Changes in the mean incidence and variance of orthopedic diseases before and during the COVID-19 pandemic in Korea: a retrospective study.

BACKGROUND: During the coronavirus disease (COVID-19) pandemic, the amount of moderate- to high-intensity physical activity significantly decreased. Therefore, the epidemiology of musculoskeletal diseases could possibly have changed. We assessed changes in the incidence of and variance in non-traumatic orthopedic diseases before and after the COVID-19 pandemic in Korea. METHODS: This study included data from the Korea National Health Insurance Service, which covers the entire Korean population (approximately 50 million), from January 2018 to June 2021. Using International Classification of Diseases, Tenth Revision codes, 12 common orthopedic diseases were evaluated, including cervical disc disorders, lumbar disc disorders, forward head posture, myofascial pain syndrome, carpal tunnel syndrome, tennis elbow, frozen shoulder, rheumatoid arthritis, gout, hip fracture, distal radius fracture, and spine fracture diseases. "Pre-COVID-19" was the period until February 2020, and "COVID-19 pandemic period" was the period starting March 2020. Differences in the mean incidence and variance of diseases before and during the COVID-19 pandemic were compared. RESULTS: In most cases, the incidence of orthopedic diseases decreased at the beginning of the pandemic and then increased thereafter. Among the 12 diseases, the incidence of three diseases showed a statistically significant change. The incidence of myofascial pain syndrome (P < 0.001) was lower during the COVID-19 pandemic than during the pre-COVID-19 period. The incidences of frozen shoulder (P < 0.001) and gout (P = 0.043) were higher during the COVID-19 pandemic than during the pre-COVID-19 period. However, no statistical difference in disease variations was observed between the two periods. CONCLUSIONS: The incidence of orthopedic diseases varied during the COVID-19 pandemic among the Korean population. Although the incidence of myofascial pain syndrome was lower, that of frozen shoulder and gout was higher during the COVID-19 pandemic than during the pre-COVID-19 period. No disease variations during the COVID-19 pandemic were found.

A higher probability of subsequent stroke and ischemic heart disease in migraine patients: a longitudinal follow-up study in Korea.

BACKGROUND: Whether migraine is related to the risk of cardiovascular diseases (CVDs) remains unclear. Therefore, we conducted a longitudinal follow-up study to address the association between migraine and the development of CVDs in Korea. METHODS: Using data from the national health screening cohort, we included 45,246 patients diagnosed with migraine between 2002 and 2019 and age-, sex-, income-, and residential region-matched nonmigraine participants at a ratio of 1:4. Participants with previous CVDs were excluded. Cox proportional hazards regression models were used to estimate the hazard ratios of three CVDs, stroke, ischemic heart disease, and heart failure, in patients with migraine after adjusting for potential cardiovascular risk factors. RESULTS: The incidence rate differences of stroke, ischemic heart disease, and heart failure among patients with migraine were 2.61, 1.69, and 0.11, respectively. The probability of developing stroke and ischemic heart disease in patients with migraine was significantly higher than that in controls after controlling for multiple confounders (adjusted hazard ratio [HR] = 1.35, 95% confidence interval [CI] = 1.31-1.39 and adjusted HR = 1.31, 95% CI = 1.26-1.35, respectively). However, when compared with the patients without migraine, patients with migraine did not have an increased HR of developing heart failure (adjusted HR = 1.01, 95% CI = 0.95-1.08). The overall migraine group, as well as groups stratified by migraine subtypes with and without aura, each showed a significantly higher probability of subsequent stroke and ischemic heart disease than the control group. CONCLUSIONS: Our longitudinal follow-up study demonstrated a significant association between the presence of migraine and the development of stroke and ischemic heart disease in Korea, even after adjusting for cardiovascular risk factors.

Depressive Symptoms, Subjective Cognitive Decline, and Subjective Sleep Quality Are Associated with Slips and Falls: Data from the Community Health Survey in Korean Adults.

