Journal Articles

Permanent URI for this collectionhttps://mro.massey.ac.nz/handle/10179/7915

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    Case-Control Study of Congenital Anomalies: Study Methods and Nonresponse Bias Assessment.
    (Wiley Periodicals LLC, 2025-02-20) Eng A; Mannetje AT; Ellison-Loschmann L; Borman B; Cheng S; Lawlor DA; Douwes J; Pearce N
    BACKGROUND: To describe the methods of a congenital anomalies case-control study conducted in New Zealand, discuss the encountered methodological difficulties, and evaluate the potential for nonresponse bias. METHODS: The potential cases (n = 2710) were New Zealand live births in 2007-2009 randomly selected from the New Zealand Congenital Anomalies Registry. The potential controls (n = 2989) included live births identified from the Maternity and Newborn Information System, frequency matched to cases by the child's year of birth and sex. Mothers were invited to complete an interview covering demographic, lifestyle, and environmental factors. Response probabilities for case and control mothers were evaluated in relation to maternal age, deprivation, occupation, and ethnicity, available from the Electoral Roll, and inverse probability weights (IPWs) for participation were calculated. Odds ratios (ORs) for key demographic and selected risk factors were estimated through unconditional logistic regression, with and without IPW. RESULTS: A total of 652 (24%) of case mothers and 505 (17%) of control mothers completed the interview. Younger and more deprived mothers were underrepresented among the participants, particularly for controls, resulting in inflated ORs of associations with congenital anomalies for younger age, Māori ethnicity, deprivation, and risk factors under study, such as blue-collar occupations and smoking, indicative of nonresponse bias. Nonresponse bias was minimized through IPW, resulting in ORs and exposure prevalence estimates similar to those based on the prerecruitment sample. CONCLUSIONS: Attaining high participation rates was difficult in this study that was conducted in new mothers, particularly for the controls. The resulting nonresponse bias was minimized through IPW.
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    Germline CDH1 mutations are a significant contributor to the high frequency of early-onset diffuse gastric cancer cases in New Zealand Māori.
    (Springer Nature, 2018-03-27) Hakkaart C; Ellison-Loschmann L; Day R; Sporle A; Koea J; Harawira P; Cheng S; Gray M; Whaanga T; Pearce N; Guilford P
    New Zealand Māori have a considerably higher incidence of gastric cancer compared to non-Māori, and are one of the few populations worldwide with a higher prevalence of diffuse-type disease. Pathogenic germline CDH1 mutations are causative of hereditary diffuse gastric cancer, a cancer predisposition syndrome primarily characterised by an extreme lifetime risk of developing diffuse gastric cancer. Pathogenic CDH1 mutations are well described in Māori families in New Zealand. However, the contribution of these mutations to the high incidence of gastric cancer is unknown. We have used next-generation sequencing, Sanger sequencing, and Multiplex Ligation-dependent Probe Amplification to examine germline CDH1 in an unselected series of 94 Māori gastric cancer patients and 200 healthy matched controls. Overall, 18% of all cases, 34% of cases diagnosed with diffuse-type gastric cancer, and 67% of cases diagnosed aged less than 45 years carried pathogenic CDH1 mutations. After adjusting for the effect of screening known HDGC families, we estimate that 6% of all advanced gastric cancers and 13% of all advanced diffuse-type gastric cancers would carry germline CDH1 mutations. Our results demonstrate that germline CDH1 mutations are a significant contributor to the high frequency of diffuse gastric cancer in New Zealand Māori.
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    Why has epidemiology not (yet) succeeded in identifying the origin of the asthma epidemic?
