Clinical comorbidity in osteoarthritis: associations with physical function in older patients in family practice

OBJECTIVE: To determine the influence of comorbidity on physical function in osteoarthritis (OA) consulters aged 50 years and over in family practice. METHODS: The study design linked morbidity consultations during an 18-month period to self-reported physical function status measured at the end of the period. Clinical comorbidity was compared between consulters with (n = 1026) and without (n = 8160) OA. Comorbidity was defined by morbidity counts (1-2 low, 3-4 medium,> 5 high) and by a measure of severity of individual morbidities based on chronicity. Associations between comorbidity and physical function were assessed using unconditional logistic regression, adjusting for age, sex, and socioeconomic deprivation. RESULTS: Of the 1026 OA consulters, 38 (3.7%) had an OA consultation only, 260 (25.3%) had low, 288 (28.1%) medium, and 440 (42.9%) high morbidity counts. Higher OA comorbid counts were associated with poorer physical function, after adjusting for age, sex, and socioeconomic deprivation. Associations between OA comorbidity severity and poor physical function showed estimates that were in excess of simply multiplying the individual effects of OA and comorbidity severity separately. Comorbidity, however, did not explain all of the association between OA and poor physical function. CONCLUSION: Comorbidity increases the likelihood of poor physical function in patients with OA in population-based family practice. The combined influence is greater than would be expected from the influence of either OA or the comorbid conditions alone. Treating comorbidity in patients with OA is likely to be crucial in preventing or reducing the related physical decline.     

Occupational asthma in adults in six Canadian communities

We examined the prevalence, population attributable risk (PAR), and clinical characteristics of occupational asthma (OA) in a randomly selected population in six communities in Canada. Our study followed the European Community Respiratory Health Survey protocol. A randomly selected population of 18,701 (87% response rate) persons from the study communities, ranging in age from 20 to 44 yr, completed an initial questionnaire, of whom 2,974 (39% response rate) attended the laboratory and completed supplementary questionnaires. Of these latter individuals, 383 had asthma. Asthma was defined as physician-diagnosed asthma, and adult-onset asthma was defined as a first attack at age 15 yr or older. We used several methods for estimating OA as follows: (1) reporting of a high-risk job (occupation and industry) for OA at the time of asthma onset (Probable OA); (2) reporting of exposure to a substance that may cause OA (Possible OA) while not in a high-risk job at the time of asthma onset; and (3) combination of the PAR for high-risk jobs and exposures. The prevalence (95% confidence interval [CI]) of Probable OA and Possible OA combined was 36.1% (31.3 to 41.0%) among subjects with adult-onset asthma. The occupations most commonly reported in association with OA were nursing in the Probable OA group and clerical and food preparation in the Possible OA group. The clinical characteristics and exposures reported by both groups were similar. The PAR for adult-onset asthma in high-risk jobs and exposures was 18.2%. The assessment of occupation and industry alone, rather than of exposures, may underestimate the contribution of occupational exposures to asthma prevalence.     

Is tibiofemoral osteoarthritis in the knee joint a new disease?

OBJECTIVES--To compare the prevalence of osteoarthritis (OA) of the hip, tibiofemoral and patellofemoral joints in a skeletal population. METHODS--A total of 785 adult English skeletons (695 Saxon or Mediaeval origin) were examined for OA using established criteria. RESULTS--Twenty nine skeletons had hip OA, compared with 14 with patellofemoral joint OA, and only four tibiofemoral joint OA. CONCLUSION--Tibiofemoral OA was far less prevalent in ancient skeletons than hip or patellofemoral disease. Tibiofemoral OA may be a 'new' disease.     

