Project

Discipline

population-based cohort; air pollution; respiratory diseases; cardiovascular diseases; allergic diseases; chronic disease risk factors; genetics; gender; Lung function; Asthma; Chronic Obstructive Pulmonary Disease; Arteriosclerosis; Life style; Environment

Lead
Lay summary
Objective: the SAPALDIA study is a multi-center study in eight geographic areas representing the range of environmental, meteorological and socio-demographic conditions of Switzerland. Summary of measurements: in 1991, 9'651 subjects, aged 18 to 60 years, were recruited for detailed interview and more than 90% of them underwent lung function and allergy testing. During a first follow-up, in 2002, 8'047 (83%) provided health information, 6'528 underwent physical re-examination, and 6'345 provided blood samples. Subjects aged 50 or older had 24h monitoring of electrocardiogram to assess for heart rate variability, a sensitive parameter of cardio-vascular health. In 2010, a second follow-up was launched, and will be completed by July 2011. In addition to repeated interviews and measurements, a large subsample of the paricipants undergoes measurement of the thickness of their carotids as well as measurement of pulse wave velocity, a reflection of the state of their arteries. Their also complete extensive questionnaires on health care utilization, level of physical exercise, and the type of food they are eating. Since 1991 SAPALDIA has also been carefully following address histories of the participants. Based on actual measurements of fine particles and gaseous pollutants, it was possible through validated calculations to ascribe to each participant of the cohort the level of pollution at his/her home address and its variation over the years.Results: they allowed to assess for prevalence and development of major respiratory and allergic diseases in the Swiss population, as well as age-related decline in lung function. Then it was possible to study the association of these health indicators as well as heart rate variability with individual long term exposure to air pollution, other toxic inhalants, life style and molecular factors. The bio-bank has allowed studies on the association between some genetic profiles (gene polymorphism) and the propensity to develop asthma, allergic diseases, or accelerated lung function decline with age. SAPALDIA has numerous collaborations with research groups dealing with similar population cohorts.Signification: ongoing studies are focusing on gene-environment interactions a crucial question to understand why some persons suffer more from the effect of air pollution than others. Furthermore, beyond the effects of air pollution, the current studies will provide important information on the occurrence of chronic cardio-respiratory diseases in general as a result of interrelations between life style, environment, socio-demographics, gender and genetic susceptibility.

Direct link to Lay Summary

Last update: 21.02.2013

Number	Title	Start	Funding scheme

SAPALDIA (Swiss cohort study on Air Pollution And Lung and heart Diseases in Adults) was initiated in 1991 with a first survey (S1) of 9651 randomly selected adults, 18 to 61 years of age, from 8 distinct areas representative of the environmental diversity of Switzerland. S1 included a computer-based interview, lung function (spirometry), methacholin broncho-challenge, and allergy testing. A second exam of the entire cohort (S2) was conducted in 2002 with 8047 subjects (86% of survivors) who completed at least a short questionnaire. A biobank was established with blood samples of 6345 participants. S2 repeated S1 and added a 24h ECG in a subset of 1860 participants aged =50 years. The first period of the current grant (04/2006 to 03/2008) was devoted to data analyses (see mid-term report to SNF 03/2008). The focus of the second period (04/2008-03/2011) is the implementation of S3 data collection, continued research with S1/S2 data, and the expansion of national and international collaborations in high profile consortia.The S3 interview and questionnaires include the core questions from S1/S2 with expansions of high relevance in chronic disease research (exercise/mobility; medical history; diet; time-activity; morbidities). The S3 spirometry protocol includes for the first time post-bronchodilator lung function test. Cardiovascular health assessments have been expanded in relevant ways (sonographic measurements of carotid intima media thickness (CIMT) as marker of atherosclerosis; pulse-wave velocity; body composition by bio-impedance analysis (BIA). A state-of-the-art online system provides immediate real-time data for quality control of procedures at the study centre. Blood samples are locally stored at - 80° C until spring 2011 before centralization of freezers in two identical biobanks at two different locations. Fieldworkers were trained in workshops and through local and data driven monitoring. As of August 2010 it is expected that 3-4 centres will exceed predicted participation rates, thus, may not finish field work as of March 2011. It will be requested to carry current funds re-served for fieldwork over to prolong S3 data collection for 3-4 months, but no new funds are requested. With 25 new papers published in 29 months (03/2008-07/2010) and several papers on the way, the team remained scientifically productive during the demanding implementation of the S3 follow-up. Publications focused on the key areas i) long term effects of outdoor air pollution including gene-environment interaction research, ii) determinants of the prevalence and incidence of COPD, asthma, bronchial hyper-responsiveness and allergy, iii) inter-relation of cardio-vascular health, obesity and the respiratory system, including gender effects, and iv) genetic association studies, including collaborations with large international consortia to secure sufficient power and reproducibility of such analyses. In the 2007 NEJM article it has been shown for the first time that improvements of air quality in the SAPALDIA regions attenuated the age-related lung function decline. This effect could be corroborated in our publications showing reduced incidence of respiratory symptoms and decreased adult-onset asthma associated with improved air quality. Of particular interest is the observation that variations in genes involved in cellular division, remodeling and anti-oxidative defense co-determined the degree to which an individual may benefit from better air quality. Our studies on the prevalence and incidence of airflow obstruction also revealed that nearly 30% of participants with significant obstruction are never smokers a finding that deserves further investigation. The observed interactions between gene variants, environment (e.g. passive smoking), life style (e.g. exercising) and early markers of cardio-vascular health (e.g. heart rate variability) make a highly relevant contribution to the international search of sus-ceptibility factors. The milestones of the next 3 years will be the build-up of the S1/S2/S3 data set, the advancement of research of high clinical and public health relevance at the interplay of long-term exposure to environmental factors, lifestyle related factors (obesity, exercise), endogenous bio-markers, and cardio-pulmonary health in an aging population, and the development of tools and mechanisms to further facilitate collaborations of new investigators with SAPALDIA. Importantly, SAPALDIA is one of the key partners and leader of work pack-ages of the trans-European consortium ESCAPE to investigate long-term effects of traffic-related pollution on chronic ailments, bringing >30 existing cohort studies together. SAPALDIA is extremely well positioned in large collaboration studies on the “genetic architecture” of respiratory and cardiovascular diseases and will be central to the assessment of gene-air pollution and gene-obesity interactions.