Reliability of self-reports: data from the Canadian Multi-Centre Osteoporosis Study (CaMos)

Reliable questions enhance study design. We assessed the reliability of questions that gather demographic, sun exposure, reproductive history, and physical activity information. Subjects were participants in the Canadian Multicentre Osteoporosis Study (CaMos), a cohort study of Canadian adults recruited January 1996 to September 1997 in nine cities, stratified by sex, age, and location. Following personal interviews, 367 subjects were re-administered part of the questionnaire by telephone. Reliability was assessed using kappa and intra-class correlation. Reliability was excellent for employment status, reproductive history, weight and height (0.91 to 0.97), not differing greatly when stratified by age group or sex. Physical activity and sun exposure were reported with fair to good reliability (0.44 to 0.58), except for moderate activity (kappa = 0.30, 95% confidence interval 0.23, 0.37). Stratification by body mass index did not show significant differences. Many items can be reported reliably, especially those of height, weight, employment status and reproductive history, and, to a lesser extent, physical activity and sun exposure. Similar questions might be used reliably in future studies.     

The Relationship Between Proton Pump Inhibitor Use and Longitudinal Change in Bone Mineral Density: A Population-Based From the Canadian Multicentre Osteoporosis Study (CaMos)

OBJECTIVES:Proton pump inhibitor (PPI) use has been identified as a risk factor for hip and vertebral fractures. Evidence supporting a relationship between PPI use and osteoporosis remains scant. Demonstrating that PPIs are associated with accelerated bone mineral density (BMD) loss would provide supportive evidence for a mechanism through which PPIs could increase fracture risk.METHODS:We used the Canadian Multicentre Osteoporosis Study data set, which enrolled a population-based sample of Canadians who underwent BMD testing of the femoral neck, total hip, and lumbar spine (L1-L4) at baseline, and then again at 5 and 10 years. Participants also reported drug use and exposure to risk factors for osteoporosis and fracture. Multivariate linear regression was used to determine the independent association of PPI exposure and baseline BMD, and on change in BMD at 5 and 10 years.RESULTS:In all, 8,340 subjects were included in the baseline analysis, with 4,512 (55%) undergoing year 10 BMD testing. After adjusting for potential confounders, PPI use was associated with significantly lower baseline BMD at the femoral neck and total hip. PPI use was not associated with a significant acceleration in covariate-adjusted BMD loss at any measurement site after 5 and 10 years of follow-up.CONCLUSIONS:PPI users had lower BMD at baseline than PPI non-users, but PPI use over 10 years did not appear to be associated with accelerated BMD loss. The reasons for discordant findings between PPI use at baseline and during follow-up require further study.     

Characteristics of asthma and COPD overlap syndrome (ACOS) in the Canadian population

Objective: Asthma is a chronic disease affecting both children and adults, whereas chronic obstructive pulmonary disease (COPD) is a respiratory disease most commonly related to smoking and is usually seen in adults. When the airway disease shares features of both asthma and COPD, the phenotype is referred to as asthma and COPD overlap syndrome (ACOS). The objective of this cross-sectional study is to characterize ACOS in the Canadian population. Methods: Data from the first three cycles of the Canadian Health Measures Survey (CHMS) were used in this study. The study included 9059 subjects aged 30?years and above. The CHMS included a detailed interviewer-administered questionnaire and spirometry measurements. Based on the self-report, subjects were categorized into control, ACOS, COPD only and asthma only groups. Results: The prevalence of ACOS, COPD and asthma groups was 1.59%, 2.21% and 6.65%, respectively. The proportion of females was significantly greater than males in the ACOS group. The proportion of wheeze was highest in the ACOS group (64.93%) whereas the prevalence of shortness of breath was the highest in the COPD group (46.25%). Heart disease, cancer, arthritis and liver disease were more prevalent in the ACOS group than in COPD, asthma and control groups. Severity of airway obstruction was the highest in the ACOS group and was followed by COPD, asthma and control groups, respectively. Conclusions: Characteristics of ACOS in the Canadian population were similar to those observed in the developed countries and longitudinal studies are required to determine the incidence and risk factors of ACOS.     