Varus-valgus alignment in the progression of patellofemoral osteoarthritis

OBJECTIVE: To test the hypotheses that lateral patellofemoral (PF) osteoarthritis (OA) progression is more common than medial PF OA progression, that varus alignment increases the likelihood of medial PF OA progression, and that valgus alignment increases the likelihood of lateral PF OA progression. METHODS: Patients with knee OA were recruited from the community. Inclusion criteria were definite osteophyte presence (i.e., Kellgren/Lawrence radiographic grade >/=2) in 1 or both knees and at least some difficulty with knee-requiring activity. Varus-valgus alignment (the angle formed by the intersection of the mechanical axes of the femur and tibia) was measured on a full-limb radiograph at baseline. To assess PF OA progression, weight-bearing skyline views of the PF compartment were obtained at baseline and at 18-month followup. Knees with the highest grade of PF narrowing at baseline were excluded from analysis. Logistic regression and generalized estimating equations were used; odds ratios (ORs) were adjusted for age, sex, and body mass index. RESULTS: Lateral PF OA progression, which occurred in 120 (30%) of 397 knees, was more common than was medial PF OA progression, which occurred in 60 knees (15%). Varus (versus nonvarus) alignment increased the odds of PF OA progression isolated to the medial PF compartment (adjusted OR 1.85, 95% confidence interval [95% CI] 1.00-3.44). Valgus alignment increased the odds of PF OA progression isolated to the lateral compartment (adjusted OR 1.64, 95% CI 1.01-2.66). CONCLUSION: Lateral PF OA progression was more common than medial progression, and varus-valgus alignment influenced the likelihood of PF OA progression in a compartment-specific manner. Interventions that address the stress imposed by alignment on the PF compartments may delay PF OA progression and should be developed.     

实验性急性肺损伤大鼠脑组织中Gq/11蛋白的动态变化

目的 观察急性肺损伤(acute lung injury,ALI)大鼠脑组织中Gq/11蛋白的动态改变,从分子水平研究油酸(OA)性ALI导致脑损伤以及ALI导致多器官功能障碍综合征的可能机制,为ALI和多器官功能障碍综合征的发病机制提供实验和理论依据.方法 用尾静脉注射OA法复制ALI大鼠模型,将40只健康雄性Wistar大鼠随机分为对照组(C组)和实验组(OA组),OA组又根据不同时限将其分为30 min、60 min、90 min和120 min 4个亚组.观察检测各组大鼠血气(pH、PaO2、PaCO2)、平均动脉压(MABP)、血浆及脑组织乳酸脱氢酶(LDH)、肌酸激酶(CK)、丙二醛(MDA).免疫印迹法检测各组大鼠脑组织中的Gq/11蛋白含量.结果 Gq/11蛋白含量:除OA30 min组外,其余OA各组随着时间延长较C组分别增加至(141.85±33.82)%、(165.84±30.27)%、(174.31±32.52)%(P<0.01).除OA 30 min组外,其余OA各组血浆MDA含量均较c组升高(P<0.01);OA 30 min组和OA 60 min组脑组织MDA含量与C组比较差异无统计学意义,OA 90 min组和OA 120 min组脑组织MDA含量较C组升高(P<0.01).OA各组血浆LDH活性均较C组升高(P<0.01);除OA 30 min组外,其余OA各组脑组织LDH活性均较C组升高(P<0.01).脑组织CK活性在60 min时达到峰值(P<0.01),以后呈下降趋势.结论 ALI可导致远隔器官脑的损伤,引起细胞信号转导功能异常和脑代谢及形态的变化,Gq/11蛋白的高表达变化可能参与了ALl过程及脑损害的病理性信号转导.     

Ultrasound imaging for the rheumatologist VIII. Ultrasound imaging in osteoarthritis

The present review provides an update of the available data and discusses research issues relating to ultrasound (US) imaging in osteoarthritis (OA). Currently, the principal indications for using US in OA include: delineation of changes within articular cartilage (AC) and demonstration of synovial and adjacent soft tissue pathology together with injection into OA joints under US guidance. US has been proposed as a possible imaging tool for following the progression of OA. The main priorities requiring the attention of researchers include: addressing difficulties surrounding consensus on definitions of pathology in OA, charting the natural history of AC change in site specific OA, investigation of the link between inflammation and OA and the use of three-dimensional (3D) US in OA.     

