Why has the utilization of antiasthmatics increased in Finland?

Salt intake, asthma, and exercise-induced bronchoconstriction: a review

Despite the heterogeneous treatment options for patients with asthma, there remains a substantial burden of unaddressed disease, even with optimal treatment. Epidemiological studies indicate that patients frequently resort to complimentary and alternative therapies when being treated for asthma and other chronic health conditions. Changes in diet associated with the development of a more affluent lifestyle is one of the environmental factors considered to contribute to the increased prevalence of asthma in the past few decades. Dietary sodium in particular has been considered to be a dietary constituent implicated in this phenomenon. This article reviews the studies conducted that have questioned whether reducing dietary salt intake potentially improves pulmonary function and airway hyper-responsiveness in asthmatics, as well as studies evaluating dietary salt intake on the severity of exercise-induced bronchoconstriction (EIB). The data presented supporting dietary salt restriction for reducing airway hyper-responsiveness in asthmatics is encouraging, though not clinically convincing. Studies conducted previously have been limited for a variety of reasons, including limitations related to the experiment and populations studied. However, in studies that evaluated the severity of EIB in asthmatic individuals and involved altered dietary salt intake, data have been more convincing. A low-sodium diet maintained for 1 to 2 weeks decreases bronchoconstriction in response to exercise in individuals with asthma. There are no data regarding the longer-term effects of a low-sodium diet on either the prevalence or severity of asthma or on EIB. As a low-sodium diet has other beneficial health effects, it can be considered a therapeutic option for adults with asthma, although it should be considered as an adjunctive intervention to supplement optimal pharmacotherapy, and not as an alternative.

Dietary sodium intake and asthma: an epidemiological and clinical review

The changes in diet associated with the development of a more affluent lifestyle have been considered one of the environmental factors that may have contributed to the rise in the prevalence of asthma over the past few decades, and dietary sodium has been considered to be a dietary constituent which may be implicated in this phenomenon. The data presented in this review demonstrate that adoption of a low sodium diet for a period of 2-5 weeks may improve lung function and decrease bronchial reactivity in adults with asthma, while sodium loading appears to have a detrimental effect. Similarly, a low sodium diet maintained for 1-2 weeks decreases bronchoconstriction in response to exercise in individuals with asthma. There is no data as to the longer-term effect of a low sodium diet on either the prevalence or severity of asthma or on exercise-induced bronchoconstriction. As a low sodium diet has other beneficial health effects, it can be considered as a therapeutic option for adults with asthma, although it should be considered as an adjunctive intervention to supplement optimal pharmacological management of asthma and not as an alternative. If the relationship between higher sodium intake and increased prevalence and severity of asthma is causal, then there are potential population benefits for asthma as well as cardiovascular disease to be derived from public health measures to reduce sodium consumption.

Dietary polyunsaturated fatty acids in asthma- and exercise-induced bronchoconstriction

Despite progress that has been made in the treatment of asthma, the prevalence and burden of this disease has continued to increase. While pharmacological treatment of asthma is usually highly effective, medications may have significant side effects or exhibit tachyphylaxis. Alternative therapies for treatment that reduce the dose requirements of pharmacological interventions would be beneficial, and could potentially reduce the public health burden of this disease. Ecological and temporal data suggest that dietary factors may have a role in recent increases in the prevalence of asthma. A possible contributing factor to the increased incidence of asthma in Western societies may be the consumption of a proinflammatory diet. In the typical Western diet, 20- to 25-fold more omega (n)-6 polyunsaturated fatty acids (PUFA) than n-3 PUFA are consumed, which promotes the release of proinflammatory arachidonic acid metabolites (leukotrienes and prostanoids). This review will analyze the evidence for the health effects of n-3 PUFA in asthma- and exercise-induced bronchoconstriction (EIB). While clinical data evaluating the effect of omega-3 fatty acid supplementation in asthma has been equivocal, it has recently been shown that fish oil supplementation, rich in n-3 PUFA, reduces airway narrowing, medication use, and proinflammatory mediator generation in nonatopic elite athletes with EIB. These findings are provocative and suggest that dietary fish oil supplementation may be a viable treatment modality and/or adjunct therapy in asthma and EIB.