老年人骨质疏松与主动脉硬化的相关性研究

目的 探讨老年骨质疏松与动脉硬化的关系.方法 测定100例老年患者(60～93岁)血脂、碱性磷酸酶(ALP)、血钙、血磷、高敏C反应蛋白(hs-CRP).用双能X线骨密度仪测定腰椎(L2-4)、股骨颈、大转子及Ward's三角骨矿密度(BMD).用高分辨率彩超测定颈动脉内中膜厚度(IMT).结果 骨质疏松组年龄、hs-CRP和IMT均较非骨质疏松组高(均P<0.05),两组性别、体质指数(BMI)、血脂、ALP、血钙和血磷差异无统计学意义(均P>0.05);主动脉硬化组年龄、ha-CRP和IMT均较非主动脉硬化组高(均P<0.05),而L2-4、股骨颈及大转子BMD均较非主动脉硬化组低(均P<0.05),两组性别、BMI、血脂、ALP、血钙和血磷差异无统计学意义(均P>0.05);相关分析表明L2-4、股骨颈、大转子及Ward's三角BMD与颈动脉IMT呈负相关(均P<0.05).结论 骨质疏松与动脉硬化密切相关,炎症反应可能是骨质疏松与动脉硬化发病机制的共同基础.     

糖尿病性骨质疏松与骨羟脯氨酸含量关系的探讨

目的　探讨糖尿病性骨质疏松与骨羟脯氨酸的关系。方法　把 2 2只昆明种小鼠随机分为糖尿病模型组和正常对照组两组。腹腔注射链脲佐菌素 (STZ)造成糖尿病模型。每周监测血糖 (BG)、体重及食量等 ,5周后处死取股骨进行骨干重、骨钙、骨磷、骨镁及骨羟脯氨酸 (B- HOP)的测定和比较。结果　糖尿病小鼠骨干重与正常对照小鼠有显著性差异 (P <0 .0 0 1) ,糖尿病小鼠骨 HOP/骨干重比值 (0 .4 98± 0 .0 4 8)降低 ,与正常对照小鼠骨 HOP/骨干重比值 (0 .5 39±0 .0 33)有显著性差异 (P <0 .0 5 )。结论　糖尿病性小鼠有骨重量减轻、生长延缓、骨羟脯氨酸含量降低等特征     

糖尿病患者肾脏损害与骨质疏松关系的研究

目的探讨糖尿病患者（DM）肾脏损害与骨质疏松（Op）的关系。方法应用SD200型骨矿物仪测量86例DM（2型）患者（包括正常白蛋白尿组49例,微量白蛋白尿组17例,临床白蛋白尿组20例）和34例正常对照组的骨密度（BMD）变化。结果临床白蛋白尿组的BMD低于正常对照组（P＜0．05）,其Op的发生率随尿白蛋白增高而增加。结论肾脏损害是加重DM患者Op的重要原因。     

Transient elastography for the noninvasive assessment of liver fibrosis: a multicentre Canadian study

BACKGROUND

Liver stiffness measurement (LSM) using transient elastography (TE) is a promising tool for the noninvasive assessment of hepatic fibrosis.

OBJECTIVES

To determine the feasibility and performance of TE in a North American cohort of patients with chronic liver disease.

METHODS

LSMs were obtained using TE in 260 patients with chronic hepatitis B or C, or nonalcoholic fatty liver disease from four Canadian hepatology centres. The accuracy of TE compared with liver biopsy for the prediction of significant fibrosis (Metavir fibrosis score of F2 or greater), bridging fibrosis (Metavir fibrosis score of F3 or greater) and cirrhosis (Metavir fibrosis score of F4 ) was assessed using area under ROC curves (AUROCs), and compared with the aspartate aminotransferase-to-platelet ratio index. The influence of alanine aminotransferase (ALT) levels and other factors on liver stiffness was determined using linear regression analyses.

RESULTS

Failure of TE occurred in 2.7% of patients, while liver biopsies were inadequate for staging in 0.8%. Among the remaining 251 patients, the AUROCs of TE for Metavir fibrosis scores of F2 and F3 or greater, and F4 were 0.74 (95% CI 0.68 to 0.80), 0.89 (95% CI 0.84 to 0.94), and 0.94 (95% CI 0.90 to 0.97), respectively. LSM was more accurate than the aminotransferase-to-platelet ratio index for bridging fibrosis (AUROC 0.78) and cirrhosis (AUROC 0.88), but not significant fibrosis (AUROC 0.76). At a cut-off of 11.1 kPa, the sensitivity, specificity, and positive and negative predictive values for cirrhosis (prevalence 11%) were 96%, 81%, 39% and 99%, respectively. For significant fibrosis (prevalence 53%), a cut-off of 7.7 kPa was 68% sensitive and 69% specific, and had a positive predictive value of 70% and a negative predictive value of 65%. Liver stiffness was independently associated with ALT, body mass index and steatosis. The optimal LSM cut-offs for cirrhosis were 11.1 kPa and 11.5 kPa in patients with ALT levels lower than 100 U/L and 100 U/L or greater, respectively. For fibrosis scores of F2 or greater, these figures were 7.0 kPa and 8.6 kPa, respectively.