Evaluating the predictive value of osteoarthritis diagnoses in an administrative database

OBJECTIVE: To assess the positive and negative predictive values of osteoarthritis (OA) diagnoses contained in an administrative database. METHODS: We identified all members (> or =18 years of age) of a Massachusetts health maintenance organization with documentation of at least one health care encounter associated with an OA diagnosis during the period 1994-1996. From this population, we randomly selected 350 subjects. In addition, we randomly selected 250 enrollees (proportionally by the age and sex of the 350 subjects) who did not have a health care encounter associated with an OA diagnosis. Trained nurse reviewers abstracted OA-related clinical, laboratory, and radiologic data from the medical records of both study groups (all but 1 chart was available for review). Pairs of physician reviewers evaluated the abstracted information for both groups of subjects and rated the evidence for the presence of OA according to 3 levels: definite, possible, and unlikely. RESULTS: Among the group of patients with an administrative diagnosis of OA, 215 (62%) were rated as having definite OA, 36 (10%) possible OA, and 98 (28%) unlikely OA, according to information contained in the medical record. The positive predictive value of an OA diagnosis was 62%. In those without an administrative OA diagnosis, 44 (18%) were assigned a rating of definite OA. The negative predictive value of the absence of an administrative OA diagnosis was 78%. CONCLUSION: Use of administrative data in epidemiologic and health services research on OA may lead to both case misclassification and under ascertainment.     

The inheritance of hip osteoarthritis in Iceland

OBJECTIVE: To assess, in a population-wide study in Iceland, the genetic contribution to hip osteoarthritis (OA) leading to total hip replacement (THR). METHODS: Information from 2 population-based databases in Iceland was combined: a national registry of all THRs performed between 1972 and 1996, and a genealogy database of all available Icelandic genealogy records for the last 11 centuries. A genetic contribution to THR for OA was assessed by 1) identifying familial clusters of OA patients with THR, 2) applying the minimum founder test (MFT) to estimate the minimum number of ancestors ("founders") that would account for the genealogy of all 2,713 patients with THR for OA, compared with the average number of founders for control lists, 3) calculating an average pairwise kinship coefficient (KC) for the patient list and control lists, and 4) estimating the relative risk (RR) for THR among relatives of OA patients who have undergone the procedure. One thousand matched control lists, each the same size as the patient list, were created using the genealogy database. RESULTS: A large number of familial clusters of patients with THR for OA were identified. The MFT showed that OA patients descended from fewer founders than did subjects in the control groups (P < 0.001). The average pairwise KC among patients with OA was greater than in the control population (P < 0.001). The RR for THR among siblings of OA patients was 3.05 (95% confidence interval 2.52-3.10). CONCLUSION: This population-based study shows that Icelandic patients with hip replacement for OA are significantly more related to each other than are matched controls drawn from the Icelandic population. These findings support a significant genetic contribution to a common form of OA and encourage the search for genes conferring an increased susceptibility to OA.     

Synovial tissue inflammation in early and late osteoarthritis

OBJECTIVE: To compare selected immunohistological features of inflammation in synovial tissue from patients with early and late osteoarthritis (OA). METHODS: Synovial tissue samples were obtained from 10 patients with knee pain, normal radiographs, and arthroscopic manifestations of OA (early OA), and from 15 patients with OA undergoing knee joint arthroplasty (late OA). Conventional immunohistochemical techniques were used to measure microscopic manifestations of inflammation. The inflammatory cell infiltrate, blood vessel formation, and angiogenic factors, NF-kappaB activation, expression of tumour necrosis factor alpha (TNFalpha) and interleukin 1beta (IL1beta), and the presence of cyclo-oxygenase (COX)-1 and COX-2 were quantified. Fibroblast-like synoviocytes (FLS) were isolated from early and late OA tissue samples to compare in vitro production of prostaglandin E2 (PGE2) RESULTS: Synovial tissue from patients with early OA demonstrated significantly greater CD4+ (p = 0.017) and CD68+ (p<0.001) cell infiltration, blood vessel formation (p = 0.01), vascular endothelial growth factor (p = 0.001), and intercellular adhesion molecule-1 expression (p<0.001). Numbers of cells producing TNFalpha and IL1beta were also significantly greater in early OA (p<0.001). Manifestations of inflammation in early OA were associated with increased expression of the NF-kappaB1 (p<0.001) and RelA (p = 0.015) subunits, and with increased COX-2 expression (p = 0.04). Cytokine-induced PGE2 production by cultured FLS was similar in both groups. CONCLUSION: Increased mononuclear cell infiltration and overexpression of mediators of inflammation were seen in early OA, compared with late OA. Isolated FLS were functionally similar in both groups, consistent with microenvironmental differences in the synovial tissue during different phases of OA. These observations may have important therapeutic implications for some patients during the early evolution of OA.     