Omega-3 Fatty acids and airway hyperresponsiveness in asthma

Despite the progress that has been made in the treatment of asthma, the prevalence and burden of this disease has continued to increase. Exercise is a powerful trigger of asthma symptoms and reversible airflow obstruction and may result in the avoidance of physical activity by patients with asthma, resulting in detrimental consequences to their health. Approximately 90% of patients with asthma are hyperresponsive to exercise and experience exercise-induced bronchoconstriction (EIB). While pharmacologic treatment of asthma is usually highly effective, medications often have significant side-effects or exhibit tachyphylaxis. Alternative therapies for treatment (complementary medicine) that reduce the dose requirements of pharmacologic interventions would be beneficial, and could potentially reduce the public health burden of this disease. There is accumulating evidence that dietary modification has potential to influence the severity of asthma and reduce the prevalence and incidence of this condition. A possible contributing factor to the increased incidence of asthma in Western societies may be the consumption of a proinflammatory diet. In the typical Western diet, 20- to 25-fold more omega- 6 polyunsaturated fatty acids (PUFA) than omega-3 PUFA are consumed, which causes the release of proinflammatory arachidonic acid metabolites (leukotrienes and prostanoids). This review analyzes the existing literature on omega-3 PUFA supplementation as a potential modifier of airway hyperresponsiveness in asthma and includes studies concerning the efficacy of omega-3 PUFA supplementation in EIB. While clinical data evaluating the effect of omega-3 PUFA supplementation in asthma has been equivocal, it has recently been shown that pharmaceutical-grade fish oil (omega-3 PUFA) supplementation reduces airway hyperresponsiveness after exercise, medication use, and proinflammatory mediator generation in nonatopic elite athletes with EIB. These findings are provocative and suggest that dietary omega-3 PUFA supplementation may be a viable treatment modality and/or adjunct therapy in airway hyperresponsiveness. Further studies are needed to confirm these results and understand their mechanism of action.

Chlamydia pneumoniae infections in asthma: clinical implications

Chlamydia pneumoniae is an intracellular pathogen that has been suggested to play a role in the pathology of asthma. However, so far none of the studies have provided clear evidence for a causative role of C. pneumoniae infections in asthma, although there is little doubt that chronic C. pneumoniae infection does aggravate asthma and should be treated. The diagnosis of C. pneumoniae infection is still a matter of concern for it is dependent on trained skilled personnel and can vary significantly between different diagnostic laboratories. This fact is also one of the major problems encountered when comparing epidemiological studies investigating the possible role of C. pneumoniae infections and their impact on the pathogenesis of other diseases. With regard to therapy, long-term treatment with macrolides is the best available method to eradicate C. pneumoniae. Successful therapy for C. pneumoniae, however, can also be complicated by the high possibility of de novo infection as epidemiological studies have shown that the prevalence of antibodies to C. pneumoniae increases with age in all populations studied. In the northern hemisphere the prevalence of C. pneumoniae is also affected by seasonal conditions. It is too early to draw any conclusions from the equatorial belt countries. The available data on C. pneumoniae in tropical countries indicate a much faster infection rate during early adulthood with 100% serological prevalence at an age greater than 25 years. This data, if confirmed, would argue against C. pneumoniae causing asthma since the asthma prevalence in those countries does not increase in a parallel pattern. An alternative interpretation of most studies could be that the increased rate of C. pneumoniae infections in patients with asthma results from a modified susceptibility towards the microorganism, due to yet unknown changes of the host cell's physiology. It should be kept in mind that increased prevalence of C. pneumoniae infection is not restricted to asthma. Further studies are needed to understand the role of C. pneumoniae, especially of chronic infection, in the pathogenesis of inflammatory diseases with a specific focus on the effect that the microorganism triggers in the infected host cell. Only when we understand what C. pneumoniae does to its host cell will we be able to judge its impact on the overall status of an affected patient, and this knowledge will help us to develop a successful therapy.

Natural history of hay fever and pollen sensitization, and doctors' diagnosis of hay fever and pollen asthma in German schoolchildren

BACKGROUND

In order to prevent pollen asthma by immunotherapy it is mandatory to know the best time to initiate it. Children with hay fever complaints are at considerable risk of developing pollen asthma. Population-based data on their natural history is urgently needed.

