The Association Between Diabetic Retinopathy and the Prevalence of Age-Related Macular Degeneration-The Kailuan Eye Study.

This study aimed to investigate the prevalence of age-related macular degeneration (AMD) in patients with diabetes mellitus (DM) and diabetic retinopathy (DR) and analyze whether DR is a risk factor for AMD. This population-based epidemiological study included 14,440 people from the Kailuan Eye Study in 2016, of whom 1,618 were patients with type 2 DM aged over 50 years, and 409 had DM with DR. We analyzed whether there were differences in the prevalence of AMD between DM with DR and DM without DR, and conducted a hierarchical statistical analysis according to different stages of DR. Using variable regression analysis, we explored whether DR constituted a risk factor for AMD. In the DM population, the prevalence of wet AMD in patients with DM with and without DR was 0. 3 and 0.2%, respectively, with no significant difference (P = 0.607). Meanwhile, the prevalence of dry AMD in patients with DM with and without DR was 20.8 and 16.0%, respectively, with a significant difference. In the subgroup analysis of dry AMD, the prevalence of early, middle, and late dry AMD in DM with DR was 14.4, 5.9, and 0.5%, respectively. In DM without DR, the prevalence of early, middle, and late dry AMD was 10.5, 4.8, and 0.7%, respectively (P = 0.031). In the subgroup analysis of DR staging, statistical analysis could not be performed because of the limited number of patients with PDR. In the variable regression analysis of risk factors for dry AMD, after adjusting for age, sex, body mass index, hypertension, and dyslipidemia, DR constituted the risk factor for dry AMD. In conclusion, DM did not constitute a risk factor for AMD, and the prevalence of wet AMD and dry AMD in patients with DM and DR was higher than that in patients with DM without DR (among which dry AMD was statistically significant). Multivariate regression analysis confirmed that DR is an independent risk factor for dry AMD. Reasonable control of DM and slowing down the occurrence and development of DR may effectively reduce the prevalence of AMD in patients with DM.

Determination and Pharmacokinetics of Clopidogrel in Human Plasma by LC-MS/MS / 医药导报

Objective To establish a liquid chromatography-tandem mass spectrometric ( LC-MS/MS ) for determination of clopidogrel in human plasma and stability of clopidogrel under different conditions,which was used subsequently to investigate the pharmacokinetics of clopidogrel in healthy Chinese volunteers. Methods Clopidogrel-d4 hydrogen sulfate was used as an internal standard. Separation was achieved on a WATERS Xterra? RP18 column (4.6 mm× 100 mm,3.5μm) with a mobile phase consisting of acetonitrile-0.1% formic acid (66:34) at a flow rate of 1.0 mL.min-1 within 3.2 min. ESI source was applied and operated in positive ion mode and multiple reaction monitoring (MRM). Plasma samples were pretreated by acetonitrile precipitation. Results A good linearity of clopidogrel was obtained in the concentration range of ( 5-5 000 ) ng.L-1. The lower limit of quantification was 5 ng.L-1. The intra-and inter-run precisions at three quality control levels were within 1.3%–9.9%,the relative deviation of the assay was within -6.2%-14.3%. The blood samples were stable when chilled with crushed ice ( 0℃) and cold water ( 4℃) ,as well as kept at room temperature ( 20℃) for 40 min. The plasma QC samples were stable at room temperature ( 20 ℃) for 4 h,at -70℃ for 38 days and during three freeze-thaw cycles. Hemolysis in blood sample drawn didn’ t affect the plasma concentration. The determination and the result of incurred sample reanalysis met the requirements. Conclusion A specific, rapid, sensitive and stable LC-MS/MS method is developed and validated for determination of clopidogrel in human plasma. The method is proven to be suitable for study of the pharmacokinetics of clopidogrel in healthy Chinese volunteers after a single oral dose of 75 mg clopidogrel hydrogen sulphate tablet.