BACKGROUND: Identifying the risk factors for falls among the elderly population is arguably one of the most imperative public health issues in the current aging society. OBJECTIVES: This study aimed to determine the associations between depressive symptoms, subjective cognitive decline (SCD), and poor subjective sleep quality and the risk of slips/falls in a Korean older population. METHODS: This cross-sectional study involved 228,340 elderly individuals living in Korea. Measurements included self-reported depressive symptoms, SCD, and self-reported sleep quality. The risk of slips/falls was dichotomized depending on whether slips/falls had occurred during the past year, and the associations between different risk factors and slips/falls were explored. Multiple logistic regression was used to obtain the odds ratios (ORs) and 95% confidence intervals (CIs). Complex sampling methods were used to estimate the weighted value of each participant. RESULTS: The risk of slips/falls was significantly associated with high levels of depressive symptoms (adjusted OR 1.06, 95% CI: 1.05-1.07) and SCD (adjusted OR 1.33, 95% CI: 1.19-1.50). Regarding each sleep quality component, the adjusted ORs for slips/falls were 1.85 for very poor sleep quality, 1.49 for long sleep latency, 1.04 for <5 h of sleep duration, 1.32 for low sleep efficiency, 2.78 for high sleep disturbance, 1.52 for the use of sleep medication ≥3 times a week, and 1.82 for high daytime dysfunction due to sleep problems compared to the respective good sleep conditions. CONCLUSIONS: Our results demonstrated that depressive symptoms, SCD, and poor subjective sleep quality are independent factors affecting the occurrence of slips/falls. Thus, efforts to manage depressive symptoms and cognitive decline early and to improve sleep quality can be an alternative strategy to decrease the likelihood of falls.

Foreign Body Complications in Ears due to Mishandled Hearing Aid Fitting and Proposed Clinical Guidelines to Address the Complications.

BACKGROUND: South Korea has one of the world's fastest aging populations and is witnessing increased age-related hearing impairment cases as well as an increase in the number of hearing aid users. The aim of this study was to analyze complications caused by hearing aid mold materials. In addition, we hope to raise awareness of the harm and danger that inexperienced hearing aid providers can cause to patients. METHODS: We retrospectively reviewed the medical records of 11 patients who were diagnosed with hearing aid mold material as a foreign body in the ear at a tertiary center between 2016 and 2020. The following data were analyzed: symptoms, endoscopic findings, audiometry, temporal bone CT images, treatment methods, and complications after removal. The currently available literature was also reviewed to develop clinical guidelines, to identify the systematic weaknesses in the South Korean hearing aid market, and to identify policies that warrant better quality control. RESULTS: Among the 11 cases, 9 were restricted to the external auditory canal, all of which were successfully removed under endoscopy with minor complications. Two cases with middle ear involvement resulted in infection and thus required surgical removal with mastoidectomy. The average age of these patients was 76.4, and all patients received their molding procedure at private hearing aid shops without an otolaryngologist's examination. CONCLUSION: Thorough patient history-taking and otologic examination must be performed to identify patients at higher risk of complications. Such patients should be referred to an otolaryngologist. If a patient exhibits alarming symptoms, early referral is critical since prompt surgery can minimize complications. A CT scan is highly recommended to determine an optimal approach for foreign body removal. Systematic and regulatory changes in hearing aid dispensers, such as requiring apprenticeship, raising the required level of education, and legally mandating referrals, can help reduce these complications.

Investigation of changes in the physical activity and fall experience before and after the COVID-19 pandemic.

