Temporal dynamics in the composition of bird communities along a gradient of farmland restoration.

Revegetation plantings are a key activity in farmland restoration and are commonly assumed to support biotic communities that, with time, replicate those of reference habitats. Restoration outcomes, however, can be highly variable and difficult to predict; hence there is value in quantifying restoration success to improve future efforts. We test the expectation that, over time, revegetation will restore bird communities to match those in reference habitats; and assess whether specific planting attributes enhance restoration success. We surveyed birds in 255 sites in south-east Australia, arranged along a restoration gradient encompassing three habitat types: unrestored farmland (paddocks), revegetation plantings (comprising a chronosequence up to 52 years old) and reference habitats (remnant native vegetation). Surveys were undertaken in 2006/2007 and again in 2019, with data used to compare bird assemblages between habitat types. We also determined whether, in the intervening 12 years, bird communities in revegetation had shifted toward reference habitats on the restoration gradient. Our results showed that each habitat contained a unique bird community and that, over time, assemblages in revegetation diverged away from those in unrestored farmland and converged toward those in reference habitats. Two planting attributes influenced this transition: the bird assemblages of revegetation were more likely to have diverged away from those of unrestored farmland (with scattered mature trees) 12 years later if they were located in areas with more surrounding tree cover, and were mostly ungrazed by livestock (compared with grazed plantings). Our results highlight three key ways in which revegetation contributes to farmland restoration: (1) by supporting richer and more diverse bird assemblages than unrestored farmland, (2) by enhancing beta diversity in rural landscapes through the addition of a unique bird community, and (3) by shifting bird assemblages toward those found in reference habitats over time. However, revegetation plantings did not replicate reference habitats by ~40-50 years in our region, and complete convergence may take centuries. These findings have implications for environmental offset programs and mean that effective conservation in farmland environments depends on the retention and protection of natural and seminatural habitats as a parallel management strategy to complement restoration.

Randomised controlled trial of nebulised gentamicin in children with bronchiectasis.

AIM: Following trials of inhaled antibiotics in adults, this study investigates the efficacy of nebulised gentamicin to improve respiratory function in children with bronchiectasis. METHODS: This is a randomised, double-blind, placebo-controlled, crossover trial of 12-week nebulised placebo/gentamicin, 6-week washout, 12-week gentamicin/placebo. Participants were children (5-15 years) with bronchiectasis, chronic infection (any pathogen), and able to perform spirometry from a hospital bronchiectasis clinic. Primary outcomes were change in forced expiratory volume in 1 s (FEV1 ) and hospitalisation days. Secondary outcomes included sputum bacterial density, sputum inflammatory markers, additional antibiotics and symptom severity. Analyses were on an intention-to-treat basis. RESULTS: Fifteen children (mean 11.7-years-old) completed the study. There was no significant change in mean FEV1 (56%/55%, P = 0.38) or annual rate of hospital admissions (1.1/0, P = 0.12) between gentamicin and placebo, respectively. However, Haemophilus influenzae sputum growth (27% vs. 80%, P = 0.002) and bacterial density (2.4 log10 cfu/mL lower P < 0.001) improved with gentamicin. Sputum inflammatory markers interleukin-1ß (P < 0.001), interleukin-8 (P < 0.001) and tumour necrosis factor-α (P = 0.003) were lower with gentamicin. Poor recruitment limited study power and treatment adherence was challenging for this cohort. CONCLUSIONS: In this crossover study of nebulised gentamicin in children with bronchiectasis, there was a reduction in sputum bacterial density and inflammation. However, there were no major improvements in clinical outcomes and adherence was a challenge.

Effect of Monthly High-Dose Vitamin D Supplementation on Acute Respiratory Infections in Older Adults: A Randomized Controlled Trial.