CONCLUSIONS

The major role of TE is the exclusion of bridging fibrosis and cirrhosis. However, TE cannot replace biopsy for the diagnosis of significant fibrosis. Because liver stiffness may be influenced by significant ALT elevation, body mass index and/or steatosis, tailored liver stiffness cut-offs may be necessary to account for these factors.     

睾酮与雄性大鼠骨质疏松关系的实验研究

目的　探讨睾酮在男性骨质疏松中所起的作用及机理。方法　采用１５ 周龄雄性ＳＤ大鼠去睾后作为骨质疏松动物模型，随机分为２ 组：正常对照组（Ｎ）、去睾模型组（ＯＰ） ，术后２８ 周统一处死，行血尿生化、骨密度（ＢＭＤ）、骨生物力学及病理检查。结果　与正常组比较，模型组大鼠血清睾酮水平明显下降（Ｐ＜０ ．０１），雌二醇水平增高，但无显著差异（ Ｐ＞ ０．０５）。生化检查结果示模型组大鼠骨形成指标血清碱性磷酸酶显著降低（ Ｐ＜ ０ ．０５）；骨吸收指标———２４ 小时尿羟脯氨酸浓度／肌酐与尿钙／ 肌酐显著增高（ Ｐ＜０ ．０５）。应用ＤＥＸＡ 与ＳＰＡ法分别测定大鼠全身及股骨中点ＢＭＤ，发现模型组大鼠均明显下降（ Ｐ＜ ０．０５） 。骨生物力学测定发现，反映模型组大鼠的股骨整骨强度的指标———最大受力负荷及反映股骨整骨能承受的最大形变的指标———最大挠度均显著下降（ Ｐ＜ ０ ．０５） 。骨形态计量学测定发现模型组大鼠骨小梁体积、骨表面面积／ 体积比、平均骨小梁厚度显著下降（Ｐ＜０ ．０１），说明模型组大鼠骨小梁普遍变薄变细甚至断裂穿孔。据此，雄性大鼠去势２８ 周后已经形成了雄激素缺乏而引起的骨质疏松症。由此推断雄激素在体内不仅可转换为雌     

Canadian prediction equations of spirometric lung function for Caucasian adults 20 to 90 years of age: results from the Canadian Obstructive Lung Disease (COLD) study and the Lung Health Canadian Environment (LHCE) study

BACKGROUND:

Currently, no reference or normative values for spirometry based on a randomly selected Canadian population exist.

OBJECTIVE:

The aim of the present analysis was to construct spirometric reference values for Canadian adults 20 to 90 years of age by combining data collected from healthy lifelong nonsmokers in two population-based studies.

METHOD:

Both studies similarly used random population sampling, conducted using validated epidemiological protocols in the Canadian Obstructive Lung Disease study, and the Lung Health Canadian Environment study. Spirometric lung function data were available from 3042 subjects in the COLD study, which was completed in 2009, and from 2571 subjects in the LHCE study completed in 1995. A total of 844 subjects 40 to 90 years of age, and 812 subjects 20 to 44 years of age, were identified as healthy, asymptomatic, lifelong nonsmokers, and provided normative reference values for spirometry. Multiple regression models were constructed separately for Caucasian men and women for the following spirometric parameters: forced expiratory volume in 1 s (FEV₁), forced vital capacity (FVC) and FEV₁/FVC ratio, with covariates of height, sex and age. Comparison with published regression equations showed that the best agreement was obtained from data derived from random populations.

RESULTS:

The best-fitting regression models for healthy, never-smoking, asymptomatic European-Canadian men and women 20 to 90 years of age were constructed. When age- and height-corrected FEV₁, FVC and FEV₁/FVC ratio were compared with other spirometry reference studies, mean values were similar, with the closest being derived from population-based studies.

CONCLUSION:

These spirometry reference equations, derived from randomly selected population-based cohorts with stringently monitored lung function measurements, provide data currently lacking in Canada.     