This study aimed to investigate the changes in physical activity levels and the rate of falls during the COVID-19 pandemic in the Korean population. The Korean Community Health Survey (KCHS) conducted in 2019 was compared with that conducted in 2020. Simple or multiple linear regression with complex sampling was conducted to calculate the estimated value (EV) of physical activity in the 2020 group vs. the 2019 group. The odds ratio (OR) of fall histories was calculated using simple or multiple logistic regression with complex sampling for the 2020 group compared to the 2019 group. The time spent on vigorous and moderate physical activity was lower in the 2020 group than in the 2019 group (EV = -10.0, 95% CI = -12.1 to -8.0, P < 0.001 for vigorous exercise and EV = -24.0, 95% CI = -26.7 to -21.4, P < 0.001 for moderate exercise). The rate of falls was lower in the 2020 group than in the 2019 group (OR = 0.66, 95% CI = 0.62 to 0.70, P < 0.001). Vigorous and moderate exercise decreased after the COVID-19 pandemic compared to before the pandemic. The occurrence of falls was lower during the COVID-19 pandemic than in the pre-pandemic period.

Association between Proton Pump Inhibitors and Hearing Impairment: A Nested Case-Control Study.

This study investigated the association of previous use of proton pump inhibitors (PPIs) with the rate of hearing impairment. The ≥40-year-old population in the Korean National Health Insurance Service-Health Screening Cohort was enrolled. The 6626 registered hearing-impaired patients were matched with 508,240 control participants for age, sex, income, region of residence, and index date (date of hearing impairment diagnosis). The prescription histories of PPIs were collected for 2 years before the index date. The odds ratios of the duration of PPI use for hearing impairment were analyzed using conditional logistic regression. Subgroups of age/sex and severity of hearing impairments were additionally analyzed for the relation of PPI use with hearing impairment. PPI use for 30-365 days was associated with a 1.65-times higher odds of hearing impairment (95% confidence interval (CI) = 1.47-1.86 for 30-365 days of PPI medication). PPI use for ≥365 days was also related to 1.52-times higher odds of hearing impairment (95% CI = 1.35-1.72, p < 0.001). All age and sex subgroups demonstrated a positive association between PPI use and hearing impairment. Severe hearing impairment showed consistently higher odds of a relation with PPI use. PPI use was associated with an increased rate of hearing impairment.

Association between asthma and cardiovascular disease.

BACKGROUND: Epidemiological studies on the association between asthma and cardiovascular disease have reported conflicting results. This cross-sectional study evaluated the association between asthma and ischaemic heart disease (IHD)/stroke in Korean adults. MATERIALS AND METHODS: Data from the Korean Genome and Epidemiology Study-Health Examinees were used. Among 173 209 participants, 3162 asthmatic and 159 408 control participants were selected. Histories of asthma, IHD and stroke were obtained. Participants were categorized according to their current status of asthma management: 'well-controlled', 'being treated', and 'not being treated'. Crude and adjusted (age, gender, body mass index, income, smoking, alcohol consumption, hypertension, diabetes, dyslipidaemia and nutritional intake) odds ratios (ORs) for IHD and stroke in asthmatic patients were analysed using a multiple logistic regression model. RESULTS: Participants with asthma reported a significantly higher prevalence of IHD (6.0% vs 3.0%) and stroke (2.3% vs 1.4%) than those without asthma (P < .001). Asthmatic participants had a higher OR (1.46, 95% confidence interval [CI] = 1.251-1.71, P < .001) for IHD than those without asthma. The association between asthma and IHD was significant only in patients aged ≥53 years (men: adjusted OR = 1.31, 95% CI = 1.01-1.70, P = .046; women: adjusted OR = 1.64, 95% CI = 1.32-2.03, P < .001) according to age and sex and in the 'not being treated' asthma group (adjusted OR = 1.47, 95% CI = 1.14-1.91, P = .003) according to the asthma management status. Stroke was not significantly associated with asthma (adjusted OR = 1.17, 95% CI = 0.92-1.48, P = .203) in the adjusted model and all subgroup analyses. CONCLUSION: Asthma was associated with IHD, mainly in older patients and untreated asthma patients, but not with stroke.

Acute Alcohol Intake Deteriorates Hearing Thresholds and Speech Perception in Noise.

