OBJECTIVETo explore the risk factors for mesothelioma so as to provide epidemiological evidences for prevention of this disease and for further study of its pathogenesis.

METHODSA 1:1 paired case-control study was carried out in which asbestos exposure, life style and histories of cancer in first-degree relatives of 23 patients who had mesothelioma were compared with those of controls.

RESULTSThe mean age of patients was 57.96 years with a latency period of 52 years. There were no significant differences in mean exposure age, mean exposure periods, and smoking, drinking habits between patients and controls. The mean cumulative exposure of patients was 37.2 x 10(5) f, which was significantly higher than that of controls (32.3 x 10(5) f, P = 0.005). The odds ratio increased with the cumulative exposure. The percentage of cancer in first-degree relative of patients (26.1%) was significantly higher than that of controls [(4.4%, P < 0.05), OR = 7.75 (95% CI: 0.85-71.43)].

CONCLUSIONThere may be a dose-response relationship between mesothelioma and asbestos exposure. A family history of cancer may be a risk factor for mesothelioma, or may indicate an increased susceptibility to mesothelioma under the same level of asbestos exposure.

Asbestos, Crocidolite ; adverse effects ; Case-Control Studies ; Environmental Exposure ; Family ; Humans ; Life Style ; Mesothelioma ; etiology ; genetics ; Middle Aged ; Pleural Neoplasms ; etiology ; genetics ; Risk Factors

Objective:To identify the prevalence of multimorbidity among a Chinese population, analyze the risk of all-cause mortality with different multimorbidity patterns, and the impact of exercise on the risk of multimorbidity-related mortality and life lost.Methods:The study was based on 437 408 MJ Health Management Center participants. The classification decision tree was used to explore multimorbidity patterns composed of hypertension, diabetes, chronic kidney disease (CKD), and chronic obstructive pulmonary disease (COPD). The Cox proportional hazards model was used to calculate the all-cause mortality hazard ratio ( HR) for different multimorbidity patterns. Using Chiang's life table method, years of life lost were the difference in life expectancy for those with and without multimorbidity. Results:The prevalence rate of multimorbidity was 8.7%. Among multivariate patterns, the most common ones were "hypertension+CKD" (3.6%), "hypertension + diabetes + CKD" (1.1%) and "hypertension+diabetes+CKD+COPD" (0.1%). Compared with a healthy population, patterns with the highest mortality risk were "diabetes+CKD" ( HR=3.80, 95% CI: 3.45-4.18), "diabetes+CKD+COPD" ( HR=4.34, 95% CI: 3.43-5.49) and "hypertension+ diabetes+CKD+COPD" ( HR=4.75,95% CI:4.15-5.43). Through low-intensity and moderate to high-intensity exercise, the increased HRs were attenuatedcompared with the inactive population. People with single disease and multimorbidity shortened life by 4.6 and 13.4 years, while exercise attenuated 2.3 and 4.6 years of life lost, of which low-intensity and moderate to high-intensity exercise saved 1.5 and 3.7 years of life lost due to chronic diseases. Conclusions:Multimorbidity patterns based on "diabetes + CKD" cause the highest mortality risk, and physical activity in reducing mortality was significant for either with or without multimorbidity. Higher exercise intensity leads to a greater relative reduction of mortality risk.