BACKGROUND: Although adults with low vitamin D status are at increased risk of acute respiratory infection (ARI), randomized controlled trials of vitamin D supplementation have provided inconsistent results. METHODS: We performed a randomized, double-blinded, placebo-controlled trial of 5110 adults aged 50-84 years. In 2011-2012, participants were randomized to an initial oral dose of 200 000 IU vitamin D3 followed by 100 000 IU monthly (n = 2558) or placebo (n = 2552) until late 2013 (median follow-up, 1.6 years). Participants reported upper and lower ARIs on monthly questionnaires. Cox models analyzed time to first ARI (upper or lower) by treatment group. RESULTS: Participants' mean age was 66 years and 58% were male; 83% were of European/other ethnicity, with the rest Maori, Polynesian, or South Asian. Mean (SD) baseline blood 25-hydroxyvitamin D [25(OH)D] level was 63 (24) nmol/L; 25% were <50 nmol/L. In a random sample (n = 441), vitamin D supplementation increased mean 25(OH)D to 135 nmol/L at 3 years, while those on placebo remained at 63 nmol/L. During follow-up, 3737 participants reported ≥1 ARI: 74.1% in the vitamin D group versus 73.7% in the placebo group. The hazard ratio for vitamin D compared with placebo was 1.01 (95% CI, 0.94, 1.07). Similar results were seen in most subgroups, including those with baseline 25(OH)D <50 nmol/L and in analyses of the upper/lower components of the ARI outcome. CONCLUSIONS: Monthly high-dose vitamin D supplementation does not prevent ARI in older adults with a low prevalence of profound vitamin D deficiency at baseline. Whether effects of daily or weekly dosing differ requires further study. CLINICAL TRIALS REGISTRATION: Australian New Zealand Clinical Trials Registry, identifier ACTRN12611000402943.

The association between vitamin D concentration and pain: a systematic review and meta-analysis.

OBJECTIVE: Pain-related conditions, such as chronic widespread pain and fibromyalgia, are major burdens for individuals and the health system. Evidence from previous research on the association between circulating 25-hydroxyvitamin D (25(OH)D) concentrations and pain is conflicting. Thus, we aimed to determine if there is an association between mean 25(OH)D concentration (primary aim), or proportion of hypovitaminosis D (secondary aim), and pain conditions in observational studies. DESIGN: Published observational research on 25(OH)D concentration and pain-related conditions was systematically searched for in electronic sources (MEDLINE, EMBASE and Cochrane Central Register of Controlled Trials) and a random-effects meta-analysis was conducted on included studies. RESULTS: Eighty-one observational studies with a total of 50 834 participants were identified. Compared with controls, mean 25(OH)D concentration was significantly lower in patients with arthritis (mean difference (MD): -12·34 nmol/l; P<0·001), muscle pain (MD: -8·97 nmol/l; P=0·003) and chronic widespread pain (MD: -7·77 nmol/l; P<0·001), but not in patients with headache or migraine (MD: -2·53 nmol/l; P=0·06). The odds of vitamin D deficiency was increased for arthritis, muscle pain and chronic widespread pain, but not for headache or migraine, compared with controls. Sensitivity analyses revealed similar results. CONCLUSIONS: A significantly lower 25(OH)D concentration was observed in patients with arthritis, muscle pain and chronic widespread pain, compared with those without. These results suggest that low 25(OH)D concentrations may be associated with pain conditions.

Habitat as a mediator of mesopredator-driven mammal extinction.

A prevailing view in dryland systems is that mammals are constrained by the scarcity of fertile soils and primary productivity. An alternative view is that predation is a primary driver of mammal assemblages, especially in Australia, where 2 introduced mesopredators-feral cat (Felis catus) and red fox (Vulpes vulpes)-are responsible for severe declines of dryland mammals. We evaluated productivity and predation as drivers of native mammal assemblage structure in dryland Australia. We used new data from 90 sites to examine the divers of extant mammal species richness and reconstructed historic mammal assemblages to determine proportional loss of mammal species across broad habitat types (landform and vegetation communities). Predation was supported as a major driver of extant mammal richness, but its effect was strongly mediated by habitat. Areas that were rugged or had dense grass cover supported more mammal species than the more productive and topographically simple areas. Twelve species in the critical weight range (CWR) (35-5500 g) that is most vulnerable to mesopredator predation were extirpated from the continent's central region, and the severity of loss of species correlated negatively with ruggedness and positively with productivity. Based on previous studies, we expect that habitat mediates predation from red foxes and feral cats because it affects these species' densities and foraging efficiency. Large areas of rugged terrain provided vital refuge for Australian dryland mammals, and we predict such areas will support the persistence of CWR species in the face of ongoing mammal declines elsewhere in Australia.

