Predisposing factors associated with atypical femur fracture among postmenopausal Korean women receiving bisphosphonate therapy: 8 years' experience in a single center.

The risk factors for atypical femur fracture in patients exposed to bisphosphonates for at least 1 year were examined. Prolonged and continuous use of bisphosphonates, long-term use of glucocorticoids, and a higher body mass index were associated with increased risk of atypical femur fracture. INTRODUCTION: The purpose of the present study is to determine whether rheumatoid arthritis (RA) and other clinical factors are associated with an increased risk of bisphosphonate (BP)-related atypical femur fracture (AFF). METHODS: A retrospective nested case-control study of patients who had taken BPs for at least 1 year was conducted. Patients with AFF were identified by reviewing surgical and radiographic records. Three controls with no history of AFFs were randomly selected and age- and sex-matched to each patient with AFFs. Cox proportional hazard models were used to analyze the independent contribution of risk factors to BP-related AFF. RESULTS: Among the 35,104 patients prescribed BPs for at least 1 year, 43 females (mean age, 68 years) suffered AFFs (0.12%). Patients with AFFs were exposed to BPs for a mean of 7.3 years. Patients with AFFs were exposed to BPs for longer than those without AFFs and continued treatment without a drug holiday. More patients with AFF than controls had taken glucocorticoids and disease-modifying anti-rheumatic drugs. Multivariate Cox regression analyses estimated that long-term use of glucocorticoids, prolonged exposure to BP without cessation, and every 1 kg/m2 increase in the body mass index (BMI) increased the hazard ratio for AFFs by 3.0, 5.2, and 1.2, respectively. CONCLUSIONS: Prolonged and continuous use of BPs, long-term use of glucocorticoids, and a higher BMI increase the risk of AFFs. Switching long-term BP and glucocorticoid users to other bone-protective agents should be considered.

Bone mineral density among Korean females aged 20-50 years: influence of age at menarche (The Korea National Health and Nutrition Examination Survey 2008-2011).

To evaluate a possible correlation between bone mineral density (BMD) and age at menarche, the present study used the BMD dataset of the Korea National Health and Nutrition Examination Survey IV-V (KNHANES IV-V). Age at menarche had a small but significant association with BMD of the lumbar spine in premenopausal Korean females, aged 20-50 years. INTRODUCTION: To investigate any correlation between bone mineral density (BMD) and age at menarche in Korean females using data from the fourth and fifth Korea National Health and Nutrition Examination Survey (KNHANES IV-V; 2008-2011). METHODS: In total, 37,753 individuals participated in health examination surveys between 2008 and 2011. A total of 5032 premenopausal females aged 20-50 years were eligible. Age, height, weight, and age at menarche were assessed. RESULTS: Results from the univariate linear regression and analysis of covariance (ANCOVA) indicated that age (per 1 year), height (per 1 cm), weight (per 1 kg), exercise (per 1 day/week), familial osteoporosis history (yes), parity (n = 0 to ≥4), and menarche age distribution were associated with BMD of the total femur, femur neck, and lumbar spine. After stratifying the bone area and adjusting for age, parity, alcohol intake, smoking, exercise, and familial osteoporosis history, no effect was seen for the total femur or femur neck. Age at menarche 16~17 and ≥18 years groups were associated with BMD of the lumbar spine only. CONCLUSIONS: Age at menarche had a small but significant association with BMD of the lumbar spine in premenopausal Korean females, aged 20-50 years. Females with late menarche may achieve lower peak bone mass at some skeletal sites, which may put them at greater risk for osteoporosis in later life.

Occupational exposure and idiopathic pulmonary fibrosis: a multicentre case-control study in Korea.

SETTING: Multicentred hospital-based cases and control subjects in Korea. OBJECTIVE: To evaluate the association between idiopathic pulmonary fibrosis (IPF) and hazardous materials to which people are occupationally exposed. DESIGN: A multicentre, hospital-based, matched case-control study was performed. The ratio of IPF cases to controls was 1:1 (n = 78 in each group). IPF cases and controls were matched in terms of age group, sex and place of residence. Conditional logistic regression analysis was performed. RESULTS: In simple logistic regression analysis, exposure to metal dust and any exposure for >1 year in an occupational setting were significantly associated with IPF (metal dust OR 4.00, 95%CI 1.34-11.97; any exposure OR 3.67, 95%CI 1.02-13.14). After adjustment for environmental and military exposures and smoking history, the OR for metal dust exposure was 4.97 (95%CI 1.36-18.17) in multiple logistic regression analysis. CONCLUSIONS: Metal dust was associated with incident IPF in Seoul and Gyeonggi Provinces in Korea. This information will be used to support a tailored preventive strategy in specific industries or occupations.

Health care burden and medical resource utilisation of idiopathic pulmonary fibrosis in Korea.

SETTING: Despite the clinical importance of idiopathic pulmonary fibrosis (IPF), its epidemiology has been rarely reported. The economic burden from IPF is therefore difficult to predict. OBJECTIVE: To analyse the health care burden and current situation with respect to medical resource utilisation in patients with IPF in Korea. METHODS: We analysed nationwide data collected between 2009 and 2013 from the Korean Health Insurance Review and Assessment (HIRA) database. Patients with IPF were defined by the K-J84.18 code of the Korean Classification of Disease, 6th revision. RESULTS: The total direct health care costs increased from US$19 805 167 in 2009 to US$31 410 083 in 2013; the principal factor responsible for the highest proportion of costs was hospitalisation. The proportion of the total IPF patient population who were hospitalised at least once a year was 27.2%, and the average length of hospital stay was 12.7 days. From post-hoc analysis, hospital admission, emergency room visit and intensive care unit admission rates showed significant seasonal variations; the admission rates were highest in the spring and lowest in autumn. CONCLUSIONS: Health care costs of IPF are increasing annually, with hospital admissions representing the major financial burden.

