Prospective study.
To identify the factors that are associated with rod slippage and to study the pattern of achieved length gain with a standard distraction methodology.
Ability to achieve ...successful magnetically controlled growing rod (MCGR) distraction is crucial for gradual spine lengthening. Rod slippage has been described as a failure of internal magnet rotation leading to a slippage and an inability to distract the rod. However, its onset, significance, and risk factors are currently unknown. In addition, how this phenomenon pertains to actual distracted lengths is also unknown.
A total of 22 patients with MCGR and at least six distraction episodes were prospectively studied. Patients with rod slippage occurring less than six distraction episodes were considered early rod slippage whereas those with more than six episodes or have yet to slip were grouped as late rod slippage. The association of parameters including body habitus, maturity status, age of implantation, total number of distractions, months of distraction from initial implantation, initial and postoperative Cobb angle, T1-T12, T1-S1, T5-T12 kyphosis, curve flexibility, instrumented length, and distance between magnets in dual rods and between the magnets and apex of the curve with early or late onset of rod slippage were studied. Differences between expected and achieved distraction lengths were assessed with reference to rod slippage episodes and rod exchanges to determine any patterns of diminishing returns.
Patients had mean age of 7.1 years at diagnosis with mean follow-up of 49.8 months. A mean 32.4 distractions were performed per patient. Early rod slippage occurred in 14 patients and late rod slippage occurred in eight patients. Increased height, weight, body mass index, older age, increased T1-12 and T1-S1 lengths, and less distance between magnets were significantly associated with early rod slippage. Expected distraction lengths did not translate to achieve distraction lengths and reduced gains were only observed after achieving one-third of the allowable distracted length in the MCGR. Length gains return to baseline after rod exchange.
This is the first study to specifically analyze the impact of rod slippage on distraction lengths and the risk factors associated with its onset and frequency. Increased body habitus and reduced distance between internal magnets significantly influenced rod slippage events. Diminishing returns in distracted length gains were only observed after a period of usage.
3.
Visit-to-visit blood pressure variability (BPV) has been shown to be a predictor of cardiovascular disease. We aimed to classify the BPV levels using different machine learning algorithms. ...Visit-to-visit blood pressure readings were extracted from the SPRINT study in the United States and eHealth cohort in Hong Kong (HK cohort). Patients were clustered into low, medium, and high BPV levels with the traditional quantile clustering and 5 machine learning algorithms including K-means. Clustering methods were assessed by Stability Index. Similarities were assessed by Davies-Bouldin Index and Silhouette Index. Cox proportional hazard regression models were fitted to compare the risk of myocardial infarction, stroke, and heart failure. A total of 8133 participants had average blood pressure measurement 14.7 times in 3.28 years in SPRINT and 1094 participants who had average blood pressure measurement 165.4 times in 1.37 years in HK cohort. Quantile clustering assigned one-third participants as high BPV level, but machine learning methods only assigned 10% to 27%. Quantile clustering is the most stable method (stability index: 0.982 in the SPRINT and 0.948 in the HK cohort) with some levels of clustering similarities (Davies-Bouldin Index: 0.752 and 0.764, respectively). K-means clustering is the most stable across the machine learning algorithms (stability index: 0.975 and 0.911, respectively) with the lowest clustering similarities (Davies-Bouldin Index: 0.653 and 0.680, respectively). One out of 7 in the population was classified with high BPV level, who showed to have higher risk of stroke and heart failure. Machine learning methods can improve BPV classification for better prediction of cardiovascular diseases.
There is a growing concern that the use of anti-hypertensives may be associated with an increased risk of cancer, but it remains uncertain for the association between anti-hypertensives and lung ...cancer risk, as well as their interaction with aspirin in chemoprotective effects.
The goal of this study is to assess the association between anti-hypertensives use and the risk of lung cancer, as well as the chemopreventive impacts from the combination usage of aspirin and anti-hypertensives. A retrospective cohort study was conducted based on all the public hospital electronic medical records in Hong Kong. Patients with prescription records of anti-hypertensives (ACEi/ARB, CCB, β-blocker,α-blocker) and/or aspirin were included as the exposure groups. Using the Cox proportional hazards model with inverse probability weighting, we estimated hazard ratios (HRs) with 95% confidence intervals (CIs) for lung cancer risk from anti-hypertensives usage or combination usage of aspirin with anti-hypertensives. The likelihood ratio test and interaction model were adopted for exploring the interaction effects with aspirin.
