[A prospective study of association between physical activity and ischemic stroke in adults]

Objective: To explore the prospective associations between physical activity and incident ischemic stroke in adults. Methods: Data of China Kadoorie Biobank study in Tongxiang of Zhejiang were used. After excluding participants with cancers, strokes, heart diseases and diabetes at baseline study, a total of 53 916 participants aged 30-79 years were included in the final analysis. The participants were divided into 5 groups according to the quintiles of their physical activity level. Cox proportional hazard regression models was used to calculate the hazard ratios (HR) for the analysis on the association between baseline physical activity level and risk for ischemic stroke. Results: The total physical activity level in the participants was (30.63±15.25) metabolic equivalent (MET)-h/d, and it was higher in men [(31.04±15.48) MET-h/d] than that in women [(30.33±15.07) MET-h/d] (P<0.001). In 595 526 person-years of the follow-up (average 11.4 years), a total of 1 138 men and 1 082 women were newly diagnosed with ischemic stroke. Compared to participants with the lowest physical activity level (<16.17 MET-h/d), after adjusting for socio-demographic factors, lifestyle, BMI, waist circumference, and SBP, the HRs for the risk for ischemic stroke in those with moderate low physical activity level (16.17-24.94 MET-h/d), moderate physical activity level (24.95-35.63 MET-h/d), moderate high physical activity level (35.64-43.86 MET-h/d) and the highest physical activity level (≥43.87 MET-h/d) were 0.93 (95%CI: 0.83-1.04), 0.87 (95%CI: 0.76-0.98), 0.82 (95%CI: 0.71-0.95) and 0.76 (95%CI: 0.64-0.89), respectively. Conclusion: Improving physical activity level has an effect on reducing the risk for ischemic stroke.

[Association between self-reported gingival bleeding and prevalent hypertension among adults in a cross-sectional study in Zhejiang province]

Objective: To explore the association between self-reported gingival bleeding and prevalent hypertension among adults in Zhejiang with a cross-sectional study. Methods: After excluding participants with self-reported, physician-diagnosed heart diseases, stroke, diabetes, cancer, and those who never or rarely brush their teeth at baseline study, 48 625 participants aged 30-79 in the China Kadoorie Biobank (CKB) study from Tongxiang, Zhejiang were included for the final analysis. Three multivariable logistic regression models were used to estimate the odds ratios (ORs) for the associations of self-reported gingival bleeding with prevalent hypertension. Results: The mean age of women was (51.2±9.2) years, and 42.9% of participants had prevalent hypertension. The percentage of self-reported frequent gingival bleeding was 6.56% (95%CI: 6.38%-6.75%), significantly higher among women (8.08%, 95%CI: 7.82%-8.35%) than among men (4.36%, 95%CI: 4.12%-4.60%) (P<0.001). After adjusting for socio-demographic factors, behavioral lifestyle, sleep duration, BMI, waist circumference, snoring, in comparison with men whose gingivae never or rarely bleed while brushing teeth, the odds ratio (95%CI) of hypertension for those with occasional, and frequent gingival bleeding were 1.04 (0.96-1.12) and 1.18 (1.02-1.37), respectively (trend P =0.038). The corresponding figures for women were 0.96 (0.91-1.02) and 0.95 (0.86-1.05), respectively (trend P=0.344). Conclusion: Frequent gingival bleeding was positively associated with prevalent hypertension among men.

[Association between snoring and hypertension among Zhejiang adults in a cross sectional study]

Objective: To explore the association between snoring and prevalent hypertension among adults in Zhejiang with a cross-sectional study. Methods: After excluding participants with self-reported, physician-diagnosed heart diseases, stroke and cancer at baseline study, 56 728 participants aged 30-79 in the China Kadoorie Biobank study from Tongxiang, Zhejiang were included for the final analysis. Three multivariable logistic regression models were used to estimate the ORs for the associations of snoring with prevalent hypertension. Results: The proportion of participants who snored frequently, snored sometimes, and never snored were 24.55%, 23.94%, and 51.51%, respectively. The corresponding figures of males were 32.40%, 26.55%, and 41.05%, respectively. The corresponding figures of females were 19.00%, 22.08%, and 58.92%, respectively (P<0.001). After adjusted socio-demographic factors, behavioral lifestyle, BMI, waist circumference, and sleep duration etc., in comparison with participants who never snored, the odds ratios (95%CI) of hypertension for those who snored frequently and snored sometimes were 1.17 (1.12-1.23) and 1.12 (1.07-1.18), respectively. The effects of snoring on hypertension were statistically significantly different between women and men, participants who were central obese and those who were not, and between premenopausal and post-menopausal women. Conclusion: Snoring was associated positively with hypertension among adults. The effect of snoring on prevalent hypertension were obvious, especially among people, being female, being central obese, and being premenopausal.

