Ethnic differences in prevalence of asthma symptoms and bronchial hyperresponsiveness in New Zealand schoolchildren.

Abstract

Maoris and Pacific Islanders in New Zealand have a higher asthma mortality and hospital admission rates than Europeans. To determine whether difference in asthma prevalence is the major factor underlying these differences in mortality, 2053 Auckland children aged 7-10 years (European 1084, Maori 509, Pacific Islander 460) were randomly sampled from school classes in the Auckland Urban Area, and studied by questionnaire (completed by parents) and histamine inhalation challenge to assess the provocative dose of histamine causing a 20% fall in FEV, (PD20). Maoris had the highest prevalence rates of respiratory symptoms, and Europeans had rates similar to Pacific Islanders. For "any current wheeze" for example, the prevalence in Maoris was 22-2% compared with 16 1% and 16-3% in the Europeans and Pacific Islanders. The prevalence of diagnosed asthma was similar in the three groups. When bronchial hyperresponsiveness (defined as a PD20 < 7.8 Mmol histamine) was considered, Europeans had the highest rates (20%), followed by Maoris (13%), and then Pacific Islanders (8-7%). These differences were not accounted for by differences in socioeconomic status, rates of smoking in the home, age, gender, or height. It is concluded that differences in asthma prevalence do not satisfactorily explain the mortality and admission rate differences, although the higher symptom prevalence in the Maoris could be relevant to the higher mortality rate. Maori and Pacific Island children with symptoms of asthma were less likely to be taking pwophylactic medication than European children. It is proposed that differences in management are important factors relevant to the increased mortality and morbidity from asthma in Polynesians.

Lower prevalence of asthma and atopy in Turkish children living in Germany

“…The results of the present study demonstrate that ethnicity should be taken into consideration when performing epidemiological surveys in Europe as prevalence rates of atopic diseases may vary significantly between immigrant and indigenous populations. Similar results have previously been reported in studies of Asian immigrants to Australia [10], of Maoris [9] and South Pacific Islanders [11] who had immigrated to New Zealand, of Puerto Ricans [8] and Mexicans [17] living in the USA and of Asian children living in the UK [13]. Belonging to a certain ethnic group may lead to higher [8,9] or lower [10,11,13,17] prevalence rates of asthma and atopy compared with the indigenous population.…”

“…Moreover, the prevalence of asthma varies not only between countries but also between centres within the same country [7]. Even within study centres there are differences in the prevalence rates of atopic diseases as has been demonstrated in the USA [8], New Zealand [9] and Australia [10].…”

Physiology and treatment of cough.

“…We use concentrations ranging from 1 to 500 1M capsaicin in 90Vo saline obtained from a stock solution of 1 mM in ethanol, and count the number of coughs after each dose. In our experience normal people do not usually cough with a concentration below 10 pM and often not until 30 pM, the mean for the concentration causing two or more coughs being (95% confidence interval [6][7][8][9][10][11][12][13][14][15][16][17][18][19] MM.9 Patients with a dry cough, however, whether related to angiotensin converting enzyme inhibitor treatment" or to other causes,'025 cough with lower doses (as low as 1 pM). Patients who cough at concentrations of capsaicin below 10 pM can therefore be regarded as having increased sensitivity of their cough reflex.…”

Allergic Rhinitis and its Impact on Asthma (ARIA) 2008*

“…In England, native people were at a lower risk of developing allergic rhinitis than those born in Asia or the West Indies (272). Similarly, Maori people suffered more from allergic rhinitis than New Zealanders from English origin (273). Migrants from developing to industrialized countries seem to be at risk of allergy and asthma development (274).…”