Body mass index and vigorous physical activity in children and adolescents: an international cross-sectional study.

AIM: To examine the relationship between reported vigorous physical activity (VPA) and body mass index (BMI) in children (6-7 years) and adolescents (13-14 years). METHODS: In the International Study of Asthma and Allergies in Childhood Phase Three, 75 895 children's parents and 199 502 adolescents answered questions relating to VPA, height and weight. The association between VPA and BMI was analysed using general linear models, adjusting for country gross national index. RESULTS: Compared to children who undertook no VPA, those in the infrequent group (once or twice per week) and those in the frequent group (three or more times per week) had mean (95% CI) BMI values 0.07 kg/m2 (0.03-0.11) and 0.09 kg/m2 (0.03-0.15) greater, respectively (p = 0.001). Compared to adolescents reporting no VPA, those in the infrequent group had a BMI 0.19 kg/m2 (0.15-0.23) greater while those in the frequent group had a BMI 0.01 kg/m2 (-0.03-0.05) greater (p < 0.0001). CONCLUSION: Reported VPA is not associated with lower BMI among children and adolescents. Investigation of VPA and BMI may be best undertaken in conjunction with other variables in the energy expenditure equation. A focus on VPA alone may be an inefficient way to manage BMI.

Factors associated with photoprotection by body clothing coverage, particularly in non-summer months, among a New Zealand community sample.

Clothing coverage is important for reducing skin cancer risk, but may also influence vitamin D sufficiency, so associated plausible predictors require investigation. Volunteers (18 to 85 years), with approximately equal numbers by sex and four ethnicity groups, were recruited in cities from two latitude bands: Auckland (36.9°S) and Dunedin (45.9°S). Baseline questionnaire, anthropometric and spectrophotometer skin colour data were collected and weather data obtained. Percent body coverage was calculated from eight week diary records. Potential independent predictors (unadjusted p < 0.25) were included in adjusted models. Participants (n = 506: Auckland n = 334, Dunedin n = 172; mean age 48.4 years) were 62.7% female and had a median body clothing coverage of 81.6% (IQR 9.3%). Dunedin was cooler, less windy and had lower UVI levels than Auckland. From the fully adjusted model, increased coverage occurred in non-summer months (despite adjusting for weather), among Dunedin residents and Asians (compared to Europeans), during the middle of the day, with a dose response effect observed for greater age. Reduced coverage was associated with Pacific ethnicity and greater time spent outdoors. Additionally, higher temperatures were associated with reduced coverage, whereas increased cloud cover and wind speed were associated with increased coverage. Although the only potentially modifiable factors associated with clothing coverage were the time period and time spent outdoors, knowledge of these and other associated factors is useful for the framing and targeting of health promotion messages to potentially influence clothing coverage, facilitate erythema avoidance and maintain vitamin D sufficiency.

Does urban extent from satellite images relate to symptoms of asthma, rhinoconjunctivitis and eczema in children? A cross-sectional study from ISAAC Phase Three.

