[Interaction between family history of diabetes and hyperlipidemia on risk of diabetes in population with normotension in Harbin: a cross-sectional study]

Objective: To explore the interaction between family history of diabetes and hyperlipidemia on the risk of diabetes in population with normotension. Methods: A multistage stratified probability random sampling was conducted to select a representative sample of urban residents aged 20-74 years in Harbin. A total of 376 diabetes patients with normotension and 3 692 residents with normal blood pressure, normal fasting glucose, and normal 2 hours glucose from OGTT were surveyed. The interaction was evaluated by using crossover analysis and additive model. Results: Multivariate logistic regression analysis indicated that there was a possible additive interaction between family history of diabetes and hyperlipidemia on the risk of diabetes. The relative excess risk due to the interaction, the attributable proportion due to the interaction, and the synergy index were 1.97 (95%CI:-0.32-4.26), 0.30 (95%CI: 0.03-0.57), and 1.54 (95%CI: 0.96-2.47), respectively. There were significant combination effects between family history of diabetes and high both total cholesterol and triglyceride, isolated high total cholesterol, and isolated high triglyceride levels; the ORs were 10.55 (95%CI: 5.62-19.80), 7.81 (95%CI: 3.65-16.71) and 5.13 (95%CI: 3.22-8.16), respectively. Conclusion: There might be synergistic effect between family history of diabetes and hyperlipidemia on the risk of diabetes in population with normotension.

Vulnerability of atherosclerotic plaques is associated with type I interferon in a murine model of lupus and atherosclerosis

This study aimed to investigate the relationship between type I interferon (IFN-I) and plaque stability in pristane-treated apolipoprotein E-knockout (ApoE(-/-)) mice. Antinuclear antibody (ANA) and extractable nuclear antigen antibody (ENA) levels were measured by immunofluorescence and enzyme-linked immunospot assay. Atherosclerotic plaques were detected by Sirius red/fast green staining. Cell apoptosis was detected by terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick-end labeling. Gene expression was determined by real-time PCR analyses. We found that pristane-treated ApoE(-/-) mice developed a lupus-like syndrome characterized by an increased production of serum ANA and ENA. Pristane treatment decreased the collagen content and increased the number of apoptotic cells in plaques. Moreover, IFN-induced ISG15, IFIT1-1, and IFIT1-2 gene expression was increased in peripheral blood cells and aortic plaques. An IFN-α-stimulated macrophage supernatant inhibited collagen type I, alpha 1 gene expression in vascular smooth muscle cells. We concluded that the vulnerability of plaques was associated with the activation of IFN-I in pristane-treated ApoE(-/-) mice. Thus, we speculated that the higher prevalence of cardiovascular events in patients with systemic lupus erythematosus could be due to plaque instability.

Pulmonary hypertension in systemic lupus erythematosus

A prospective echocardiographic and clinical study was performed on 84 Chinese patients with systemic lupus erythematosus (SLE) and 99 controls to investigate the prevalence and the mechanism of pulmonary hypertension (PH) in SLE. Comparison between Doppler estimation and catheterization measurement was made in 12 cases to validate the predictive method. Compared to normal subjects, lupus patients had significantly increased systolic pulmonary artery pressure (SPAP) (29.59 +/- 12.52 vs 19.64 +/- 5.82, P < 0.001), mean pulmonary artery pressure (MPAP) (15.11 +/- 7.36 vs 10.21 +/- 4.72, P < 0.001) and total pulmonary resistance (TPR) (315.85 +/- 190.65 vs 220.37 +/- 55.92, P < 0.001). Nine of the 84 patients presented PH, defined as SPAP < 30 mmHg and MPAP > 20 mmHg. Pulmonary hypertensive patients had higher serum endothelin (ET) than non-pulmonary hypertensive patients, were more commonly in active stages, and presented Raynaud's phenomenon and rheumatoid factors. ET level was correlated with echocardiographic pulmonary pressure. Pulmonary hypertension commonly occurs in Chinese patients with SLE (11%), and it correlates with the lupus activity and the elevation of serum endothelin.

[Labial salivary gland biopsy in the diagnosis of Sjogren's syndrome]

Labial salivary gland biopsy (LSG-B) along with Schirmer test and kerato-conjunctival staining with fluorescein dye was performed in 196 patients with suspected Sjogren's syndrome (SS). Of the 196 patients, 117 were found to have 2 or more lymphocytic focus scores (LFS/4mm2) on their LSG-B specimens. 92 of them having keratoconjunctivitis sicca (KCS) as well met the diagnostic criteria of SS. Among the cases (25) without KCS, 16 with another CTD were diagnosed as secondary SS. 9 cases were classified as probable primary SS in this study because they had clinical manifestations of SS. Of the 11 cases with KCS only, 6 with another CTD were diagnosed as secondary SS; 5 befitted primary SS for abnormal findings on sialography. We also found that lymphocytic infiltration in LSG-B was much more severe in primary SS than in secondary SS; this could be attributed to the use of immunotherapy for the accompanying CTD in secondary SS. There was good association in our study between the severity of lymphocytic infiltration and systemic involvement.

[Measurement of anticardiolipin antibodies and its significance in systemic lupus erythematosus]

A method for detection of anticardiolipin (ACL) antibodies with enzyme-linked immunosorbent assay was developed. Microtitre plates were coated with cardiolipin at a concentration of 20 micrograms/ml by evaporation under 4 degree centigrade overnight. Non-specific binding of diluted sera was eliminated by blocking of plates with 10% fetal calf serum in phosphate buffered saline (FCS/PBS) for 2 hours at room temperature. Sera (50 microliters/well) at a dilution of 1:100 were incubated for 2 hours at room temperature. Horseradish peroxidase conjugated rabbit anti-human IgG, IgM, IgA at a dilution of 1:2000, 1:1000, 1:500 respectively was added to the wells, and incubated for one and half hours at room temperature. The results were read at 490nm after incubation with substrates at 37 degree centigrade. 85 patients with systemic lupus erythematosus (SLE), 45 with rheumatoid arthritis (RA), 25 with progressive systemic scleroderma (PSS), and 18 primary Sjogren's syndrome were tested. The frequency of ACL antibody in SLE (48%) was much higher than that in RA (11%), PSS (12), SS (5.5). Three isotypes of ACL (IgG, IgM, IgA) were detected in the study with predominance of IgG isotype. ACL antibody was significantly associated with thrombosis, cutaneous vasculopathy, thrombocytopenia, and spontaneous abortion in patients with SLE. Strong relationship between ACL antibody and lupus anticoagulant was found. There was no correlation between ACL and anti-DNA antibodies, nor was ACL and VDRL test. The level of ACL antibody could be reduced by use of corticosteroids.