骨代谢生化标志物在氟骨症研究中的应用

氟骨症骨转换加速，骨代谢异常。用成骨细胞分泌的酶如骨碱性磷酸酶、骨钙素等骨代谢生化标志物评估骨形成，用破骨细胞分泌的酶如抗酒石酸酸性磷酸酶及骨吸收中形成的代谢产物如尿羟脯氨酸等生化标志物评估骨吸收。目的是为氟骨症的研究提供新的参考。     

氟骨症患者骨密度与血清骨钙素和生化指标的相关分析

目的　了解饮水型氟骨症患者骨密度 (BMD)与血清骨钙素 (BGP)和生化指标的改变 ,以及相互之间的变化关系。方法　选取氟中毒病区氟骨症患者 6 8例 ,采用单光子骨矿物仪测量 BMD,放射免疫法测血清BGP,生化检查血清钙 (Ca)、磷 (P)、碱性磷酸酶 (AKP)及尿 Ca、尿 P、羟脯氨酸 (Hop)、肌酐 (Cr)。结果　氟骨症组的 BMD低于对照组 (P<0 .0 1) ,血清 BGP明显高于对照组 (P<0 .0 1) ,反映骨代谢生化指标血清 AKP和尿Hop/ Cr值显著升高 (P<0 .0 1) ,血清 Ca、P降低 (P<0 .0 5 )。骨密度与血清 BGP、AKP、Hop/ Cr呈显著负相关 ,与血清 Ca呈正相关。结论　骨密度及血清骨钙素和骨代谢生化指标的联合测定 ,对氟骨症患者的早期诊断均有较高临床价值     

Role of biochemical markers in the management of osteoporosis

Several serum and urine biochemical markers of bone resorption and formation have been developed. Biochemical bone markers have been used as intermediate end-points in all major studies of anti-osteoporotic therapies. Bone resorption markers, in particular, may add an independent, predictive value to the assessment of bone loss and fracture risk. There are also potential advantages in monitoring anti-osteoporotic treatment in the short-term in addition to bone densitometry, to rapidly identify non-responders to therapy, or non-compliance. Despite these recent advances, until now bone markers have simply been very useful research tools, with their clinical utility being limited by intra-individual and diurnal variability. However, the probability of the true bone mineral density response to hormone replacement therapy for the individual patient may be predicted using algorithms based on a spectrum of cut-off bone marker levels with varying false positive and negative rates. Thus, the transition of biochemical bone markers into everyday clinical practice may be rapidly approaching.     

A multicentre trial of bucillamine in the treatment of early rheumatoid arthritis (SNOW study)

In this study, we enrolled early rheumatoid arthritis (RA) patients at multiple institutes who fulfilled the American Rheumatism Association 1987 revised criteria for the classification of RA, and followed the clinical results of disease-modifying anti-rheumatic drug (DMARD) treatment prospectively. With the aim of developing therapeutic guidelines using the disease activity score 28 (DAS28) as disease indices, we investigated the usefulness of bucillamine (BUC), one of the most widely used DMARDs in Japan. Eighty-one patients with early RA who had not previously been treated with DMARDs were suitable for BUC therapy as first-choice treatment. After 24 months of treatment, at least moderate improvement was seen in 87.5% of patients using the DAS28 erythrocyte sedimentation rate (ESR). After 24 months of BUC therapy, 7 patients (43.8%) met the remission criterion of DAS28 (ESR) <2.6. The 24-month BUC continuation rate was 60.5% (49/81, monotherapy + combination therapy), of which 59.2% (29/49) were on BUC monotherapy. From the efficacy and safety viewpoints alike, BUC was useful as first-choice treatment for early RA.     

Eliciting Canadian population preferences for health states using the Classification and Measurement System of Functional Health (CLAMES)

A major objective of the Population Health Impact of Disease in Canada (PHI) research program was to obtain Canadian-specific preferences for health states associated with various diseases, in order to estimate the morbidity component of summary measures of population health embodying the Canadian experience of disease. In this study, preferences for health states were elicited from lay panels (N=146) in nine Canadian communities (Vancouver, Edmonton, Saskatoon, Toronto, Ottawa, Montréal, Québec, Moncton and Halifax); the study was conducted from January to June of 2003. Information on health states was presented to raters using the CLAssification and MEasurement System of Functional Health (CLAMES), which assesses functional capacity using 11 health status attributes, each with four to five levels ranging from normal to severely limited functioning. Preferences for 238 health states classified by CLAMES were elicited using the standard gamble (SG) technique in both individual and group exercises. Mean preferences for these health states were then used to estimate the parameters of a log-linear scoring function for CLAMES. The function provides a convenient method of computing preference scores for any health state classified by CLAMES, without the need for direct measurement in surveys. Further, the SG appears feasible in group settings. Key words: Canadian health state preferences, classification and measurement system of functional health, Population Health Impact, preference-based scoring function, standard gamble.