Classical regression equations of spirometric parameters are not applicable for diagnosing spirometric abnormalities in adipotic adults

The prevalence of overweighing and obese adults (defined as “adipotic” adults), has markedly increased over the world. A remarkable increase in the adipotic population urgently needs developing the regression equations for predicting spirometric parameters (SPs), which are specifically applicable to adipotic adults. Unfortunately, however, the reliable equations suitable for adipotic adults have not been reported to date. Recently, Yamaguchi et al have proposed the quantitative method to estimate the effects of adiposity on deciding the SPs incorporating with age-specific contributions of various explanatory, independent variables such as age (A), standing height (H), body weight (BW), and fat fraction of body mass (F). Extending the method proposed by Yamaguchi et al, we attempted to elaborate the novel regression equations applicable for diagnosing the spirometric abnormality in adipotic adults. For accomplishing this purpose, never-smoking, adipotic adults with body mass index (BMI) over 25 kg/m² and no respiratory illness were recruited from the general population in Japan (n = 3696, including men: 1890 and women: 1806). Introducing the four explanatory variables of A, H, BW, and F, gender-specific and age-dependent regression equations that allowed for prescribing the SPs in adipotic adults were constructed. Comparing the results obtained for non-adipotic adults (i.e., those with normal BMI), the negative or positive impact of height on SPs was preserved in adipotic adults, as well. However, the negative impact of age on SPs was blunted in adipotic men and the positive effect of BW on SPs was impeded in adipotic men and women. The fat fraction of body mass-elicited negative impact on SPs vanished in adipotic women. These results indicate that the regression equations of SPs for adipotic adults differ significantly from those for non-adipotic adults, leading to the conclusion that the regression equations for non-adipotic adults should not be used while judging the spirometric abnormalities in adipotic adults.     

Reference equation for the incremental shuttle walk test in Japanese adults

Background

The incremental shuttle walk test (ISWT) is widely used in clinical and research settings. However, there are no reference equations to predict the walk distance achieved in the ISWT (ISWD) for healthy Japanese adults. We aimed to establish a reference equation for the ISWD prediction in Japanese adults.

A rebreathing method to determine carbon monoxide diffusing capacity in children: Reference values for six 18-year-olds and validation in adult volunteers

The diffusing capacity of carbon monoxide (D_L,CO) and its value normalized to alveolar volume (D_L,CO/V_A) are usually estimated with the single breath method at total lung capacity (TLC). Severely ill patients and small children are not able to deliver a satisfactory vital capacity (VC) or hold their breath for 10 s at TLC. The aim of this study was to develop a rebreathing procedure in which diffusing capacity can be determined during spontaneous tidal breathing. The conventional rebreathing method during hyperventilation was modified so that rebreathing volume and gas concentrations were kept constant by CO₂ absorption and O₂ supplementation. In adult healthy volunteers and in patients who were able to perform both tests, the diffusion indices obtained with this rebreathing method during resting ventilation were compared with those obtained by the single breath method. Predicted (reference) values for rebreathing D_L,CO and D_L,CO/V_A for children were determined. D_L,CO/V_A decreased with alveolar volume (V_A) and increased with alveolar ventilation (V′_A). In adults at V′_A above 35 L · min⁻¹ rebreathing D_L,CO/V_A was similar to single breath D_L,CO/V_A at similar alveolar volumes. The D_L,CO/V_A relative to their corresponding reference values were the same for both methods in adult patients, irrespective of ventilation distribution disturbances. In children the newly described diffusing capacity obtained by the rebreathing method during resting ventilation can serve as a valuable index to assess and follow a diffusion disorder. Pediatr Pulmonol. 1998; 25:205–212. © 1998 Wiley-Liss, Inc.     

Reference interval for glycated haemoglobin in a Montevideo population using a spectrophotometric assay,and comparison with a chromatographic method

The reference interval for glycated haemoglobin in 174 apparently healthy individuals from Montevideo City (mean 94, SD 7 mol fructose/10 mg haemoglobin) was determined using the thiobarbituric acid spectrophotometric method. In diabetic patients (n=222) the mean was significantly higher than in the control group (mean 117, SD 19 mol fructose/10 mg haemoglobin). The spectrophotometric method for the determination of glycated haemoglobin was compared to a microcolumn kit method (Boehringer, Mannheim, FRG). The correlation for glycated haemoglobins was acceptable (r=0.85;n=44;P<0.001). The colorimetric reference interval for glycated haemoglobin was converted to an equivalent value in the chromatographic method, expressed as per cent HbA (mean 8.7%, SD 1.2%), using the least squares regression line (y=0.603+ 0.0857x).     