Tenascin-C concentration in synovial fluid correlates with radiographic progression of knee osteoarthritis

OBJECTIVE: Osteoarthritis (OA) is a major cause of disability and represents the most common disease in the aging population. Although the course of the disease is generally assessed using standard radiographic images, biochemical markers may be employed to detect the disease and determine the degree of severity. We developed an enzyme linked immunosorbent assay (ELISA) system using a monoclonal antibody specific for the large-splice variants of tenascin-C (TN-C) and examined whether TN-C in synovial fluid (SF) is an adequate biochemical marker of OA progression. METHODS: SF samples were obtained from knees of 74 patients with OA and 16 without OA. Based on the radiographic grading of the OA severity, the knees were divided into 3 groups: mild, moderate, and severe OA. Expression of TN-C splice variants was examined using immunoblotting. TN-C concentrations were determined by ELISA. RESULTS: Western blotting showed the presence of large TN-C variants in SF from severe OA. TN-C levels were 5-fold higher in OA samples compared to subjects without OA (p < 0.0001). TN-C levels were not different between control cases and mild OA, but increased significantly in moderate (p = 0.0244) and severe OA (p < 0.0001). After adjusting TN-C levels for age, body mass index, and sex, TN-C levels correlated with radiographic progression of knee OA (R2 = 0.404, p < 0.0001). CONCLUSION: TN-C, including the large-variant subunits, is a useful biochemical marker for OA progression in the later stages of disease.     

Chondroitin sulphation patterns in synovial fluid in osteoarthritis subsets

OBJECTIVES: To determine concentrations of chondroitin sulphate (CS) disaccharides in knee synovial fluid (SF) from normal subjects and patients with osteoarthritis (OA) or rheumatoid arthritis (RA), to test whether these variables differ between different diseases and subsets of OA. METHODS: OA was subdivided into large joint OA (LJOA), nodal generalised OA (NGOA), and OA with calcium pyrophosphate crystal deposition (CPA), with 25, 9, and 11 people in each subset respectively. The SF of 13 normal subjects was also volunteered for analysis along with 15 RA patients. Clinical assessment of inflammation (0-6) was undertaken on OA and RA knees. Concentrations of unsaturated CS disaccharides Deltadi6S and Deltadi4S were measured by capillary zone electrophoresis. RESULTS: Concentrations of Deltadi6S were lower in RA (5.90 ng/ml) and OA (13.24 ng/ml) fluids compared with normal (21.0 ng/ml) but no significant differences were seen between disease and normal fluids for Deltadi4S (about 4-6 ng/ml). The ratio of Deltadi6S:Deltadi4S were RA相似文献   

Joint space narrowing and relationship with symptoms and signs in adults consulting for hip pain in primary care

