Evaporative gasoline emissions and asthma symptoms

Attached garages are known to be associated with indoor air volatile organic compounds (VOCs). This study looked at indoor exposure to VOCs presumably from evaporative emissions of gasoline. Alaskan gasoline contains 5% benzene making benzene a marker for gasoline exposure. A survey of randomly chosen houses with attached garages was done in Anchorage Alaska to determine the exposure and assess respiratory health. Householders were asked to complete a health survey for each person and a household survey. They monitored indoor air in their primary living space for benzene, toluene, ethylbenzene and xylenes for one week using passive organic vapor monitoring badges. Benzene levels in homes ranged from undetectable to 58 parts per billion. The median benzene level in 509 homes tested was 2.96 ppb. Elevated benzene levels in the home were strongly associated with small engines and gasoline stored in the garage. High concentrations of benzene in gasoline increase indoor air levels of benzene in residences with attached garages exposing people to benzene at levels above ATSDR’s minimal risk level. Residents reported more severe symptoms of asthma in the homes with high gasoline exposure (16%) where benzene levels exceeded the 9 ppb.

The impact of the method of consent on response rates in the ISAAC time trends study

BACKGROUND

Centres in Phases I and III of the International Study of Asthma and Allergies in Childhood (ISAAC) programme used the method of consent (passive or active) required by local ethics committees.

METHODS

Retrospectively, relationships between achieved response rates and method of consent for 13-14 and 6-7-year-olds (adolescents and children, respectively), were examined between phases and between English and non-English language centres.

RESULTS

Information was obtained for 113 of 115 centres for adolescents and 72/72 centres for children. Both age groups: most centres using passive consent achieved high response rates (>80% adolescents and >70% children). English language centres using active consent showed a larger decrease in response rate. Adolescents: seven centres changed from passive consent in Phase I to active consent in Phase III (median decrease of 13%), with five centres showing lower response rates (as low as 34%). Children: no centre changed consent method between phases. Centres using active consent had lower median response rates (lowest response rate 45%).

CONCLUSION

The requirement for active consent for population school-based questionnaire studies can impact negatively on response rates, particularly English language centres, thus adversely affecting the validity of the data. Ethics committees need to consider this issue carefully.

PCOSMIC: a multi-centre randomized trial in women with PolyCystic Ovary Syndrome evaluating Metformin for Infertility with Clomiphene

BACKGROUND

Ovulation induction treatment with metformin, either alone or in combination with clomiphene citrate (CC), remains controversial even though previous randomized trials have examined this.

METHODS

A double blinded multi-centre randomized trial was undertaken including 171 women with anovulatory or oligo-ovulatory polycystic ovary syndrome. Women with high body mass index (BMI) > 32 kg/m(2) received placebo ('standard care') or metformin; women with BMI < or = 32 kg/m(2) received CC ('standard care'), metformin or both. Treatment continued for 6 months or until pregnancy was confirmed. Primary outcomes were clinical pregnancy and live birth.

RESULTS

For women with BMI > 32 kg/m(2), clinical pregnancy and live birth rates were 22% (7/32) and 16% (5/32) with metformin, 15% (5/33) and 6% (2/33) with placebo. For women with BMI < or = 32 kg/m(2), clinical pregnancy and live birth rates were 40% (14/35) and 29% (10/35) with metformin, 39% (14/36) and 36% (13/36) with CC, 54% (19/35) and 43% (15/35) with combination metformin plus CC.

CONCLUSIONS

There is no evidence that adding metformin to 'standard care' is beneficial. Pregnancy and live birth rates are low in women with BMI > 32 kg/m(2) whatever treatment is used, with no evidence of benefit of metformin over placebo. For women with BMI < or = 32 kg/m(2) there is no evidence of significant differences in outcomes whether treated with metformin, CC or both. ClinicalTrials.gov number NCT00795808; trial protocol accepted for publication November 2005: Johnson, Aust N Z Journal Obstet Gynaecol 2006;46:141-145.

Which population level environmental factors are associated with asthma, rhinoconjunctivitis and eczema? Review of the ecological analyses of ISAAC Phase One

The International Study of Asthma and Allergies in Childhood (ISAAC) Phase One showed large worldwide variations in the prevalence of symptoms of asthma, rhinoconjunctivitis and eczema, up to 10 to 20 fold between countries. Ecological analyses were undertaken with ISAAC Phase One data to explore factors that may have contributed to these variations, and are summarised and reviewed here.In ISAAC Phase One the prevalence of symptoms in the past 12 months of asthma, rhinoconjunctivitis and eczema were estimated from studies in 463,801 children aged 13 - 14 years in 155 centres in 56 countries, and in 257,800 children aged 6-7 years in 91 centres in 38 countries. Ecological analyses were undertaken between symptom prevalence and the following: Gross National Product per capita (GNP), food intake, immunisation rates, tuberculosis notifications, climatic factors, tobacco consumption, pollen, antibiotic sales, paracetamol sales, and outdoor air pollution.Symptom prevalence of all three conditions was positively associated with GNP, trans fatty acids, paracetamol, and women smoking, and inversely associated with food of plant origin, pollen, immunisations, tuberculosis notifications, air pollution, and men smoking. The magnitude of these associations was small, but consistent in direction between conditions. There were mixed associations of climate and antibiotic sales with symptom prevalence.The potential causality of these associations warrant further investigation. Factors which prevent the development of these conditions, or where there is an absence of a positive correlation at a population level may be as important from the policy viewpoint as a focus on the positive risk factors. Interventions based on small associations may have the potential for a large public health benefit.

A pilot survey of the impact of menstrual cycles on adolescent health

BACKGROUND

The experience of menstruation and reproductive health by adolescent girls has been poorly studied in New Zealand.

AIMS

To develop and pilot a Web-based survey of 16-year-olds' experience of menstruation and reproductive health with the eventual objective of conducting a larger population-based survey. A secondary aim was to report on the experience of menstrual and reproductive health in a group of 16-year-old girls in an urban setting.

METHODS

A Web-based survey was developed and tested in 2006 with assistance of a multidisciplinary advisory group. The final version of the questionnaire had 146 questions in 11 sections and the topics were menstrual history, general health including use of medications, access to medical care or health information, sexual health, family history and personal information including smoking, height, weight, ethnicity, paid employment of parents, drug and alcohol use and exercise patterns.

RESULTS

Seventy-five 16-year-old students completed the survey. Twenty-five per cent considered that their periods were quite a bit or a lot of trouble and 10% avoided certain activities during their menstrual periods, nearly 50% of girls always experienced some pain with every period, and 30% had seen a health professional about their period pains. Thirty-three stated that menstruation was moderately to severely painful and that daily activity was affected. Fifty per cent of girls were sexually active and of these 80% described it as painful.

CONCLUSIONS

The Web-based survey was a successful approach to collecting information and could be used in a larger study.

Self-reported truck traffic on the street of residence and symptoms of asthma and allergic disease: a global relationship in ISAAC phase 3

BACKGROUND

Associations between traffic pollution on the street of residence and a range of respiratory and allergic outcomes in children have been reported in developed countries, but little is known about such associations in developing countries.

METHODS

The third phase of the International Study of Asthma and Allergies in Childhood (ISAAC) was carried out in 13- to 14-year-old and 6- to 7-year-old children across the world. A question about frequency of truck traffic on the street of residence was included in an additional questionnaire. We investigated the association between self-reported truck traffic on the street of residence and symptoms of asthma, rhinoconjunctivitis, and eczema with logistic regression. Adjustments were made for sex, region of the world, language, gross national income, and 10 other subject-specific covariates.

RESULTS

Frequency of truck traffic on the street of residence was positively associated with the prevalence of symptoms of asthma, rhinoconjunctivitis, and eczema with an exposure-response relationship. Odds ratios (95% confidence intervals) for "current wheeze" and "almost the whole day" versus "never" truck traffic were 1.35 (1.23-1.49) for 13- to 14-year-olds and 1.35 (1.22-1.48) for 6- to 7-year-olds.

CONCLUSIONS

Higher exposure to self-reported truck traffic on the street of residence is associated with increased reports of symptoms of asthma, rhinitis, and eczema in many locations in the world. These findings require further investigation in view of increasing exposure of the world's children to traffic.

Characteristics, head shape measurements and developmental delay in 287 consecutive infants attending a plagiocephaly clinic

AIM

To describe the characteristics, developmental status and severity of head shape deformation in infants presenting to a plagiocephaly clinic.

METHODS

Head shape was measured and neck function assessed in 287 consecutive infants presenting to a plagiocephaly outpatient clinic. Information was obtained on demographic and obstetric factors, plagiocephaly history and current positioning strategies. Development was assessed by the Ages and Stages Questionnaire (ASQ).

RESULTS

After clinical examination, craniosynostosis was suspected in seven infants (2%) and a skull computed tomography (CT) scan was performed; five showed suture abnormalities. Fifty-eight percent of cases had a history of limitation of neck function; this was more likely in plagiocephalic infants than brachycephalic infants. Males, firstborn infants, instrument-delivered infants, supine sleep position and right-sided flattening were predominant. One or more delays on the ASQ were seen in 36% of infants.