OBJECTIVE: The relationship between urbanisation and the symptom prevalence of asthma, rhinoconjunctivitis and eczema is not clear, and varying definitions of urban extent have been used. Furthermore, a global analysis has not been undertaken. This study aimed to determine whether the symptom prevalence of asthma, rhinoconjunctivitis and eczema in centres involved in the International Study of Asthma and Allergies in Childhood (ISAAC) were higher in urban than rural centres, using a definition of urban extent as land cover from satellite data. METHODS: A global map of urban extent from satellite images (MOD500 map) was used to define the urban extent criterion. Maps from the ISAAC centres were digitised and merged with the MOD500 map to describe the urban percentage of each centre. We investigated the association between the symptom prevalence of asthma, rhinoconjunctivitis and eczema and the percentage of urban extent by centre. RESULTS: A weak negative relationship was found between the percentage of urban extent of each ISAAC centre and current wheeze in the 13-14-year age group. This association was not statistically significant after adjusting for region of the world and gross national income. No other relationship was found between urban extent and symptoms of asthma, rhinoconjunctivitis and eczema. CONCLUSIONS: In this study, the prevalence of symptoms of asthma, rhinoconjunctivitis and eczema in children were not associated with urbanisation, according to the land cover definition of urban extent from satellite data. Comparable standardised definitions of urbanisation need to be developed so that global comparisons can be made.

A description of sleep behaviour in healthy late pregnancy, and the accuracy of self-reports.

BACKGROUND: The importance of maternal sleep and its contribution to maternal and fetal health during pregnancy is increasingly being recognised. However, the ability to accurately recall sleep practices during pregnancy has been questioned. The aim of this study is to test the accuracy of recall of normal sleep practices in late pregnancy. METHODS: Thirty healthy women between 35 and 38 weeks of gestation underwent level III respiratory polysomnography (PSG) with infrared digital video recordings in their own homes. Data regarding sleep positions, number of times getting out of bed during the night and respiratory measures were collected. A sleep questionnaire was administered the morning after the recorded sleep. Continuous data were assessed using Spearman's Rho and Bland-Altman. Cohen's Kappa was used to assess recall in the categorical variables. RESULTS: Two-thirds of participants went to sleep on their left side. There was good agreement in sleep onset position between video and questionnaire data (Kappa 0.52), however the there was poor agreement on position on wakening (Kappa 0.24). The number of times getting out of bed during the night was accurately recalled (Kappa 0.65). Twenty five out of 30 participants snored as recorded by PSG. Questionnaire data was inaccurate for this measure. Bland-Altman plots demonstrated acceptable agreement between video and questionnaire data for estimated sleep duration, but not the time taken to fall asleep (sleep latency). One participant had mild obstructive sleep apnoea and another probable high upper airways resistance. CONCLUSIONS: Sleep onset position, sleep duration and the number of times getting out of bed during the night were accurately recalled, but sleep latency and sleep position on waking were not. This study identifies the sleep variables that can be accurately obtained by questionnaire and those that cannot.

Survival disparities between Maori and non-Maori men with prostate cancer in New Zealand.

OBJECTIVE: To examine temporal trends and current survival differences between Maori and non-Maori men with prostate cancer in New Zealand (NZ). PATIENTS AND METHODS: A cohort of 37,529 men aged ≥ 40 years diagnosed with prostate cancer between 1996 and 2010 was identified from the New Zealand Cancer Registry and followed until 25 May 2011. Cause of death was obtained from the Mortality Collection by data linkage. Survival for Maori compared with non-Maori men was estimated using the Kaplan-Meier method, and Cox proportional hazard regression models, adjusted for age, year of diagnosis, socioeconomic deprivation and rural/urban residence. RESULTS: The probability of surviving was significantly lower for Maori compared with non-Maori men at 1, 5 and 10 years after diagnosis. Maori men were more likely to die from any cause [adjusted hazard ratio (aHR) 1.84, 95% confidence interval (CI) 1.72-1.97] and from prostate cancer (aHR 1.94, 95% CI 1.76- 2.14). The aHR of prostate cancer death for Maori men diagnosed with regional extent was 2.62-fold (95% CI 1.60-4.31) compared with non-Maori men. The survival gap between Maori and non-Maori men has not changed throughout the study period. CONCLUSION: Maori men had significantly poorer survival than non-Maori, particularly when diagnosed with regional prostate cancer. Despite improvements in survival for all men diagnosed after 2000, the survival gap between Maori and non-Maori men has not been reduced with time. Differences in prostate cancer detection and management, partly driven by higher socioeconomic deprivation in Maori men, were identified as the most likely contributors to ethnic survival disparities in NZ.