OBJECTIVE: To study whether clinical symptoms and signs can predict radiological osteoarthritis (OA) of the hip in primary care patients with hip pain. METHODS: Consecutive patients (n = 220) aged 50 years or older consulting the general practitioner for hip pain and referred for radiological investigation underwent a standardized history, radiological, laboratory, and physical examination. Radiological OA was confirmed with joint space < or = 2.5 mm. Additionally, a more stringent definition was used (< or = 1.5 mm). The relationship between radiological OA and possible clinical symptoms/signs of OA was tested. Combinations of clinical symptoms/signs that had shown an independent relationship with radiological OA in multivariate analyses were tested for their predictive value. RESULTS: Radiological OA (joint space < or = 2.5 mm) of the (more) symptomatic hip was present in 35.5% of the study population and more severe OA (joint space < or = 1.5 mm) in 11.4%. Presence of 4 specific symptoms/signs from history and examination showed a positive predictive value (PPV) of 73% (specificity 91%, sensitivity 45%) for radiological OA. When 5 specific symptoms/signs were present, the PPV for the more severe radiological OA was 82% (specificity 98%, sensitivity 72%), and when 6 or 7 specific symptoms/signs were present the PPV was 100% (specificity 100%, sensitivity 40% and 8%, respectively). Negative predictive values were high for almost all combinations. CONCLUSION: In primary care patients with hip pain, clinical symptoms and signs can to a moderate extent predict radiological OA and to a large extent more severe radiological OA.     

Development and characteristics of pannus-like soft tissue in osteoarthritic articular surface in rat osteoarthritis model

OBJECTIVES: Pannus is invasive granulation tissue found on the articular cartilage having rheumatoid arthritis (RA). However, pannus-like tissue has also been found in osteoarthritis (OA). Our previous study showed that pannus-like tissue in OA (OA pannus) was frequently found in human OA samples. The purpose of the study is to investigate the development and the characteristics of OA pannus in a rat OA model. DESIGN: Ligaments of the knee joint were transected in Wister rats to induce OA. The knee joints were removed at weeks 1, 2, 4 and 6, and subjected to histological study. Samples were stained with hematoxylin and eosin (HE), Safranin-O and immuno-stained for vimentin, CD34, type II collagen and MMP-3. The whole knee joint of OA rats was implanted in SCID mice and kept for a further 3 weeks. Then the histological findings were evaluated in HE sections. RESULT: OA pannus appeared at week 2 and extend over the articular surface. OA pannus cells were positive for vimentin and/or CD34. At week 6, a part of articular surface was restored with matrix. OA pannus cells expressed MMP-3 as well as type II collagen. Histological study of rat OA knees implanted in SCID mice showed that OA pannus cells filled the joint space and invaded articular cartilage. CONCLUSIONS: The presence of OA pannus was found in a rat OA model and its features were similar to those in human OA. OA pannus had both catabolic and reparative features, and the latter feature were speculated to be dominant in the later phase of the disease under a certain environmental condition.     

Spontaneous osteoarthritis in rhesus macaques. I. Chemical and biochemical studies

We analyzed the articular cartilage of 41 rhesus macaques for elemental concentrations including [Ca] calcium, [P] phosphorus, [Mg] magnesium, [S] sulfur, [K] potassium and glycosaminoglycan (GAG) and collagen content. Our findings revealed an increase in all elements with aging. Within the osteoarthritic (OA) groups, young OA had higher levels of all elements than old OA, and significantly greater levels compared to young normals. In addition, GAG content was dramatically increased in young OA. Old OA did not differ from old normals for any elements although GAG levels decreased. Collagen was shown to be stable with increasing age in both normal and OA cartilage, but decreased in OA cartilage. This macaque model of spontaneous OA is valuable because it demonstrates early OA changes typical of experimental models and late changes similar to human OA.     

Cigarette smoking and risk of osteoarthritis in women in the general population: the Chingford study.