CONCLUSION

Physical examination of infants with head shape deformities is essential in order to rule out craniosynostosis. Infants with deformational plagiocephaly frequently have neck muscle dysfunction. We postulate that the higher than expected number of developmental delays may be related to the effects of supine sleep position, low or variable tone, lower activity levels, male gender and neck muscle dysfunction.

Ethnic differences in time trends in asthma prevalence in New Zealand: ISAAC Phases I and III

SETTING

The International Study of Asthma and Allergies in Childhood (ISAAC) Phase III survey, New Zealand.

OBJECTIVE

To assess the prevalence of asthma symptoms and time trends by ethnicity between ISAAC Phase I (1992-1993) and Phase III (2001-2003).

DESIGN

Information on asthma symptoms and environmental exposures was collected in children aged 6-7 years (n = 10,873) and adolescents aged 13-14 years (n = 13,317).

RESULTS

In children, the prevalence of current wheeze was 28.5% in Māori (prevalence odds ratio [POR] = 1.49, 95%CI 1.32-1.68), and 25.2% in Pacific Islanders (POR 1.28, 95%CI 1.07-1.54) compared with 20.7% in Europeans/Pakeha. In adolescents, 29.9% of Māori (POR = 1.13, 95%CI 1.03-1.23) and 20.8% of Pacific Islanders (POR 0.74, 95%CI 0.62-0.87) experienced current wheeze compared to 28.6% of Europeans/Pakeha. Between Phases I and III, the prevalence of current wheeze increased significantly by 0.49%/year in Pacific Islanders, increased non-significantly by 0.12%/year in Māori, and decreased significantly by 0.25%/year in Europeans/Pakeha children. In adolescents, the prevalence of current wheeze increased by 0.05%/year in Pacific Islanders and decreased by 0.33%/year in Europeans/Pakeha and by 0.07%/year in Māori.

CONCLUSION

Ethnic differences in asthma symptom prevalence in New Zealand have increased. The reasons for this are unclear, but may reflect inequalities in access to health services.

Cross-sectional survey of risk factors for asthma in 6-7-year-old children in New Zealand: International Study of Asthma and Allergy in Childhood Phase Three

AIM

To identify risk factors for asthma in primary school-aged children in New Zealand.

METHODS

A cross-sectional survey of 10,873 6-7-year-old children in Auckland, Bay of Plenty, Nelson and Christchurch (a response rate of 85.2%). A questionnaire was completed by the parent or care giver.

RESULTS

22.2% of children wheezed in the last 12 months (current wheeze). Maori children were at greater risk of current wheeze compared with European children (adjusted odds ratio (adjOR) = 1.37; 95% confidence interval = 1.18-1.59). Antibiotics and paracetamol used in the first year of life were associated with an increased risk of current wheeze (adjOR = 1.78 (1.56-2.04) and adjOR = 1.31 (1.06-1.61), respectively). Watching television for 5 or more hours per day was associated with an increased risk of current wheeze (adjOR = 1.44 (1.13-1.83)). Milk and egg consumption in the last 12 months was associated with a reduced risk of current wheeze.

CONCLUSIONS

 This study has identified risk factors for asthma in children aged 6-7 years, although causal pathways cannot be established. These associations have important public health implications if causal.

New Zealand Ginger mouse: novel model that associates the tyrp1b pigmentation gene locus with regulation of lean body mass

The study of spontaneous mutations in mice over the last century has been fundamental to our understanding of normal physiology and mechanisms of disease. Here we studied the phenotype and genotype of a novel mouse model we have called the New Zealand Ginger (NZG/Kgm) mouse. NZG/Kgm mice are very large, rapidly growing, ginger-colored mice with pink eyes. Breeding NZG/Kgm mice with CAST/Ei or C57BL/6J mice showed that the ginger coat colour is a recessive trait, while the excessive body weight and large body size exhibit a semidominant pattern of inheritance. Backcrossing F1 (NZG/Kgm x CAST/Ei) to NZG/Kgm mice to produce the N2 generation determined that the NZG/Kgm mouse has two recessive pigmentation variant genes (oca2(p) and tyrp-1(b)) and that the tyrp-1(b) gene locus associates with large body size. Three coat colors appeared in the N2 generation; ginger, brown, and dark. Strikingly, N2 male coat colour associated with body weight; the brown-colored mice weighed the most followed by ginger and then dark. The male brown coat-colored offspring reached adult body weights indistinguishable from NZG/Kgm males. The large NZG/Kgm mouse body size is a result of excessive lean body mass since these mice are not obese or diabetic. NZG/Kgm mice exhibit an unusual pattern of fat distribution; compared with other mouse strains they have disproportionately higher amounts of subcutaneous and gonadal fat. These mice are susceptible to high-fat diet-induced obesity but are resistant to high-fat diet-induced diabetes. We propose NZG/Kgm mice as a novel model to delineate gene(s) that regulate 1) growth and metabolism, 2) resistance to Type 2 diabetes, and 3) preferential fat deposition in the subcutaneous and gonadal areas.

A prospective randomized comparison of ultrasound and neurostimulation as needle end points for interscalene catheter placement

BACKGROUND

In this prospective, randomized study, we tested the hypothesis that interscalene catheters placed for shoulder surgery using an ultrasound needle end point provide postoperative analgesia similar in quality to those placed using a neurostimulation needle end point. Secondary end points included needle time under the skin, procedure-related pain, and the incidence of early neurological complications.

METHODS

Patients presenting for shoulder surgery were recruited. Needles introduced for catheter insertion were initially guided with out-of-plane ultrasound imaging but were prospectively randomized to either sonographic placement immediately lateral to the interscalene interface (n = 41) or to an appropriate motor response at <0.5 mA (n = 40). Catheters were then advanced blindly 2-3 cm beyond needle tip. All surgery was conducted under general anesthesia. At the end of surgery, an infusion of ropivacaine 0.2% 2 mL/h with as-required hourly 5 mL boluses was instituted and continued at home for 2-5 days. Needle time under the skin and numerical rating pain score (NRPS) during insertion were recorded. Patients recorded worst NRPS, the need for supplementary ropivacaine boluses and tramadol on postoperative days 1 and 2. All patients were questioned at Day 10 for new neurological symptoms.

RESULTS

There was no significant difference in the worst NRPS at rest and on movement and the requirement for supplementary ropivacaine boluses or tramadol during the first 48 postoperative hours. In one patient in group ultrasound, a satisfactory ultrasound image was unobtainable. An appropriate motor response was obtained in all subjects in group neurostimulation. The median (quartiles) needle time under the skin was 78 (65-101) s in group ultrasound and 108 (94-129) s in group neurostimulation (P < 0.001). The median (quartiles) insertion NRPS was 2 (0-4) in group ultrasound and 3 (1-5) in group neurostimulation (P < 0.048). There was no difference in the frequency of neurological complications between groups.

CONCLUSIONS

Interscalene catheters placed for shoulder surgery using an ultrasound needle end point provide postoperative analgesia that is of similar quality to that obtained when using a neurostimulation needle end point. The ultrasound end point was associated with a reduction in needle under the skin time and procedure-related pain.

Has the prevalence and severity of symptoms of asthma changed among children in New Zealand? ISAAC Phase Three

AIM

To investigate time trends in prevalence of symptoms of asthma by repeating, during 2001-3 (Phase Three), the International Study of Asthma and Allergies in Childhood (ISAAC) Phase One study that was conducted in New Zealand in 1992-3.

METHODS

ISAAC Phase Three involved repeating the cross-sectional questionnaire survey of two age groups of school children (6-7 years and 13-14 years, children and adolescents respectively) using the same methodology as Phase One. In New Zealand it was conducted in Auckland, Bay of Plenty, Christchurch, Nelson, and Wellington.

RESULTS

After 9 years, reported asthma ever increased from 24.6% to 30.2% in children and from 24.1% to 32.4% in adolescents (p<0.001). Current wheeze (written questionnaire) significantly decreased in children from 23.6% to 22.2% (p=0.002) and in adolescents from 29.7% to 26.7% (p=0.047), and for the video questionnaire from 18.1% to 11.1% (p<0.001). There was a significant reduction in wheezing limiting speech from 5.0% to 3.7% in children, and 7.9% to 6.2% in adolescents. Little regional variation was found. A higher proportion of children with asthma symptoms now report having ever had asthma.

CONCLUSIONS

The decrease in prevalence and severity of symptoms of asthma is encouraging, but the reasons for these trends are currently unclear. Increases in asthma labelling are likely to be due to greater awareness of asthma. A trend of decreasing prevalence of asthma symptoms, if maintained, has positive implications for lessened burden of disease among asthmatics and lowered cost of treatment.

Prone sleeping position increases the risk of SIDS in the day more than at night

BACKGROUND

SIDS mortality is higher during the night than in the day.

AIM

(1) To examine risk factors for SIDS by time of day and (2) to see if the proportion of deaths at night has changed from prior to the 'Back to Sleep' campaign, which recommended infants sleep supine.