[Evaluation on the effect of comprehensive intervention combined with clinical preventive services and lifestyle adjustment among high-risk populations of cardiovascular disease in Tongxiang City]

Objective: To evaluate the effect of comprehensive intervention combined with clinical preventive services and lifestyle adjustment on high-risk populations of cardiovascular disease. Methods: In 2015, 4 towns (streets) in Tongxiang City, of Zhejiang Province including Heshan Town, Longxiang Street, Wutong Street, and Fengming Street, were selected by using the typical sampling. The towns (streets) were allocated to the intervention group (Heshan Town and Longxiang Street) and the control group (Wutong Street and Fengming Street) by using the cluster random sampling. In each town (street), hypertension patients aged 50 to 74 years old who were taking community medicine management and with a 10-year cardiovascular disease risk ≥10% were recruited as subjects. There were 1 823 subjects in the intervention group and 1 883 in the control group. The intervention group was given a 1-year comprehensive intervention combining clinical preventive services and lifestyle adjustment, while the control group received routine chronic disease management. After the intervention, the final questionnaire investigation was conducted and health physical examination data were obtained. The death, acute coronary heart disease events and stroke incidence were the primary outcomes, and cardiovascular disease-related knowledge and behavior, clinical preventive services utilization, physical changes, blood fat index and 10-year cardiovascular disease risk were the secondary outcomes. The difference-in-difference model was used to evaluate the effects of interventions. Results: The age of subjects in the intervention and control group was (68.76±3.75) and (67.90±4.56) years old, respectively. After 1-year intervention, the incidence of mortality, acute coronary events and stroke in intervention group was 1.65% (30 cases), 0.27% (5 cases) and 2.69% (49 cases), respectively, which showed no statistical difference compared to the control group [1.33% (25 cases), 0.32% (6 cases) and 2.07% (39 cases)]. After adjusting for the age, gender, education, marital status, self-assessed family income level and situation of taking antihypertensive drugs, the difference-in-difference model showed that the body mass index and diastolic blood pressure in the intervention group decreased by 0.33 kg/m(2) and 1.49 mmHg (1 mmHg=0.133 kPa). Compared with the control group, daily vegetable consumption proportion, the awareness rates of aspirin, stains, salt intake, and oil intake increased by 4.76%, 26.22%, 29.56%, 10.80%, and 15.17%, respectively (P<0.05). Conclusion: After the 1-year comprehensive intervention, there was no significant change in primary outcomes among high-risk populations of cardiovascular disease. In secondary outcomes, body mass index and diastolic blood pressure declined and cardiovascular disease-related knowledge awareness increased.

[Association between tea drinking and stroke in adults in Zhejiang province: a prospective study]

Objective: To prospectively explore the association between tea drinking and incidence of stroke of adults of Zhejiang province. Methods: After excluding participants with heart disease, stroke, cancer and diabetes at baseline study, 53 916 participants aged 30-79 years in the China Kadoorie Biobank (CKB) study from Tongxiang were included for final analysis. Cox regression model was used to estimate the hazard ratio (HR) for the association of tea drinking with incident stroke. Results: The main type of drinking tea was black tea (79.78%), followed by green tea (20.08%). Of the 53 916 participants, the proportion of participants who drank tea at least once per week was 31.27%. The corresponding proportions for men and women were 60.24% and 10.30%, respectively. Among 391 512 person-years of the follow-up program (median 7.26 years), a total of 1 487 men and 1 769 women were diagnosed with stroke. After adjusting for socio-demographic status, lifestyle, BMI, waist circumference, and systolic blood pressure, HR for incident stroke decreased with the increase of daily average tea consumption amount (P=0.000 6). Compared with participants who did not drink tea weekly, the HRs for incident stroke in those consuming tea 0.1-, 3.0- and ≥5.0 g/d were 0.93 (95%CI: 0.85-1.00), 0.88 (95%CI: 0.77-0.99) and 0.79 (95%CI: 0.69-0.89), respectively. The HRs for incident stroke in smokers and non-smokers who consumed tea ≥5.0 g/d were 0.71 (95%CI: 0.59-0.86) and 0.97 (95%CI: 0.77-1.21), respectively, compared with current smokers and non-smokers who did not drink tea weekly (P=0.040 0). The corresponding HRs for alcohol drinkers and non-drinkers were 0.96 (95%CI: 0.76-1.22) and 0.70 (95%CI: 0.58-0.84), respectively (P=0.040 0). The corresponding HRs for central obese persons and non-central obese persons were 0.60 (95%CI: 0.44-0.81) and 0.86 (95%CI: 0.73-1.01), respectively (P=0.040 0). Conclusion: Tea drinking had an effect on reducing the possibility of incident stroke, especially among those who were current smokers, non-alcohol drinkers and central obese.