A total of 6592 and 84,116 lung cancer cases were identified from the groups of anti-hypertensives users and anti-hypertensives users with aspirin, respectively. The group of non-aspirin patients who received anti-hypertensives showed a significantly lower risk of lung cancer (HR: 0.63, 95% CI: 0.60-0.66), compared to those without anti-hypertensives. When aspirin and α-blocker were used simultaneously, it could lower the risk of lung cancer significantly (HR: 0.53, 95% CI: 0.34-0.84). Moreover, the lower risk of lung cancer persisted with a longer follow-up period of anti-hypertensives usage. Combination usage with aspirin in the users of ACEi/ARB, CCB, and α-blocker showed significant interaction effects. However, the smoking effect could not be eliminated in this analysis.
Anti-hypertensive treatment was associated with a lower risk of lung cancer, which is associated with the anti-hypertensives exposure period. The potential interaction on the chemopreventive influence from combination usage of α-blocker and aspirin might exist. More corroborations on these findings are needed to focus on the different settings in future studies.
The Omicron variant is rapidly becoming the dominant SARS-CoV-2 virus circulating globally. It is important to define reductions in virus neutralizing activity in the serum of convalescent or ...vaccinated individuals to understand potential loss of protection against infection by Omicron. We previously established that a 50% plaque reduction neutralization antibody titer (PRNT
) ≥25.6 in our live virus assay corresponded to the threshold for 50% protection from infection against wild-type (WT) SARS-CoV-2. Here we show markedly reduced serum antibody titers against the Omicron variant (geometric mean titer (GMT) < 10) compared to WT virus 3-5 weeks after two doses of BNT162b2 (GMT = 218.8) or CoronaVac vaccine (GMT = 32.5). A BNT162b2 booster dose elicited Omicron PRNT
titers ≥25.6 in 88% of individuals (22 of 25) who previously received 2 doses of BNT162b2 and 80% of individuals (24 of 30) who previously received CoronaVac. However, few (3%) previously infected individuals (1 of 30) or those vaccinated with three doses of CoronaVac (1 of 30) met this threshold. Our findings suggest that countries primarily using CoronaVac vaccines should consider messenger RNA vaccine boosters in response to the spread of Omicron. Studies evaluating the effectiveness of different vaccines against the Omicron variant are urgently needed.
Knowledge of the epidemiology of non-alcoholic fatty liver disease (NAFLD) is incomplete because liver biopsy cannot be performed on the general population to assess disease severity. New ...non-invasive tests allow accurate and safe assessment in healthy individuals. The aim of this study was to examine the prevalence of NAFLD and advanced fibrosis in the general Hong Kong Chinese population.
Subjects were recruited from the community by random selection from the government census database. Liver fat and fibrosis were assessed by proton-magnetic resonance spectroscopy and transient elastography, respectively.
Overall, 264 of 922 (28.6%) subjects had intrahepatic triglyceride content ≥5%. Excluding 12 subjects with significant alcohol consumption, the population prevalence of NAFLD was 27.3% (95% CI 24.5% to 30.2%). Each component of the metabolic syndrome increased the risk of fatty liver in a dose-dependent manner (prevalence of 4.5% in subjects without any component and 80.0% in those with all five components). 8 (3.7%) patients with fatty liver had liver stiffness ≥9.6 kPa, a level suggestive of advanced fibrosis. Body mass index and alanine aminotransferase level were independent factors associated with liver stiffness. Together with other clinical prediction scores, the estimated prevalence of advanced fibrosis in patients with fatty liver in the community was <10%. Compared with non-drinkers, modest drinkers (<10 g per day) did not have higher risk of fatty liver after adjustment for demographic and metabolic factors. The liver stiffness was 4.7±1.9 kPa in modest drinkers and 4.6±1.7 kPa in non-drinkers (p=0.54).
NAFLD is found in over a quarter of the general adult Chinese population, but the proportion of patients with advanced fibrosis is low. Modest alcohol consumption does not increase the risk of fatty liver or liver fibrosis.