METHODS

A large population-based SIDS matched case-control (GeSID) study conducted from 1998 to 2001 (when the prevalence of infants placed prone to sleep was 4.1%). The reference sleep of the controls was matched for the estimated time of death for the case. Risk factors for SIDS were examined for night-time and day-time deaths. The estimated time of death was compared with that from an earlier study in Germany (1990-1994 when prevalence of prone sleeping was 32.2%).

RESULTS

There were 333 SIDS cases and 998 matched controls. The increased risk with placed prone to sleep was significantly different during the day [adjusted OR = 18.15 (95% CI = 5.91-55.69)] compared with during the night [adjusted OR = 3.49 (95% CI = 1.46-8.39; p-value for interaction = 0.011)]. There was no significant difference in the other risk factors examined by time of day in the multivariate analysis. The mean time found dead was 09:07. In the earlier study the mean time found dead was 08:54 and the difference was not significant (p = 0.57).

CONCLUSIONS

This study confirms previous observations that prone sleeping position carries a greater risk during the day than at night. However, the reduction in infants sleeping prone has not been associated with a reduced number of deaths in the day in Germany.

Lipiodol fertility enhancement: two-year follow-up of a randomized trial suggests a transient benefit in endometriosis, but a sustained benefit in unexplained infertility

BACKGROUND

A New Zealand randomized trial has shown that lipiodol treatment enhances fertility with high short-term effectiveness for women with endometriosis.

METHODS

An open randomized trial in a single-centre secondary- and tertiary-level infertility service assessing lipiodol flushing versus no intervention. A total of 158 women with unexplained infertility (62 women with mild endometriosis and 96 women with pure unexplained infertility) were evaluated at 24 months after trial entry. The main outcome measure was clinical pregnancy, assessed using a Cox proportional hazards regression model.

RESULTS

There was a significant benefit in overall pregnancy rate following lipiodol [hazard ratio 2.0, 95% confidence interval (CI) 1.3-3.2]. Among women with endometriosis, the benefit in pregnancy rate seen in the first 6 months following lipiodol (hazard ratio 5.4, 95% CI 2.1-14.2) was not present at 6-24 months (hazard ratio 0.6, 95% CI 0.2-2.1). There was a more consistent effect of lipiodol on fertility throughout the 24-month follow-up among women with unexplained infertility (hazard ratio 2.0, 95% CI 1.1-3.5).

CONCLUSIONS

Lipiodol flushing is effective at enhancing fertility not only for women with endometriosis, but also for those with pure unexplained infertility.

The continuing decline in SIDS mortality

The "Back to Sleep" campaign resulted in a dramatic decrease in sudden infant death syndrome (SIDS) worldwide. SIDS mortality has continued to decline (in New Zealand by 63% from 1993 to 2004), but the reason for this has not been explained. A postal survey found that the proportion of infants sleeping on their back has increased substantially (from 24.4% in 1992 to 72.3% in 2005), and this could account for the 39%-48% decrease in SIDS mortality.

Design effects associated with dietary nutrient intakes from a clustered design of 1 to 14-year-old children

OBJECTIVE

To calculate intra-cluster and intra-household design effects and intra-class correlation coefficients for dietary nutrients obtained from a 24 h record-assisted recall.

DESIGN

Children were recruited using clustered probability sampling. Randomly selected starting-point addresses were obtained with probability proportional to mesh block size.

SETTING

Children aged 1-14 years in New Zealand.

SUBJECTS

There were 125 children in 50 clusters, giving an average of 2.498 children per cluster. In 15 homes, there were two children for the calculation of intra-household statistics.

RESULTS

Intra-cluster design effects ranged from 1.0 for cholesterol, beta-carotene, vitamin A, vitamin D, vitamin E, selenium, fructose and both carbohydrate and protein expressed as their contribution to total energy intakes to 1.552 for saturated fat, with a median design effect of 1.148. Their corresponding intra-cluster correlations ranged from 0 to 0.37, respectively. Intra-household design effects ranged from 1.0 for height to 1.839 for vitamin B(6), corresponding to intra-household correlations of 0 and 0.839. The median intra-household design effect was 1.550. Using a sampling design of two to three households per cluster for estimating dietary nutrient intakes would need, on average, a 15% increase in sample size compared with simple random sampling with a maximum increase of 55% to cover all nutrients.

CONCLUSIONS

These data enable sample sizes for dietary nutrients to be estimated for both cluster and non-cluster sampling for children aged 1-14 years. The larger design effects found within households suggest that little extra information may be obtained by sampling more than one child per household.

SIDS-protective infant care practices among Auckland, New Zealand mothers

AIM

To survey the knowledge and implementation of sudden infant death syndrome (SIDS)-protective infant care practices in mothers of infants aged less than 4 months.

METHODS

A postal survey was carried out of knowledge of SIDS risk factors and infant care practices of 200 mothers with infants aged 6-8 weeks and 3-4 months.

RESULTS

Mothers who could cite supine sleeping as protective comprised 84%, while 73% knew that smoking was a risk factor. Fewer knew that room sharing, keeping the face clear of bedding, and avoiding bed sharing and overheating are also protective. Fifty-four percent of the infants usually room-share with a parent, while 39% both room-share and sleep in their own bed. Sixteen percent usually co-slept for part or all of the night. Nearly one-third used pacifiers. Mothers who smoked during pregnancy comprised 8%, while 7% had smoked in the last 24 hours. Most infants (97%) had been breastfed at some time.

CONCLUSIONS

Maternal education of the benefits of supine sleeping, not smoking, and breastfeeding appear well understood by these mothers. However, more education is needed about other SIDS-protective behaviours such as keeping the face clear and sleeping the infant in their own bed in the parents' room.

The epidemiology of recurrent miscarriage: A descriptive study of 1214 prepregnant women with recurrent miscarriage

AIMS

To describe the characteristics of the prepregnant population attending the Recurrent Miscarriage Clinic (RMC) at the National Women's Hospital (NWH), Auckland, between 1986 and 2003, and to compare them with the overall obstetric booking population of the hospital.

METHODS

The identifying details of 1214 prepregnant women attending the RMC were obtained. Both hospital and RMC records, which were kept separately, were retrospectively reviewed for demographic information and results of diagnostic investigations. Data from Auckland residents who attended the clinic were compared with data from all Auckland women booking or delivering at NWH.

RESULTS

RMC attendees were older than the general NWH population, but had similar parity. Clinic attendees had a higher incidence of personal and family history of antepartum haemorrhage, fetal abnormalities, stillbirths and neonatal deaths than reported rates for the general population. Chromosomal anomalies were detected in 86 women, reproductive tract anomalies were found in 142 women, and polycystic ovarian syndrome was detected in 49 women. The majority (52.7%) of women had no identifiable cause for recurrent miscarriage detected.

CONCLUSIONS

These data support the concept of women with recurrent miscarriage being at high risk for adverse obstetric outcomes including fetal abnormalities, stillbirths and neonatal deaths, even when the pregnancies are ongoing. We conclude that recurrent miscarriage is different from subfertility, and provide information of use in planning care for such women.

The Nepal Longitudinal Study: biometric characteristics of developing eyes

PURPOSE

To identify differences in potential biometric markers for predicting refractive error in school children.

METHODS

Biometric data on 895 Tibetan children, aged 6 to 18 years, residing in Katmandu, Nepal, were collected biennially from 1992 to 2000. Measurements included cycloplegic autorefraction, A-scan ultrasonography, and video phakometry. Only those children who had been studied at least once at age 12 years or more were included in the analysis. Subjects were divided into two groups: a myopia group if the refractive error was myopic by more than -0.50 D and a nonmyopia group if the refractive error was maximally myopic by -0.50 D, expressed as a spherical equivalent error in the left eye.

RESULTS

Biometric measures that differed significantly with increasing age between the two refractive groups included: anterior chamber depth + 0.012 mm/year (p = 0.014), anterior lens radius of curvature + 0.073 mm/year (p = 0.001), lens power -0.059 D/year (p = 0.082), lens thickness -0.005 mm/year (p = 0.02), and vitreous chamber depth + 0.084 mm/year (p < 0.001). Corneal radii of curvature of the myopic group were steeper at all ages by 0.09 mm (p < 0.001), but the rate of change with age was equivalent across the refractive groups.

CONCLUSIONS

Compared with those who remained nonmyopic, children who developed myopia had a crystalline lens that was initially thicker and steeper, and a vitreous chamber that was initially shorter. With age, children who became myopic developed greater lens thinning, greater flattening of the anterior lens surface radius, and a greater increase in vitreous chamber depth than their nonmyopic counterparts.

Longitudinal pulmonary function of childhood bronchiectasis and comparison with cystic fibrosis

BACKGROUND

Little has been published on the progression of non-cystic fibrosis bronchiectasis (BX), especially in childhood. Data are needed for prognosis and evaluation of the effectiveness of treatments. A study was undertaken to evaluate the change in lung function over time in children with BX, and to consider covariates and compare them with the local cystic fibrosis (CF) population.