[Prospective study on the effect of BMI and waist circumference on diabetes of adults in Zhejiang province]

Objective: To explore the effect of BMI and waist circumference on diabetes of adults. Methods: After excluding participants with heart disease, stroke, cancer and diabetes at baseline study, 53 916 people aged 30-79 in the China Kadoorie Biobank (CKB) study from Tongxiang city of Zhejiang province were recruited. Cox regression model was used to estimate the hazards ratios (HR) for the associations of baseline BMI and waist circumference with incident diabetes. Results: Among 391 512 person-years of the follow-up program between 2004 and 2013 (median 7.26 years), a total of 944 men and 1 643 women were diagnosed as having diabetes. Compared to those with normal weight, after adjusting for known or potential factors, HR of both overweight and obesity in men for incident diabetes appeared as 2.72 (95%CI: 2.47-2.99) and 6.27 (95%CI: 5.33-7.36), respectively. The corresponding figures in women were 2.19 (95%CI: 2.04-2.36) and 3.78 (95%CI: 3.36-4.26). Compared to those with normal waist circumference, after adjusting for known or potential factors, HR of Ⅰgrade andⅡgrade in men for diabetes were 2.56 (95%CI: 2.22-2.95) and 4.66 (95%CI: 4.14-5.24), respectively. The corresponding figures in women were 1.99 (95%CI: 1.80-2.21) and 3.16 (95%CI: 2.90-3.44), respectively. Conclusions: Overweight, obesity and central obesity were all associated with the increased incident of diabetes. Strategies on diabetes prevention should include not only losing weight, but reducing waist circumference as well.

[Effect of acid etching of retropreparation cavities on seal of retrofill materials]

OBJECTIVE

To evaluate the effect of acid etching of retropreps on seal of different retrofill materials.

METHODS

In the study, 80 freshly extracted lower molar teeth were used. They were examined under 3.5× magnifying glass to rull out fractures. They were cleaned and stored in distilled water before use. The distal roots were sectioned off and underwent root canal treatment. Rotary nickel-titanium instruments were used during instrumentation and the roots were obturated using lateral condensation technique. The apical portion (3 mm in length) was removed with a fine grit diamond bur, the root tip was retroprepared with a ultrasonic tip (3 mm in depth). The retroprepared roots were randomly assigned to 4 groups and retrofilled with amalgam, intermediate restorative material (IRM), iRoot BP Plus and mineral trioxide aggregate (MTA). The groups were further divided into subgroups according to treatment of the root end cavity (etch and non-etch). The root tips were covered with alginate impression material and were left to set in PBS solution for a week and stained with methylene blue for a week. The roots were removed from the dye solution, thoroughly rinsed and dried, split in halves along the long axis with a diamond disk and observed under a stereoscope. The linear dye leakage was measured and analyzed. One way ANOVA and Tamhane's T2 method were used to analyze the data. The significance level was set at 0.05.

RESULTS

The dye leakage results (mean±standard deviation) according to the treatment groups were: amalgam etch (2.80±0.72) mm, amalgam non-etch (2.07±0.86) mm, IRM etch (1.54±0.19) mm, IRM non-etch (1.12±0.28) mm , iRoot BP Plus etch (0.20±0.20) mm, iRoot BP Plus non-etch (0.11±0.08) mm, MTA etch (0.19±0.19) mm, and MTA non-etch (0.17±0.14) mm. One way ANOVA showed significant differences between the groups. Comparison between the groups using Tamhane's T2 method showed roots retrofilled with iRoot BP Plus and MTA had significant less leakage than those retrofilled with amalgam and IRM (P<0.05); There was no significant difference in terms of leakage between iRoot BP Plus and MTA; Acid etching increased leakage of IRM but did not affect MTA, iRoot BP Plus or amalgam retrofillings.

CONCLUSION

Acid etching is not shown to benefit apical sealing of retrofill materials.