METHODS

A longitudinal cohort study was conducted over four years in six rural towns in Baden-Württemberg, Germany. A questionnaire with questions taken from the International Study of Asthma and Allergies in childhood (ISAAC) was filled in every spring and autumn. Hay fever complaints, asthma defining symptoms and new doctors' diagnosis of hay fever and asthma were recorded. Additionally a skin prick test with pollen allergens was performed every autumn.

RESULTS

In 1996, 19.7% of 1101 elementary school children (age: 8.1-9.9 years (5-95%)) were found to be sensitized to pollen and 8.7% had already been diagnosed as having hay fever. In a pooled analysis of 2478 children-summers, children with positive pollen sensitization had a significantly higher risk of developing hay fever symptoms (2.63; 2.17-3.10 odds ratio (OR); 95% confidence interval (CI)) and of being diagnosed as suffering from hay fever (7.88; 4.70-13.20). Furthermore, although their OR for the development of asthma symptoms during the pollen season was 3.88 (2.48-6.07 CI), it was only 0.69 (0.24-2.01 CI) for doctors' diagnosis of pollen asthma.

CONCLUSION

Children of elementary school age with pollen sensitization and a history of hay fever are at considerable risk of getting pollen asthma, but they are not quickly diagnosed as such. Specific immunotherapy might be a means of preventing asthma completely in such a situation. Our data helps to estimate the sample size for intervention studies of this kind.

Increased frequency of Chlamydia pneumoniae antibodies in patients with asthma

The worldwide increase in asthma incidences and the impact of the disease on public health care have led to new investigations of the cause of the disease. Besides well-defined environmental causes, accumulating evidence suggests that respiratory tract infections play an important role in the pathogenesis of asthma. Among these microorganisms Chlamydia pneumoniae is an intracellular pathogen causing persistent infection. Chlamydia pneumoniae infection has been discussed as possibly inducing the development of asthma. This study was designed to investigate the presence of C. pneumoniae-specific IgG, IgA, and IgM antibodies in serum samples of 33 adults with a clinical history of asthma, positive methacholine test, and reduced FEV(1). Patients with asthma were compared with age-, sex-, and locality-matched control subjects (n = 33). We observed no acute infection either in patients with asthma or in control subjects, but 63% of all investigated individuals had signs of past infection. Chlamydia pneumoniae-specific IgA was detected in 52% of the patients with asthma and in 15% of the healthy control subjects (p < 0.01). Serological evidence of chronic infection with C. pneumoniae (high IgG [> pr = 1:512] and high IgA [> or = 1:40]) was more frequent in patients with asthma (18.2%) compared with control subjects (3.0%) (p < 0.01). Our results provide further evidence that chronic infection with C. pneumoniae is linked to asthma.

Self-care in adults with asthma: how they cope

The purpose of this study was to find out how well adult asthma patients in Finland cope with self-care in three areas of asthma treatment. The areas of physical, psychological and social asthma treatment were examined. Associations between demographic background data and self-care were also studied. Data (n = 130) for the study were collected using a questionnaire specially developed for this study. A deductive perspective was employed in data analysis. Respondents showed fairly good competence in self-care in all three areas of asthma treatment. However, up to 30% of the asthma patients had pets and 16% were smokers. Extra stress was reduced by exercise and positive thinking. Humour was also important in helping most of the respondents cope mentally. Social support played a significant part in fighting the sense of powerlessness which is caused by asthma. According to the results, women coped better than men in the social area of self-care.

[Evaluation of a program for asthmatic children treated in primary care outpatient units in Embu, São Paulo, 1988-1993]

The main objective of this study was to evaluate the effectiveness of the Program Targeting Children with 'Chest Wheezing' carried in the city of Embu, São Paulo. The study analyzed a total of 434 children aged zero to 14 years, admitted to the program from May 1988 to July 1993. Over 90% had never been treated for this medical problem in outpatient clinics. Only 6.2% had to be referred to other health care services during follow-up in this program. The program successfully performed clinical diagnosis of asthma in children over 2 years of age. The moderate and severe cases followed up for over a year showed the best clinical evolution, with the positive factor being better compliance with medication. The number of exacerbations decreased among the severe patients after a year of regular follow-up, although patients used bronchodilators during the 12 months of our analysis. Of the children enrolled, 53.2% gave up treatment principally in the first six months, most of them from the moderate group. We concluded that children with steadier compliance with the program benefited in spite of both the simplicity and the lack of some currently existing medications.