Previous studies have suggested that smoking might be protective against the development of osteoarthritis (OA) of the knee. A group of 1003 women aged 45-64 years (mean 54.2 years) from the Chingford general population survey were studied to examine the effect of cigarette smoking on the prevalence of radiologically confirmed OA at different sites. Standard anteroposterior radiographs of the hand and knee were available in 985 women. Disease classification was made on the basis of radiological OA and symptomatic radiological OA. Odds ratios were calculated and adjusted for age and body mass index. A total of 463 (46.2%) women were ever smokers compared with 540 (53.8%) non-smokers. Ever smokers had consumed an average of 14.9 cigarettes a day for a mean of 25.7 years. For radiological OA of the distal interphalangeal joint (DIP) (140 women), proximal interphalangeal joint (40 women), carpometacarpal joint (160 women), and knee joint (118, women) there was no reduced risk of OA in ever smokers. In the small number of subjects with generalised OA (22 women) there was a non-significant 40% reduction of radiological OA in ever smokers (odds ratio 0.63; 95% confidence interval 0.24 to 1.68). Results were similar for subjects with radiographic clinical OA, except the DIP joint which showed a positive association between smoking and Heberden's nodes (odds ratio 2.02, 95% confidence interval 1.89 to 3.42). Results were similar when analysed using current smokers against never smokers. These results do not support an inverse association between cigarette smoking and OA in women. A possible inverse relation with the small subgroup of women with generalised OA and an effect of cigarettes on disease severity cannot, however, be discounted.     

白细胞介素-18在骨关节炎滑膜细胞中的表达及意义

目的 了解白细胞介素(IL)-18在骨关节炎(OA)患者和非OA患者滑膜细胞中表达的差异.方法 取OA患者(22例)与非OA患者(8例)关节滑膜组织,分别原代培养滑膜细胞,采用酶联免疫吸附测定法(ELISA)定量检测2组滑膜细胞培养上清液中IL-18蛋白的表达水平,采用免疫细胞化学方法 定性观察IL-18在2组滑膜细胞问表达的差异,统计学处理采用t检验.结果 ELISA检测OA患者细胞培养上清液中IL-18的含量为(63.9±21.4)pg/ml, 非OA患者细胞培养上清液中IL-18的含量为(17.7±1.5)pg/ml,2组比较差异有统计学意义(t=10.044,P<0.01);免疫细胞化学方法 显示在OA患者滑膜细胞中IL-18蛋白的表达呈阳性.胞质为棕黄色深染,而在非OA患者滑膜细胞中胞质淡染.结论 IL-18在OA关节滑膜细胞中表达上调, 提示IL-18可能直接参与了OA的发病过程.     

Serum hyaluronan levels and radiographic knee and hip osteoarthritis in African Americans and Caucasians in the Johnston County Osteoarthritis Project

OBJECTIVE: Serum hyaluronan (HA) has been proposed as a potential biomarker of osteoarthritis (OA). We examined associations between serum HA and radiographic OA in an ethnically diverse, population-based sample. METHODS: Participants were selected from the Johnston County Osteoarthritis Project, using stratified simple random sampling to achieve balance according to radiographic knee OA status, ethnic group, sex, and age group. Serum HA was measured by enzyme-linked immunosorbent assay. Radiographic OA variables included knee OA, knee OA laterality, knee OA severity, concomitant knee and hip OA, and total number of OA-affected knee and hip joints. Analysis of covariance was used to assess differences in mean serum levels of natural log-transformed HA (ln serum HA) between groups, adjusting for ethnicity, sex, age, body mass index (BMI), and self-reported comorbidities. RESULTS: Levels of ln serum HA were positively associated with all definitions of radiographic OA (P < 0.0001). Levels of ln serum HA were higher in Caucasians (P = 0.0094) and in men (P = 0.0038) and were moderately correlated with age (r = 0.35, P < 0.0001). The associations with radiographic OA, ethnicity, sex, and age remained statistically significant after adjustment (P < 0.0045). There were no interactions between ethnicity and the other covariates. CONCLUSION: These cross-sectional data support a role for serum HA as a biomarker of radiographic OA. The variations in levels of serum HA attributable to ethnicity, sex, and age were not explained by radiographic OA, BMI, or comorbidities. The lack of strong confounding between serum HA and comorbidities further supports a role for serum HA as a potential biomarker.     

