Age-related modification effect on the association between body mass index and the risk of hypertension: A Cohort Study on Chinese people living in the rural areas / 中华流行病学杂志

Objective: To study the modification effect of age on the association between body mass index and the risk of hypertension. Methods: People age ≥18 years old were selected by clusters, from a rural area of Henan province. In total, 20 194 people were recruited at baseline during 2007 and 2008, and the follow-up study was completed from 2013 to 2014. Logistic regression model was used to assess the risk of incident hypertension by baseline BMI and age-specific BMI. Results: During the 6-year follow-up period, 1 950 hypertensive persons were detected, including 784 men and 1 166 women, with cumulative incidence rates as 19.96%, 20.51%, and 19.61%, respectively. Compared with those whose BMI<22 kg/m(2), the RRs of hypertension were 1.09 (0.93-1.27), 1.17 (1.01-1.37), 1.34 (1.14-1.58) and 1.31 (1.09-1.56) for participants with BMI as 22-, 24-, 26- and ≥28 kg/m(2), respectively. In young and middle-aged populations, the risk of hypertension gradually increased with the rise of BMI (trend P<0.05). However, in the elderly, the increasing trend on the risk of hypertension risk was not as significantly obvious (trend P>0.05). Conclusion: The effect of BMI on the incidence of hypertension seemed to depend on age. Our findings suggested that a weight reduction program would be more effective on young or middle-aged populations, to prevent the development of hypertension.

Risk factors analysis and a new risk scoring system predicting hepatocarcinogenesis for chronic genotype C HBV infected patients / 中华流行病学杂志

Objective: To investigate the effects of hepatitis B virus (HBV) genotype and mutations on the development of hepatocellular carcinoma (HCC) and to establish a new qualified HCC risk scores. Methods: A cohort study enrolling patients with chronic HBV infection was conducted. HBV genotypes were identified by nested multiplex PCR. HBV mutations in the basic core promoter region and PreS region were sequenced after PCR amplification. Scores on risk factors were set based on nomogram. Results: Totally, 1 525 patients were followed-up in this research. A total of 1 110 patients infected with genotype C were followed-up for 8.52 (Q(R): 5.36-11.68) years on average, of whom the incidence of HCC was 11.93/1 000 person-years. In genotype C HBV infected patients, male gender, aged 40 years and over, and four DNA mutations (T1674CG, A1762T/G1764A, A3120T, and A2962G) can increase the risk of HCC (P<0.05); interferon therapy can reduce the risk of HCC (P<0.05). A new HCC predicting model was established according to the results. After validation, the predicted disease-free survival rate was consistent with the real one. Conclusions: Hepatitis B virus genotypes and mutations were closely associated with HCC. The new risk scoring system can well predict HCC occurrence in genotype C HBV infected patients.

Ecotoxicity of chloramphenicol and Hg acting on the root elongation of crops in north China

Single and joint toxicity of chloramphenicol and Hg acting on wheat [Triticum aestivum L.] Chinese cabbage [Brassica campestris L.] and corn [Zea mays L.] were investigated. The results showed positive correlations between root elongation inhibition of three plants and concentrations of pollutants added to soil [P<0.01] in test concentration range. In terms of root elongation, wheat was the most sensitive to toxicity of chloramphenicol with an IC[50] [concentration when 50% plants show inhibition] value as high as 26.8 mg/kg and also was the most sensitive one to the toxicity of Hg with the IC[50] value as high as 300.8 mg/ kg. The toxicity of chloramphenicol to the plants is stronger than that of Hg. Chloramphenicol and Hg had an antagonistic effect on the inhibition of root elongation of the three plants when the concentration of added Hg reached 30 mg/kg. Chloramphenicol and Hg had significantly synergistic effects on the inhibition of root elongation when Hg concentration was up to 200 mg/kg [P<0.05]