Synthesis of 2,3-dideoxy-2-fluoro-2,3-endo-methylene- and 2,3-Dideoxy-2-fluoro-3-C-hydroxymethyl-2,3-endo-methylene-pentofuranoses and their use in the preparation of conformationally locked bicyclic nucleosides.

Construction of protected 2,3-dideoxy-2-fluoro-2,3-endo-methylene-pentofuranoses from d-glyceraldehyde and 2,3-dideoxy-2-fluoro-3-C-hydroxymethyl-2,3-endo-methylene-pentofuranoses from d-isoascorbic acid, via Simmons-Smith-type stereoselective cyclopropanations on the respective fluoroallyl alcohols, is described. Synthesis of the corresponding conformationally locked sugar modified uridine and guanosine nucleosides was achieved via Vorbrüggen or Mitsunobu methodologies. Stereochemical confirmation of the novel nucleosides was performed on the basis of 2D NOESY NMR experiments. Analysis of 2',3'-dideoxy-2'-fluoro-3'-C-hydroxymethyl-2',3'-endo-methylene-uridine by X-ray crystallography yielded the principal conformational parameters and indicated that the furanoid ring adopted an (o)E/(o)T1, East pucker. The uridine and guanosine nucleosides were found to be inactive in the hepatitis C virus (HCV) cell-based replicon assay, which was corroborated on examination of the corresponding nucleoside triphosphates against the HCV NS5B polymerase.

Validation of thoracic impedance cardiography by echocardiography in healthy late pregnancy.

BACKGROUND: Assessment of stroke volume (SV) is often necessary in clinical and research settings. The clinically established method for SV assessment in pregnancy is echocardiography, but given its limitations, it is not always an appropriate measurement tool. Thoracic impedance cardiography (ICG) allows continuous, non-invasive SV assessment. However, SV determination relies on assumptions regarding the thoracic shape that may mean the algorithm is not valid in pregnancy. The available data regarding the validity of ICG against an established reference standard using modern SV algorithms are both limited and conflicting. We aimed to test the validity of ICG in a clinically realistic setting in late pregnancy using echocardiography. METHODS: Twenty-nine women in late pregnancy underwent standard echocardiography assessments with simultaneous ICG measurement. Agreement between devices was tested using Bland-Altman analysis. RESULTS: Bland-Altman analysis of the relationship between ICG and echocardiography demonstrated that the 95% limits of agreement exceeded acceptable or expected ranges. Measures of maternal and fetal anthropometry do not account for the lack of agreement. CONCLUSIONS: Absolute values of SV as determined by ICG are not valid in pregnancy. Further work is required to examine the ability of ICG to assess relative changes in maternal haemodynamics in late pregnancy.

Maternal post-natal tobacco use and current parental tobacco use is associated with higher body mass index in children and adolescents: an international cross-sectional study.

BACKGROUND: We investigated whether maternal smoking in the first year of life or any current parental smoking is associated with childhood or adolescent body mass index (BMI). METHODS: Secondary analysis of data from a multi-centre, multi-country, cross-sectional study (ISAAC Phase Three). Parents/guardians of children aged 6-7 years completed questionnaires about their children's current height and weight, whether their mother smoked in the first year of the child's life and current smoking habits of both parents. Adolescents aged 13-14 years completed questionnaires about their height, weight and current parental smoking habits. A general linear mixed model was used to determine the association between BMI and parental smoking. RESULTS: 77,192 children (18 countries) and 194 727 adolescents (35 countries) were included. The BMI of children exposed to maternal smoking during their first year of life was 0.11 kg/m(2) greater than those who were not (P = 0.0033). The BMI of children of currently smoking parents was greater than those with non-smoking parents (maternal smoking: +0.08 kg/m(2) (P = 0.0131), paternal smoking: +0.10 kg/m(2) (P < 0.0001)). The BMI of female adolescents exposed to maternal or paternal smoking was 0.23 kg/m(2) and 0.09 kg/m(2) greater respectively than those who were not exposed (P < 0.0001). The BMI of male adolescents was greater with maternal smoking exposure, but not paternal smoking (0.19 kg/m(2), P < 0.0001 and 0.03 kg/m(2), P = 0.14 respectively). CONCLUSION: Parental smoking is associated with higher BMI values in children and adolescents. Whether this is due to a direct effect of parental smoking or to confounding cannot be established from this observational study.

