Date Published: January 31, 2019
Publisher: Public Library of Science
Author(s): Jessica Ares, Sergio Valdés, Patricia Botas, Cecilia Sánchez-Ragnarsson, Sandra Rodríguez-Rodero, Paula Morales-Sánchez, Edelmiro Menéndez-Torre, Elías Delgado, Venkata Naga Srikanth Garikipati.
People who develop type 2 diabetes (T2D) are known to have a higher mortality risk. We estimated all-cause, cardiovascular, and cancer mortality-risks in our patient cohort according to categories of impaired glucose metabolism. This 18-year retrospective analysis included a region-wide, representative sample of a population aged 30–75 years. Age- and sex-stratified hazard ratios (HRs) were calculated for 48 participants with diagnosed T2D, 83 with undiagnosed T2D (HbA1c ≥6.5%, fasting glycemia ≥126 mg/dL, or glycemia after 75 g glucose load ≥200 mg/dL); 296 with prediabetes (HbA1c 5.7%-6.4%, fasting glycemia 100–125 mg/dL, or glycemia after 75 g glucose load 140–199 mg/dL), and 607 with normoglycemia. Over 18,612 person-years, 32 individuals with undiagnosed T2D, 30 with diagnosed T2D, 62 with prediabetes, and 80 with normoglycemia died. Total sample crude mortality rate (MR) was 10.96 deaths per 1,000 person-years of follow-up. MR of the diagnosed T2D group was more than 3-times higher and that of newly diagnosed T2D was 2-times higher (34.72 and 21.42, respectively) than total sample MR. Adjusted HR for all-cause mortality was 2.02 (95% confidence interval 1.29–3.16) and 1.57 (95% CI 1.00–2.28) in the diagnosed T2D group and the newly diagnosed T2D group, respectively. Adjusted HR for cardiovascular mortality in the T2D group was 2.79 (95% CI 1.35–5.75); this risk was greatly increased in women with T2D: 6.72 (95% CI 2.50–18.07). In Asturias, age- and sex-standardized all-cause mortality is more than 2-times higher for adults with T2D than for adults without T2D. The HR for cardiovascular mortality is considerably higher in T2D women than in normoglycemic women.
Worldwide mortality caused by diabetes reached four million in 2017 . About half of diabetes-related mortality (48%) occurs in people younger than 60 years. Although a decrease in mortality caused by diabetes has been observed in Europe and North America , diabetes continues to reduce life expectancy by 6–8 years in people diagnosed at the age of 50 years. The majority (>50%) of diabetes-caused mortality is from cardiovascular diseases.
In this Spanish population-based sample, regionally representative with up to 18-year follow-up, mortality risk was more than two-times higher (2.02) among adults with known T2D than among adults in the NGT group. Risk of death associated with T2D was especially increased in younger age groups. Moreover, mortality risk was notably higher in women with T2D than in men (both with known and undiagnosed T2D) because of an increase in cardiovascular mortality.
Individuals with diabetes (especially those with diagnosed diabetes) had a significantly higher mortality risk than those with NGT after 18 years of follow-up even after adjusting for multiple confounders. Excess mortality was especially noticeable in younger women, predominantly due to cardiovascular disease.