Type and timing of exercise during lunch breaks for suppressing postprandial increases in blood glucose levels in workers.

OBJECTIVES: Suppression of postprandial hyperglycemia may aid in preventing lifestyle-related diseases in working people. The present study aimed to identify the types and timings of exercises that can be performed by working people during a 60-minute lunch break that are effective in attenuating postprandial increases in blood glucose levels. METHODS: Healthy working people aged 20 years and older were subjected to aerobic (AER) or resistance (RES) exercise before (Pre) and after (Post) lunch, assuming a 60-minute lunch break, with fixed 20-minute lunch and rest periods. These exercise sessions of 4 different patterns were performed by each participant. Serial measurements of blood glucose levels were obtained every 15 minute using a Flash Glucose Monitoring System. RESULTS: Data were analyzed for 11 participants who completed the protocol. Our incremental area under the curve (IAUC) analysis indicated that the AER-Post condition was associated with the most significant hypoglycemic effect, followed by the AER-Pre condition. Although the RES-Post showed no significant difference, a decrease in the IAUC comparison is apparent. However, the RES-Pre condition exerted no acute effect on blood glucose levels. CONCLUSIONS: Workers may benefit from a 20-minute aerobic exercise period, following a 20-minute lunch and a 20-minute rest period, as this may help prevent progression to diabetes. Furthermore, performing 20-minute aerobic exercises prior to lunch may also attenuate postprandial increases in blood glucose levels. Therefore, if the lunch breaks are short, aerobic exercises are recommended before lunch.

Evaluation of cellular toxicity of TAFMAG, a natural substitute for asbestos from China.

Asbestos is a very important material for industrial use. However, the need for a substitute for asbestos fiber is currently on the rise due to its high disease causing potential. This study evaluated the potential bio-hazardous effects of TAFMAG, a natural fibrous silicate produced in China, in comparison with chrysotile, a typical toxic asbestos. The physicochemical properties of TAFMAG were very similar to those of chrysotile when it was examined by a scanning electron microscope (SEM) and X-ray diffraction (XRD) analyses. Both of TAFMAG and chrysotile showed high content of magnetite and Fenton activity when compared with wollastonite, a non-asbestos fiber with a known low toxicity. When their cellular toxicity was assessed, TAFMAG showed no or less comparable to that of chrysotile in the hemolysis and lipid peroxidation of erythrocytes, and also on a MTT assay in RLE-6TN, a rat alveolar epithelial cell line. Pre-treatment of fibers with desferrioxamine, an iron chelator, showed that iron content of TAFMAG and chrysotile might be important in their cellular toxicity. These results suggest that TAFMAG is potentially toxic when inhaled into the lung and appropriate laws and regulations should be established for its use.

Methodological Issues for a Large-Scale Intervention Trial of Lifestyle Modification: Interim Assessment of the High-Risk and Population Strategy for Occupational Health Promotion (HIPOP-OHP) Study

Objective: To clarify the methodological issues for the High-risk and Population Strategy for Occupational Health Promotion Study (HIPOP-OHP study), which is a 4-year non-randomized control trial, an interim assessment of male participants was performed 3 years after the baseline survey. Methods: We had approximately 2,500 and 4,000 participants in the intervention and control groups, respectively. The population measures and prevalence of risk factors at each year, and between the baseline and 4th examinations were compared between the two groups. The personal trends of returning participants who were in the study at the 1st and 4th examinations were also evaluated. Results: During the 3 years, an increase in serum HDL cholesterol (2.7 mg/dl), and a reduction in the prevalence of hypertriglycemia detected with fasting blood samples (3.6%) and current smokers (5.4%) were observed in the intervention group. The mean HDL cholesterol level was significantly higher in the intervention group than in the control group at the 4th examination, reversed from the baseline survey. The serum non-HDL cholesterol level was significantly increased only in the control group. There was also a significant increase in the prevalence of hypertriglycemia and high plasma glucose detected with fasting blood samples in the control group. The return participation rate after 3 years was 72.2% for the intervention group and 74.9% for the control group. The above-mentioned changes for risk factors were mainly due to returning participants at each examination. Conclusion: These interventional methods may be effective in improving overall cardiovascular risk factors in the population. However, the low return participation rate will dilute the effect of the intervention.

Methodological issues for a large-scale intervention trial of lifestyle modification: Interim assessment of the high-risk and population strategy for occupational health promotion (HIPOP-OHP) study

<p><b>OBJECTIVE</b>To clarify the methodological issues for the High-risk and population Strategy for Occupational Health Promotion Study (HIPOP-OHP study), which is a 4-year non-randomized control trial, an interim assessment of male participants was performed 3 years after the baseline survey.</p><p><b>METHODS</b>We had approximately 2,500 and 4,000 participants in the intervention and control groups, respectively. The population measures and prevalence of risk factors at each year, and between the baseline and 4th examinations were compared between the two groups. The personal trends of returning participants who were in the study at the 1(st) and 4(th) examinations were also evaluated.</p><p><b>RESULTS</b>During the 3 years, an increase in serum HDL cholesterol (2.7 mg/dl), and a reduction in the prevalence of hypertriglycemia detected with fasting blood samples (3.6%) and current smokers (5.4%) were observed in the intervention group. The mean HDL cholesterol level was significantly higher in the intervention group than in the control group at the 4th examination, reversed from the baseline survey. The serum non-HDL cholesterol level was significantly increased only in the control group. There was also a significant increase in the prevalence of hypertriglycemia nad high plasma glucose detected with fasting blood samples in the control group. The return participation rate after 3 years was 72.2% for the intervention group and 74.9% for the control group. The above-mentioned changes for risk factors were mainly due to returning participants at each examination.</p><p><b>CONCLUSION</b>These interventional methods may be effective in improving overall cardiovascular risk factors in the population. However, the low return participation rate will dilute the effect of the intervention.</p>