    (Oxford University Press, 2023-04-02) Antó JM; Pearce N; Douwes J; Garcia-Aymerich J; Pembrey L; Richiardi L; Sunyer J
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    Pesticide exposure in New Zealand school-aged children: Urinary concentrations of biomarkers and assessment of determinants
    (Elsevier Ltd, 2022-05) Li Y; Wang X; Feary McKenzie J; 't Mannetje A; Cheng S; He C; Leathem J; Pearce N; Sunyer J; Eskenazi B; Yeh R; Aylward LL; Donovan G; Mueller JF; Douwes J
    This study aimed to assess pesticide exposure and its determinants in children aged 5-14 years. Urine samples (n = 953) were collected from 501 participating children living in urban areas (participant n = 300), rural areas but not on a farm (n = 76), and living on a farm (n = 125). The majority provided two samples, one in the high and one in the low spraying season. Information on diet, lifestyle, and demographic factors was collected by questionnaire. Urine was analysed for 20 pesticide biomarkers by GC-MS/MS and LC-MS/MS. Nine analytes were detected in > 80% of samples, including six organophosphate insecticide metabolites (DMP, DMTP, DEP, DETP, TCPy, PNP), two pyrethroid insecticide metabolites (3-PBA, trans-DCCA), and one herbicide (2,4-D). The highest concentration was measured for TCPy (median 13 μg/g creatinine), a metabolite of chlorpyrifos and triclopyr, followed by DMP (11 μg/g) and DMTP (3.7 μg/g). Urine metabolite levels were generally similar or low compared to those reported for other countries, while relatively high for TCPy and pyrethroid metabolites. Living on a farm was associated with higher TCPy levels during the high spray season. Living in rural areas, dog ownership and in-home pest control were associated with higher levels of pyrethroid metabolites. Urinary concentrations of several pesticide metabolites were higher during the low spraying season, possibly due to consumption of imported fruits and vegetables. Organic fruit consumption was not associated with lower urine concentrations, but consumption of organic food other than fruit or vegetables was associated with lower concentrations of TCPy in the high spray season. In conclusion, compared to other countries such as the U.S., New Zealand children had relatively high exposures to chlorpyrifos/triclopyr and pyrethroids. Factors associated with exposure included age, season, area of residence, diet, in-home pest control, and pets.
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    Asthma inflammatory phenotypes on four continents: most asthma is non-eosinophilic
    (Oxford University Press on behalf of the International Epidemiological Association, 2023-04) Pembrey L; Brooks C; Mpairwe H; Figueiredo CA; Oviedo AY; Chico M; Ali H; Nambuya I; Tumwesige P; Robertson S; Rutter CE; van Veldhoven K; Ring S; Barreto ML; Cooper PJ; Henderson J; Cruz AA; Douwes J; Pearce N; WASP Study Group
    BACKGROUND: Most studies assessing pathophysiological heterogeneity in asthma have been conducted in high-income countries (HICs), with little known about the prevalence and characteristics of different asthma inflammatory phenotypes in low-and middle-income countries (LMICs). This study assessed sputum inflammatory phenotypes in five centres, in Brazil, Ecuador, Uganda, New Zealand (NZ) and the United Kingdom (UK). METHODS: We conducted a cross-sectional study of 998 asthmatics and 356 non-asthmatics in 2016-20. All centres studied children and adolescents (age range 8-20 years), except the UK centre which involved 26-27 year-olds. Information was collected using questionnaires, clinical characterization, blood and induced sputum. RESULTS: Of 623 asthmatics with sputum results, 39% (243) were classified as eosinophilic or mixed granulocytic, i.e. eosinophilic asthma (EA). Adjusted for age and sex, with NZ as baseline, the UK showed similar odds of EA (odds ratio 1.04, 95% confidence interval 0.37-2.94) with lower odds in the LMICs: Brazil (0.73, 0.42-1.27), Ecuador (0.40, 0.24-0.66) and Uganda (0.62, 0.37-1.04). Despite the low prevalence of neutrophilic asthma in most centres, sputum neutrophilia was increased in asthmatics and non-asthmatics in Uganda. CONCLUSIONS: This is the first time that sputum induction has been used to compare asthma inflammatory phenotypes in HICs and LMICs. Most cases were non-eosinophilic, including in settings where corticosteroid use was low. A lower prevalence of EA was observed in the LMICs than in the HICs. This has major implications for asthma prevention and management, and suggests that novel prevention strategies and therapies specifically targeting non-eosinophilic asthma are required globally.