Type 2 diabetes and colorectal cancer survival: The multiethnic cohort.

This analysis examined type 2 diabetes (T2D) as a predictor of colorectal cancer (CRC) survival within the Multiethnic Cohort Study. Registry linkages in Hawaii and California identified 5,284 incident CRC cases. After exclusion of cases with pre-existing cancer diagnosis within 1 year and systemic disease, the analytic dataset had 3,913 cases with 1,800 all-cause and 678 CRC-specific deaths after a mean follow-up of 9.3 ± 5.2 years. Among CRC cases, 707 were diagnosed with T2D 8.9 ± 5.3 years before CRC. Cox regression with age as time metric was applied to estimate hazard ratios (HR) and 95% confidence intervals (CI) for T2D status as predictor of CRC-specific and all-cause survival while adjusting for known confounders. Overall, CRC-specific survival was not associated with pre-existing T2D (HR = 0.84; 95% CI = 0.67-1.07). However, a significant interaction was seen for comorbidity (pinteraction  = 0.03) with better survival among those without pre-existing conditions (HR = 0.49; 95% CI = 0.25-0.96) while no association was seen in patients with comorbid conditions. All-cause mortality was also not related to pre-existing T2D (HR = 1.11; 95% CI = 0.98-1.27), but significantly elevated for individuals with T2D reporting comorbid conditions (HR = 1.36; 95% CI = 1.19-1.56). Stratification by T2D duration suggested higher CRC-specific and all-cause mortality among participants with a T2D history of ≥10 than <10 years. The findings were consistent across sex and ethnic subgroups. In contrast to previous reports, pre-existing T2D had no influence on disease-specific and all-cause survival among CRC patients. Only participants with additional comorbidity and possibly those with long T2D duration experienced higher mortality related to T2D.

Sleep duration and incidence of type 2 diabetes: the Multiethnic Cohort.

OBJECTIVES: As an emerging risk factor for the rising incidence of type 2 diabetes, we examined sleep duration in relation to type 2 diabetes and several biomarkers. DESIGN: Prospective cohort recruited 1993-1996. SETTING: The Multiethnic Cohort in Hawaii and California. PARTICIPANTS: A cohort of 151,691 White, African American, Japanese American, Native Hawaiian, and Latino participants; 9695 cohort members had biomarker measurements. MEASUREMENTS: Sleep duration was self-reported at cohort entry. Diabetes status was obtained from 3 questionnaires and confirmed by 3 administrative data sources. Biomarkers were measured by standard assays 9.6±2.1 years after cohort entry. We estimated diabetes risk as a time-varying outcome using Cox regression adjusted for body mass index assessed at 3 time points and other known confounders and computed adjusted means of biomarkers by sleep hours. RESULTS: During 7.9±3.5 years of follow-up, 8487 new diabetes cases were diagnosed. Long sleep duration (≥9 hours), as compared with 7-8 hours, was significantly associated with higher incidence (hazard ratio, 1.12; 95% confidence interval 1.04-1.21), but the 4% elevated incidence for short sleep duration (≤6 hours) did not reach significance (95% confidence interval 0.99-1.09). After stratification, the associations appeared stronger in Japanese American than other ethnic groups and in participants without comorbidity. Hours of sleep were positively associated with C-reactive protein and triglycerides and inversely related to high-density lipoprotein cholesterol and adiponectin but not with leptin levels and homeostatic model assessment of insulin resistance. CONCLUSION: In this multiethnic population, the 12% higher diabetes risk for long sleep hours may be mediated through inflammation, a poor lipid profile, and lower adiponectin levels.