METHODS

Children with BX or CF and > or =3 calendar years of lung function data were identified from hospital clinics. Diagnosis was made by high resolution CT scans, sweat tests, and genetic studies. Lung function performed on a single plethysmograph between 6 and 15 years of age and > or =6 weeks after diagnosis was analysed longitudinally (linear mixed model). The impact of reference equation and "best annual" versus "all data" approaches were evaluated.

RESULTS

There were 44 children in each of the BX and CF groups with an overall mean 5.7 calendar years follow up data. The estimated forced expiratory volume in 1 second (FEV(1)) in the BX group had an intercept of 68% predicted (Polgar) at 10 years of age which fell at a rate of 1.9% per annum using "best annual" data compared with 63% and 0.9% using "all data". Those with post-infectious BX or chronic Haemophilus influenzae infection had more severe disease. In CF the FEV(1) ("best annual") intercept was 85% predicted with a slope of -2.9% per annum. The choice of reference equation affected the magnitude of the result but not the conclusions.

CONCLUSION

Children with BX have significant airway obstruction which deteriorates over time, regardless of analysis strategy or reference. Effective interventions are needed to prevent significant morbidity and adult mortality.

A prospective study of 3 years of outcomes after hysterectomy with and without oophorectomy

OBJECTIVE

This study was undertaken to determine the outcomes of hysterectomy with and without conservation of the ovaries.

STUDY DESIGN

Data were collected prospectively for 3 years from 257 women undergoing hysterectomy (group 1) and 57 women undergoing hysterectomy with oophorectomy (group 2).

RESULTS

Pelvic pain, abdominal pain, and depression scores were reduced in the 3 years after hysterectomy. Twenty-one percent of the women in group 1 and 43% in group 2 regretted the loss of fertility 3 years after hysterectomy. Satisfaction with the operation was greater than 90% after 3 years in both groups. New symptoms of pelvic pain were infrequent in groups 1 (3%) and 2 (5%).

CONCLUSION

Three years after undergoing hysterectomy with and without oophorectomy, satisfaction is high although some women regret the loss of fertility.

Vulvar intraepithelial neoplasia: aspects of the natural history and outcome in 405 women

OBJECTIVE

To determine the clinical characteristics, outcome following surgical treatment, and natural history of cases of untreated vulvar intraepithelial neoplasia (VIN).

METHODS

Four hundred five cases of VIN 2-3 seen between 1962 and 2003 were reviewed.

RESULTS

The mean age of women with VIN decreased from 50.0 years before 1980 to 39.0 in subsequent years. After treatment of VIN by excision and/or laser vaporization, half the women required at least one further treatment by the 14th year. It is estimated that 50% of women with positive surgical margins had at least one further treatment within 5 years, but only 15% of women with negative surgical margins required further treatment. Invasive vulvar, perianal, or urethral carcinoma occurred in 17 (3.8%) women (mean age 42 years) after treatment. Nine (2%) cases represented treatment failure, with a median treatment-to-invasion interval of 2.4 years. Eight (1.8%) cases represented new "field" carcinomas, with a median initial treatment-to-invasion interval of 13.5 years. Ten untreated cases, aged 32-76 years (mean age 55 years), progressed to invasion in 1.1-7.3 years (mean 3.9 years). Age, previous pelvic radiotherapy, unifocality, immunosuppression, and association with multicentric neoplasia were not risk factors for the development of invasive vulvar carcinoma in this study. Spontaneous regression of VIN occurred in 47 women (mean age 24.6 years), with a median interval to complete regression of 9.5 months.

CONCLUSION

Surgically treated VIN has a high rate of recurrence. Untreated VIN in women over 30 years has an appreciable invasive potential.

Customized birthweight centiles predict SGA pregnancies with perinatal morbidity

OBJECTIVES

To determine the following: (1) the proportion of babies reclassified as small or appropriately grown using customized and population centiles; and (2) the relative risks of perinatal morbidity, including abnormal umbilical Doppler studies, in babies classified as small for gestational age (SGA) and appropriate for gestational age (non-SGA) using the two centile calculations.

DESIGN

Cohort study in SGA and general hospital populations.

SETTING

National Women's Hospital, Auckland, NZ.

POPULATION

A cohort of SGA pregnancies (n= 374) and a general obstetric population (n= 12,879).

METHODS

Pregnancy outcomes were compared between 'non-SGA both' (> or =10th% by population and customized centiles) and those who were 'SGA both' (<10th% by population and customized centiles), 'SGA customized only' (SGA by customized but non-SGA by population centiles) and 'SGA population only' (SGA by population but non-SGA by customized centiles).

MAIN OUTCOME MEASURES

Maternal and newborn morbidity and perinatal death.

RESULTS

In the SGA cohort 271 (72%) babies were 'SGA both', 27 (7%) were 'SGA customized only', 32 (9%) were 'population SGA only' and 44 (12%) were 'non-SGA both'. In the general obstetric population 863 (6.7%) babies were 'SGA both', 445 (3.5%) were 'customized SGA only', 285 (2.2%) were 'population SGA only' and 11,286 (88%) were 'non-SGA both'. Perinatal death and newborn morbidity including nursery admission and long hospital stay were increased and comparable between 'SGA both' and 'customized SGA only' in both study populations. Newborn morbidity was low and comparable between 'population SGA only' and 'non-SGA both'. No perinatal deaths occurred in 'population SGA only' babies. Abnormal Doppler studies were more common in 'SGA both' or 'customized SGA only' but not in 'population SGA only' groups compared with 'non-SGA both'.

CONCLUSIONS

Customized birthweight centiles identified small babies at risk of morbidity and mortality. Use of customized centiles is likely to detect more babies at risk of perinatal morbidity and mortality than would be detected by population centiles.

The association of hysterectomy and menopause: a prospective cohort study

OBJECTIVE

To determine whether or not hysterectomy leads to an earlier onset of the menopause.

DESIGN

A prospective cohort study.

SETTING

Gynaecology service of large urban hospital.

POPULATION

Premenopausal women with and without hysterectomy.

METHODS

Multivariate survival analysis techniques were used to adjust for differences in initial follicle stimulating hormone (FSH) levels, body mass index, smoking and unilateral oophorectomy between the groups.

MAIN OUTCOME MEASURES

FSH levels were measured for five years following hysterectomy and compared with the comparison group. Menopause was defined as a single FSH measurement of at least 40 IU/L.

RESULTS

Two hundred and fifty-seven women undergoing hysterectomy were compared with 259 women who had not undergone a hysterectomy. Fifty-three women (20.6%) in the hysterectomy group and 19 women (7.3%) in the comparison group reached menopause over the five years of the study. Women in the hysterectomy group with a pre-operative FSH <10 IU/L reached menopause 3.7 years (95% CI 1.5-6.0 years) earlier than women in the comparison group independent of BMI, smoking and unilateral oophorectomy. Twenty-eight women in the hysterectomy group had unilateral oophorectomy and 10 (35.7%) of these women reached menopause over the five years of follow up. Women in the hysterectomy group with unilateral oophorectomy reached menopause 4.4 years (95% CI 0.6, 7.9 years) earlier than women with both ovaries in the hysterectomy group independent of baseline FSH, BMI and smoking.

CONCLUSIONS

Hysterectomy is associated with an earlier onset of menopause. Hysterectomy with unilateral oophorectomy is associated with an even earlier onset of the menopause in this study.

Ethnicity and birth outcome: New Zealand trends 1980-2001: Part 2. Pregnancy outcomes for Maori women

BACKGROUND

While traditionally Maori perinatal mortality has been similar to that of other ethnic groups, rates of preterm birth, small for gestational age (SGA) and teenage pregnancy have remained high.

AIMS

To review current trends in preterm birth, SGA and teenage pregnancy for Maori during 1980-2001 and to highlight the major factors that have influenced Maori reproductive outcomes during this period.

METHODS

De-identified birth registration data from 1 189 120 singleton live births and 5775 stillbirths were analysed for 1980-2001. Outcomes of interest included preterm birth, SGA and late fetal death while explanatory variables included maternal ethnicity, age and NZ Deprivation Index decile. Trend analysis was undertaken for 1980-1994 and multivariate logistic regression was used to explore risk factors for 1996-2001.

RESULTS

During 1980-1994, Maori women had the highest preterm birth rates of any ethnic group in New Zealand, but in relative terms, inequalities declined as a consequence of a non-significant 7% fall in rates being offset by a statistically significant 30% increase for the European/other ethnic group. Rates of SGA were also higher amongst Maori women but declined by 25% during the 1980-1994 period. In addition, Maori women experienced significant socioeconomic gradients in SGA, with risk for Maori women in the most deprived NZDep areas being double that of Maori living affluent areas. Paradoxically, while Maori women had high rates of teenage pregnancy, this did not confer additional risk for preterm birth or SGA during the 1996-2001 period.

CONCLUSIONS

While high rates of teenage pregnancy amongst Maori women appear not to confer additional risk for preterm birth or SGA, the social consequences of early childbearing may well be significant. The persistence of elevated rates of preterm birth and large socioeconomic gradients in SGA amongst Maori suggest that broader social and policy interventions are necessary if Maori are to achieve optimal birth outcomes in the coming decades.