Prospective study.
To determine whether a learning curve exists for ultrasound measurement of magnetically controlled growing rod (MCGR) distractions.
For patients managed by MCGRs, close monitoring ...of interval distraction length gains is important to determine whether the distractions are translating into actual spine growth. Radiographs are the criterion standard for measuring length gains, but ultrasound has been shown to be effective in monitoring distraction lengths without radiation exposure. It is, however, an operator-dependent tool and thus the accuracy of ultrasound measurement of distracted length may improve with experience.
This is a prospective correlation analysis of patients who underwent MCGR treatment for scoliosis. The study period was inclusive of 19th February 2013 to 31st March 2015. All subjects were consecutively recruited in a prospective manner. Data regarding date of the distraction visit, and the interval radiograph and ultrasound measurements of the distracted lengths were collected. Only those episodes with both radiograph and ultrasound performed were used for analysis. The mean differences in change of radiograph and ultrasound measurements were plotted to determine correlation differences and to observe for a learning curve.
A total of 379 distraction episodes were analyzed. The mean differences between ultrasound and radiograph measurements per distraction episode were -0.3 mm for the right rod and -0.1 mm for the left rod. For learning curve analysis, there were three distinct timepoints in which the difference of correlation became significantly better and were described as clusters. The correlation in the first cluster (19th February 2013 to 15th October 2013) was 0.612 (right rod) and 0.795 (left rod), the second cluster (16th October 2013 to 20th May 2014) was 0.879 (right rod) and 0.918 (left rod), and the third cluster (21st May 2014 to 31st March 2015) was 0.956 (right rod) and 0.932 (left rod). Thus, a plateau was observed at the second cluster, which translated to 97 to 146 rod measurements.
Correlation between radiograph and ultrasound measurements is reasonable to begin with but improves with time. During initial use, successful distractions should correlate between the clinical feel and ultrasound confirmation. Although the absolute value may not be accurate and may require radiographs to confirm, with time and experience, ultrasound measurements can then be more reliable.
3.
Virtual reality (VR) technology is a potential method to use in cognitive intervention, but the use of VR in cognitive stimulation intervention for older adults has not been investigated. Therefore, ...the aim of this study was to investigate the mood change of older adults after participating in the VR cognitive stimulation activity.
This is a multicenter randomized controlled, cross-over trial. The intervention was a VR cognitive stimulation activity, and the control was a paper-and-pencil activity. The participants were older adults with age over 60 and recruited in the elderly community centers. The Positive and Negative Affect Score (PANAS) was used to measure mood change. Mean difference (MD) with 95% confidence interval (95% CI) was calculated. The Simulator sickness questionnaire was used to measure adverse events.
A total of 236 participants from 19 community centers were recruited. After the VR activity, the participants had a significant increase in total PANAS positive affect score (MD = 2.09, 95% CI = 0.69 to 3.49), and a significant reduction in total negative affect score (MD = -1.99, 95% CI = -2.55 to -1.43). The reduction in negative affect score was significantly larger in VR activity than paper-and-pencil activity (MD = -0.48, 95% CI = -0.98 to 0.00). Besides, only three participants reported severe advance events after VR activity.
The use of VR technology is well accepted by older adults. Therefore, the use of VR technology through smartphone and a mobile app can be a potential method for future cognitive training interventions.
Background and Aim: Liver stiffness measurement (LSM) with transient elastography is a non‐invasive and reliable test for liver fibrosis. However a small proportion of patients may have unreliable ...LSM or LSM failure. The aim of the present study was to investigate the factors associated with unreliable LSM or LSM failure in Chinese patients.
Methods: We prospectively recruited liver patients for LSM. Unreliable LSM was defined as < 10 valid shots, an interquartile range (IQR)/LSM > 30%, or a success rate < 60%. LSM failure was defined as zero valid shots.
