were independently associated with lower childhood socioeconomic status, lower childhood IQ scores and ratings of an imagined stimulus made on the same scale (r(2)=0.12). Results suggest that psychosocial variables, sex and scale use, in addition to established genetic determinants, may help explain variability in ratings of supra-threshold concentrations of PROP.

Changes in medication use from age 26 to 32 in a representative birth cohort.

BACKGROUND: To date, longitudinal studies of medications have been confined to older adults or clinical samples, with no data from prospective studies of younger adults. The aim of the study was to examine changes in medication usage between ages 26 and 32 in a prospective study of a representative birth cohort. METHODS: Medication use during the previous 2 weeks was investigated among 960 individuals at ages 26 and 32. RESULTS: Nearly two-thirds took at least one medication at each age, with medication prevalence higher among women than among men. Three-quarters of those taking at least one at age 26 were doing so at 32. Over-the-counter medication prevalence increased from 35 to 43% between 26 and 32 years of age. Although the prevalence of prescribed medications decreased (from just under half to just over one-third, and from two-thirds to below half among women), there was no significant difference between the ages once hormonal contraceptives were accounted for. By 32, reduced usage of hormonal contraceptives was apparent, with one-third of age-26 users still taking these at 32. Other categories showing major changes were analgesics (increased), anti-asthma drugs (decreased), antidepressants (increased) and antiulcer drugs (increased). At 32, 82% of those taking analgesics, 85% of those taking nutrient supplements, 71% of those taking antihistamines and 33% of those taking antiulcer drugs had self-prescribed them. CONCLUSION: A considerable proportion of the sample used medications by age 32, and there was considerable change between 26 and 32. The changes are likely to have been due to a mix of ageing and period effects.

Audit of acute admissions of chronic obstructive pulmonary disease: inpatient management and outcome.

BACKGROUND: Despite the publication of several management guidelines for exacerbations of chronic obstructive pulmonary disease (COPD), there is little information on standards of care in clinical practice. The aim of this audit was to examine the assessment, management and outcome of COPD admissions to a secondary and tertiary referring New Zealand hospital during two different seasons. Compliance to current recommendations was examined and compared with the available international published work. METHODS: All COPD-related admissions to Waikato Hospital during the months of May and October 2004 were reviewed. Ninety-four cases (from 84 patients) were audited. RESULTS: General characteristics, clinical features and lung function tests were similar to that of other cohorts. Twenty-three per cent of the admissions were Maori and the mean age of Maori admissions were significantly less than that of the non-Maori admissions (57 and 72 years, respectively; P = 0.0001). The geometric mean length of stay was 3.4 days, which is significantly less than most other reported hospital lengths of stays related to exacerbations of COPD. Fifty-five per cent of the cohort was admitted more than once to the hospital for COPD in the 12 months before the index admission. Thirteen per cent of all admissions received assisted ventilation. Overall 30-day mortality was 8% and the 12-month mortality was 31%. Decreased body mass index was a risk factor for death as was an increased CURB-65 (confusion, urea, respiratory rate, blood pressure age) score--a simple bedside assessment score, which has previously been used to predict mortality in patients with community-acquired pneumonia. CONCLUSION: This audit documented the general characteristics, assessment, management and outcome of the COPD admissions to a secondary New Zealand hospital. Further investigations into factors contributing to shorter length of stay and predictors of mortality are needed.

Watching television is associated with childhood obesity: but is it clinically important?

OBJECTIVE: To assess the impact of television viewing during childhood and adolescence on body mass index (BMI) in children up to the age of 15 years. DESIGN: Unselected birth cohort, assessed at birth and every 2 years from age 3 to 15 years. SUBJECTS: In all, 1037 individuals were assessed at age 3 years. At age 15 years, 976 (95% of living cohort) continued to participate. MEASUREMENTS: Parental estimates of weekday television viewing between age 5 and 11 years. Self-reports of television viewing at age 13 and 15 years. Weight and height were measured at each age to calculate BMI. RESULTS: BMI and prevalence of overweight at all ages were significantly associated with mean hours of television viewing reported in the assessments up to that age. These associations were stronger in girls than boys. The associations remained significant after adjusting for parental body mass indices and socio-economic status. CONCLUSION: Time spent watching television is a significant predictor of BMI and overweight in childhood. Although the effect size appears small, it is larger than the effect sizes commonly reported for nutritional intake and physical activity. Television viewing should be regarded as an important contributing factor to childhood obesity.

Association between C-reactive protein, metabolic cardiovascular risk factors, obesity and oral contraceptive use in young adults.

OBJECTIVE: This study sought to determine the relationship between levels of the inflammatory marker, C-reactive protein (CRP), cardiovascular risk factors and oral contraceptive use in young adults. DESIGN: Cross-sectional study of a community cohort. SUBJECTS: A total of 822 men and women aged 26 y. MEASUREMENTS: CRP, body mass index (BMI), blood pressure, lipid and lipoprotein levels, smoking status, socioeconomic status, health status, and hormonal contraceptive use in women. RESULTS: Multiple regression analysis showed that obesity was independently related to CRP with an increase in ratio CRP of 1.03 (95% CI 1.01, 1.05) for men and 1.07 (1.05, 1.09) for women associated with a 1 kg/m(2) increase in BMI. In women, combined oral contraceptive use was associated with a ratio change in CRP of 1.52 (1.27, 1.82) compared with nonusers. Other independent determinants of CRP in men and women were apolipoprotein B level, systolic blood pressure and apolipoprotein A1 in men. Univariate analysis showed that the relationship between CRP and BMI, systolic blood pressure and apolipoprotein B was significantly stronger in women than men. CONCLUSION: These findings suggest that obesity is associated with inflammation independent of other cardiovascular risk factors that may contribute to an increased risk for cardiovascular disease in men and women. Elevated CRP related to combined oral contraceptive use may influence the rate of cardiovascular events in young women.

Relationship between socioeconomic status and asthma: a longitudinal cohort study.

BACKGROUND: There is conflicting information about the relationship between asthma and socioeconomic status, with different studies reporting no, positive, or inverse associations. Most of these studies have been cross sectional in design and have relied on subjective markers of asthma such as symptoms of wheeze. Many have been unable to control adequately for potential confounding factors. METHODS: We report a prospective cohort study of approximately 1000 individuals born in Dunedin, New Zealand in 1972-3. This sample has been assessed regularly throughout childhood and into adulthood, with detailed information collected on asthma symptoms, lung function, airway responsiveness, and atopy. The prevalence of these in relation to measures of socioeconomic status were analysed with and without controls for potential confounding influences including parental history of asthma, smoking, breast feeding, and birth order using cross sectional time series models. RESULTS: No consistent association was found between childhood or adult socioeconomic status and asthma prevalence, lung function, or airway responsiveness at any age. Having asthma made no difference to educational attainment or socioeconomic status by age 26. There were trends to increased atopy in children from higher socioeconomic status families consistent with previous reports. CONCLUSIONS: Socioeconomic status in childhood had no significant impact on the prevalence of asthma in this New Zealand born cohort. Generalisation of these results to other societies should be done with caution, but our results suggest that the previously reported associations may be due to confounding.