Reference values of inspiratory spirometry for Finnish adults

Inspiratory spirometry is used in evaluation of upper airway disorders e.g. fixed or variable obstruction. There are, however, very few published data on normal values for inspiratory spirometry. The main aim of this study was to produce reference values for inspiratory spirometry for healthy Finnish adults.Inspiratory spirometry was preplanned to a sample of the Finnish spirometry reference values sample. Data was successfully retrieved from 368 healthy nonsmoking adults (132 males) between 19 and 83years of age. Reference equations were produced for forced inspiratory vital capacity (FIVC), forced inspiratory volume in one second (FIV1), FIV1/FIVC, peak inspiratory flow (PIF) and the ratios of FIV1/forced expiratory volume in one second and PIF/peak expiratory flow. The present values were compared to PIF values from previously used Finnish study of Viljanen etal. (1982) reference values and Norwegian values for FIV1, FIVC and FIV1/FIVC presented by Gulsvik etal. (2001). The predicted values from the Gulsvik etal. (2001), provided a good fit for FIVC, but smaller values for FIV1 with mean 108.3 and 109.1% of predicted values for males and females, respectively. PIF values were 87.4 and 91.2% of Viljanen etal. (1982) predicted values in males and females, respectively. Differences in measurement methods and selection of results may contribute to the observed differences. Inspiratory spirometry is technically more demanding and needs repeatability criteria to improve validity. New reference values are suggested to clinical use in Finland when assessing inspiratory spirometry. Utility of inspiratory to expiratory values indices in assessment of airway collapse need further study.Peer reviewe

The birth and development of clinical physiology in Finland

The specialty of clinical physiology was established in Finland about 20 years later than in Sweden. In the early 1960s, six physicians working mainly in preclinical departments of physiology were certified as specialists in clinical physiology. Many of the first specialists working in hospitals received specialist training in Sweden. The first hospital laboratories of clinical physiology were established in Tampere Central Hospital and Turku University Hospital in 1968. Thereafter, laboratories of clinical physiology were also established in Helsinki University Hospital and in Kuopio University Hospital and later also in most central hospitals. After clinical physiology laboratories were set up in hospitals and the number of specialists increased, the specialty gradually had more impact in clinical work. In the 1999 reform, nuclear medicine, which had previously been a subspecialty, was combined with clinical physiology. Arto Uusitalo was nominated the first professor of clinical physiology in Tampere University in 1984. The first professor in Helsinki University was Anssi Sovijarvi (1994), in Kuopio University Esko Lansimies (1998), and in Turku University Jaakko Hartiala (2003). Today, at four universities professors of clinical physiology and nuclear medicine lead research and medical education in this specialty. The hospital laboratories have modern equipment, which promotes multidisciplinary research with clinicians in fruitful collaboration. The Finnish Society of Clinical Physiology was founded in 1975. Today, it has about 160 members, about half of whom are specialists in the field. On its 40th anniversary, the Society decided to publish the history of clinical physiology in Finland.Peer reviewe

Measurement of bronchial hyperreactivity : comparison of three Nordic dosimetric methods

Clinical testing of bronchial hyperreactivity (BHR) provides valuable information in asthma diagnostics. Nevertheless, the test results depend to a great extent on the testing procedure: test substance, apparatus and protocol. In Nordic countries, three protocols predominate in the testing field: Per Malmberg, Nieminen and Sovijarvi methods. However, knowledge of their equivalence is limited. We aimed to find equivalent provocative doses (PD) to obtain similar bronchoconstrictive responses for the three protocols. We recruited 31 patients with suspected asthma and health care workers and performed BHR testing with methacholine according to Malmberg and Nieminen methods, and with histamine according to Sovijarvi. We obtained the individual response-dose slopes for each method and predicted equivalent PD values. Applying a mixed-model, we found significant differences in the mean (standard error of mean) response-dose (forced expiratory volume in one second (FEV1)%/mg): Sovijarvi 7.2 (1.5), Nieminen 13.8 (4.2) and Malmberg 26 (7.3). We found that the earlier reported cut-point values for moderate BHR and marked BHR between the Sovijarvi (PD15) and Nieminen (PD20) methods were similar, but with the Malmberg method a significant bronchoconstrictive reaction was measured with lower PD20 values. We obtained a relationship between slope values and PD (mg) between different methods, useful in epidemiological research and clinical practice.Peer reviewe