Results: Among 3205 patients with LSM, 371 (11.6%) and 88 (2.7%) had unreliable LSM and LSM failure, respectively. The rates started to increase when body mass index (BMI) ≥ 28.0 kg/m2. Comparing patients with BMI ≥ 28.0–29.9 kg/m2 versus those with BMI ≥ 30.0 kg/m2, the rates of unreliable LSM (16.4% vs 18.9%; P = 0.62) and LSM failure (11.8% vs 17.8%; P = 0.16) were similar. BMI ≥ 28.0 kg/m2 was the most important factor associated with unreliable LSM (odds ratio OR = 2.9, 95% confidence interval CI = 2.1–3.9, P < 0.0001) and LSM failure (OR = 10.1, 95% CI = 6.4–14.2, P < 0.0001). Central obesity, defined as waist circumference > 80 cm in women and > 90 cm in men, was another independent risk factor of unreliable LSM (OR = 1.3, 95% CI = 1.0–1.6, P = 0.04) and LSM failure (OR = 5.8, 95% CI = 2.9–11.5, P < 0.0001).
Conclusion: BMI ≥ 28.0 kg/m2 and central obesity were the independent risk factors of unreliable LSM and LSM failure in Chinese, and these rates were significantly higher in patients with extreme BMI.
Background & Aims Unreliable results of liver stiffness measurement are obtained in 16% of cases and are independently associated with body mass index (BMI) greater than 30 kg/m2 . A new FibroScan® ...probe (XL probe) was designed specifically for obese patients. The aim of this study was to evaluate the accuracy of liver stiffness measurement using M and XL probes of Fibroscan® for the diagnosis of fibrosis and cirrhosis in a large cohort of patients. Methods Consecutive patients undergoing liver biopsies for chronic liver disease were prospectively recruited. Liver stiffness measurement was performed within 1 week before liver biopsy using both M and XL probes of FibroScan®. Results A total of 286 patients were evaluated. A reliable liver stiffness measurement using M probe was obtained in 79.7% of cases. In the other 21.3%, liver stiffness measurement using XL probe was obtained in 56.9% of patients. A strong correlation was found between M and XL values, regardless of BMI. In all groups, median liver stiffness measurement using the XL probe was significantly lower than liver stiffness measurement using the M probe. By multivariate analysis, unsuccessful liver stiffness examination with M probe was independently associated with age >50 years and BMI >30 kg/m2 . By univariate analysis, only BMI >30 kg/m2 was associated with unsuccessful liver stiffness measurement with XL probe. No significant difference was observed between the M and XL probes for the diagnosis of liver fibrosis. Conclusions Liver stiffness measurement with either M or XL probe is possible in 91.2% of patients with comparable diagnostic accuracy. In clinical practice, the M probe could be used as first step for liver stiffness measurement. In case of no valid shot or unreliable measurement, the XL probe could be used. This result could be useful for the assessment of liver fibrosis in NAFLD and/or obese patients.
Background & Aims In animal studies, expression of hepatitis B virus (HBV) proteins causes hepatic steatosis. We aimed to study the prevalence of fatty liver in people with and without HBV infection ...in the general population. Methods We performed a cross-sectional population study in Hong Kong Chinese. Intrahepatic triglyceride content (IHTG) was measured by proton-magnetic resonance spectroscopy. Results One thousand and thirteen subjects (91 HBV patients and 922 controls) were recruited. The median IHTG was 1.3% (0.2–33.3) in HBV patients and 2.1% (0–44.2) in controls ( p <0.001). Excluding subjects with significant alcohol consumption, the prevalence of nonalcoholic fatty liver disease was 13.5% (95% confidence interval CI 6.4%, 20.6%) in HBV patients and 28.3% (95% CI 25.3%, 31.2%) in controls ( p = 0.003). The fatty liver prevalence differed in HBV patients and controls aged 40–59 years but was similar in those aged 60 years or above. After adjusting for demographic and metabolic factors, HBV infection remained an independent factor associated with lower risk of fatty liver (adjusted odds ratio 0.42; 95% CI 0.20, 0.88; p = 0.022). HBV patients also had a lower prevalence of metabolic syndrome (11.0% vs. 20.2%; p = 0.034), but the difference was mainly attributed to lower triglyceride levels. Among HBV patients, viral genotypes, HBV DNA level and hepatitis B e antigen status were not associated with fatty liver. Conclusions HBV infection is associated with a lower prevalence of fatty liver, hypertriglyceridemia and metabolic syndrome. Viral replication may affect lipid metabolism and this warrants further studies.
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