Effects of maternal cigarette smoking and cocaine use in pregnancy on fetal response to vibroacoustic stimulation and habituation

BACKGROUND

Cigarette smoking and cocaine use in pregnancy are common in the US and both are risk factors for sudden infant death syndrome (SIDS). Although the cause of SIDS is not known, one postulated mechanism involves abnormalities of arousal and arousal regulation. Cigarette smoking and cocaine use may cause deficits of arousal. Many believe arousal deficits occur prenatally.

AIMS

The aim of this study was to assess the effects of cigarette smoke and cocaine exposure during pregnancy on measures of fetal arousal and arousal competency: 1) the fetal response to vibroacoustic stimulation (VAS) and 2) habituation to VAS.

HYPOTHESIS

Maternal cigarette smoking and cocaine use in pregnancy are associated with altered arousal and arousal regulation in the fetus.

METHODS

Three groups of mother-fetal dyads were enrolled: 1) cigarette smokers (n = 54), 2) cocaine users (n = 30), and 3) controls (n = 60). One hundred eight fetuses were tested at 29-31 wk gestation, 119 at 32-35 wk, and 118 at 36+ wk. The fetal response to VAS was assessed using real-time ultrasound and a paradigm of arousal responsiveness. Responders were tested with repeated VAS to assess habituation. Also, the quality of fetal reactivity to repeated stimuli was assessed as a measure of arousal and arousal regulation competence (Behavioral Reactivity Scale).

RESULTS

The control group had a larger proportion of fetuses who were too active to initiate testing ("too active to test") (p = 0.013); the proportion of fetuses too active to test decreased with increasing gestational age. The majority of the fetuses who could be tested responded to the initial VAS, and there were no group differences. The proportion of fetuses that habituated and the rate of habituation did not differ between the groups. Behavioral reactivity did not differ between groups.

CONCLUSIONS

The original hypotheses were not confirmed. However, the chosen assessment paradigms may have lacked sensitivity. The proportion of fetuses that were "too active to test" decreased with gestational age. The control group had a larger proportion of fetuses that were "too active to test" compared with the exposure groups. We speculate that these findings indicate that prenatal exposure to these neuroteratogens may have produced an acceleration of the behavioral response to vibroacoustic stimulation.

The international study of asthma and allergies in childhood (ISAAC): phase three rationale and methods

The International Study of Asthma and Allergies in Childhood (ISAAC) programme commenced in 1991 to study the aetiology of asthma, allergic rhinoconjunctivitis and atopic eczema in children in different populations using standardised methodology and facilitating international collaboration. ISAAC Phase One (1992-1996) found marked differences in the prevalence of symptoms of asthma and allergic disease throughout the world which have not been explained by the current understanding of these diseases. ISAAC Phase Two (1998-2004) uses intensive investigations to further examine the potential role of risk and protective factors that may contribute to the international difference observed in Phase One. Phase Three (2000-2003) essentially represents a repeat of Phase One, in which more detailed standardised data are obtained to enable the time trends of symptom prevalence to be determined as well as the development of a more comprehensive 'world map'. The ISAAC Phase Three rationale and methods are described in this paper. With over 280 centres in 106 countries, we anticipate that ISAAC Phase Three will comprehensively determine the prevalence of symptoms of asthma and allergic disease worldwide, explore recent time trends in the prevalence of these symptoms and cast new light on the aetiology of asthma and allergic disease.

Ethnicity and birth outcome: New Zealand trends 1980-2001: Part 4. Pregnancy outcomes for European/other women

BACKGROUND

In the early 1980s European/other women made up 80% of New Zealand's population and experienced rates of preterm birth that were lower than for other ethnic groups. Rates of small for gestational age (SGA) and late fetal death were intermediate between those of Maori and Pacific women.

AIMS

To examine trends in preterm birth, SGA and late fetal death for European/other women during 1980-2001 and to explore risk factors which make this group vulnerable to adverse birth outcome.

METHODS

De-identified birth registration data from 1 189 120 singleton live births and 5775 stillbirths were analysed for 1980-2001. Outcomes of interest included preterm birth, SGA and late fetal death while explanatory variables included maternal ethnicity, age and NZ Deprivation Index decile. Trend analysis was undertaken for 1980-1994 and multivariate logistic regression was used to explore risk factors for 1996-2001.

RESULTS

During 1980-1994, rates of preterm birth rose by 30% for European/other women, in contrast to a non-significant decline of 7% for Maori women and 4% for Pacific women. Rates of SGA declined 19% for European/other women, compared to 25% for Maori and 30% for Pacific women. Preterm birth and SGA were positively associated with teenage pregnancy and increasing NZDep deprivation. During 1980-1994, rates of late fetal death declined by 49%, with declines being similar for all ethnic groups.

CONCLUSIONS

The progressive rise in preterm birth during the past two decades is a cause of concern for European/other women, particularly as it appears confined to this ethnic group. While rates of SGA have declined, albeit at a slower rate than for other ethnic groups, the elevated risk amongst teenagers and those living in the more deprived NZDep areas suggests that greater gains are achievable if interventions are targeted towards these particular groups.

Ethnicity and birth outcome: New Zealand trends 1980-2001: Part 3. Pregnancy outcomes for Pacific women

BACKGROUND

Pacific women in New Zealand reside in areas of higher socioeconomic deprivation compared to women from other ethnic groups. Pacific women and their health are further disadvantaged because of genetic predisposition and sociocultural factors that cause ill-health. The correlations between pregnancy outcomes, risk factors and other health indices in Pacific women need evaluation.

AIMS

To examine trends in preterm birth, small for gestational age (SGA) and late fetal death for Pacific women during 1980-2001 and to explore risk factors which make this group vulnerable to adverse birth outcome.

METHODS

De-identified birth registration data from 1 189 120 singleton live births and 5775 stillbirths were analysed for 1980-2001. Outcomes of interest included preterm birth, SGA and late fetal death while explanatory variables included maternal ethnicity, age and NZ Deprivation Index decile. Trend analysis was undertaken for 1980-1994 and multivariate logistic regression was used to explore risk factors for 1996-2001.

RESULTS

Pacific women had the lowest rates of preterm birth and SGA when compared to Maori and European women. In addition, preterm birth rates underwent a non-significant 4% decline and SGA rates a 30% decline during 1980-1994. Although there has been a 49% decline in late fetal deaths during 1980-1994, the rate remained higher for Pacific women than for Maori and European/other women.

CONCLUSIONS

Despite residing in areas of high socioeconomic deprivation, which is associated with poor pregnancy outcomes for Maori and European/other women, Pacific women had better pregnancy outcomes, with lower preterm and SGA rates. The significant decline in rates of late fetal death during the past two decades is a cause for celebration; however, the rate remains higher for Pacific women than for other ethnic groups. Biological, cultural and social factors might explain the better pregnancy outcomes for Pacific women and these factors should be considered when developing future prevention programmes.

Ethnicity and birth outcome: New Zealand trends 1980-2001. Part 1. Introduction, Methods, Results and Overview

BACKGROUND

New Zealand Government policy during the past decade has placed a high priority on closing socioeconomic and ethnic gaps in health outcome.

AIM

To analyse New Zealand's trends in preterm and small for gestational age (SGA) births and late fetal deaths during 1980-2001 and to undertake ethnic specific analyses, resulting in risk factor profiles, for each ethnic group.

METHODS

De-identified birth registration data from 1 189 120 singleton live births and 5775 stillbirths were analysed for the period 1980-2001. Outcomes of interest included preterm birth, SGA and late fetal death while explanatory variables included maternal ethnicity, age and New Zealand Deprivation Index decile. Trend analysis was undertaken for 1980-1994 while multivariate logistic regression was used to explore risk factors for 1996-2001.

RESULTS

During 1980-1994, preterm birth rates were highest amongst Maori women. Preterm rates increased by 30% for European/other women, in contrast to non-significant declines of 7% for Maori women and 4% for Pacific women during this period. During the same period, rates of SGA were highest amongst Maori women. Rates of SGA declined by 30% for Pacific women, 25% for Maori women and 19% for European/other women during this period. Rates of late fetal death were highest amongst Pacific women during 1980-1994, but declined by 49% during this period, the rate of decline being similar for all ethnic groups.

CONCLUSIONS

The marked differences in both trend data and risk factor profiles for women in New Zealand's largest ethnic groups would suggest that unless ethnicity is specifically taken into account in future policy and planning initiatives, the disparities seen in this analysis might well persist into future generations.

Term birthweight centiles for babies from New Zealand's main ethnic groups

BACKGROUND

There are significant differences in mean birthweights between New Zealand's main ethnic groups. Birthweight centiles developed predominantly from babies of European ethnicity may therefore not be appropriate to classify babies from other ethnic groups.

AIMS

To develop ethnic specific birthweight centiles for New Zealand babies delivered at term (>37 weeks).

METHODS

Births from the National Women's Hospital database from 1993 to 2000 who also had scan data at <24 weeks comprised the study population (n = 10 292). Multiple pregnancies, fetal abnormalities, stillbirths and preterm births were excluded. For six ethnic groupings, born at gestational weeks from 38 to 41, sex specific centiles were generated and smoothed.