[Interaction between smoking and indoor air pollution on chronic obstructive pulmonary diseases]

Objective: To investigate the prevalence of chronic obstructive pulmonary diseases (COPD) in Tongxiang, Zhejiang province, and analyze the interaction between smoking and indoor air pollution on COPD. Methods: Townships of Chongfu, Zhouquan, Gaoqiao, Shimen, Wuzhen were randomly selected from Tongxiang. All the local people aged 30-79 years were asked to receive questionnaire survey, physical examination and pulmonary function testing. FEV₁max/FVC max≤0.7 was the criterion of COPD diagnosis. Logistic regression model was used to analyze the relationship between smoking/indoor air pollution and COPD, multiplied interaction between smoking and indoor air pollution was evaluated, Excel table prepared by Andersson et al. was used to calculate the adding interaction. Results: The overall prevalence of COPD was 6.6%, and adjusted for age, educational level, occupation, marriage, income level, BMI, waist-to-hip and other factors, multivariate logistic regression analysis showed that males who had quit smoking, started smoking at age of <25 years had a high risk of COPD; females who smoked every day <15 g, inhaled smoke into mouth or throat had high risk of COPD. Interaction analysis showed that using fuel of firewood/charcoal/coal, briquettes for cooking and regular smoking had multiplied interaction on COPD. Use no chimney or exhaust system in cooking and regular smoking had adding interaction in females. Conclusion: The prevalence of COPD in Tongxiang was close to the national average level. Female smokers had higher risk for COPD than male smokers. Improving kitchen ventilation, using natural gas or fuel gas for cooking and active tobacco control would facilitate the prevention of COPD.

[Association and interaction between age at menarche and risk of diabetes in adult women]

Objective: To explore the associations between age at menarche and diabetes in adult women. Methods: We analyzed the baseline data of 32 364 female participants who were aged 30-79 years and had been enrolled into China Kadoorie Biobank (CKB) study from Tongxiang, Zhejiang province. Multiple logistic regression analysis were used to investigate the putative associations after adjusting for potential confounders. Variables of menarche age and others were added to the logistic regression model to evaluate the multiplicative interaction, respectively. Results: The mean age of female participants was (51.42 ± 9.63) years. And 3.73% and 24.17% of them reported their menarche age, ≤12 years, ≥17 years, respectively. The prevalence of diabetes among them was 5.75%. Compared with those with menarche age ≤12 years, the OR(95%CI) of 15-16, 13-14 and ≤12 years group were 1.13(1.00-1.27), 1.29(1.12-1.49) and 1.68(1.31-2.15) after adjusting for age, socioeconomic status, family history, health behaviors, menopause status, BMI and waist circumference. No significant differences were found in multiplicative interaction on diabetes between menarche age and smoking, alcohol consumption, physical activity, obesity, etc. (P>0.05). Conclusions: Menarche age is associated with higher risk of diabetes in female adults. The earlier menarche age is the higher risk of diabetes. There are no multiplicative interaction on diabetes between menarche age and other adults factors.

Fracture resistance of root filled premolar teeth restored with direct composite resin with or without cusp coverage

AIM

To evaluate the fracture resistance and fracture patterns of root filled maxillary first premolar teeth (with mesio-occlusal cavity preparation) restored with several composite restoration designs.

METHODOLOGY

One hundred extracted sound human maxillary first premolars were randomly divided into five groups. Group 1 remained untreated (negative control). Conventional root canal treatment with additional mesial-occlusal cavity preparation was carried out on teeth in groups 2-5. In group 2, the teeth were restored intra-coronally with direct composite resin (positive control). In group 3, the palatal cusps of the teeth were reduced, and the cavities were restored with composite resin covering the palatal cusp (partial coverage). In group 4, the buccal and palatal cusps along with the distal marginal ridges were reduced; the cavities and cusps were restored with composite resin (conventional full coverage). In group 5, the buccal and palatal cusps were reduced but the distal marginal ridges were conserved. The cavities and the cusps were restored with composite resin (modified full coverage). All teeth were subjected to a progressive compressive loading parallel to their longitudinal axis until fracture. Fracture resistance was analysed using the one-way ANOVA and Fisher's LSD test. Fracture patterns were analyzed with chi-square test. The significance level was set at 0.05.

RESULTS

The fracture resistance (mean ± SD) of groups 1-5 was 1131 ± 207N, 904 ± 184N, 927 ± 224N, 1095 ± 289N and 1085 ± 243N, respectively (groups 1, 4, 5 > groups 2, 3; P = 0.004). Cusp fractures were recorded as the fracture pattern in 20 (100%), 19 (95%), 16 (80%), 8 (40%) and 12 (60%) premolars in groups 1-5, respectively (groups 1, 2 > groups 4, 5; group 3 > group 4; P < 0.001).

CONCLUSIONS

When direct composite resin was used to restore root filled maxillary first premolar teeth involving a proximal surface, those restored with full-coverage designs had greater fracture resistance.