Serial 6-month change in forced vital capacity predicts subsequent decline and mortality in Japanese patients with newly diagnosed idiopathic pulmonary fibrosis

BackgroundThe clinical course of idiopathic pulmonary fibrosis (IPF) is characterized by a progressive decline in lung function; however, predicting changes in lung function is difficult. We sought to determine whether the prior 6-month trend in forced vital capacity (FVC) could predict mortality and the subsequent 6-month trend in FVC.MethodsWe retrospectively analyzed consecutive patients with newly diagnosed IPF who underwent serial pulmonary function tests. The immediate two years after the initial evaluation were divided into four terms of six months each and stratified on the basis of presence or absence of a ≥10% relative decline in FVC at six months (declined and stable groups, respectively).ResultsWe included 107 patients with %predicted FVC of 80.8% and %predicted diffusing capacity of the lung for carbon monoxide of 58.9%. In multivariate analysis, a decline in %predicted FVC in the initial six months was found to be an independent prognostic factor (hazard ratio 4.45, 95% confidence interval 2.62–7.56, p < 0.01). Among the 46 terms in which the FVC declined during the initial 1.5-year study period, a decline in FVC was exhibited in 23 (50.0%) of the subsequent terms. Among 231 terms in which FVC remained stable, a decline was observed in 32 (13.9%) of the subsequent terms (relative risk 3.61, p < 0.01). The frequency of FVC decline in each term was 16–27%. FVC was stable or declined in all four terms in 50.5% and 15.9% of cases, respectively.ConclusionsSix-month decline in FVC predicts subsequent FVC change and mortality in IPF patients in the era of antifibrotic agents.     

Replacement therapy for iron deficiency improves exercise capacity and quality of life in patients with cyanotic congenital heart disease and/or the Eisenmenger syndrome

Introduction

Iron deficiency is common in cyanotic congenital heart disease (CHD) and results in reduced exercise tolerance. Currently, iron replacement is advocated with limited evidence in cyanotic CHD. We investigated the safety and efficacy of iron replacement therapy in this population.

Methods

Twenty-five iron-deficient cyanotic CHD patients were prospectively studied between August 2008 and January 2009. Oral ferrous fumarate was titrated to a maximum dose of 200 mg thrice-daily. The CAMPHOR QoL questionnaire, 6 minute walk test (6MWT) and cardiopulmonary exercise testing were conducted at baseline and after 3 months of treatment.

Results

Mean age was 39.9 ± 10.9 years, 80% females. Fourteen had Eisenmenger syndrome, 6 complex cyanotic disease and 5 Fontan circulation. There were no adverse effects necessitating termination of treatment. After 3 months of treatment, hemoglobin (19.0 ± 2.9 g/dL to 20.4 ± 2.7 g/dL, p < 0.001), ferritin (13.3 ± 4.7 μg/L to 54.1 ± 24.2 μg/L, p < 0.001) and transferrin saturation (17.8 ± 9.6% to 34.8 ± 23.4%, p < 0.001) significantly increased. Significant improvements were also detected in the total CAMPHOR score (20.7 ± 10.9 to 16.2 ± 10.4, p = 0.001) and 6MWT distance (371.7 ± 84.7 m to 402.8.0 ± 74.9 m, p = 0.001). Peak VO₂ remained unchanged (40.7 ± 9.2% to 43.8 ± 12.4% of predicted, p = 0.15).

Conclusion

Three months of iron replacement therapy in iron-deficient cyanotic CHD patients was safe and resulted in significant improvement in exercise tolerance and quality of life. Identification of iron deficiency and appropriate replacement should be advocated in these patients.     

