Circadian rhythm of melatonin and blood pressure changes in patients with essential hypertension / 中华心血管病杂志

<p><b>OBJECTIVE</b>To observe the association between melatonin (MLT) secretion and blood pressure changes during 24 hours in hypertensive patients (HPT) with (dipping) or without (non-dipping) night time blood pressure reduction.</p><p><b>METHODS</b>The 24-hour blood pressure and urine 6-SMT (6-sulfatoxymelatonin, metabolism product of MLT in urine) in the daytime and nighttime were measured in normal control subjects (n = 20), non-dipping HPT group (n = 32) and dipping HPT group (n = 36).</p><p><b>RESULTS</b>As expected, blood pressure reduction during the night was significantly lower in non-dipping HPT group compared to control and dipping HPT groups. Nighttime 6-SMT was significantly higher than daytime 6-SMT in all groups and nighttime urine 6-SMT levels and ratio of nighttime/daytime urine 6-SMT levels were significantly lower in non-dipping HPT group compared to control and dipping HPT groups (all P < 0.01). Moreover, ratio of nighttime/daytime urine 6-SMT levels are positively correlated blood pressure reduction during nighttime (P < 0.05) in all groups.</p><p><b>CONCLUSIONS</b>Circadian rhythm of MLT secretion is maintained but nighttime MLT secretion was significantly reduced and related to disorders of circadian rhythm of blood pressure in non-dipping HPT group.</p>

Smoking prevention and control among elementary school students in Xuhui district, Shanghai / 中华流行病学杂志

<p><b>OBJECTIVE</b>To evaluate the effectiveness of a school-based smoking prevention and control intervention program among elementary school students.</p><p><b>METHODS</b>Through two phase cluster sampling, 566 pupils in grade 4 and grade 5 of two schools were assigned to intervention group and control group. One year comprehensive smoking intervention was conducted in the intervention group. The assessment was carried out through three questionnaires: pre- and post-intervention, 6-month after intervention.</p><p><b>RESULTS</b>After one year intervention, pupils in the intervention group significantly improved their knowledge and attitudes related to tobacco use. The rate of attempting smoking decreased form 7.8% to 2.6% and the rate of passive smoking from 53.6% to 41.8%. The difference between the intervention and control groups was statistically significant. However, several index started to decline at 6-month follow up survey.</p><p><b>CONCLUSION</b>The result demonstrated the effectiveness and feasibility of tobacco control in elementary school and the positive effect must be developed.</p>