Cartilage Damage Pathological Characteristics of Diabetic Neuropathic Osteoarthropathy.

Background: Diabetic neuropathic osteoarthropathy (DNOAP) is a rare and easily missed complication for diabetes that leads to increased morbidity and mortality. DNOAP is characterized by progressive destruction of bone and joint, but its pathogenesis remains elusive. We herein aimed to investigate the pathological features and pathogenesis of the cartilages damage in DNOAP patients. Methods: The articular cartilages of eight patients with DNOAP and eight normal controls were included. Masson staining and safranine O/fixed green staining (S-O) were used to observe the histopathological characteristics of cartilage. The ultrastructure and morphology of chondrocytes were detected by electron microscopy and toluidine blue staining. Chondrocytes were isolated from DNOAP group and control group. The expression of receptor activator of nuclear factor kappaB ligand (RANKL), osteoprotegerin (OPG), interleukin-1 beta (IL-1ß), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and Aggrecan protein was evaluated by western blot. Reactive oxygen species (ROS) levels were measured using a 2',7'-dichlorofluorescin diacetate (DCFH-DA) probe. The percentage of apoptotic cells was determined by flow cytometry (FCM). The chondrocytes were cultured with different glucose concentrations to observe the expression of RANKL and OPG. Results: Compared with the control group, the DNOAP group showed fewer chondrocytes, subchondral bone hyperplasia, and structural disorder, and a large number of osteoclasts formed in the subchondral bone area. Moreover, mitochondrial and endoplasmic reticulum swellings were observed in the DNOAP chondrocytes. The chromatin was partially broken and concentrated at the edge of nuclear membrane. The ROS fluorescence intensity of chondrocyte in DNOAP group was higher than that in normal control group (28.1 ± 2.3 vs. 11.9 ± 0.7; P < 0.05). The expression of RANKL, TNF-α, IL-1ß, and IL-6 protein in DNOAP group was higher than that in normal control group, whereas OPG and Aggrecan protein were lower than that in normal control group (both P < 0.05). FCM showed that the apoptotic rate of chondrocyte in DNOAP group was higher than that in normal control group (P < 0.05). The RANKL/OPG ratio showed significant upward trend when the concentration of glucose was over than 15 mM. Conclusions: DNOAP patients tend to have severe destruction of articular cartilage and collapse of organelle structure including mitochondrion and endoplasm reticulum. Indicators of bone metabolism (RANKL and OPG) and inflammatory cytokines (IL-1ß, IL-6, and TNF-α) play an important role in promoting the pathogenesis of DNOAP. The glucose concentration higher than 15 mM made the RANKL/OPG ratio change rapidly.

Analysis of the association and predictive value of hyperhomocysteinaemia for obstructive coronary artery disease.

OBJECTIVE: To investigate the predictive value of hyperhomocysteinaemia (HHcy) for obstructive coronary artery disease (CAD) in an Asian population in northern China. METHODS: This retrospective study enrolled patients at their first cardiac assessment and assigned them to an obstructive CAD group or a non-obstructive CAD group according to the coronary angiography results. HHcy was defined as a homocysteine (Hcy) level > 15 µmol/l. RESULTS: This study enrolled 2987 participants: 1172 in the non-obstructive CAD group and 1815 in the obstructive CAD group. Hcy level in the obstructive CAD group was significantly higher than in the non-obstructive CAD group. The proportion of patients with HHcy in the obstructive CAD group was significantly greater than in the non-obstructive CAD group. Multivariate logistic regression analysis demonstrated that HHcy was independently correlated with obstructive CAD in both young (aged ≤ 55 years) and old patients (aged > 55 years). HHcy showed a higher sensitivity (93.1%), specificity (86.1%) and accuracy (90.0%) for obstructive CAD. The odds ratio for HHcy was 84.2. The Kappa value (0.8) showed substantial agreement between obstructive CAD and HHcy. CONCLUSIONS: HHcy was associated with obstructive CAD and may be a potentially independent risk factor for obstructive CAD with good predictive value.

Pathogenesis and potential relative risk factors of diabetic neuropathic osteoarthropathy.

Diabetic neuropathic osteoarthropathy (DNOAP) is an uncommon, but with considerable morbidity and mortality rates, complication of diabetes. The real pathogenesis is still unclear. The two popular theories are the neuro-vascular theory and neuro-traumatic theory. Most theories and pathways focused on the uncontrolled inflammations that resulted in the final common pathway, receptor activator of nuclear factor κß ligand (RANKL)/osteoprotegerin (OPG) axis, for the decreased bone density in DNOAP with an osteoclast and osteoblast imbalance. However, the RANKL/OPG pathway does not explain all the changes, other pathways and factors also play roles. A lot of DNOAP potential relative risk factors were evaluated and reported in the literature, including age, gender, weight, duration and type of diabetes, bone mineral density, peripheral neuropathy and arterial disease, trauma history, and some others. However, most of them are still in debates. Future studies focus on the pathogenesis of DNOAP are still needed, especially for the genetic factors. And, the relationship between DNOAP and those potential relative risk factors are still need to further clarify.