The study covered in this summary was published on medRxiv.org as a preprint and has not yet been peer reviewed.
UK residents with type 2 diabetes had a significantly higher mortality rate compared with people without diabetes. This excess risk increased with the age at diagnosis.
The mortality hazard from type 2 diabetes was constant across all birth cohorts examined, demonstrating that there has been no progress over time in reducing the relative risk of mortality associated with type 2 diabetes.
Preexisting medical conditions, especially untreated hypertension and smoking, increased the mortality hazards, and this effect increased in later birth cohorts.
Prescription of antihypertensive or antihypercholesterolemia drugs was linked with improved survival.
Why This Matters
The effect of type 2 diabetes on all-cause mortality compared with people without diabetes has not been extensively studied in the UK population.
No reported study in any population has examined the effect of age at diagnosis of type 2 diabetes on mortality.
The study included 221,182 people in the Health Improvement Network, a UK primary care database that in 2017 included medical records for 15.6 million people collected from 711 registered general practitioners.
The total cohort included 68,199 people with type 2 diabetes whom researchers selected because they were born between 1930 and 1960 inclusive and were diagnosed with type 2 diabetes between 2000 and 2016 inclusive when they were at least 50 years old. The selection excluded people with a history of various comorbidities, including stroke, cognitive impairment, cancer, or chronic kidney disease.
Researchers matched each of these patients with up to three people from the database without type 2 diabetes to create a control cohort of 152,983 people.
The analysis broke the study population into three subgroups based on their birth year: 1930–1939, 1940–1949, and 1950–1959.
Overall, people with type 2 diabetes had an adjusted 38% higher mortality rate compared with people without diabetes.
The relative risk varied by age. People with type 2 diabetes who were 60–74 years old had an adjusted 52% higher mortality rate compared with similarly aged people without diabetes. Among those 50–59 years old, diabetes boosted mortality by 21% relative to those without diabetes. These relative hazard rates were constant across the three birth cohorts.
Men had a 38% increased hazard of mortality compared with women. Obesity was associated with a significant 16% higher mortality, but overweight was not significantly different from normal weight.
Although the study adjusted for the potential role of several possible confounders, the list of included variables was not exhaustive, and there may have been residual confounding due to unavailable data, such as changes in therapy or lifestyle or intensity of smoking.
Other important variables not included in the analytic models were ethnicity, antidiabetic drug use, and A1c values.
The study was funded by the Institute and Faculty of Actuaries.
None of the authors had disclosures.
This is a summary of a preprint research study, "On the Survival of Individuals Diagnosed With Type 2 Diabetes Mellitus in the United Kingdom: A Retrospective Matched Cohort Study," written by a team of researchers at the University of East Anglia in Norwich, UK, published on medRxiv and provided to you by Medscape. This study has not yet been peer reviewed. The full text of the study can be found on medRxiv.org.
Mitchel L. Zoler is a reporter for Medscape and MDedge based in the Philadelphia area. @mitchelzoler
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Cite this: Type 2 Diabetes Increases Risk of Adult Mortality - Medscape - Dec 28, 2021.