Reduced primary care respiratory infection visits following pregnancy and infancy vitamin D supplementation: a randomised controlled trial.

AIM: To determine whether vitamin D supplementation reduces primary care visits for acute respiratory infection (ARI). METHODS: A randomised, double-blind, placebo-controlled trial was conducted in New Zealand and powered to determine the vitamin D dose needed to achieve normal vitamin D status during infancy. Healthy pregnant women, from 27 weeks' gestation to birth, and their infants, from birth to age 6 months, were assigned to placebo or one of the two dosages of daily oral vitamin D3 . Woman/infant pairs were randomised to placebo/placebo, 1000 IU/400 IU or 2000 IU/800 IU. For this ad hoc analysis, the primary care records of enrolled children were audited to age 18 months. RESULTS: Two hundred and sixty pregnant women were randomised to placebo (n = 87), lower-dose (n = 87) or higher-dose (n = 86) vitamin D3 . In comparison with the placebo group (99%), the proportion of children making any ARI visits was smaller in the higher-dose (87%, p = 0.004), but not the lower-dose vitamin D3 group (95%, p = 0.17). The median number of ARI visits/child was less in the higher-dose vitamin D3 group from age 6-18 months (placebo 4, lower dose 3, higher dose 2.5; p = 0.048 for higher-dose vitamin D3 vs. placebo). CONCLUSION: Vitamin D3 supplementation during pregnancy and infancy reduces primary care visits for ARI during early childhood.

Synthesis of 2'-O,4'-C-alkylene-bridged ribonucleosides and their evaluation as inhibitors of HCV NS5B polymerase.

The synthesis of 2'-O,4'-C-methylene-bridged bicyclic guanine ribonucleosides bearing 2'-C-methyl or 5'-C-methyl modifications is described. Key to the successful installation of the methyl functionality in both cases was the use of a one-pot oxidation-Grignard procedure to avoid formation of the respective unreactive hydrates prior to alkylation. The 2'-C-methyl- and 5'-C-methyl-modified bicyclic guanosines were evaluated, along with the known uracil-, cytosine-, adenine-, guanine-LNA and guanine-ENA nucleosides, as potential antiviral agents and found to be inactive in the hepatitis C virus (HCV) cell-based replicon assay. Examination of the corresponding nucleoside triphosphates, however, against the purified HCV NS5B polymerase indicated that LNA-G and 2'-C-methyl-LNA-G are potent inhibitors of both 1b wild type and S282T mutant enzymes in vitro. Activity was further demonstrated for the LNA-G-triphosphate against HCV NS5B polymerase genotypes 1a, 2a, 3a and 4a. A phosphorylation by-pass prodrug strategy may be required to promote anti-HCV activity in the replicon assay.

Prostate-specific antigen (PSA) screening and follow-up investigations in Maori and non-Maori men in New Zealand.