OBJECTIVES: The hearing process involves complex peripheral and central auditory pathways and could be influenced by various situations or medications. To date, there is very little known about the effects of alcohol on the auditory performances. The purpose of the present study was to evaluate how acute alcohol administration affects various aspects of hearing performance in human subjects, from the auditory perceptive threshold to the speech-in-noise task, which is cognitively demanding. METHODS: A total of 43 healthy volunteers were recruited, and each of the participants received calculated amounts of alcohol according to their body weight and sex with a targeted blood alcohol content level of 0.05% using the Widmark formula. Hearing was tested in alcohol-free conditions (no alcohol intake within the previous 24 h) and acute alcohol conditions. A test battery composed of pure-tone audiometry, speech reception threshold (SRT), word recognition score (WRS), distortion product otoacoustic emission (DPOAE), gaps-in-noise (GIN) test, and Korean matrix sentence test (testing speech perception in noise) was performed in the 2 conditions. RESULTS: Acute alcohol intake elevated pure-tone hearing thresholds and SRT but did not affect WRS. Both otoacoustic emissions recorded with DPOAE and the temporal resolution measured with the GIN test were not influenced by alcohol intake. The hearing performance in a noisy environment in both easy (-2 dB signal-to-noise ratio [SNR]) and difficult (-8 dB SNR) conditions was decreased by alcohol. CONCLUSIONS: Acute alcohol elevated auditory perceptive thresholds and affected performance in complex and difficult auditory tasks rather than simple tasks.

Analyses of the association between cervical cancer and osteoporosis/osteoporotic fracture: a cross-sectional study using KoGES HEXA data.

BACKGROUND: This study aimed to evaluate the association between cervical cancer and the occurrence of osteoporosis and osteoporotic fracture using data from the Korean Genome and Epidemiology Study (KoGES). METHODS: In this national cohort study using KoGES health examination (HEXA) data, we extracted data for patients with cervical cancer (n = 493) and control participants (n = 77,571); we then analyzed the occurrence of osteoporosis and osteoporotic fracture at baseline from 2004 to 2013 and during follow-up from 2012 to 2016. A logistic regression model was used to analyze the odds ratios (ORs) and the 95% confidence intervals (CIs). RESULTS: The ORs (95% CIs) for osteoporosis and osteoporotic fracture were 1.49 (95% CI 1.15-1.92, p = 0.03) and 1.06 (95% CI 0.82-1.38, p = 0.634), respectively, in the cervical cancer group. The ORs (95% CIs) for osteoporosis were 2.12 (95% CI 1.14-3.95, p = 0.018) in the ≤ 51-year-old group and 1.43 (95% CI 1.08-1.89, p = 0.011) in the ≥ 52-year-old group of cervical cancer patients. CONCLUSION: We concluded that Korean women with cervical cancer had a higher risk of osteoporosis than healthy women, but the same finding was not observed for osteoporotic fracture.

Increased risk of herpes zoster in patients with psoriasis: A longitudinal follow-up study using a national sample cohort.

BACKGROUND/OBJECTIVE: Although previous studies reported the relationship between psoriasis and herpes zoster, the number of study is not sufficient to support the conclusions. The purpose of this study was to evaluate the association between psoriasis and herpes zoster. METHODS: The data of a nationally representative Korean cohort collected in the Korean Health Insurance Review and Assessment (HIRA) System from 2002 to 2013 were used. Psoriasis was defined ≥ 2 International Classification of Diseases 10th revision (ICD-10) L40 codes. Among them, severe psoriasis was defined as psoriatic medication use, including acitretin, systemic corticosteroid, cyclosporine and methotrexate. Other psoriasis was defined as mild psoriasis. Herpes zoster was defined as ≥ 2 ICD-10 B02 codes or ≥ 1 B02 code with antiviral medication use. Psoriasis patients (n = 11 009) and control participants (n = 44 036) were matched 1:4 by age, sex, income and region of residence. A stratified Cox proportional hazard model was used stratified by age, sex, income and region of residence. Crude and adjusted hazard ratios (HRs) were calculated for the risk of herpes zoster in the total psoriasis group, mild psoriasis group, and severe psoriasis group and compared with those in each matched control group. RESULTS: The HR for herpes zoster was higher in the psoriasis group than in control group (adjusted HR = 1.22, 95% CI = 1.12-1.33, P < 0.001). The findings were consistent between the mild psoriasis and severe psoriasis patients and their matched controls, and between male psoriasis patients in all age groups and their matched male controls. CONCLUSIONS: Psoriasis may increase the risk of herpes zoster, especially in males.

