Consumption of hot beverages and foods and the risk of esophageal cancer: a meta-analysis of observational studies.

BACKGROUND: Previous studies have mostly focused on the effects of specific constituents of beverages and foods on the risk of esophageal cancer (EC). An increasing number of studies are now emerging examining the health consequences of the high temperature of beverages and foods. We conducted a meta-analysis to summarize the evidence and clarify the association between hot beverages and foods consumption and EC risk. METHODS: We searched the PubMed, Embase, and Web of Science databases for relevant studies, published before May 1, 2014, with the aim to estimate the association between hot beverage and food consumption and EC risk. A random-effect model was used to pool the results from the included studies. Publication bias was assessed by using the Begg test, the Egger test, and funnel plot. RESULTS: Thirty-nine studies satisfied the inclusion criteria, giving a total of 42,475 non-overlapping participants and 13,811 EC cases. Hot beverage and food consumption was significantly associated with EC risk, with an odds ratio (OR) of 1.82 (95% confidence interval [CI], 1.53-2.17). The risk was higher for esophageal squamous cell carcinoma, with a pooled OR of 1.60 (95% CI, 1.29-2.00), and was insignificant for esophageal adenocarcinoma (OR: 0.79; 95% CI: 0.53-1.16). Subgroup analyses suggests that the association between hot beverage and food consumption and EC risk were significant in Asian population (OR: 2.06; 95% CI: 1.62-2.61) and South American population (OR: 1.52; 95% CI: 1.25-1.85), but not significant in European population (OR: 0.95; 95% CI: 0.68-1.34). CONCLUSIONS: Hot beverage and food consumption is associated with a significantly increased risk of EC, especially in Asian and South American populations, indicating the importance in changing people's dietary habits to prevent EC.

Breakfast skipping and the risk of type 2 diabetes: a meta-analysis of observational studies.

OBJECTIVE: Breakfast skipping has been reported to be associated with type 2 diabetes (T2D), but the results are inconsistent. No meta-analyses have applied quantitative techniques to compute summary risk estimates. The present study aimed to conduct a meta-analysis of observational studies summarizing the evidence on the association between breakfast skipping and the risk of T2D. DESIGN: Systematic review and meta-analysis. SETTING: Relevant studies were identified by a search of PubMed, Embase, Web of Science, China National Knowledge Infrastructure (CNKI) and SINOMED up to 9 August 2014. We also reviewed reference lists from retrieved articles. We included studies that reported risk estimates (including relative risks, odds ratios and hazard ratios) with 95% confidence intervals for the association between breakfast skipping and the risk of T2D. SUBJECTS: Eight studies involving 106,935 participants and 7419 patients with T2D were included in the meta-analysis. RESULTS: A pooled adjusted relative risk for the association between exposure to breakfast skipping and T2D risk was 1·21 (95% CI 1·12, 1·31; P=0·984; I² =0·0%) in cohort studies and the pooled OR was 1·15 (95% CI, 1·05, 1·24; P=0·770; I² =0·0%) in cross-sectional studies. Visual inspection of a funnel plot and Begg's test indicated no evidence of publication bias. CONCLUSIONS: Breakfast skipping is associated with a significantly increased risk of T2D. Regular breakfast consumption is potentially important for the prevention of T2D.

Shift work and diabetes mellitus: a meta-analysis of observational studies.

BACKGROUND: Observational studies suggest that shift work may be associated with diabetes mellitus (DM). However, the results are inconsistent. No systematic reviews have applied quantitative techniques to compute summary risk estimates. OBJECTIVES: To conduct a meta-analysis of observational studies assessing the association between shift work and the risk of DM. METHODS: Relevant studies were identified by a search of PubMed, Embase, Web of Science and ProQuest Dissertation and Theses databases to April 2014. We also reviewed reference lists from retrieved articles. We included observational studies that reported OR with 95% CIs for the association between shift work and the risk of DM. Two authors independently extracted data and assessed the study quality. RESULTS: Twelve studies with 28 independent reports involving 226 652 participants and 14 595 patients with DM were included. A pooled adjusted OR for the association between ever exposure to shift work and DM risk was 1.09 (95% CI 1.05 to 1.12; p=0.014; I(2)=40.9%). Subgroup analyses suggested a stronger association between shift work and DM for men (OR=1.37, 95% CI 1.20 to 1.56) than for women (OR=1.09, 95% CI 1.04 to 1.14) (p for interaction=0.01). All shift work schedules with the exception of mixed shifts and evening shifts were associated with a statistically higher risk of DM than normal daytime schedules, and the difference among those shift work schedules was significant (p for interaction=0.04). CONCLUSIONS: Shift work is associated with an increased risk of DM. The increase was significantly higher among men and the rotating shift group, which warrants further studies.