RESULTS

Birthweight centiles were constructed from 5203 European, 801 Maori, 825 Samoan, 577 Tongan, 1058 Chinese, 433 Indian and 1395 other ethnic group births. Mean birthweights by ethnic group were: European 3521 g, Maori 3467 g, Samoan 3691 g, Tongan 3791 g, Chinese 3418 g, Indian 3192 g and other 3466 g. Tongan and Samoan babies were significantly heavier and Indian babies were significantly lighter than babies from all other ethnic groups (P < 0.001 for all comparisons). Overall Maori babies were approximately 50 g lighter than European babies but this difference was not statistically significant (P = 0.08), whereas Chinese babies were significantly lighter with a mean birthweight 100 g less than European (P < 0.001).

CONCLUSIONS

These ethnic specific centile charts are likely to identify term babies with inappropriate growth better than population centiles generated predominantly from one ethnic group.

A customised birthweight centile calculator developed for a New Zealand population

BACKGROUND

Traditionally, small for gestational age is defined as birthweight <10th percentile using sex-adjusted centile charts. However, this criterion includes constitutional variation due to maternal height, weight, ethnic group and parity.

AIMS

To develop customised birthweight centiles for a New Zealand population.

METHODS

National Women's Hospital database of births from 1993 to 2000 was used to identify eligible women with singleton pregnancies who had data available on the following: scan result for dating at gestation <24 weeks, maternal height and weight at booking, parity and ethnic origin. Multiple regression was used to determine the coefficients applicable to New Zealand.

RESULTS

A total of 4707 pregnancies met the inclusion criteria comprising: European 1688 (36.0%), Maori 419 (8.9%) Samoan 506 (10.7%), Tongan 326 (6.9%), Chinese 751 (16.0%), Indian 214 (4.6%) and other 803 (17.1%). Mean term birthweight for an average nulliparous European woman was 3530 g. Babies of Maori and Indian ethnicity were on average 67 g and 150 g lighter, respectively, than European babies. Samoan, Tongan and Chinese babies were 84 g, 124 g and 101 g heavier, respectively.

CONCLUSIONS

There are significant differences in birthweight between European and the other major ethnic groups in New Zealand. They relate to maternal physiological variables, for which coefficients have been derived and incorporated into freely available software that enables improved clinical assessment of fetal and neonatal weight.

Causes of late fetal death in New Zealand 1980-1999

BACKGROUND

In recent years there has been an emerging interest in sudden unexplained intrauterine death.

AIMS

To determine the major causes of late fetal death (LFD) in New Zealand during 1980-1999 and to document the proportion of deaths considered unexplained. In addition, to quantify the number of LFD undergoing post-mortem during this period.

METHODS

Using the Office for National Statistics (UK) hierarchical classification system, all information available on death certificates was used to assign a single cause to LFD for the period 1980-1999. Trends were analysed using logistic regression and risk factor profiles established for each cause of death. Post-mortem rates and the characteristics of those failing to undergo post-mortem were analysed for the period 1989-1999.

RESULTS

LFD rates declined from 60.1 per 10 000 in 1980-1981 to 30.5 in 1998-1999. The declines were not uniform across all causes, with intrapartum deaths declining 73%, congenital anomalies 70% and antepartum asphyxia 50%. In contrast, unspecified deaths increased 1%, and with the decline in other causes of death, also increased proportionally, from 10.8% of LFD in 1980-81 to 28.1% in 1998-1999. Post-mortem rates fell by 31% during 1989-1999, with Maori and Pacific babies and those in more deprived New Zealand Deprivation Index areas being significantly less likely to undergo post-mortem.

CONCLUSIONS

While total LFD rates declined significantly during 1980-1999, rates of unspecified LFD remained static. Low post-mortem rates, however, suggest that many of these deaths may be uninvestigated rather than truly unexplained. Nevertheless, the persistence of a category of death which, to date, has failed to improve with advances in obstetric technology suggests that further measures are necessary if New Zealand's LFD rates are to continue to decline.

Asthma prevalence in European, Maori, and Pacific children in New Zealand: ISAAC study

The International Study of Asthma and Allergies in Childhood (ISAAC) demonstrated that the highest prevalence of asthma in the world is in English-speaking countries, including New Zealand. In this paper, we compare asthma symptom prevalence in the three major ethnic groups (Maori, Pacific, and European) in the six participating centers in New Zealand. Hospital admission rates for asthma are higher among Maori and Pacific children compared to European children. The working hypothesis was that there were important differences in prevalence of asthma symptoms or diagnosis between ethnic groups which might explain these observed differences in asthma morbidity. In each center in 1992-1993, we sampled approximately 3000 children at each of the age brackets 6-7 years and 13-14 years. There were 37592 participants. Maori children had higher rates of diagnosed asthma and reported asthma symptoms than Pacific children in both age groups (diagnosed asthma in 6-7-year-olds: Maori, 31.7%; Pacific, 21.2%; 95% confidence interval on difference (CID), 7.2, 13.8; P < 0.001; 13-14-year-olds: Maori, 24.7%; Pacific, 19.2%; CID 2.5, 8.5; P < 0.001; recent wheeze in 6-7-year-olds: Maori, 27.6%; Pacific, 22.0%; CID, 2.6, 8.6; P < 0.001; 13-14-year-olds: Maori, 30.8%; Pacific, 21.1%; CID, 4.8, 14.5; P < 0.001;). European children had rates intermediate between those of Maori and Pacific children (6-7-year-olds) or similar to those of Maori children (13-14-year-olds), but had the lowest prevalence of night waking with wheeze in both age groups (e.g., 6-7-year-olds: European, 2.6%; Maori, 5.8%; Pacific, 5.7%; European-Maori CID: -4.2, -2.2, P < 0.001; European-Pacific CID: -4.7, -1.7, P < 0.001; Maori-Pacific CID: -1.7, 1.8, P = 1.0). The pattern of differences closely resembled that in a 1985 Auckland study, despite a 1.5-1.7-fold overall increase in prevalence. In conclusion, there are important differences in asthma prevalence among Maori, Pacific, and European children. These differences are small compared to worldwide variation, but their pattern is stable over time. The higher rate of severe asthma symptoms that Maori and Pacific children report may be one reason for the increased asthma morbidity in these groups. Further studies are needed to determine the reasons for these apparent differences in asthma severity.

The Nepal longitudinal study: predicting myopia from the rate of increase in vitreous chamber depth

Biometric data on 897 Tibetan children living in Kathmandu, Nepal were collected over the period 1992 to 2000 with regular visits every 2 years. Measurements included cycloplegic autorefraction, A-scan ultrasonography, and video phakometry. Children who had not been studied at least once at age 12 years or older were not included in these analyses. The other subjects were divided into two groups; myopic if the refractive error was ever <-0.50 D, and emmetropic/hyperopic if the refractive error was never <-0.50 D, the nonmyopic group. Using all children who had been examined with four or five observations over time, the change of vitreous chamber depth with age by group was determined using a mixed-model regression method. The increase in vitreous length was 0.070 mm/year for the emmetropic group and 0.165 mm/year for the myopic group, with the differences apparent before the onset of myopia. An independent group of 59 children in whom there were two vitreous chamber depth measures before the age of 12 years and one measure taken after 12 years of age were used to assess the rate of increase in vitreous chamber depth as a predictor of myopia. Two other methods were examined using the independent group; the ratio of axial length to corneal radius of curvature and refractive error at age 10 years. Predictors based on rate of increase in vitreous chamber depth and axial length/corneal radius of curvature had sensitivities of 75% and 45%, respectively, and refractive error at age 10 years as a predictor for those who will not become myopic had a sensitivity of 88%.

Long-term treatment outcome in acromegaly

A number of groups have developed guidelines to indicate whether an individual with acromegaly has been cured by treatment. However, studies to date do not provide a robust definition of biochemical remission of the disorder based on correlation with long-term outcome. Available data suggest that those with a random serum growth hormone (GH) level of <2.5 microg/l, or a glucose-suppressed GH level of <1 microg/l following treatment have mortality figures indistinguishable from the general population. However, the confidence limits for these mortality estimates are quite wide. It remains possible that growth hormone levels lower than 1 microg/l for random samples, or even lower when using ultrasensitive GH assays, may indicate superior outcome, but this remains to be confirmed. There are limited data relating serum insulin-like growth factor-I (IGF-I) levels to outcome, although normalisation of serum IGF-I clearly improves outcome compared with continued elevation of measurements after treatment. Current evidence suggests that a post-treatment random serum GH <2.5 microg/l and a normal serum IGF-I value defines biochemical cure. Available data suggest that achieving similar growth hormone levels after treatment also reduces the prevalence of chronic complications of the disorder, which is subsequently reflected in improved mortality.

Uterine contractile response to the graded infusion of oxytocin in guinea pigs near term

OBJECTIVE

Myometrial oxytocin binding characteristics do not change near term in guinea pigs. We tested the hypothesis that the uterine contractile response to oxytocin does not change near term.

