Relationship of sleep duration and annual changes in sleep duration with the incidence of gastrointestinal cancers: a prospective cohort study.

BACKGROUND: Prospective analyses have yet to identify a consistent relationship between sleep duration and the incidence of gastrointestinal (GI) cancers. The effect of changes in sleep duration on GI cancer incidence has scarcely been studied. Therefore, we aimed to examine the association between baseline sleep duration and annual changes in sleep duration and GI cancer risk in a large population-based cohort study. METHODS: A total of 123,495 participants with baseline information and 83,511 participants with annual changes in sleep duration information were prospectively observed from 2006 to 2015 for cancer incidence. Cox proportional-hazards models were used to calculate hazard ratios (HRs) and their confidence intervals (CIs) for GI cancers according to sleep duration and annual changes in sleep duration. RESULTS: In baseline sleep duration analyses, short sleep duration (≤5 h) was significantly associated with a lower risk of GI cancer in females (HR: 0.31, 95% CI: 0.10-0.90), and a linear relationship between baseline sleep duration and GI cancer was observed (P = 0.010), especially in males and in the >50-year-old group. In the annual changes in sleep duration analyses, with stable category (0 to -15 min/year) as the control group, decreased sleep duration (≤-15 min/year) was significantly associated with the development of GI cancer (HR: 1.29; 95% CI: 1.04-1.61), especially in the >50-year-old group (HR: 1.32; 95% CI: 1.01-1.71), and increased sleep duration (>0 min/year) was significantly associated with GI cancer in females (HR: 2.89; 95% CI: 1.14-7.30). CONCLUSIONS: Both sleep duration and annual changes in sleep duration were associated with the incidence of GI cancer.

Esophageal Thermal Exposure to Hot Beverages: A Comparison of Metrics to Discriminate Distinct Consumption Habits.

BACKGROUND: Hot beverage consumption is a probable risk factor for esophageal squamous cell carcinoma (ESCC). No standardized exposure assessment protocol exists. METHODS: To compare how alternative metrics discriminate distinct drinking habits, we measured sip temperatures and sizes in an international group of hot beverage drinkers in France (n = 20) and hot porridge consumers (n = 52) in a high ESCC incidence region of China. Building on the knowledge that sip size and temperature affect intraesophageal liquid temperature (IELT), IELTs were predicted by modeling existing data, and compared with first sip temperature and, across all sips, mean temperature and sip-weighted mean temperature. RESULTS: Two contrasting exposure characteristics were observed. Compared with the international group, Chinese porridge consumers took larger first sips [mean difference +17 g; 95% confidence interval (CI), 13.3-20.7] of hotter (+9.5°C; 95% CI, 6.2-12.7) liquid, and their mean sip size did not vary greatly across sips, but the former groups increased in size as temperature decreased. This resulted in higher predicted IELTs (mean 61°C vs. 42.4°C) and sip-weighted temperatures (76.9°C vs. 56°C) in Chinese porridge consumers, and compared with first sip and mean temperature, these two metrics separated the groups to a greater extent. CONCLUSIONS: Distinguishing thermal exposure characteristics between these groups was greatly enhanced by measuring sip sizes. Temperature at first sip alone is suboptimal for assessing human exposure to hot foods and beverages, and future studies should include sip size measurements in exposure assessment protocols. IMPACT: This study provides a logistically feasible framework for assessing human exposure to hot beverages.