Factors Associated with Cancer- and Non-Cancer-Related Deaths among Taiwanese Patients with Diabetes after 17 Years of Follow-Up

Abstract

Objective: A previous 12-year follow-up of a large diabetes cohort in Taiwan suggested a survival advantage in the patients with obesity. The present study further investigated additional determinants for cancer and non-cancer death in the cohort after a follow-up of 17 years.

Methods: A cohort of 92546 diabetes patients recruited since 1995 was followed for vital status by matching the National Death Certificate Database until 2011. Cox regression estimated the hazard ratios for the following variables: age at baseline, sex, diabetes type, screen-detected diabetes (diabetes diagnosed accidentally through epidemiological screening programs or during visits to medical settings without a history of diabetes), diabetes duration, body mass index, insulin use, hypertension, smoking, and living region. Fasting glucose and history of dyslipidemia were available for additional adjustment in a subcohort of the patients (n = 14559).

Results: A total of 40229 diabetes patients (43.5% of the cohort) died during follow-up and 10.9% died under the age of 60. Insulin use and smoking significantly predicted cancer and non-cancer death. The adjusted hazard ratio (95% confidence interval) associated with insulin use was 1.161 (1.052-1.281) for cancer death and 1.469 (1.413-1.526) for non-cancer death. Screen-detected diabetes and body mass index were consistently associated with a lower risk, but diabetes duration a higher risk, for non-cancer death, with adjusted hazard ratio of 0.683 (0.666-0.702), 0.955 (0.951-0.958) and 1.018 (1.017-1.020), respectively. Diabetes type had a null association disregarding the causes of death and living in rural areas was significantly associated with a higher mortality from non-cancer death. Hypertension, fasting glucose and dyslipidemia showed differential impacts on cancer and non-cancer death, and were significantly predictive for non-cancer death.

Conclusions: Screen-detected diabetes and a higher body mass index provide a survival advantage, especially for non-cancer death. However, insulin use is associated with a significantly higher risk of either cancer or non-cancer death.

Fig 1. Survival curve for the diabetes cohort by different strata of attained age

Fig 2. Survival curve for the diabetes cohort by sex