BACKGROUND AND PURPOSE:

Stroke is a known cerebrovascular complication in lung cancer patients; however, whether lung cancer patients are at elevated risk of developing stroke relative to the noncancer population remains unclear.

METHODS:

The present study used population-based claims data from the Taiwan National Health Insurance, which identified 52,089 patients with an initial diagnosis of lung cancer between 1999 and 2007, and 104,178 matched noncancer subjects from all insured subjects age 20 years and older. Subsequent occurrence of stroke was measured until 2008, and the association between lung cancer and the hazard of developing stroke was estimated using Cox proportional hazard models.

RESULTS:

The incidence of stroke was 1.5 times higher (25.9 versus 17.4 per 1000 person-years) in the lung cancer group compared with the comparison group. The multivariate-adjusted hazard ratio (HR) comparing lung cancer patients with the noncancer group was 1.47 (95% CI, 1.39-1.56) for stroke, 1.78 (95% CI, 1.54-2.05) for hemorrhagic stroke, and 1.43 (95% CI, 1.34-1.51) for ischemic stroke. The risk of stroke fell over time, decreasing after 1 year of follow-up for men and after 2 years of follow-up for women. Within the first year of follow-up, the risk of stroke peaked during the first 3 months for men and within 4 to 6 months for women.

CONCLUSIONS:

Lung cancer is associated with increased risk of subsequent stroke within 1 year after diagnosis for men and 2 years after diagnosis for women.

BACKGROUND:

The health benefits of leisure-time physical activity are well known, but whether less exercise than the recommended 150 min a week can have life expectancy benefits is unclear. We assessed the health benefits of a range of volumes of physical activity in a Taiwanese population.

METHODS:

In this prospective cohort study, 416,175 individuals (199,265 men and 216,910 women) participated in a standard medical screening programme in Taiwan between 1996 and 2008, with an average follow-up of 8·05 years (SD 4·21). On the basis of the amount of weekly exercise indicated in a self-administered questionnaire, participants were placed into one of five categories of exercise volumes: inactive, or low, medium, high, or very high activity. We calculated hazard ratios (HR) for mortality risks for every group compared with the inactive group, and calculated life expectancy for every group.

FINDINGS:

Compared with individuals in the inactive group, those in the low-volume activity group, who exercised for an average of 92 min per week (95% CI 71-112) or 15 min a day (SD 1·8), had a 14% reduced risk of all-cause mortality (0·86, 0·81-0·91), and had a 3 year longer life expectancy. Every additional 15 min of daily exercise beyond the minimum amount of 15 min a day further reduced all-cause mortality by 4% (95% CI 2·5-7·0) and all-cancer mortality by 1% (0·3-4·5). These benefits were applicable to all age groups and both sexes, and to those with cardiovascular disease risks. Individuals who were inactive had a 17% (HR 1·17, 95% CI 1·10-1·24) increased risk of mortality compared with individuals in the low-volume group.

INTERPRETATION:

15 min a day or 90 min a week of moderate-intensity exercise might be of benefit, even for individuals at risk of cardiovascular disease.

FUNDING:

Taiwan Department of Health Clinical Trial and Research Center of Excellence and National Health Research Institutes.

Background

This study investigated mortality risks from all causes, circulatory and respiratory diseases for the elderly associated with prolonged exposure to extreme temperatures in four major cities of Taiwan.

Methods

Daily average temperatures at the high 99th, 97th, and 95th percentiles were defined as extreme heat, and those at the low 10th, 5th, and 1st percentiles were defined as extreme cold for each city in 1994–2007. Distributed lag non-linear model was used to estimate the relative risk (RR) of mortality associated with 30-day lag temperature, and heat and cold extremes lasting for 3–5, 6–8, and >8 days. The random-effects meta-analysis summarized the risks of temperature and extreme temperatures events.

Results

The lowest overall mortality among the elderly was when the temperature was 26 °C on average. Low temperatures caused greater adverse effects than high temperatures, particularly for mortality from circulatory diseases. After accounting for the cumulative 30-day temperature effects, meta-analysis showed that mortality risk slightly increased with strengthened and prolonged heat extremes (≥99th and >3 days; ≥97th and >8 days; and ≥ 95th and >8 days) that RRs ranged from 1.04–1.05, 1.01–1.05, and 1.05–1.13 for mortality from all causes and from circulatory and respiratory diseases, respectively. The corresponding RRs ranged from 0.98–1.01, 0.92–1.06, and 0.97–1.03, respectively, for shorter duration of heat extremes. This study did not identify significant effect for stronger or prolonged cold extremes.

Conclusions

Extreme temperatures and their duration cause varied mortality associations in the elderly. Short-term extremely low temperatures exhibit the greatest effect on mortality, and intensified and longer periods of heat extremes also exert a slightly increased effect on mortality.

OBJECTIVE:

To compare occupational exposure to extremely-low-frequency magnetic field (ELF-MF) between dentists practicing in dental clinics and those employed in hospitals.

METHODS:

Thirty-two dentists who worked at clinics (n=15) and 33 dentists employed at hospital dental departments (n=7) voluntarily provided their informed consent to participate in this measurement study. The study dentists were requested to wear an ELF-MF dosimeter for some 3 h at work to determine their personal exposure. Spot measurements taken at a number of locations in each dental office were used to indicate the work environment exposure level. Additionally, ELF-MF emitted from common dental equipment was also measured. All measurements were performed with EMDEX Lite meters.

RESULTS:

The average environmental exposure to ELF-MF is higher in clinic dental offices than in hospital dental departments (0.55 vs. 0.15 µT, p=0.008). Personal dosimetry showed that on average, clinic dentists spent 35.71 and 19.39% of their time at exposures above 0.3 and 0.4 µT at work, respectively. The corresponding figures for hospital dentists were 19.61 and 13.92%. Additionally, ELF-MF was greater than 0.4 µT at 30 cm from all selected equipment, but the ELF-MF generally diminished as the distance from dental equipment increased. Uultraviolet air sterilization system produced 3 times as much ELF-MF as other dental equipment.

CONCLUSIONS:

This study suggests the possibility of over-exposure of dentists to power frequency ELF-MF. Additionally, certain dental equipment may produce ELF-MF levels greater than 0.4 µT in areas where dentists usually work when treating patients.

OBJECTIVES:

This study used a population-based retrospective cohort design to examine whether depression is a risk factor of temporomandibular disorder (TMD).

METHODS:

From a universal insurance database, we identified 7587 patients who are newly diagnosed individuals with depression in 2000 and 2001. A total of 30,197 comparison subjects were randomly selected from a nondepression cohort. Both groups were followed until the end of 2008 to measure the incidence of TMD.

RESULTS:

The incidence of TMD was 2.65 times higher in the depression cohort than in the nondepression cohort (6.16 versus 2.32 per 1000 person-years). The hazard ratio (HR) measured by multivariate Cox's proportional hazard regression analysis of TMD for the depression cohort was 2.21 (95% confidence interval (CI) 1.83-2.66), after controlling for socio-demographic factors and other psychiatric comorbidities. Women had higher risk to develop TMD than men (HR 1.61, 95% CI 1.36-1.92 for women without depression; HR 3.54, 95% CI 2.81-4.45 for women with depression).

CONCLUSIONS:

This study demonstrates that patients with depression are at an elevated risk of developing TMD.