BACKGROUND: Maori men in New Zealand have higher mortality from prostate cancer, despite having lower incidence rates. The objective of this study was to examine patterns of screening for prostate cancer in primary care and follow-up investigations after an elevated prostate-specific antigen (PSA) result in Maori and non-Maori men in order to help explain the observed differences in incidence and mortality. METHODS: Men aged 40+ years were identified from 31 general practices across the Midland Cancer Network region. Computerised practice records were cross-referenced with laboratory data to determine the number and value of PSA tests undertaken between January 2007 and December 2010. Screening rates were calculated for the year 2010 by age, ethnicity, and practice. For men with an elevated PSA result information on specialist referrals and biopsy was extracted from practice records. Practice characteristics were assessed with respect to screening rates for Maori and non-Maori men. RESULTS: The final study population included 34,960 men aged 40+ years; 14% were Maori. Maori men were less likely to be screened in 2010 compared with non-Maori men (Mantel Haenszel (M-H) age-adjusted risk ratio (RR), 0.52 [95% CI, 0.48, 0.56]). When screened, Maori men were more than twice as likely to have an elevated PSA result compared with non-Maori men (M-H age-adjusted RR, 2.16 [95% CI, 1.42, 3.31]). There were no significant differences between Maori and non-Maori men in the rate of follow-up investigations and cancer detection. Maori provider practices showed equal screening rates for Maori and non-Maori men, but they were also the practices with the lowest overall screening rates. CONCLUSIONS: Maori men were half as likely to be screened compared to non-Maori men. This probably explains the lower reported incidence of prostate cancer for Maori men. Practice characteristics had a major influence on screening rates. Large variation in screening behaviour among practices and differences in follow-up investigations for men with an elevated PSA result seems to reflect the uncertainty among GPs regarding PSA screening and management.

Small doses from artificial UV sources elucidate the photo-production of vitamin D.

To clarify the relation between UV exposure and vitamin D status, 201 volunteers wore personal electronic UV dosimeters during daylight hours, to record their UV exposure over a 10 week period when ambient UV levels were significantly less than the summer maxima. Blood samples to determine serum 25-hydroxyvitamin D3 [25(OH)D3] levels were taken at the end of week 4 and week 8. Participants were then given a single full-body exposure of approximately 2 SED from one of four artificial UV sources with different spectral outputs and a further blood sample taken at study completion, nominally week 10. The artificial UV exposure reversed the mean seasonal decline in 25(OH)D3. Increases in 25(OH)D3 from week 8 to week 10 were related to total UV exposure, including the ambient sun exposures. These exposures were weighted by the erythemal action spectrum and separately for three different action spectra for pre-vitamin D production. For the erythema weighting function, 25(OH)D3 increased 1.78 ± 0.25 nmol per litre per SED, a value consistent with other studies. Any differences due to age, BMI, gender, and skin reflectance were not statistically significant. Ethnicity differences were the only significant factor, with Asians producing the least vitamin D, and Maori the most. There was no statistically significant improvement in consistency between sources for any of the three pre-vitamin weightings compared with that for erythema. Further work is needed to verify which vitamin D action spectrum is most appropriate. Nevertheless, these small doses of UV from artificial sources were helpful in quantifying the relationship between UV exposure and vitamin D status among the New Zealand population.

Ethnicity and risk of caesarean section in a term, nulliparous New Zealand obstetric cohort.

BACKGROUND: One in four New Zealand (NZ) women undergo caesarean section (CS); however, little is understood about how ethnicity influences CS rates. Previous NZ studies do not include many of NZ's ethnic groups and have been unable to account comprehensively for clinical risk factors. AIM: To investigate ethnicity as an independent risk factor for elective and emergency CS in nulliparous women at term. We hypothesised that compared with European, Maori and Pacific women would have a lower risk of elective CS, but there would be no ethnic differences in emergency CS. METHODS: This was a retrospective cohort analysis of prospectively recorded maternity data at National Women's Health, Auckland, NZ from 2006 to 2009. The study population was 11 848 singleton, nulliparous, term births. Multivariable logistic regression analysis was performed for elective and emergency CS, accounting for comprehensive confounding factors. RESULTS: The overall CS rate was 31.2% (elective 7.8%, n = 923 and emergency 23.4%, n = 2770). Compared with European ethnicity, Pacific and Chinese women had a reduced odds of elective CS (adjusted odds ratios, aOR 0.42, [95% CI 0.24-0.73] and 0.68, [0.49-0.94], respectively), while Indian women had an increased odds of emergency CS (aOR 1.54, [1.26-1.88]). Rates of elective or emergency CS for other ethnicities were similar to European. CONCLUSIONS: After adjustment for confounding, we report ethnic differences in elective and emergency CS rates, which may be related to patient and/or care provider factors. Further prospective research is recommended to examine reasons for these ethnic differences in CS rates.