Glycaemic control and hypoglycaemia with insulin glargine 300 U/mL compared with glargine 100 U/mL in Japanese adults with type 2 diabetes using basal insulin plus oral anti-hyperglycaemic drugs (EDITION JP 2 randomised 12-month trial including 6-month extension)

AimsTo compare insulin glargine 300 U/mL (Gla-300) with glargine 100 U/mL (Gla-100) in Japanese adults with uncontrolled type 2 diabetes on basal insulin and oral anti-hyperglycaemic drugs over 12 months.MethodsEDITION JP 2 was a randomised, open-label, phase 3 study. Following a 6-month treatment period, participants continued receiving previously assigned once daily Gla-300 or Gla-100, plus oral anti-hyperglycaemic drugs, in a 6-month extension period. Glycaemic control, hypoglycaemia and adverse events were assessed.ResultsThe 12-month completion rate was 88% for Gla-300 and 96% for Gla-100, with comparable reasons for discontinuation. Mean HbA_1c decrease from baseline to month 12 was 0.3% in both groups. Annualised rates of confirmed (≤ 3.9 mmol/L [≤ 70 mg/dL]) or severe hypoglycaemia were lower with Gla-300 than Gla-100 (nocturnal [00:00–05:59 h]: rate ratio 0.41; 95% confidence interval: 0.18 to 0.92; anytime [24 h]: rate ratio 0.64; 95% confidence interval: 0.44 to 0.94). Cumulative number of hypoglycaemic events was lower with Gla-300 than Gla-100. Adverse event profiles were comparable between treatments.ConclusionOver 12 months, Gla-300-treated participants achieved sustained glycaemic control and experienced less hypoglycaemia, particularly at night, versus Gla-100, supporting 6-month results.     

Faecal immunochemical tests for haemoglobin (FIT) in the assessment of patients with lower abdominal symptoms: current controversies

Faecal immunochemical tests for haemoglobin (FIT), as an adjunct to clinical information, assist in the triage of patients presenting in primary care with lower abdominal symptoms. Controversy remains regarding whether and which qualitative and quantitative FIT can be used, which groups of patients would benefit most from FIT, whether FIT should be done in primary and/or secondary care, and how FIT should be incorporated into diagnostic pathways. Controversy also exists as to the optimum cut-off used for referral for colonoscopy. A single sample of faeces may be sufficient. Reporting of results requires consideration. FIT provide a good rule in test for colorectal cancer and a good rule out test for significant bowel disease, but robust safety-netting is required for patients with negative results and ongoing symptoms. Risk scoring models have been developed, but their value is unclear as yet. Further evaluation of these topics is required to inform good practice.     

Diagnosis and prognostic value of restrictive ventilatory disorders in the elderly: a systematic review of the literature

Although less extensively studied compared to pulmonary obstructive diseases, restrictive lung disease (RLD) is highly prevalent and frequently disabling in the adult and, more, the elderly population. The underlying conditions may be either primarily pulmonary diseases, such as idiopathic pulmonary fibrosis, or non respiratory conditions secondarily affecting the lung, e. g. congestive heart failure, or else conditions affecting the lung expansion, e. g. obesity or rib cage deformity. The diagnosis is frequently based on the measurement of surrogate indexes such as the forced vital capacity (FVC) used as a proxy for total lung capacity (TLC). As a consequence, diagnosis of RLD is often characterized by poor specificity. In the elderly, worsening in the quality of life and poor prognosis are variably, but significantly, associated to RLD, being the underlying condition an important source of variability. Several causes of RLD are preventable and treatable conditions. A prompt identification of these conditions may allow to slow the decline of respiratory reserve and, thus, to preserve both personal independence and resistance to acute respiratory infections. This review gives an update on the latest evidence available on the prevalence and the prognosis of RLD in the elderly. Studies were identified through systematic searches of the electronic database MEDLINE. Reference list of eligible papers were also manually searched.     