Bone mineral density and knee osteoarthritis in elderly men and women. the framingham study

Objective. To examine the possible inverse relationship between osteoporosis and osteoarthritis (OA) by evaluating the association between bone mineral density (BMD) and knee OA in the Framingham Study cohort. Methods. Of the 1,154 Framingham Study cohort subjects in whom BMD measurements were obtained at biennial examination 20, 932 (81%) had had knee OA assessed during the Framingham Knee OA Study 4 years earlier. BMD of the proximal femur and radius was measured by densitometry. Knee OA was assessed from a weight-bearing anteroposterior radiograph and graded on a scale of 0 (no OA) to 4 (severe OA). Osteophytes and joint space narrowing were also evaluated separately. Linear regression was used to test the association of BMD with knee OA, with osteophytes, and with joint space narrowing, after adjustment for age, body mass index, and mean number of cigarettes smoked per day. Results. The subjects included 572 women and 360 men with an age range of 63–91 years (mean 71 years). Of these, 351 had no OA, 269 had grade 1 OA, 170 had grade 2 OA, 93 had grade 3 OA, and 49 had grade 4 OA. Mean femoral BMD at the 3 proximal femur sites was 5–9% higher in men and women with either grade 1, grade 2, or grade 3 knee OA, compared with those with no knee OA (P < 0.0001). Mean femoral BMD in those with grade 4 OA was not higher than in those with no OA. Radius BMD was not associated with knee OA in subjects of either sex. Women with osteophytes had higher BMD compared with women with no osteophytes. Mean BMD did not differ across levels of joint space narrowing. Conclusion. We conclude that, among women, femoral BMD is higher in those with osteophytosis of the knee, and BMD is not necessarily associated with joint space narrowing.     

骨关节炎软骨基质蛋白多糖变化的实验研究

目的：观察骨关节炎（OA）不同时期关节软骨基质蛋白多糖的变化，探索与软骨基质代谢相关的OA的发病机制。方法：以家兔制作OA动物模型，在病变的早、中晚期获取关节软骨，提取葡糖氨基聚糖（GAG），用生化和放射免疫技术测定其中不同种类GAG及其功能基团的含量。结果：在病变的不同时期，GAG的总量、透明质酸的含量和其中所含的硫酸基团的含量均减少，而硫酸软骨素与硫酸角质素的比例增高。这些改变均随病变的进展而渐不明显。结论：OA时，软骨基质蛋白多糖各组分和功能基团均发生了有意义的变化，这种变化有助于阐明OA的发病机制。     

Descriptive epidemiology of osteoarthritis in British Columbia, Canada

OBJECTIVE: Osteoarthritis (OA) is a highly prevalent and often disabling disease. Data on the incidence of OA in the general population are limited. Our objectives were (1) to estimate OA prevalence and incidence rates by age and sex in a geographically defined population of 4 million people [British Columbia (BC), Canada] using an administrative database; and (2) to determine the effects of different administrative definitions of OA and observation (run-in) time on such estimates. METHODS: We used data on all visits to health professionals and hospital admissions covered by the Medical Services Plan (MSP) of BC for the fiscal years 1991-92 through 2000-01. OA was defined based on International Classification of Diseases, 9th Revision, diagnostic codes required for administrative purposes. RESULTS: The overall prevalence of OA in 2001 was 10.8%: 8.9% in men and 12.6% in women. Prevalence was higher in women in all age groups. By age 70-74 years, about one-third of men and 40% of women had OA. Incidence rates in 2000-01 were 11.7 per 1000 person-years in the total population, 10.0 in men and 13.4 in women. Rates increased linearly with age between 50 and 80 years. Both prevalence and incidence depended strongly on the definition of OA and the run-in period. CONCLUSION: Prevalence of physician-diagnosed OA in BC was slightly lower than self-reported prevalence of arthritis in population surveys. Routinely collected administrative data could be a valuable source of information for OA surveillance, but more research is needed on the validity of OA diagnosis in administrative databases.