Bone Regeneration of a 3D-Printed Alloplastic and Particulate Xenogenic Graft with rhBMP-2.

This study aimed to evaluate the bone regeneration capacity of a customized alloplastic material and xenograft with recombinant human bone morphogenetic protein-2 (rhBMP-2). We prepared hydroxyapatite (HA)/tricalcium phosphate (TCP) pure ceramic bone blocks made using a 3D printing system and added rhBMP-2 to both materials. In eight beagle dogs, a total of 32 defects were created on the lower jaws. The defective sites of the negative control group were left untreated (N group; 8 defects), and those in the positive control group were filled with particle-type Bio-Oss (P group; 12 defects). The defect sites in the experimental group were filled with 3D-printed synthetic bone blocks (3D group; 12 defects). Radiographic and histological evaluations were performed after healing periods of 6 and 12 weeks and showed no significant difference in new bone formation and total bone between the P and 3D groups. The 3D-printed custom HA/TCP graft with rhBMP-2 showed bone regeneration effects similar to that of particulate Bio-Oss with rhBMP-2. Through further study and development, the application of 3D-printed customized alloplastic grafts will be extended to various fields of bone regeneration.

Analysis of the relationship between periodontitis and osteoporosis/fractures: a cross-sectional study.

BACKGROUND: Chronic periodontitis is a multifactorial inflammatory disease resulting in patients exhibiting high levels of inflammatory factors causing systemic inflammatory bone destruction that may lead to osteoporosis development. The association between periodontitis and osteoporosis has been documented; however, the findings remain unclear. This study aimed to identify the association between periodontitis and osteoporosis using a cross-sectional study design and Korean Genome and Epidemiology Study (KoGES) health examinee data. METHODS: This cross-sectional study used epidemiological data from the KoGES during 2004-2016. Of 125,324 participants (age, 40-79 years), 9969 with periodontitis and 115,332 controls (without periodontitis) were selected. We analyzed the history of osteoporosis and fractures of all participants. All participants were examined according to age, sex, income group, obesity, smoking habits, alcohol consumption, and food intake. To analyze the odds ratio (OR) of periodontitis for those with osteoporosis and fractures, a logistic regression model was used. RESULTS: The adjusted odds ratio (aOR) of periodontitis for osteoporosis was 2.16 (95% confidence interval [CI], 2.01-2.31; P < 0.001). The aOR of periodontitis for any fracture was 1.54 (95% CI 1.46-1.62; P < 0.001). CONCLUSION: Osteoporosis and fractures are associated with periodontitis. Performing regular oral hygiene and examinations of bone mineral density are recommended to prevent aggravation of osteoporosis and periodontitis.

Evaluation of Mortality and Morbidity According to Initial Symptoms in COVID-19 Patients Using Clinical Epidemiologic Data from the Korea Centers for Disease Control & Prevention.

