Life expectancy is shorter for patients diagnosed with type 2 diabetes at a younger age, below 40 years, according to a new research published in The Lancet Diabetes & Endocrinology.¹ For every decade of earlier diagnosis of diabetes, life expectancy is reduced by about 3-4 years.

This observational study was conducted to evaluate the association between age at diagnosis of diabetes and mortality, overall and due to a specific cause. Data from 19 high-income countries was obtained from the Emerging Risk Factors Collaboration (ERFC) and the UK Biobank databases. The study included a total of 1,515,718 participants, mean age 55 years. More than half (54%) were women. The follow up was for a median of 12.5 years (23.1 million person–years). Diabetes was either self-reported or was determined from medical records and use of antidiabetic medication. Mortality was categorised on the basis of the primary cause or the underlying cause if no primary cause could be identified.

Participants who had been diagnosed with diabetes at an earlier age were significantly more likely to have a higher risk of dying due to any cause when compared to those who did not have diabetes. After adjusting for age and sex, those who had been diagnosed at 30-39 years of age were more than 2.5 times at higher risk of dying due to any cause with a hazard ratio of 2.69 vs those without diabetes. The risk was seen to decline as the age of diagnosis advanced but was still high. The HR was 2.26 for diagnosis at 40-49 years, 1.84 at 50-59 years, 1.57 at 60-69 years and 1.39 at 70 years and older. When the mortality risk was evaluated for men and women, the sex-adjusted hazard ratios were found to be similar between the two.

The HRs for every decade of earlier diagnosis of diabetes were 1.14 for all-cause mortality, 1.19 for vascular mortality, 0.95 for cancer mortality and 1.18 for mortality from other causes. In the age group 30-39 years, the HR for vascular mortality was 4.20; for mortality due to cancer, the HR was 1.55 and for mortality due to other causes, the HR was 3.99.

When US mortality rates were used to analyse the reduction in life expectancy, those who had been diagnosed at the age of 30 years died an average of 14 years before persons without diabetes. The life expectancy was reduced by 10 years when diagnosed at the age of 40 years and by 6 years among those who had been diagnosed at the age of 50 years. When European death rates were utilised, results were comparable. The life expectancy reduced by 13, 9, or 5 years, respectively.

In this study, the risk of all-cause mortality was highest among people diagnosed with diabetes at a younger age, between 30-39 years. Life expectancy is also reduced by 10-14 years for patients in this age group. Hence, the prevention of diabetes becomes imperative. Therapeutic interventions to modify the risk factors for diabetes should be intensified to help prevent or delay the onset of type 2 diabetes and diabetes-related complications including premature mortality, especially among young adults.

Reference

1. Emerging Risk Factors Collaboration. Life expectancy associated with different ages at diagnosis of type 2 diabetes in high-income countries: 23 million person-years of observation. Lancet Diabetes Endocrinol. 2023 Sep 11;S2213-8587(23)00223-1. doi: 10.1016/S2213-8587(23)00223-1.