Incidence and prevalence of idiopathic interstitial pneumonia and idiopathic pulmonary fibrosis in Korea.

SETTING: Although the incidence and prevalence of idiopathic interstitial pneumonia (IIP) and idiopathic pulmonary fibrosis (IPF) have been assessed in Western countries, their epidemiology has not been analysed in Asian countries, including the Republic of Korea. OBJECTIVE: To estimate the prevalence and incidence of IIP, including IPF, in Korea, using a large, nationwide database. DESIGN: The Health Insurance Review and Assessment Services claims database, which includes information on every patient with diagnostic codes for IPF and IIP from 2010 to 2013, was reviewed. Age- and sex-specific IPF and IIP prevalence and incidence rates were estimated. RESULTS: Among Korean males and females, IPF prevalence from 2010 to 2013 was estimated at respectively 39.7 and 24.3 per 100 000 population, while IIP prevalence was estimated at respectively 97.1 and 66.5/100 000. The annual incidence rates among Korean males and females during 2011 and 2012 were respectively 16.4 and 9.7/100 000, for IPF, and respectively 42.3 and 27.5/100 000 for IIP. CONCLUSIONS: IPF is more prevalent in Korea than previously reported; its prevalence may be similar to or higher than in the United States and in European countries.

Risk factors for lung function impairment among the general non-smoking Korean population.

SETTING: Nationwide general population in South Korea. OBJECTIVE: Except for tobacco smoking, risk factors for the impairment of lung function have not been widely evaluated. We evaluated the risk factors for lung function impairment among the general non-smoking Korean population. DESIGN: A total of 8164 non-smokers from the spirometry data set of the Korean National Health and Nutrition Examination Surveys IV and V (2008-2010) were included in the study. After sex stratification, multiple survey logistic regression analyses were performed to estimate the association between potential risk factors and impaired lung function in this nationwide cross-sectional study. RESULTS: The proportion of non-smokers among the general Korean population with forced expiratory volume in 1 s (FEV1) < 80% of predicted, forced vital capacity (FVC) < 80% of predicted and FEV1/FVC ratio < 0.7 were respectively 46.2%, 50.3% and 30.2%. In multiple survey logistic regression analyses, lung function impairment was associated with tuberculosis (TB) and asthma in female non-smokers and asthma in male non-smokers. CONCLUSIONS: TB and asthma are risk factors for lung function impairment among Korean non-smokers. To prevent further lung function impairment, a careful control system for these factors should be considered when setting health policy priorities.

Dose-related effect of urinary cotinine levels on pulmonary function among Korean women.

SETTING: Country-wide general population in South Korea. BACKGROUND: The dose-response relationship between smoking and pulmonary function in women may have been significantly over-estimated by studies that employed a self-reporting questionnaire. OBJECTIVE: To evaluate whether this relationship was still observed among Korean women when smoking levels were determined by urinary cotinine measurements. DESIGN: A total of 4584 Korean women from the spirometry data set of the Korean National Health and Nutrition Examination Surveys IV and V (2008-2010) were included. Analysis of covariance was performed to estimate the dose-related effect of urinary cotinine levels on pulmonary function after adjusting for covariates in this country-wide cross-sectional study. RESULTS: Compared to urinary cotinine levels (cut-off 50 ng/ml), the false-positive rate of self-reported smoking was 53.2%. After the smokers were divided into deciles, the regression coefficients for percentage forced expiratory volume in 1 second (FEV1%) and percentage forced expiratory volume/forced volume capacity (FEV1/FVC) ratio (FEV1/FVC%) were -0.2903 and -0.2680 (%/decile), respectively (both P < 0.001). CONCLUSION: It is necessary to use objective methods when determining the smoking status of Korean women. Even after reducing information bias, smoking affected pulmonary function in a dose-dependent manner.

Dose-related effect of urinary cotinine levels on bone mineral density among Korean females.

UNLABELLED: To evaluate the dose-dependent relationship between smoking and bone mineral density (BMD), the present study used the BMD dataset of the Korean National Health and Nutrition Examination Survey IV (KNHANES IV). The linearity of BMD for urinary cotinine levels was demonstrated with statistical significance in postmenopausal females. INTRODUCTION: It is well established that smoking is an important lifestyle risk factor for bone health (bone loss, osteoporosis, and fracture). However, several studies demonstrated conflicting evidence for a dose-dependent relationship between smoking and bone health. To evaluate the dose-dependent relationship between smoking and BMD, the present study estimated dose-related effects of smoking (urinary cotinine level) on BMD at various sites (femur neck, total femur, and lumbar spine) in females with controlling menopausal status. METHODS: The present study used the BMD dataset of the KNHANES IV, which was performed in 2008 and 2009. A total of 4,260 pre- and postmenopausal females were included in the present study. Dose-response relationships between BMD and urinary cotinine levels were estimated using analysis of covariance in pre-menopausal females and postmenopausal females, respectively. RESULTS: In postmenopausal females, the regression coefficients for BMD with urinary cotinine levels were -0.006, -0.006, and -0.008 (g/cm2 per ng/ml) at femur neck, total femur, and lumbar spine, respectively (p value<0.05). Thus, the linearity of BMD for urinary cotinine levels was demonstrated with statistical significance in postmenopausal females. CONCLUSION: Our findings suggested a significant dose-related effect of urinary cotinine level with BMD at femur neck, total femur, and lumbar spine among postmenopausal females.