Background and Objectives: This study aimed to investigate whether initial symptoms of COVID-19 are associated with mortality and morbidity. Materials and Methods: The data of 5628 laboratory-confirmed COVID-19 patients were collected by the Korea Centers for Disease Control and Prevention. The maximum level of morbidity during hospital admission was classified as mild or severe, and patient mortality was recorded. Clinical symptoms were categorized as respiratory, gastrointestinal, general, and neurologic symptoms. The hazard ratios (HRs) for clinical symptoms associated with mortality were analyzed using the Cox proportional hazards model. The odds ratios (ORs) for clinical symptoms associated with morbidity were analyzed using the logistic regression model. Results: Of the included COVID-19 patients, 15.4% (808/5253) were classified as having severe morbidity. Morbidity was related to the clinical symptoms of cough, sputum, shortness of breath, vomiting/nausea, diarrhea, fever, and altered mental status or confusion. According to the symptom categories, respiratory and general symptoms were related to high morbidity (OR = 1.41, 95% CI = 1.30-1.53, p < 0.001 for respiratory symptom and OR = 1.37, 95% CI = 1.18-1.59, p < 0.001 for general symptom). Mortality was associated with the clinical symptoms of shortness of breath, fever, and altered mental status or confusion. Among the symptom categories, respiratory symptoms were associated with a 1.17-fold increased HR for mortality (95% CI = 1.04-1.32, p = 0.008). Conclusions: Initial respiratory symptoms were related to high morbidity and mortality in COVID-19 patients.

Hepatitis virus B and C infections are associated with an increased risk of non-Hodgkin lymphoma: A nested case-control study using a national sample cohort.

BACKGROUND: Hepatitis B virus (HBV) and hepatitis C virus (HCV) are suspected of being associated with non-Hodgkin lymphoma (NHL); however, persuasive data are lacking. Hence, a nested large-population case-control study was performed to investigate such associations in Koreans. METHODS: Data were collected from 929 patients with NHL and 3716 healthy subjects, who were matched 1:4 for age, sex, income, and region of residence, from the Korean Health Insurance Review and Assessment Service-National Sample Cohort. The diagnoses of NHL and HBV/HCV infection were based on the International Classification of Diseases (version 10) codes. Conditional logistic regression models were used to assess odds ratios (ORs) for NHL with respect to HBV or HCV with adjustment for the Charlson comorbidity index. RESULTS: HBV and HCV rates were higher in the NHL group (3.3% and 1.3%, respectively) than in the control group (0.9% and 0.3%, respectively; P < .001 for each). The adjusted OR of hepatitis infection in patients with NHL were 3.25 (95% confidence interval [CI] = 1.99-5.31) for HBV and 3.36 (95% CI = 1.51-7.46) for HCV (P < .001 for each). Subgroups categorized by age (<55 vs ≥55 years) or sex showed significantly higher adjusted ORs of HBV for NHL. Moreover, patients with NHL ≥ 55 years of age or those who were female showed significantly higher adjusted ORs of HCV; those <55 years or who were male also tended to have higher ORs of HCV. CONCLUSION: Infection with either HBV or HCV is associated with NHL in Koreans.

Association between depression and rheumatoid arthritis: two longitudinal follow-up studies using a national sample cohort.

OBJECTIVE: To investigate the bidirectional relation between RA and depression. METHODS: Data from the Korean Health Insurance Review and Assessment Service - National Sample Cohort from 2002 to 2013 were analysed. Patients ≥20 years of age were included. Study I was conducted with 38 087 depression patients and 152 348 matched control participants. Study II was conducted with 7385 RA patients and 29 540 matched control participants. Stratified Cox proportional hazards models were used to analyse the hazard ratios (HRs) for depression and RA (study I) and for RA and depression (study II). The data were adjusted by the Charlson comorbidity index; rheumatic disease was excluded. Subgroups were also analysed according to age and sex. RESULTS: A total of 0.7% (1260/38 087) of the depression group and 0.6% (883/152 348) of the control I group had RA (P = 0.02). The HR for RA in the depression group was not significantly higher than that in control I group. In study II, 5.5% (408/7385) of the RA group and 4.3% (1246/29 540) of the control II group presented with depression (P < 0.001). The RA patients showed an adjusted depression HR that was 1.20 times higher (95% CI 1.07, 1.34; P = 0.002) than that of the control group. The >30-years-old and women subgroups of RA patients showed higher depression HRs than the control subgroups. CONCLUSION: RA increased the risk of depression; however, depression did not increase the risk of RA in the Korean adult population.

