Association of knee pain and different definitions of knee osteoarthritis with health-related quality of life: a population-based cohort study in southern Sweden.

BACKGROUND: While the impact of knee pain and knee osteoarthritis (OA) on health-related quality of life (HRQoL) has been investigated in the literature, there is a lack of knowledge on the impact of different definitions of OA on HRQoL. The main aim of this study was to measure and compare the impact of knee OA and its different definitions on HRQoL in the general population. METHODS: A random sample of 1300 participants from Malmö, Sweden with pain in one or both knees in the past 12 months with duration ≥4 weeks and 650 participants without were invited to clinical and radiographic knee examination. A total of 1527 individuals with a mean (SD) age 69.4 (7.2) participated and responded to both generic (EQ-5D-3L) and disease-specific (the Knee injury and Osteoarthritis Outcome Score) questionnaires. Knee pain was defined as pain during the last month during most of the days. Knee OA was defined radiographically (equivalent to Kellgren and Lawrence grade ≥2) and clinically according to the American College of Rheumatology (ACR) criteria. RESULTS: Of participants with either knee pain or knee OA or both, 7 % reported no problem for the EQ-5D-3L attributes. The corresponding proportion among references (neither knee pain nor OA) was 42 %. The participants with knee pain and OA had all HRQoL measures lower compared to those with knee pain but no OA. The ACR clinical definition of knee OA was associated with lower HRQoL than the definition based on radiographic knee OA (adjusted difference -0.08 in UK EQ-5D-3L index score). CONCLUSIONS: Applying different definitions of knee OA result in different levels of HRQoL and this is mainly explained by the knee pain experience. These differences may lead to discrepant conclusions from cost-utility analyses.

Detection of COPD Exacerbations and compliance with patient-reported daily symptom diaries using a smart phone-based information system [corrected].

BACKGROUND: Paper-based diaries and self-report of symptom worsening in COPD may lead to underdetection of exacerbations. Epidemiologically, COPD exacerbations exhibit seasonal patterns peaking at year-end. We examined whether the use of a BlackBerry-based daily symptom diary would detect 95% or more of exacerbations and enable characterization of seasonal differences among them. METHODS: Fifty participants with GOLD (Global Initiative for Chronic Obstructive Lung Disease) stage I to IV COPD began a community-based study in December 2007. Another 30 began in December 2008. Participants transmitted daily symptom diaries using a BlackBerry. Alerts were triggered when symptom changes, missed diary transmissions, or medical care for a respiratory problem occurred. Participant encounters were initiated if COPD exacerbations were suspected. Participants used their BlackBerrys to report returns to normal breathing. RESULTS: Participants transmitted 99.9% of 28,514 possible daily diaries. All 191 (2.5/participant-year) COPD exacerbations meeting Anthonisen criteria were detected. During 148 of the 191 exacerbations (78%, 1.97/participant-year), patients were hospitalized and/or ordered prednisone, an antibiotic, or both. Respiratory viruses were detected in 78 of the 191 exacerbations (41%). Those coinciding with a respiratory viral infection averaged 12.0 days, and those without averaged 8.9 days (P < .04), with no difference in Anthonisen score. Respiratory symptom scores before exacerbations and after normal breathing return showed no differences. Exacerbations were more frequent during the Christmas period than the rest of the year but were not more frequent than in the rest of winter alone. CONCLUSIONS: Smartphone-based collection of COPD symptom diaries enables near-complete identification of exacerbations at inception. Exacerbation rates in the Christmas season do not reach levels that necessitate changes in disease management.

Genetic and environmental influence on lung function impairment in Swedish twins.

BACKGROUND: The understanding of the influence of smoking and sex on lung function and symptoms is important for understanding diseases such as COPD. The influence of both genes and environment on lung function, smoking behaviour and the presence of respiratory symptoms has previously been demonstrated for each of these separately. Hence, smoking can influence lung function by co-varying not only as an environmental factor, but also by shared genetic pathways. Therefore, the objective was to evaluate heritability for different aspects of lung function, and to investigate how the estimates are affected by adjustments for smoking and respiratory symptoms. METHODS: The current study is based on a selected sample of adult twins from the Swedish Twin Registry. Pairs were selected based on background data on smoking and respiratory symptoms collected by telephone interview. Lung function was measured as FEV1, VC and DLco. Pack years were quantified, and quantitative genetic analysis was performed on lung function data adjusting stepwise for sex, pack years and respiratory symptoms. RESULTS: Fully adjusted heritability for VC was 59% and did not differ by sex, with smoking and symptoms explaining only a small part of the total variance. Heritabilities for FEV1 and DLco were sex specific. Fully adjusted estimates were 10 and 15% in men and 46% and 39% in women, respectively. Adjustment for smoking and respiratory symptoms altered the estimates differently in men and women. For FEV1 and DLco, the variance explained by smoking and symptoms was larger in men. Further, smoking and symptoms explained genetic variance in women, but was primarily associated with shared environmental effects in men. CONCLUSION: Differences between men and women were found in how smoking and symptoms influence the variation in lung function. Pulmonary gas transfer variation related to the menstrual cycle has been shown before, and the findings regarding DLco in the present study indicates gender specific environmental susceptibility not shown before. As a consequence the results suggest that patients with lung diseases such as COPD could benefit from interventions that are sex specific.

Twins studies as a model for studies on the interaction between smoking and genetic factors in the development of chronic bronchitis.

