Hypnotics and Risk of Cancer: A Meta-Analysis of Observational Studies

Insomnia disorder and cancer mortality in South Korea: a secondary analysis of musculoskeletal disease cohort

PURPOSE

The association between insomnia disorder and cancer-related mortality risk remains controversial. Therefore, this study aimed to investigate the correlation between insomnia disorder and cancer-related mortality.

METHODS

Patients who were diagnosed with musculoskeletal disease (MSD) between 2010 and 2015 were included in this study as a secondary analysis of a patient cohort with MSD in South Korea. Cancer mortality was evaluated between January 1, 2016, and December 31, 2020, using multivariable Cox regression modeling. Patients with and without insomnia disorder constituted the ID and non-ID groups, respectively.

RESULTS

The final analysis incorporated a total of 1,298,314 patients diagnosed with MSDs, of whom 11,714 (0.9%) died due to cancer. In the multivariable Cox regression model, the risk of total cancer-related mortality was 14% (hazard ratio [HR], 1.14; 95% confidence interval [CI], 1.10-1.19; P < 0.001) higher in the ID group than in the non-ID group. Moreover, the ID group had a higher risk of mortality due to esophageal (HR, 1.46; 95% CI, 1.08-1.96; P = 0.015), colorectal (HR, 1.20; 95% CI, 1.05-1.36; P = 0.007), head and neck (HR, 1.39; 95% CI, 1.01-1.94; P = 0.049), lung (HR, 1.17; 95% CI, 1.08-1.27; P < 0.001), and female genital organ (HR: 1.39, 95% CI: 1.09, 1.77; P = 0.008) cancers; leukemia; and lymphoma (HR, 1.30; 95% CI, 1.12-1.49; P < 0.001).

CONCLUSION

Insomnia disorder was associated with elevated overall cancer mortality in patients with MSDs, which was more evident for cancer mortality due to esophageal, colorectal, head and neck, lung, and female genital organ cancers; leukemia; and lymphoma.

Sleep disorders and cancer incidence: examining duration and severity of diagnosis among veterans

Introduction

Sleep disruption affects biological processes that facilitate carcinogenesis. This retrospective cohort study used de-identified data from the Veterans Administration (VA) electronic medical record system to test the hypothesis that patients with diagnosed sleep disorders had an increased risk of prostate, breast, colorectal, or other cancers (1999-2010, N=663,869). This study builds upon existing evidence by examining whether patients with more severe or longer-duration diagnoses were at a greater risk of these cancers relative to those with a less severe or shorter duration sleep disorder.

Methods

Incident cancer cases were identified in the VA Tumor Registry and sleep disorders were defined by International Classification of Sleep Disorder codes. Analyses were performed using extended Cox regression with sleep disorder diagnosis as a time-varying covariate.

Results

Sleep disorders were present among 56,055 eligible patients (8% of the study population); sleep apnea (46%) and insomnia (40%) were the most common diagnoses. There were 18,181 cancer diagnoses (41% prostate, 12% colorectal, 1% female breast, 46% other). The hazard ratio (HR) for a cancer diagnosis was 1.45 (95% confidence interval [CI]: 1.37, 1.54) among those with any sleep disorder, after adjustment for age, sex, state of residence, and marital status. Risks increased with increasing sleep disorder duration (short [<1-2 years] HR: 1.04 [CI: 1.03-1.06], medium [>2-5 years] 1.23 [1.16-1.32]; long [>5-12 years] 1.52 [1.34-1.73]). Risks also increased with increasing sleep disorder severity using cumulative sleep disorder treatments as a surrogate exposure; African Americans with more severe disorders had greater risks relative to those with fewer treatments and other race groups. Results among patients with only sleep apnea, insomnia, or another sleep disorder were similar to those for all sleep disorders combined.

Discussion

The findings are consistent with other studies indicating that sleep disruption is a cancer risk factor. Optimal sleep and appropriate sleep disorder management are modifiable risk factors that may facilitate cancer prevention.

Benzodiazepine Use and Long-Term Mortality in South Korean Adult Population: A Cohort Study

PURPOSE

Studies have reported mixed results on the association between benzodiazepine use and mortality. Here, we investigated whether benzodiazepine use is associated with a higher risk of 5-year all-cause mortality, and examined the association between benzodiazepine use and 5-year disease-specific mortality.

MATERIALS AND METHODS

In this population-based cohort study, a nationally representative sample cohort in South Korea was examined. In 2010, benzodiazepine users were defined as individuals prescribed benzodiazepine continuously over 30 days for regular administration, and all other subjects were included in the control group. The primary endpoint was 5-year all-cause mortality, evaluated from 2011 to 2015. Propensity score (PS) matching and time-dependent Cox regression were performed for statistical analysis, which included benzodiazepine use during 2011-2015 as a time-dependent variable.

RESULTS

A total of 822414 adult individuals were included in the final analysis, and the all-cause 5-year mortality was recorded in 20991 individuals (2.7%). The benzodiazepine group included 30837 patients and the control group comprised 791377 patients. After PS matching, 61672 individuals (30836 in each group) were included in the final analysis. After PS matching, the 5-year all-cause mortality in the benzodiazepine group was 10.0% (3082/30836), whereas that in the control group was 9.4% (2893/30836). In time-dependent Cox regression analysis of the PS-matched cohort, the benzodiazepine group showed 1.15-fold higher 5-year all-cause mortality (hazard ratio: 1.15, 95% confidence interval: 1.09-1.22; p<0.001) compared to the control group.

CONCLUSION

Benzodiazepine use was associated with increased 5-year all-cause mortality in the South Korean adult population. Further studies are needed to confirm these findings.