STUDY DESIGN

Chronically instrumented guinea pigs were given graded infusions of oxytocin (n = 19 animals) or saline solution (n = 4 animals) on days 58, 60, and 62 and then daily until delivery (term, 68 days). Uterine contractile response was assessed by the area of the quasi-integrated electromyogram. Concentrations of 13,14-dihydro-15-keto-prostaglandin F(2)(alpha) were measured in maternal plasma.

RESULTS

The uterine contractile response to oxytocin increased with advancing gestation (P =.007, random coefficients model) and labor (P =.005). Plasma concentrations of 13,14-dihydro-15-keto-prostaglandin F(2)(alpha) increased during oxytocin infusion (P <.022 vs saline solution infusion).

CONCLUSION

The uterine contractile response to oxytocin increases during the 1 to 2 weeks before term in guinea pigs, despite stable myometrial oxytocin receptor density. Oxytocin stimulates the production of prostaglandin F(2)(alpha).

The ecological relationship of tobacco smoking to the prevalence of symptoms of asthma and other atopic diseases in children: the International Study of Asthma and Allergies in Childhood (ISAAC)

This study examined the relationship between parental smoking and asthma and other atopic diseases at the ecological level. The prevalence of atopic symptoms in 6-7- and 13-14-year old children was assessed in 91 centres (from 38 countries) and 155 centres (from 56 countries) respectively in the International Study of Asthma and Allergy in Childhood (ISAAC). These symptoms were related to prevalence of tobacco smoking for each country by gender as reported by the World Health Organisation. There was a significant negative association between the prevalence of smoking by men and the prevalence of symptoms of asthma and rhinitis, but not eczema in the 13-14-year age group. There was a significant positive relationship between prevalence of smoking by women and prevalence of wheeze in the last 12 months, but not for any other symptoms in the 13-14-year age group. In the 6-7-year age group, there was a significant negative correlation between prevalence of smoking by men and the prevalence of wheeze causing sleep disturbance and a close to significant negative association at the 5% level with the prevalence of wheeze in the last 12 months and rhinitis. Thus, for the countries that are included in this analysis, countries that have high adult male smoking rates have a lower risk of asthma and rhinitis symptoms in children. It should be stressed that this analysis does not involve information on individual exposures and therefore does not contradict the well-established association of active and passive smoking in individuals with the occurrence of asthma symptoms in the same individuals. Rather, it indicates that this well-established individual-level association does not account for the international differences in asthma prevalence, and that other risk factors for asthma must be responsible for the observed international patterns.

Melanocortin-3 receptor gene variants in a Maori kindred with obesity and early onset type 2 diabetes

Genetic studies suggest a diabetes susceptibility locus on human chromosome 20, near the melanocortin receptor-3 (MC3-R) gene. We examined the MC3-R as a candidate gene for type 2 diabetes in 12 members of a large Maori kindred with multiple affected members. The coding region of the MC3-R gene was sequenced for both diabetic and non-diabetic individuals. Two separate single base pair substitutions were found in the MC3-R coding sequence and these resulted in amino acid changes, Lysine6Threonine and Isoleucine81Valine. Neither of these MC3-R variants tracked with the presence of diabetes. Furthermore, the variant and wild type MC3-R showed similar functional coupling to adenylyl cyclase. A polymorphic marker (D20S32e) close to the human MC3-R (hMC3-R) coding sequence was investigated in a 60-member pedigree for association with diabetes and other metabolic parameters. There was an association between D20S32e genotype and fasting insulin (P=0.0085) and the insulin resistance index, HOMA-R (P=0.0042). An association was also found between genotype and HDL levels during oral glucose tolerance testing (P=0.0037). These associations were independent of BMI, age, gender and diabetes. Our data do not support a role for variations in the coding region of the hMC3-R in the development of type 2 diabetes in this Maori kindred, but suggest that a locus on chromosome 20 q, close to D20S32e, may contribute to both insulin secretion and action in the Maori kindred.

The burden of symptoms of asthma, allergic rhinoconjunctivitis and atopic eczema in children and adolescents in six New Zealand centres: ISAAC Phase One

AIM

To describe the burden of symptoms of asthma, allergic rhinoconjunctivitis and atopic eczema in children in six New Zealand centres.

METHODS

The International Study of Asthma and Allergies in Childhood (ISAAC) Phase One was undertaken in Auckland, Bay of Plenty, Hawke's Bay, Wellington, Nelson and Christchurch during 1992-1993. In each centre, approximately 3,000 six to seven year old children and 3,000 thirteen to fourteen year old adolescents were studied, a total of 37,592 participants. Both age groups answered written questionnaires and the adolescents a video questionnaire about asthma symptoms.

RESULTS

The prevalences of symptoms were high, for asthma 25% and 30%, allergic rhinoconjunctivitis 10% and 19%, and atopic eczema 15% and 13% in each age group respectively. More than 40% of participants had symptoms in the last year of at least one condition, most commonly asthma. There were no significant differences among regions, except for six to seven year olds in Nelson who had significantly lower prevalences of some symptoms of asthma and allergic rhinoconjunctivitis.

CONCLUSIONS

Asthma and allergies are common in New Zealand, with resultant morbidity and cost. However, there is little regional variation with the exception of lower rates in Nelson children. Explanations for these findings will be the subject of further studies.

A mutation in alpha-tropomyosin(slow) affects muscle strength, maturation and hypertrophy in a mouse model for nemaline myopathy

Nemaline myopathy is a hereditary disease of skeletal muscle defined by a distinct pathology of electron-dense accumulations within the sarcomeric units called rods, muscle weakness and, in most cases, a slow oxidative (type 1) fiber predominance. We generated a transgenic mouse model to study this disorder by expressing an autosomal dominant mutant of alpha-tropomyosin(slow) previously identified in a human cohort. Rods were found in all muscles, but to varying extents which did not correlate with the amount of mutant protein present. In addition, a pathological feature not commonly associated with this disorder, cytoplasmic bodies, was found in the mouse and subsequently identified in human samples. Muscle weakness is a major feature of this disease and was examined with respect to fiber composition, degree of rod-containing fibers, fiber mechanics and fiber diameter. Hypertrophy of fast, glycolytic (type 2B) fibers was apparent at 2 months of age. Muscle weakness was apparent in mice at 5-6 months of age, mimicking the late onset observed in humans with this mutation. The late onset did not correlate with observed changes in fiber type and rod pathology. Rather, the onset of muscle weakness correlates with an age-related decrease in fiber diameter and suggests that early onset is prevented by hypertrophy of fast, glycolytic fibers. We suggest that the clinical phenotype is precipitated by a failure of the hypertrophy to persist and therefore compensate for muscle weakness.

The relationship of per capita gross national product to the prevalence of symptoms of asthma and other atopic diseases in children (ISAAC)

BACKGROUND

Increasing prevalence and worldwide variation in asthma and other atopic diseases suggest the influence of environmental factors, at least one possibly related to socioeconomic wellbeing. This paper examines the relationship of symptoms of asthma, rhinitis and eczema with gross national product per capita (GNP per capita).

METHODS

The prevalences of atopic symptoms in 6-7- and 13-14-year-old children were assessed in 91 centres (from 38 countries) and 155 centres (from 56 countries), respectively, in the International Study of Asthma and Allergy in Childhood (ISAAC). These symptoms were related to 1993 GNP per capita for each country as reported by the World Bank. The relationships between symptoms of atopic diseases and infant mortality, the human development index and 1982 GNP per capita were also considered.

RESULTS

The countries in the lowest quartile of GNP per capita have the lowest median positive responses to all the questions on symptoms of asthma, rhinitis and eczema. There was a statistically significant positive association between wheeze in the last 12 months and GNP per capita in the 13-14-year age group, but not in the 6-7-year age group. There was also a positive association between GNP per capita and eczema in both age groups.

CONCLUSIONS

The positive associations between GNP per capita and atopic symptoms being of only moderate strength suggests that the environmental factors are not just related to the wealth of the country.

Maternal cannabis use in the sudden death syndrome

The smoking of cannabis and tobacco is common in many countries. In contrast to tobacco, which is an established risk factor for the sudden infant death syndrome (SIDS), nothing is known about cannabis and its effects on SIDS risk. We analysed data collected in a nation-wide case control study in New Zealand (393 cases, 1592 controls) to determine if there is any association between maternal cannabis use and SIDS risk. Adjusting for ethnicity and maternal tobacco use, the SIDS odds ratio for >weekly maternal cannabis use since the infant's birth was 2.23 (95% CI = 1.39, 3.57) compared to non-users; and the multivariate odds ratio was 1.55 (95% CI = 0.87, 2.75). We conclude that frequent maternal cannabis use may be a weak risk factor for SIDS, but this finding requires further research.

Myospherulosis in renal cell carcinoma

OBJECTIVE

To study retrospectively the identification, characteristics, and localization of myospherulosis in different types of renal cell carcinomas.

DESIGN

Twenty-seven consecutive renal cell carcinomas treated by radical nephrectomy in 1 year were studied. All the tumor and nontumor slides were examined for myospherulosis. The demographic data, histological type of renal cell carcinoma, Robson stage, and Fuhrman grades were recorded.

