Sensitization to pets is a major determinant of persistent asthma and new asthma onset in Sweden.

INTRODUCTION: Our knowledge about atopy as a longitudinal predictor of asthma is limited. The purpose of this study was to investigate the prognosis of asthma and risk factors for asthma onset, especially sensitization of specific allergens in a population sample. MATERIAL AND METHODS: A cohort responded to a respiratory questionnaire in 1990 and 2003. At baseline, 2,060 subjects who, in the screening questionnaire, reported respiratory symptoms and 482 controls were investigated with interviews, spirometry, and skin-prick test. A total of 721 asthmatics and 976 subjects without respiratory disease were clinically verified. At follow-up in 2003, 340 subjects with persistent asthma and 186 subjects with asthma remission were identified, while 76 subjects reported new asthma onset. RESULTS: Sensitization to pets and a high symptom score were significant determinants of persistent asthma (odds ratio (OR) 3.2 (95% CI 1.9-5.6) and 5.7 (2.5-13.3), respectively) and onset of asthma (OR 2.6 (1.1-6.0), and 1.7 (1.2-2.3)). A high self-reported responsiveness to airway irritants (OR 1.6 (1.1-2.2)), and more asthma medications (OR 2.0 (1.3-2.9)) were additional indicators of persistent asthma at the follow-up. Belonging to the older age group decreased the risk both of having persistent asthma and asthma onset. DISCUSSION: Asthmatics sensitized to pets have a more severe outcome than asthmatics not sensitized to pets. Sensitization to pets was also a strong predictor for onset of asthma. Special attention should be given to asthmatics who report having severe symptoms and problems with airway irritants as such patients are more likely to have persistent problems.

Determinants for a low health-related quality of life in asthmatics.

People with asthma suffer from impaired health-related quality of life (HRQL), but the determinants of HRQL among asthmatics are not completely understood. The aim of this investigation was to study determinants of low HRQL in asthmatics and to study whether the determinants of HRQL differ between sexes and age groups. A cohort of three age groups in Sweden was investigated in 1990 using a questionnaire with focus on respiratory symptoms. To study quality of life, the generic instrument Gothenburg Quality of Life was used. The participants were also investigated with interviews, spirometry, and allergy testing. Asthma was diagnosed in 616 subjects. Fifty-eight per cent (n = 359) of the subjects were women; and 24% were smokers, 22% ex-smokers, and 54% were non-smokers. Women were more likely than men to report poor health-related quality of life. Respiratory symptoms severity was another independent determinant of a lower quality of life as well as airway responsiveness to irritants. Current and former smokers also reported lower quality of life. Finally, absenteeism from school and work was associated with lower quality of life. Factors such as sex, smoking habits, airway responsiveness to irritants, respiratory symptom severity, allergy, and absenteeism from school and work were associated with low HRQL in asthmatics.

Associations between mortality, asthma, and health-related quality of life in an elderly cohort of Swedes.

BACKGROUND: Asthma is a common chronic health condition among the elderly and an important cause of morbidity and mortality. Some studies show that subjective assessments of health-related quality of life (HRQL) are important predictors of mortality and survival. The primary aim of this study was to investigate whether low HRQL was a predictor of mortality in elderly subjects and whether such an association differed between subjects with and without asthma. METHODS: In 1990, a cohort in middle Sweden was investigated using a respiratory questionnaire. To assess HRQL, the generic instrument Gothenburg Quality of Life (GQL) was used. The participants were also investigated by spirometry and allergy testing. The present study was limited to the subjects in the oldest age group, aged 60-69 years in 1990, and included 222 subjects with clinically verified asthma, 148 subjects with respiratory symptoms but no asthma or other lung diseases, and 102 subjects with no respiratory symptoms. Mortality in the cohort was followed during 1990-2008. RESULTS: Altogether, 166 of the 472 subjects in the original cohort had died during the follow-up period of 1990-2008. Mortality was significantly higher in men, in older subjects, in smokers, and subjects with a low forced expiratory volume in one second (FEV(1)). There was, however, no difference in mortality between the asthmatic and the nonasthmatic groups. A higher symptoms score for GQL was significantly related to increased mortality. No association between HRQL and mortality was found when limiting the analysis to the asthmatic group, although the asthmatics had a lower symptom score for GQL compared to the other groups. CONCLUSION: A higher symptom score in the GQL instrument was significantly related to increased mortality, but this association was not found when analyzing the asthmatic group alone. The negative prognostic implications of a low HRQL in the whole group and the fact that the asthmatic group had a lower HRQL than the other group supports the use of HRQL instruments in clinical health assessments.

High BMI is related to higher incidence of asthma, while a fish and fruit diet is related to a lower- Results from a long-term follow-up study of three age groups in Sweden.