Shorter corridors can be used for the six-minute walk test in subjects with chronic lung diseases

BackgroundThe main limitation of the six-minute walk test (6-MWT) is that not all pulmonary function testing facilities have an indoor flat, 30-m-long corridor. Therefore, this study aimed 1) to evaluate the correlation and agreement of the distances walked in 30-m- vs. 15-m-long corridors by subjects with chronic lung diseases (CLD group) and 2) to compare the levels of oxygen saturation (nSpO₂), blood pressure (BP), heart rate recovery at minute one post-exercise (HRR1), and Borg scale scores for dyspnea and fatigue between the two distances walked.MethodsA prospective, cross-sectional study was conducted at the National Institute of Respiratory Diseases in Mexico City. Subjects with chronic lung diseases and healthy adults were invited to participate. The distance of the 6-MWT was randomly assigned based on whether the first test was in the 15-m or 30-m corridor.ResultsNinety individuals were included; the correlation in meters walked between the two corridors was r = 0.96 in CLD; the 95% limits of agreement for the 6-MWT ranged from −73 to +37 m. Most subjects walked further in the 30-m corridor (82%); however, the percent predicted values for the CLD group were 3.5% lower for the 15-m corridor than the 30-m corridor. Only 10.5% of the subjects with CLD would have been falsely classified as having a normal 6-MWT (false negative). No significant differences in the nSpO2, Borg scale, BP or HRR1 were found between the two 6-MWT corridor lengths.ConclusionThe 6-MWT can be performed using a 15-m corridor in subjects with CLD, and the results for the distance walked, HRR1, nSpO₂, and Borg scale scores are similar to between the 15-m and 30-m corridors.     

Small airway disease and its predictors in patients with rheumatoid arthritis

BackgroundRheumatoid arthritis (RA) is a connective tissue disease, characterized by symmetric peripheral polyarthritis. Extra-articular disease occurs in approximately 50% of the patients with lung being a common site. The presence of functional or morphological abnormalities in small airways has recently been noted in patients with RA but its exact prevalence and clinical significance is still a subject of debate. This study was aimed to determine the prevalence of small airway disease (SAD) in patients with RA and the factors influencing it.MethodsFifty consecutive patients with RA were included in this cross-sectional observational study. All patients were subjected to pulmonary function tests (PFT) including Spirometry and Forced Oscillation technique (FOT). Those with features of SAD on PFT were subjected to High-Resolution Computed Tomography (HRCT) of the chest.ResultsSpirometry was suggestive of SAD in 17 patients, with 34% prevalence and FOT was abnormal in 9 patients, with 18% prevalence in the study population. Of 17 patients with SAD on spirometry, 8 (47.05%) patients showed mosaic attenuation, a sign of SAD on the HRCT chest. On univariate analysis, age, Disease Activity Score (DAS-28), joint erosions on X-ray, RF and anti-CCP were found to be associated with SAD.ConclusionSAD was present in one-third of the patients with RA, even in those with short duration of disease, low to moderate disease activity and no respiratory symptoms. It is thus inferred that the complete workup of RA patients should include pulmonary function assessment.     

Spirometric criteria for airway obstruction: Use percentage of FEV1/FVC ratio below the fifth percentile, not < 70%

BACKGROUND: Current authoritative spirometry guidelines use conflicting percentage of FEV1/FVC ratios (FEV1/FVC%) to define airway obstruction. The American Thoracic Society/European Respiratory Society Task Force characterizes obstruction as a FEV1/FVC% below the statistically defined fifth percentile of normal. However, many recent publications continue to use the Global Initiative for Chronic Obstructive Lung Disease (GOLD) primary criterion that defines obstruction as a FEV1/FVC% < 70%. Data from the Third National Health and Nutrition Examination Survey (NHANES-III) should identify and quantify differences, help resolve this conflict, and reduce inappropriate medical and public health decisions resulting from misidentification. METHODS: Using these two guidelines, individual values of FEV1/FVC% were compared by decades in 5,906 healthy never-smoking adults and 3,497 current-smokers of black (African American), Hispanic (Latin), or white ethnicities aged 20.0 to 79.9 years. RESULTS: In the never-smoking population, the lower limits of normal used in other reference equations fit reasonably well the NHANES-III statistically defined fifth percentile guidelines. But nearly one half of young adults with FEV1/FVC% below the NHANES-III fifth percentile of normal were misidentified as normal because their FEV1/FVC% was > 70% (abnormals misidentified as normal). Approximately one fifth of older adults with observed FEV1/FVC% above the NHANES-III fifth percentile had FEV1/FVC% ratios < 70% (normals misidentified as abnormal). CONCLUSIONS: The GOLD guidelines misidentify nearly one half of abnormal younger adults as normal and misidentify approximately one fifth of normal older adults as abnormal.