Regional differences in long-term mortality among hospital-treated asthma and COPD patients

Chronic obstructive pulmonary diseases, which have increased due to smoking and ageing of the population, constitute a national health problem, the treatment of which can be expected to arouse considerable discussion in health care organisations currently preoccupied with economic problems. Although extensive medication and easy access to treatment are often regarded as therapeutically desirable, it may be questioned whether they have any impact on objective measures such as mortality. International recommendations for the early treatment of asthma have met with satisfaction and the asthma situation can be said to be under control, even though occurrences tend to be on the increase. It should be noted, however, that the COPD treatment recommendations still remain to be tested and the general attitude towards treatment is still reserved, even pessimistic. By combining data from the Finnish national hospital discharge register and register of deaths with findings regarding the use of medications, differences in the survival of asthmatic and COPD patients can be discerned between areas with different treatment practices. Stressing the fact that effect-differences between different treatment strategies can not be proven on the basis register data and that random clinical trials are needed to gain further knowledge in the field, our results show that extensive medication and easy access to treatment are characteristic of areas where the survival of asthmatics and COPD patients is better.

Prescribing trends for anti-asthma drugs in Tasmania following the National Asthma Campaign

In recent years there has been a change in asthma pharmacotherapy, with considerably greater emphasis placed on the use of preventive therapy (inhaled corticosteroids and sodium cromoglycate) and less reliance on bronchodilator therapy. This study examined Tasmanian prescribing trends to determine whether the recommended changes in the treatment of asthma had transpired into practice and to compare the State prescribing trends with national Australian data. Computerized dispensing records, consisting of summarized monthly lists of all drugs dispensed, from almost one-third of all the community pharmacies within the State were retrospectively collected at intervals of 6 months between 1991 and 1994. Anti-asthma drugs were grouped into beta-agonists, inhaled corticosteroids, theophylline, ipratropium bromide and sodium cromoglycate, and quantities were converted to defined daily doses (DDDs)/1000 population/day, by extrapolation to the entire Tasmanian population. The Tasmanian data were compared with estimated national dispensing data for anti-asthma drugs provided by the Drug Utilization Subcommittee of the Pharmaceutical Benefits Advisory Committee. Tasmanian prescribing was generally similar to the national data, with large rises in the prescribing of inhaled corticosteroids (61% increase), ipratropium bromide (138% increase) and sodium cromoglycate (52% increase), and a decline in theophylline usage (43% decrease) over the period of the study. The prescribing of beta-agonists remained fairly stable over the period of the study, while there was a marked decrease in the ratio of dispensed DDDs of beta-agonists: inhaled corticosteroids (from 2.9 to 1.7). The overall usage of anti-asthma medication in Tasmania was found to be significantly higher than the national data for 1991 and 1992, with an April 1994 level of 74.7 DDDs/1000 population/day (an increase of 6% from April 1991). Tasmanian and national prescribing of anti-asthma drugs appears to have changed in line with current management guidelines, with greater emphasis on the use of inhaled corticosteroids. More attention could also be given to the prescribing of anti-allergy preventive drugs.

Incidence of occupational asthma and persistent asthma in young adults has increased in Finland

To investigate the incidence of occupational asthma and its relationship to new cases of persistent asthma, the data was collected from two national registers which cover practically all new cases of both diseases. In 1986 to 1993, the annual incidence of persistent asthma in adults (from 15 to 64 years) increased from 6,645 to 8,056 (21%). The incidence of asthma in women increased from 3,302 to 4,717 (43%). In the age group of 15 to 29 the increase was 91%, in 30 to 49 it was 60%, and in 50 to 64 the increase was 7%. Among men, the annual incidence remained stable. However, in the age group of 15 to 29 it increased by 87%, in 30 to 49 by 46%, while a decrease of 43% was detected in the age group of 50 to 64 years. During the same period, the annual incidence of occupational asthma increased from 227 to 386 (70%), from 109 to 185 (70%) in women and from 118 to 201 (70%) in men. In 1993 the population in Finland in the age range from 15 to 64 was 2.026 million. Thus, the incidence of persistent asthma was 0.4%. The proportion of newly diagnosed occupational asthma out of all new cases of asthma was 4.8%.