Bidirectional association between GERD and asthma in children: two longitudinal follow-up studies using a national sample cohort.

BACKGROUND: The causal relationship between asthma and gastroesophageal reflux disease (GERD) is unknown in children. METHODS: The Korean Health Insurance Review and Assessment Service-National Sample Cohort 2002-2013 was used. The population age <15 years was selected. In study I, 86,096 asthmatic children were 1:1 matched with 86,096 control I participants. In study II, 532 GERD children were 1:2 matched with 1064 control II participants. The stratified Cox proportional hazard ratios for GERD in patients with asthma (study I) and asthma in patients with GERD (study II) were analyzed. RESULTS: In total, 0.7% (583/86,096) of the asthma group and 0.5% (430/86,096) of the control I group had GERD (P < 0.001). The asthma group demonstrated a 1.36 times higher HR for GERD than the control I group (95% CI = 1.20-1.54, P < 0.001). Subgroup analyses according to age and sex showed consistent results. In total, 15.0% (80/532) of the GERD group and 10.0% (106/1,064) of the control II group had asthma (P < 0.001). The GERD group showed a 1.62-fold higher HR for asthma than the control II group (95% CI = 1.21-2.18, P < 0.001). CONCLUSION: GERD and asthma demonstrated a bidirectional relationship in children.

The association between sialolithiasis and smoking, alcohol drinking and obesity in Korea: a nested case-control study.

BACKGROUND: Smoking and alcohol consumption are the most common social habits in patients with sialolithiasis. Moreover, obesity has been reported to have a significant association with poor oral hygiene, one of the causes of sialolithiasis. The purpose of this study was to evaluate the relationships among tobacco smoking, drinking alcohol, obesity and sialolithiasis in a Korean population. METHODS: The Korean National Health Insurance Service-Health Screening Cohort, which includes patients ≥40 years old, was assessed from 2002 to 2013. A total of 947 sialolithiasis participants were matched with 3788 control subjects at a ratio of 1:4 with respect to age group, sex, income group, region of residence, hypertension, diabetes, and dyslipidemia. We analyzed the participants' previous histories of smoking (current or past smokers compared to nonsmokers) and alcohol consumption (≥ 1 time per week compared to < 1 time per week) in the sialolithiasis and control groups. Obesity was measured using body mass index (BMI, kg/m2), which was categorized as < 18.5 (underweight), ≥ 18.5 and < 23 (normal), ≥ 23 and < 25 (overweight), ≥ 25 and < 30 (obese I), and ≥ 30 (obese II). Crude and adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using conditional logistic regression analyses. RESULTS: The rate of smoking was higher in the sialolithiasis group (32.4% [307/947]) than in the control group (29.1% [1103/3788], P = 0.047). The adjusted OR of smoking for the sialolithiasis group was 1.31 (95% CI = 1.08-1.59, P = 0.006). Alcohol consumption and obesity were not statistically significantly related to sialolithiasis. CONCLUSION: The odds of smoking were increased in sialolithiasis patients compared with control subjects in the population ≥ 40 years of age.

Mortality and cause of death in physical activity and insufficient physical activity participants: a longitudinal follow-up study using a national health screening cohort.