Thoracic gas compression during forced expiration in patients with emphysema, interstitial lung disease and obesity

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Restriction of lung volumes but normal function of pulmonary tissue in mulibrey nanism

Background Mulibrey nanism (MUL) is a rare growth restriction disorder with multiple organ manifestations caused by genetic defects affecting the TRIM37 protein. A perimyocardial heart disease is the most serious manifestation. Many MUL children appear to suffer from airway obstruction related to infection or exercise, prompting use of inhaled therapies. Asthma medication is continued up to adolescence or even to adulthood due to persisting of symptoms. The pulmonary pathophysiology has previously not been evaluated in any MUL cohort. Methods Thirty three finnish MUL patients (median age 20 years) were investigated with several lung function tests: spirometry with bronchodilatation test, single-breath diffusing capacity for carbon monoxide, single-breath lung volume measurements with helium dilution, and thoracic gas volume, airway resistance and specific conductance measurements with a body plethysmograph. As MUL typically affects body proportions, all variables were compared with reference values and with predicted values calculated from sitting height. Results Total lung capacity and forced vital capacity were markedly reduced (total lung capacity [TLC] and forced vital capacity [FVC], P = 12% and >= 200 mL) was found only in one patient. Conclusion MUL patients typically have volume restriction of the lungs, but function of the pulmonary tissue remains intact. Evidence of asthma in lung function testing at adult age is rare.Peer reviewe

Restrictive spirometric pattern in the general adult population : Methods of defining the condition and consequences on prevalence

Background: Attempts have been made to use dynamic spirometry to define restrictive lung function, but the definition of a restrictive spirometric pattern (RSP) varies between studies such as BOLD and NHANES. The aim of this study was to estimate the prevalence and risk factors of RSP among adults in northern Sweden based on different definitions. Methods: In 2008-2009 a general population sample aged 21-86y within the obstructive lung disease in northern Sweden (OLIN) studies was examined by structured interview and spirometry, and 726 subjects participated (71% of invited). The prevalence of RSP was calculated according to three different definitions based on pre-as well as post-bronchodilator spirometry: 1) FVC 0.7 2) FVC LLN 3) FVC LLN Results: The three definitions yielded RSP prevalence estimates of 10.5%, 11.2% and 9.4% respectively, when based on pre-bronchodilator values. The prevalence was lower when based on post-bronchodilator values, i.e. 7.3%, 7.9% and 6.6%. According to definition 1 and 2, the RSP prevalence increased by age, but not according to definition 3. The overlap between the definitions was substantial. When corrected for confounding factors, manual work in industry and diabetes with obesity were independently associated with an increased risk for RSP regardless of definition. Conclusions: The prevalence of RSP was 7-11%. The prevalence estimates differed more depending on the choice of pre-compared to post-bronchodilator values than on the choice of RSP definition. RSP was, regardless of definition, independently associated with manual work in industry and diabetes with obesity. (C) 2016 The Authors. Published by Elsevier Ltd.Peer reviewe

Evaluation of the global lung function initiative 2012 reference values for spirometry in a Swedish population sample

Background: The Global Lung Function Initiative 2012 (GLI) reference values are currently endorsed by several respiratory societies but evaluations of applicability for adults resident in European countries are lacking. The aim of this study was to evaluate if the GLI reference values are appropriate for an adult Caucasian Swedish population. Methods: During 2008-2013, clinical examinations including spirometry were performed on general population samples in northern Sweden, in which 501 healthy Caucasian non-smokers were identified. Predicted GLI reference values and Z-scores were calculated for each healthy non-smoking subject and the distributions and mean values for FEV1, FVC and the FEV1/FVC ratio were examined. The prevalence of airway obstruction among these healthy non-smokers was calculated based on the Lower Limit of normal (LLN) criterion (lower fifth percentile) for the FEV1/FVC ratio. Thus, by definition, a prevalence of 5% was expected. Results: The Z-scores for FEV1, FVC and FEV1/FVC were reasonably, although not perfectly, normally distributed, but not centred on zero. Both predicted FEV1 and, in particular, FVC were lower compared to the observed values in the sample. The deviations were greater among women compared to men. The prevalence of airway obstruction based on the LLN criterion for the FEV1/FVC ratio was 9.4% among women and 2.7% among men. Conclusions: The use of the GLI reference values may produce biased prevalence estimates of airway obstruction in Sweden, especially among women. These results demonstrate the importance of validating the GLI reference values in different countries