Combination of type 2 diabetes and smoking increases total cancer mortality in Japanese men using competing risk analysis: the Tanno-Sobetsu study

Association of smoking cessation after new-onset type 2 diabetes with overall and cause-specific mortality among Korean men: a nationwide population-based cohort study

INTRODUCTION

This study aimed to examine the association between smoking cessation after new-onset type 2 diabetes and overall and cause-specific mortality risks among Korean men.

RESEARCH DESIGN AND METHODS

The Korean National Health Insurance Service-National Health Screening Cohort database was searched, and 13 377 Korean men aged ≥40 years diagnosed with new-onset type 2 diabetes between 2004 and 2007 were included and followed up until 2013. We defined smoking status changes by comparing participants' answers in the last survey before diagnosis to those in the first survey after diagnosis. We estimated the adjusted HR (AHR) and 95% CI for mortality risk using multivariable Cox proportional hazards regression models.

RESULTS

We identified 1014 all-cause mortality events (cancer, n=406 and cardiovascular disease (CVD), n=184) during an average follow-up duration of 7.2 years. After adjustment for all confounding factors, the reduced risk of all-cause mortality was more significant among short-term quitters (AHR 0.78; 95% CI 0.64 to 0.95), long-term quitters (AHR 0.68; 95% CI 0.54 to 0.85), and never smokers (AHR 0.66; 95% CI 0.56 to 0.78) compared with current smokers (p for trend <0.001). The lower risk of mortality from cancer was significant among the short-term quitters (AHR 0.60; 95% CI 0.44 to 0.83), long-term quitters (AHR 0.67; 95% CI 0.46 to 0.90), and never smokers (AHR 0.50; 95% CI 0.39 to 0.65) compared with current smokers (p for trend <0.001). There was no significant association between changes in smoking status and death from CVD. Smoking cessation after diagnosis in non-obese individuals (AHR 0.73; 95% CI 0.58 to 0.92) and exercisers (AHR 0.54; 95% CI 0.38 to 0.76) was significantly associated with reduced mortality risk than current smoking.

CONCLUSIONS

Smoking cessation after new-onset type 2 diabetes was associated with reduced mortality risk.

Prospective study of cancer in Japanese patients with type 2 diabetes: the Fukuoka Diabetes Registry

Background

Although the association between type 2 diabetes and cancer has been reported, few epidemiological studies have been conducted in Japanese patients whose leading cause of death is cancer. We prospectively studied the incidence of site-specific cancer, risk factors for developing cancer, cancer death, and survival in Japanese patients with type 2 diabetes.

Methods

We followed 4923 participants (mean age, 65 years) with type 2 diabetes attending an outpatient diabetes clinic for a median of 5.3 years (follow-up rate, 99.0%).

Results

During the follow-up period, cancer occurred in 450 participants (incidence rate, 22.3/1000 person-years in men and 12.2/1000 person-years in women). In men, prostate cancer was the most common cancer (4.3/1000 person-years), colorectal cancer was the second (3.6/1000 person-years), and gastric cancer was the third (3.3/1000 person-years). In women, colorectal cancer was the most common cancer (2.6/1000 person-years), gastric cancer was the second (2.0/1000 person-years), and breast cancer was the third (1.4/1000 person-years). Smoking, male sex, low-density lipoprotein cholesterol, family history of cancer, and reduced intake of isoflavone daidzein were significant risk factors for developing cancer using multivariable Cox proportional hazards models. The leading cancer death was lung cancer in men and pancreatic cancer in women. The survival was the best for prostate cancer and the worst for pancreatic cancer (2-year cancer-specific survival 95.4%, 30.0%, respectively).

Conclusions

Since the leading cause of death in patients with type 2 diabetes is cancer in Japan, clinicians should be aware of epidemiological data regarding cancer besides diabetic complications.

The global prevalence of tobacco use in type 2 diabetes mellitus patients: A systematic review and meta-analysis

BACKGROUND

A multi-layered association between tobacco use and type 2 diabetes mellitus (T2DM) is well established. However, global epidemiological patterns of tobacco use among T2DM patients are not well documented; this review thus aims to estimate the overall global burden of tobacco use in T2DM.

METHODS

A systematic review of studies published from Jan 1, 1990 to October 5, 2017 was undertaken, comprising: a comprehensive literature search on multiple electronic databases; quality assessment of studies; data extraction for the primary (prevalence of tobacco use in T2DM patients) and secondary outcomes (patterns of tobacco use in T2DM patients); and a meta-analysis. The review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement guidelines. A protocol for this review is available on PROSPERO (CRD42016038793).

FINDINGS

74 studies were included in the review, reporting data from 3.2 million participants across 33 countries. Global mean prevalence of tobacco use in T2DM was 20·81% (95% CI 18·93-22·76), and was higher in the WHO East Asia and Pacific and South Asia regions, compared to the Americas, Middle East and North Africa, Europe and Central Asia. In studies which compared prevalence of tobacco use in patients to non-patients, patients with T2DM were 26% less likely to use tobacco (pooled OR = 0·74 (CI 0·61-0·88).

INTERPRETATION

Tobacco is used by one in five T2DM patients globally, but usage is less likely in patients than in non-patients. Global patterns of use demonstrated by this review have implications for both prevention and The understanding of diabetes burden, and the success of tobacco cessation strategies.