Independent risk factors for infants who are small for gestational age by customised birthweight centiles in a multi-ethnic New Zealand population.

BACKGROUND: Infants born small for gestational age (SGA) by customised birthweight centiles are at increased risk of adverse outcomes compared with those SGA by population centiles. Risk factors for customised SGA have not previously been described in a general obstetric population. AIM: To determine independent risk factors for customised SGA in a multi-ethnic New Zealand population. METHODS: We performed a retrospective cohort analysis of prospectively recorded maternity data from 2006 to 2009 at National Women's Health, Auckland, New Zealand. After exclusion of infants with congenital anomalies and missing data, our final study population was 26,254 singleton pregnancies. Multivariable logistic regression analysis adjusted for ethnicity, body mass index, maternal age, parity, smoking status, social deprivation, hypertensive disease, antepartum haemorrhage (APH), diabetes and relevant pre-existing medical conditions. RESULTS: Independent risk factors for SGA included obesity (adjusted odds ratio 1.24 [95% CI 1.11-1.39] relative to normal weight), maternal age ≥ 35 years (1.16 [1.05-1.30] relative to 20-29 years), nulliparity (1.13 [1.04-1.24] relative to parity 1), cigarette smoking (2.01 [1.79-2.27]), gestational hypertension (1.46 [1.21-1.75]), pre-eclampsia (2.94 [2.49-3.48]), chronic hypertension (1.68 [1.34-2.09]), placental abruption (2.57 [1.74-3.78]) and APH of unknown origin (1.71 [1.45-2.00]). Gestational diabetes (0.80 [0.67-0.96]) and type 1 diabetes (0.26 [0.11-0.64]) were associated with reduced risk. CONCLUSIONS: We report independent pregnancy risk factors for customised SGA in a general obstetric population. In contrast to population SGA, obesity is associated with increased risk. Our findings may help identify pregnancies that require increased fetal growth surveillance.

Serum 25-hydroxyvitamin-D responses to multiple UV exposures from solaria: inferences for exposure to sunlight.

We investigate the relationship between blood serum 25-hydroxyvitamin D (25(OH)D) and UV exposure from two artificial sources. We then use the results to test the validity of the action spectrum for vitamin D production, and to infer the production from summer and winter sunlight. The results are based on a two-arm randomised clinical trial of biweekly UV exposure for 12 weeks using two different types of dermatological booths: one emitting primarily UV-A radiation, and the other emitting primarily UV-B radiation (booth A and booth B respectively). In terms of the vitamin D production per unit erythema, one of the booths mimics summer noon sunlight, while the other mimics winter noon sunlight. Blood samples were taken before and after the exposures. For all participants, the phototherapy booth treatments arrested the usual wintertime decline in 25(OH)D, and for most the treatments from either booth resulted in significant increases. The increases were highly non-linear and there was a high degree of variability in 25(OH)D and its response to UV from person to person. By the end of the 12 week period, the mean increase was >30 nmol l(-1) from a cumulative exposure of 17 SED from the UV-A booth, and twice that for the UV-B booth for which the cumulative exposure was 268 SED. Assuming a logarithmic relationship between UV and vitamin D, the results for the two booths show no obvious inconsistency in the action spectrum for pre-vitamin D production. However, further measurements with similar exposures from each booth are required to confirm its validity. A model was developed to describe the increases in serum 25(OH)D resulting from the UV exposures, which differed markedly between the two booths. The deduced initial rate of increase of 25(OH)D was approximately 5 nmol l(-1) per SED. From the large increases in 25(OH)D from each booth, along with knowledge of the spectral distribution of sunlight and assuming the currently-accepted action spectrum for photo-conversion to pre-vitamin D, we infer that the production of 25(OH)D from sunlight should be possible throughout the year, although in winter the exposures necessary to maintain optimal levels of 25(OH)D would be impractically long. This finding is at variance with the commonly-held view that no vitamin D is produced at mid-latitudes in the winter. Further work is needed to resolve that inconsistency.