Smoking is the main risk factor for COPD (chronic obstructive pulmonary disease) but genetic factors are of importance, since only a subset of smokers develops the disease. Sex differences have been suggested both in disease prevalence and response to environmental exposures. Furthermore, it has been shown that acquisition of 'addiction' to smoking is partly genetically mediated. Disease cases and smoking habits were identified in 44919 twins aged >40 years from the Swedish Twin Registry. Disease was defined as self-reported chronic bronchitis or emphysema, or recurrent cough with phlegm. The results showed that chronic bronchitis seems to be more prevalent among females, and that the heritability estimate for chronic bronchitis was a moderate 40% and only 14% of the genetic influences were shared by smoking. In addition, 392 twins have been invited to a clinical investigation to evaluate: (i) to what extent genetic factors contribute to individual differences (variation) in FEV(1) (forced expiratory volume in 1 s), vital capacity and DL(CO) (diffusion capacity), taking sex into consideration, and (ii) whether smoking behaviour and respiratory symptoms influence these estimates.

Outcome of pregnancy in a randomized controlled study of patients with asthma exposed to budesonide.

BACKGROUND: Budesonide is the only inhaled corticosteroid to be given a category B pregnancy rating by the US Food and Drug Administration, based on observational data from the Swedish Medical Birth Registry. However, data from large randomized controlled trials are lacking. OBJECTIVE: To compare pregnancy outcomes among patients with recent-onset mild-to-moderate persistent asthma receiving low-dose budesonide vs placebo. METHODS: In a randomized, double-blind, placebo-controlled trial, 7241 patients aged 5 to 66 years with mild-to-moderate persistent asthma for less than 2 years and no previous regular corticosteroid therapy received once-daily budesonide or placebo via dry powder inhaler in addition to their usual asthma medication for 3 years. This trial was followed by a 2-year open-label treatment period. The daily dose of budesonide was 400 microg for adults. The study included 2473 females aged 15 to 50 years at randomization. Pregnancy was not an exclusion criterion (except for U.S. patients). RESULTS: Of 319 pregnancies reported, 313 were analyzed. Healthy children were delivered in 81% and 77% of all pregnancies in the budesonide and placebo groups, respectively. Of the 196 pregnancies reported by participants taking budesonide, 38 (19%) had adverse outcomes: 23 (12%) had miscarriages, 3 (2%) had congenital malformations, and 12 (6%) had other outcomes. Of the 117 pregnancies reported in the placebo group, 27 (23%) had adverse outcomes: 11 (9%) had miscarriages, 4 (3%) had congenital malformations, and 12 (10%) had other outcomes. CONCLUSIONS: Treatment with low-dose inhaled budesonide in females with mild-to-moderate persistent asthma does not seem to affect the outcome of pregnancy.

Use of inhaled corticosteroids and bone mineral density in a population based study: the Nord-Trøndelag Health Study (the HUNT Study).

Conflicting results have been reported of the long-term effects of treatment with inhaled corticosteroids (ICS) on bone. The objective of this study was to compare ICS users and non-users regarding bone mineral density (BMD) in a large population. A total of 65,225 adults participated in a cross-sectional study in the Nord-Trøndelag Health Study 1995-1997. Those reporting asthma or asthma-related symptoms, were invited to have bone densitometry of the forearm, flow volume spirometry and a personal interview. Altogether 4482 women and 4142 men participated, of whom 2113 reported ever use and 6511 never use of ICS. Never-users of corticosteroids had a mean BMD, adjusted for confounders (age, square age, sex, body mass index, height, physical activity, work load, packyears, family history of osteoporosis and in women number of years since menopause and use of hormone replacement therapy), of 0.493 g/cm2 at the distal site. Subjects having only used ICS or combined with courses of prednisolone, had 0.008 g/cm2 (95%CI: 0.005-0.011) lower BMD whilst users of prednisolone > or = 6 months had 0.038 g/cm2 (0.021-0.055) lower level. No dose response association between ICS and BMD, or difference in BMD by type of ICS was found. The association between CS use and BMD was independent of the measuring site. ICS use was associated with lower BMD. The lack of dose response in this study might be due to a narrow dose range or indicates that other characteristics of the patient group are contributing to the observed difference in ICS users compared to never-users.

Normal pregnancy outcomes in a population-based study including 2,968 pregnant women exposed to budesonide.

BACKGROUND: Inhaled corticosteroids are recommended as first-line therapy for pregnant women with moderate to severe asthma, although the effects on pregnancy outcome are uncertain. A low compliance with the recommendations might lead to inadequate control of asthma, which has been associated with adverse outcomes both for the mother and the infant. OBJECTIVE: To investigate whether the reported use of inhaled budesonide (Pulmicort) during pregnancy influences birth outcome. METHODS: Data were derived from the Swedish Medical Birth Register, which includes 99% of births in Sweden. During 1995 to 1998, 293,948 newborn infants were identified. Pregnancy outcomes were compared for mothers in Sweden reporting asthma medication usage with those reporting no asthma medication usage. RESULTS: The 2,968 mothers who reported use of inhaled budesonide during early pregnancy gave birth to infants of normal gestational age, birth weight, and length, with no increased rate of stillbirths or multiple births. The rate of caesarean births was higher among mothers who used asthma medication during their pregnancy than among the control group. CONCLUSIONS: The use of inhaled budesonide in Sweden is not linked with any clinically relevant effects associated with pregnancy outcome.