The causes of the worldwide increase in asthma seen during the last decades remain largely unexplained, but lifestyle and diet are suggested to play important roles. In this follow up of a large-scale population sample in Sweden, we wanted to identify modifiable risk factors for the cumulative incidence over a 13-year follow-up period. In 1990, a self-administered questionnaire was completed by 12,560 individuals from three age groups (16, 30-39 and 60-69 years of age) in two counties of Sweden. In 2003, the eligible subjects (n = 11,282) were sent a new postal questionnaire. In total 8150 (response rate 73%) answered the questionnaire. The prevalence of asthma in 2003 had increased in all ages. In the young adults, the asthma prevalence rose from 11.3% in 1990 to 25.0% in 2003. Adult asthma onset was identified in 791 of the participants. Smoking [RR (95% CI) = 1.37 (1.12-1.68)], BMI [1.49 (1.25-1.77 per inter quartile range)], and nocturnal gastro-oesophageal reflux (GOR) [2.16 (1.72-2.72)] were significant independent risk factors for the cumulative incidence of asthma. The impact of risk factors differed between the age groups where BMI and GOR had a significantly higher impact in the middle aged and the elderly (p < 0.05). High consumption of fruit and fish was protective especially in the elderly [0.52 (0.35-0.77)]. No significant difference was found in the impact of risk factors between men and women. Weight loss, smoking cessation and a diet rich in fruit and fish may be of importance in preventing onset of adult asthma.

Non-respiratory symptoms and well-being in asthmatics from a general population sample.

BACKGROUND: Different instruments have been developed to assess health-related quality of life (HRQL) in asthma patients. However, relatively few studies have assessed HRQL in asthma patients from a general population, and it is still unclear which instrument is most suitable. The purpose of this study was to compare HRQL in clinically verified asthmatics with subjects with respiratory symptoms without asthma and with subjects with no respiratory symptoms from a general population. The generic instrument Gothenburg Quality of Life (GQL) was used. A secondary aim was to study if GQL had any prognostic value in asthma. METHODS: A cohort of three age groups in Sweden was investigated in 1990 using a respiratory questionnaire and GQL. The cohort consisted of 616 subjects with asthma, 488 subjects with respiratory symptoms but no asthma, and 347 subjects without respiratory symptoms. The participants were also investigated by spirometry and allergy testing. In a follow-up study, subjects were identified who had persistent and improved asthma. RESULTS: The prevalence of 28 of the 30 common symptoms in GQL was significantly increased (p < 0.001) in subjects with asthma as compared to non-asthmatics. All symptoms in the domains heart and lung, head, musculoskeletal, tension, and depression were significantly increased among the asthmatics. The asthmatics also rated their physical well-being lower (p < 0.001) than subjects with no respiratory symptoms. Subjects with persistent asthma had a significantly higher prevalence of 7 of the 30 symptoms and lower social well-being than subjects showing improvement in asthma during the follow-up. All differences remained significant after adjusting for age, sex, and smoking habits. CONCLUSION: Subjects with asthma had different symptom-profiles compared to those of non-asthmatics, with a higher prevalence of both respiratory and non-respiratory symptoms. Asthma is also a disease that is related to low well-being. The use of quality-of-life questionnaires such as the GQL may provide useful information for evaluating the non-respiratory aspects of asthma as well as for assessing the impact of disease on health status and well-being.

Health-related quality of life predicts onset of asthma in a longitudinal population study.

BACKGROUND: Health-related quality of life (HRQL) has been increasingly used as an outcome measure in asthma, but less is known about the prognostic implication of low health-related quality of life. The purpose of this study was to investigate if a set of quality of life measures could predict onset of asthma. METHODS: In the baseline study 391 subjects without asthma answered a respiratory questionnaire and the Gothenburg Quality of Life (GQL) instrument in 1990. The GQL questionnaire included two parts: (1) the prevalence of HRQL-related symptoms and (2) well-being scores for physical, mental and social dimensions. The participants were also investigated with spirometry and allergy testing. In 2003, the same respiratory questionnaire that had been used in 1990 was sent. There were 290 responders, of whom 22 subjects had developed asthma. RESULTS: Participants who had developed asthma by the follow-up had a higher prevalence of sleep disturbances (30% vs. 10%), problems with chest pain (16% vs. 2%), depression (40% vs. 20%) difficulty relaxing (40% vs. 13%) and constipation (25% vs. 2%) at baseline than participants who did not develop asthma (p<0.05). Subjects who developed asthma also scored significantly lower on well-being variables as sleep, energy, mood, patience, memory, appetite, fitness and sense of appreciation outside home. These differences remained after adjusting for age, sex, smoking habits, asthma heredity, socioeconomic groups and building dampness. CONCLUSION: Participants with low health-related quality of life at baseline were more likely to report having developed asthma 12 years later.