BACKGROUND: Few studies have examined the association between physical activity (PA) and various causes of mortality in Korea. The aim of our study was to evaluate mortality and causes of death between PA and insufficient PA using Korean national cohort data. METHODS: The health screening cohort data from the Korean National Health Insurance Service-National Sample Cohort from 2009 to 2015 were used. 'PA' was determined if participants walked or performed moderate-intensity activity ≥5 d/week for ≥30 min, or vigorous-intensity activity ≥3 d/week for ≥20 min. Other participants were classified as 'insufficient PA'. The PA and insufficient PA groups were matched by age, sex, income, and region of residence in a 1:1 ratio. Causes of death were classified into 13 categories. Crude and adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) for all mortality rates were analyzed using a stratified Cox proportional hazard model. Age, sex, income, and region of residence were stratified. Subgroup analyses were performed according to age, sex, and obesity status. The odds ratio according to the causes of death was calculated by the chi-square test. RESULTS: The adjusted HR for mortality in the PA group was 0.85 (95% CI = 0.82-0.88). In subgroup analyses according to age, sex, and obesity status, results were consistent with the main findings in < 60-year-old females, ≥ 60-year-old males and females, and in all subgroups by obesity. The death rate by neoplasm, mental diseases, neurologic disease, circulatory disease, respiratory disease, digestive disease, abnormal finding, and trauma were lower in the PA than the insufficient PA group. CONCLUSIONS: These results suggest that PA is inversely associated with mortality caused specifically by diseases reflected by mental, respiratory, cancer, and cardiovascular conditions. Additionally, PA is inversely associated with mortality compared to insufficient PA in all obesity status.

Herpes zoster does not increase the risk of sudden sensory neural hearing loss: a longitudinal follow-up study using a national sample cohort.

Objective: This study aimed to investigate the risk of sudden sensorineural hearing loss (SSNHL) in Herpes zoster patients from a representative population cohort.Design: A longitudinal follow-up studyStudy sample: Data were obtained from the Korean National Health Insurance Service-National Sample Cohort for the period from 2002 to 2013. We matched 61,702 subjects in the Herpes zoster group with subjects in a control group (246,808 subjects with no history of Herpes zoster) based on demographic factors (age, sex, income, and region of residence) and medical history (diabetes, dyslipidemia, and hypertension). The crude (simple) and adjusted hazard ratios (HRs) for Herpes zoster with SSNHL were analysed using the Cox-proportional hazard model.Results: Only 0.5% (338/61,364) of the Herpes zoster group and 0.7% (1664/245,144) of the control group showed SSNHL. The Herpes zoster group did not exhibit a higher rate of SSNHL (adjusted HR = 0.81, 95% CI = 0.72-0.91, p < 0.001) than the control group. In subgroup analyses, no age subgroups showed a significant risk of SSNHL in the Herpes zoster group.Conclusions: After adjusting for confounding factors, the risk of SSNHL did not increase in the Herpes zoster group compared with the control group.

Bone Regeneration Capability of 3D Printed Ceramic Scaffolds.

In this study, we evaluated the bone regenerative capability of a customizable hydroxyapatite (HA) and tricalcium phosphate (TCP) scaffold using a digital light processing (DLP)-type 3D printing system. Twelve healthy adult male beagle dogs were the study subjects. A total of 48 defects were created, with two defects on each side of the mandible in all the dogs. The defect sites in the negative control group (sixteen defects) were left untreated (the NS group), whereas those in the positive control group (sixteen defects) were filled with a particle-type substitute (the PS group). The defect sites in the experimental groups (sixteen defects) were filled with a 3D printed substitute (the 3DS group). Six dogs each were exterminated after healing periods of 4 and 8 weeks. Radiological and histomorphometrical evaluations were then performed. None of the groups showed any specific problems. In radiological evaluation, there was a significant difference in the amount of new bone formation after 4 weeks (p < 0.05) between the PS and 3DS groups. For both of the evaluations, the difference in the total amount of bone after 8 weeks was statistically significant (p < 0.05). There was no statistically significant difference in new bone between the PS and 3DS groups in both evaluations after 8 weeks (p > 0.05). The proposed HA/TCP scaffold without polymers, obtained using the DLP-type 3D printing system, can be applied for bone regeneration. The 3D printing of a HA/TCP scaffold without polymers can be used for fabricating customized bone grafting substitutes.