RESULTS

Myospherules were found in 10 cases. They were associated with the clear cell type and a higher nuclear grade. The cell type remained the only significant factor when these 2 factors were tested together with the tumor stage by logistic regression. Myospherulosis tended to be found in younger patients but was not associated with the sex or the side of the tumor. They were scattered within tumor cystic spaces or among sheets of tumor cells. Some of the myospherules might arise from histiocytes or even tumor cells. Compared with previous reports of myospherulosis associated with exogenous or endogenous lipid, the myospherules associated with renal cell carcinoma were smaller and more uniform in size. There is no associated fibrosis or foreign body giant cell reaction.

CONCLUSION

As far as we know, this is the first report of myospherulosis occurring in malignant tumors in human, and their associated features are different from those previously described for myospherulosis related to exogenous or endogenous lipid.

Deprivation and sudden infant death syndrome

This research uses a case-control study to examine the relationship between deprivation of area of residence and incidence of sudden infant death syndrome (SIDS) in New Zealand. Three hundred sixteen cases and 1221 controls were elicited with geocodable addresses. Infants living in the most deprived areas had a 5.9- (95%CI = 2.9, 12.2) fold increased risk of SIDS compared with those infants living in the least deprived areas. After adjusting for individual-level factors there was no remaining area-level effect. Nearly 27% of control infants lived in the two lowest deciles of deprivation, and almost half of SIDS deaths occurred in these areas. Incidence of SIDS is strongly associated with both deprivation of area of residence and individual socioeconomic factors. This indicates the importance of reaching parents in deprived areas, however, given that approximately 50% of SIDS deaths occurred in areas other than the two most deprived, we recommend that SIDS health messages be delivered to the general population.

Umbilical artery Doppler studies in small for gestational age babies reflect disease severity

OBJECTIVES

To determine: 1. whether abnormal umbilical artery Doppler studies were independently associated with newborn morbidity; and 2. whether small for gestational age babies with normal umbilical artery Doppler studies had small mothers and a low rate of newborn malnutrition and morbidity.

DESIGN

Prospective observational study.

SETTING

National Women's Hospital, a tertiary referral centre, Auckland, New Zealand.

POPULATION

One hundred eighty-six women and their small for gestational age babies (birthweight < 10th%) who had been participants in one of two randomised controlled trials of small for gestational age pregnancies between 1993 and 1997.

METHODS

Newborn morbidity and morphometry were compared between small for gestational age babies with normal and abnormal umbilical artery Doppler studies (resistance index > 95th%). Maternal demographic characteristics and morbidity were also compared.

RESULTS

Compared with small for gestational age babies with normal umbilical artery Doppler studies (n = 109), small for gestational age babies with abnormal umbilical artery Doppler studies (n = 77) were diagnosed earlier in pregnancy as being small for gestational age (30.3 vs 32.9 weeks, P < 0.001), were smaller in all body proportions at birth (median Z score birthweight -1.82 vs -1.70, P = 0.004, Z score length -1.86 vs -1.36, P < 0.0001, Z score head circumference -1.31 vs -0.89, P < 0.0001) and were more likely to experience newborn morbidity. When birthweight and gestation were entered into a logistic regression model, an abnormal umbilical artery Doppler study was not an independent predictor of prolonged newborn nursery admission or hypoglycaemia. Of small for gestational age babies with normal umbilical artery Doppler studies, 53 (49%) had low ponderal indices, 26/98 (26%) were hypoglycaemic and 38 (35%) required admission to the newborn nursery. There was no difference in maternal height, weight and ethnicity between the abnormal and normal umbilical artery Doppler groups.

CONCLUSIONS

Abnormal umbilical artery Doppler studies reflect earlier onset and more severe growth restriction and are not independently associated with newborn morbidity. Small for gestational age babies with normal Doppler studies have a high rate of newborn nursery admission and malnutrition at birth and are not all just normal small babies.

The dose-effect relationship for morphine and vomiting after day-stay tonsillectomy in children

A dose-response curve for intravenous morphine and vomiting was investigated in children having day-stay tonsillectomy. A retrospective chart review was performed for the 164 children fulfilling the inclusion criteria. Morphine (mean 0.09 mg/kg SD 0.05) was used in 108 children in the perioperative period and a further 56 children were given no opioid. Fifty-five of these 164 children vomited and 20 children required an overnight stay in hospital because of vomiting. The probability of vomiting or overnight stay in hospital was related to morphine dose (by logistic regression). The overall probability of vomiting after morphine 0.1 mg/kg was 50% and the probability of admission for vomiting with this dose was 10%. Pharmacodynamic parameter estimates for postoperative vomiting were P0 (the baseline probability of vomiting, with no opioid) 0.115, Pmax (the maximal probability of vomiting due to morphine) 0.997, ED50 (morphine dose that induces an effect equivalent to 50% of the logit Pmax) 0.18 mg/kg. Parameter estimates for overnight stay because of vomiting after morphine administration were P0 0.038, Pmax 0.999, ED50 0.369 mg/kg. Satisfactory postoperative analgesia in children has been reported with morphine 0.05 to 0.15 mg/kg. Doses above 0.1 mg/kg are associated with a greater than 50% incidence of vomiting. Our data suggests that lower doses of morphine are associated with a decreased incidence of emesis after tonsillectomy in children.

A pilot randomized controlled trial of two regimens of fetal surveillance for small-for-gestational-age fetuses with normal results of umbilical artery doppler velocimetry

OBJECTIVE

This study was undertaken to determine whether the frequency of fetal surveillance could be safely reduced from twice weekly to fortnightly in the case of small-for-gestational-age fetuses with normal results of umbilical artery Doppler velocimetry studies.

STUDY DESIGN

Pregnant women between 24 and 36 weeks' gestation (n = 167) with small-for-gestational-age fetuses and normal results of umbilical artery Doppler velocimetry studies were randomly allocated to undergo twice-weekly or fortnightly fetal surveillance. Statistical analysis was carried out according to intention to treat.

RESULTS

Eighty-five women were randomly assigned to undergo twice-weekly fetal surveillance and 82 were randomly assigned to undergo fortnightly fetal surveillance. Those randomly assigned to twice-weekly surveillance were delivered 4 days earlier (264 vs 268 days; P =.04) and were more likely to have labor induced (n = 70, 82%, vs n = 54, 66%; P =.02) than those randomly assigned to fortnightly surveillance. Fifty-four babies (23%) were admitted to the neonatal nursery, but there were no differences in neonatal morbidity between the groups.

CONCLUSIONS

Maternal intervention (induction) was more common in the twice-weekly group. No differences in neonatal outcomes were detected. A much larger trial is required to determine the safety and potential benefits of less frequent surveillance of small-for gestational-age fetuses with normal results of umbilical artery Doppler velocimetry studies.

Water fluoridation and the sudden infant death syndrome

AIMS

To determine whether exposure to fluoridated water supplies prenatally or postnatally at the time of death increases the risk of sudden infant death syndrome (SIDS).

METHODS

A nationwide, case-control study, with infant's water fluoridation status determined from census area unit information for mother's usual address at the time of the infant's birth, infant's usual address at the time of death / nominated sleep and address where infant died / was at nominated sleep. SIDS risk associated with fluoride exposure postnatally was assessed according to method of infant feeding (breast or reconstituted formula), for the two days prior to infant's death / nominated sleep.

RESULTS

Infants exposed to fluoridated water supplies during pregnancy were not at increased risk for SIDS, adjusted odds ratio (OR) 1.19 (95% confidence interval (CI) 0.82, 1.74). For breast-fed infants at the time of death / nominated sleep, fluoridated water exposure was not associated with an increased risk for SIDS, adjusted OR 1.09 (95% CI 0.66, 1.79). Similarly, 'fluoridated' formula feeding, when compared with 'unfluoridated' formula feeding, showed no increased risk of SIDS, adjusted OR 1.25 (95% CI 0.73, 2.13). There was no evidence of an interaction between fluoridation and infant feeding for the last two days (chi2 = 0.171, df = 1, p = 0.68).

CONCLUSION

Exposure to a fluoridated water supply prenatally or postnatally at the time of death did not affect the relative risk for SIDS.

Trends in three-year survival following acute myocardial infarction, 1983-1992

AIMS

As part of an investigation into the decline in coronary heart disease mortality rates in New Zealand, we examined long-term survival trends following acute myocardial infarction.

METHODS AND RESULTS

A 3-year follow-up of patients on a community-based register of coronary heart disease for the period 1983-1992 in Auckland, New Zealand, part of the World Health Organization's MONICA (multinational Monitoring of Trends and Determinants in Cardiovascular Disease) Project, has been completed. The 3-year survival status of acute myocardial infarction patients aged 25-64 years who were alive 28 days after their first event has been obtained. The 2940 men and women followed for 3 years after an acute myocardial infarction showed significant steady improvement over the 10-year study period (P=0.004). The 3-year survival of patients registered in 1983-1984 was 86% and by 1991-1992 it was 92%.

CONCLUSION

The gains in long-term survival following acute myocardial infarction are statistically significant but contribute only marginally to the decline in coronary heart disease death rates in Auckland since most deaths occur in the first 28 days after the event.