Differences in utilization of asthma drugs between two neighbouring Swedish provinces: relation to treatment in individuals with airway disease

OBJECTIVE

To assess the extent to which drugs were used by individuals found to have asthma in a population survey. To assess the relative influence of the proportion of patients treated and doses reported on the sales of drugs. To study if observed differences in sales of asthma drugs between the county of Jämtland (with high sales) and Gävleborg (with lower sales) correlated to a difference in the control of the disease.

DESIGN

A cross-sectional population study with a postal questionnaire followed by an interview and examination of symptomatic individuals. Asthma was diagnosed in subjects reporting a typical history of asthma or repeated episodes of dyspnoea and wheezing, or dry cough combined with reversibility in FEV1, PEF-variability or PC20 < or = 4 mg ml-1.

SETTING

The county of Jämtland, and Gästrikland, a southern part of the county of Gävleborg in central Sweden.

SUBJECTS

All 16 year olds, and 13% (randomly selected) of 30-39 and of 60-69 year olds (totalling 12732 individuals). Subjects reporting airway symptoms in the questionnaire (n = 2100) and 450 asymptomatic controls were further investigated.

MAIN OUTCOME MEASURES

Drug use and symptoms reported by individuals found to have asthma or chronic obstructive pulmonary disease (COPD).

RESULTS

Inhaled beta 2 agonists and inhaled steroids were used more often by individuals with asthma and COPD in Jämtland. However, regular use was more common in Gävleborg. Most of the asthmatics did not use any medication in spite of the fact that symptoms were commonly reported. The drug combinations most often used were inhaled beta 2 agonists alone or in combination with inhaled steroids. There were only minor differences in the prevalence of symptoms reported by individuals with asthma treated in different ways.

CONCLUSION

Differences in the way anti-asthma drugs were used contributed to the observed difference in the sales of drugs. However, this difference was mainly caused by differences in the prevalence of asthma. The goals of asthma management plans were fulfilled only in a minority of patients despite the sales of asthma drugs being high.

Regional distribution of asthma-related hospital treatment periods in Finland in 1972-86

We examined the use of asthma-related hospital services in geographically different areas of Finland in 1972-86, using data obtained from hospital discharge registers. A total of 254,402 cases diagnosed as asthma was identified (diagnosis 493, International Classification of Diseases, 8th Revision), information on the patient's place of residence enabling comparison of the southern, western, eastern, and northern parts of the country. Annual hospitalizations and the occurrence of new cases were calculated relative to the population, the former being found to increase throughout the country during the period studied, the most marked rise being 8.8% in Northern Finland (95% confidence interval 6.4-11.3%), and the smallest, 1.1%, in Western Finland (-0.2 to +2.5). A corresponding trend was also noted in the annual occurrence of new cases, which increased most in Northern Finland, i.e. by 4.8% (3.0-6.6), and decreased in Western Finland by 2.9% (-3.6 to -2.1). The change in asthma and the organization of treatment and factors related to the cold environment may, in combination, contribute to difficulties in the treatment of asthma in Northern Finland.

Asthma-related hospital use among Finnish asthmatics of working age

The aim was to examine asthma-related use of hospital services among persons of working age (15-64 years) in Finland on the basis of hospital discharge registers over a period of 15 years. A total of 155,080 asthma-induced treatment periods and 1,270,453 hospitalisation days were observed in the working-age population during the period concerned. Although the use of hospital services was found to be smallest in the second youngest male age-group (25-34 years), the numbers of treatment periods and hospitalisation days observed among men relative to population were found to increase by age. Middle-aged (35-44) female asthmatics tend to use hospital services more often than men of the same age, but no difference was observed between the sexes in the oldest age-group (55-64 years). The long-term monitoring and guidance of asthmatics and the specialist services required should be coordinated within the basic health care system as in the case of other chronic diseases. The long-term monitoring of asthmatics should be performed by general practitioners, and in the light of the present findings special emphasis should be placed on subjects aged 35 years and older.