队列研究的进展及其对中国健康与营养调查的启示

营养调查是营养研究的重要手段之一,通过调查研究可以获得大量的膳食、社会环境、身体活动以及健康状况的数据信息,为分析和探讨膳食和非膳食因素对健康的影响提供了基础.随着人们对健康有害因素认识的深入,对营养调查在获取各种信息方面提出了更高的要求,为此需要应用更加有效、敏感的方法来探索可能存在的各种有害因素以及对健康的影响程度.

Objectives The purposes were to determine the relationship between silicosis among foundry workers and their cumulative exposure to silica dust, and to establish a regression model to predict the risk for developing silicosis by a given length of employment and air concentrations of silica at worksites. Methods A 29-year cohort study was conducted, including all those employed for more than one year during January 1, 1980 to December 31, 1996 and all members of the cohort were followed-up to December 31, 2008. In total, 2 009 workers of an automobile foundry in Shiyan, Hubei province were recruited in the study, 1 300 at eight worksites including sand preparation, cast shakeout, and finishing, melting, moulding, core-making, overhead crane operation and pouring as exposed group, and the other 709 auxiliary workers at the same factory, such as electricians, inspectors, fitters, and so on, as control group. Person-years of observation were calculated by persons observed and years followed-up for each of them. Person-year incidence of silicosis and its relative risk (RR) or odds ratio (OR) and 95% confidence intervals (CI) among the workers were estimated, adjusted for relevant factors with logistic regression model using SPSS version 15.0 software. Results Totally, 2 009 workers were followed-up for 37 151 person-years and 48 cases of silicosis were found, with an overall incidence of 1.34 per thousand, 2.02 per thousand in exposed group, and 0.15 per thousand in control one. Risk of silicosis was significantly higher in the exposed group than that in the control one (RR=13.13, 95% CI 3.18-54.13), higher in men than that in women (RR=13.92, 95% CI 1.92-100.93). Risks of silicosis varied by job, highest in those exposed to cast shakeout and finishing (RR=28.14, 95% CI 6.43-123.11), followed by those exposed to pouring (RR=22.23, 95% CI 5.01-98.55) in the foundry. Average length of employment at onset of silicosis was 25.94 years, and silicosis incidence increased with length of employment. Average age at onset of silicosis was 47.83 years old. The risk of silicosis in workers with pulmonary tuberculosis was 2.57 folds as those without it (P<0.01). Ten deaths were recorded in those with silicosis, with a case-fatality rate of 20.83 percent three of them died of lung cancer, three of liver cancer, two of ischemic heart disease, and two of other diseases as their immediate causes of death. Incidence of silicosis in foundry workers positively correlated with their currulative silica exposure (OR=3.00, 95% CI 2.34-3.83). Risks of silicosis increased by 4.38 folds with an increase of 1 mg/m3-year of cumulative silica exposure, and by 3.79 folds with smoking, respectively, adjusted for alcohol drinking and age. Based on a logistic regression model fitted, incidence of silicosis is expected to be 44.6 per thousand for those with daily exposure to silica of 4.18 mg/m3 in average for 30 years, and if incidence of silicosis is expected to be less than 1 per thousand, daily exposure to silica should be controlled below 0.2 mg/m3 for those with 20 years of employment, or below 0.1 mg/m3 for those with 30 or 40 years of silica exposure. Conclusions At present, foundry workers in China still face high risk of developing silicosis. For lowering occurrence of silicosis in exposed workers, it seems necessary that current occupational exposure limits for silica at worksites in China should be reexamined and silica dust control measures be strengthend.

阻塞性睡眠呼吸暂停低通气综合征的诊断与治疗

关于阻塞性睡眠呼吸暂停低通气综合征(obstructive sleep apnoea hypopnea syndrome, OSAHS)的WSCS(wisconsin sleep cohort study) 人群调查显示,30～60岁人群中呼吸暂停和低通气指数 (apnea hypopnea index,AHI)大于和等于5的男性占24%、女性占9%.尽管AHI大于和等于5者并不意味就是OSAHS患者,但是这个数据毕竟是OSAHS可能性较高的人群,比先前报告的男性4%、女性2%的OSAHS发病率高了许多.这是一个数目可观的人群,也是社会和医学界无法忽视的重要问题.OSAHS发病率和被诊断率调查结果也在不断地证实,对庞大的OSAHS人群来说世界范围内都存在着严重的诊断和治疗不足.有必要进一步增强对医生有关OSAHS知识和诊断能力的再教育,提高诊断效率与改进诊断和治疗方法.

活体供肝与尸体供肝影响移植后丙型肝炎严重程度的观察比较

供体因素可以影响肝移植受者术后丙型肝炎（HCV）的严重程度。活体肝移植供者通常较为年轻，冷缺血时间较短，可能对HCV感染患者更为有利。本文作者选取成人间活体肝移植研究队列（Adult-to-Adult Living Donor Liver Transplantation Cohort Study，A2ALL）中术后存活超过90天的HCV感染患者，中位随访时间为4.7年，观察其是否出现严重肝纤维化（Ishak分期≥3）和移植物失功。活体肝移植（LDLT）患者严重肝纤维化5年累积发生率为44%，而尸体肝移植（DDLT）组为37%（P＝0.16）。接受肝移植时的天冬氨酸转氨酶（AST）水平〔AST升高2倍时风险比（HR）＝1.38，P＝0.005〕和胆道狭窄（HR＝2.68，P＝0.0001）与严重肝纤维化相关，而LDLT则与严重肝纤维化无关〔HR＝1.11，95%可信区间（95%CI）0.73～1.69，P＝0.63〕。LDLT组患者和移植物的5年累积存活率分别为79%和78%，DDLT组分别为77%和75%（P＝0.43，P＝0.32）。HCV导致移植物失功的比例在LDLT组为27%、DDLT组为20%（P＝0.45）。胆道狭窄（HR＝2.25，P＝0.0006）、接受肝移植时的肌酐水平（肌酐升高2倍时HR＝1.74， P＝0.0004）以及AST水平（AST升高2倍时HR＝1.36，P＝0.004）与移植物失功相关，而LDLT则与移植物失功无关（HR＝0.76，95%CI 0.49～1.18，P＝0.23）。结论：供肝类型不影响HCV感染受者肝移植术后严重肝纤维化或移植物失功的发生。尽管LDLT可以缩短患者肝移植术前等待时间，但对术后HCV疾病进展并无明显益处。胆道狭窄是发生严重肝纤维化以及移植物失功的危险因素，接受肝移植时的高AST水平可能是移植后肝纤维化的重要预测因素。