Younger Age at Type 2 Diabetes Diagnosis in Adults Increases Risk for Poor Outcomes

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Age at diagnosis of type 2 diabetes (T2D) was found differentially and signficantly associated with adverse outcomes in a cohort study of more than 36 000 adults, with younger age groups at increased risk of later cardiovascular disease (CVD), cognitive impairment, and death.

As age at T2D diagnosis increased, the research team found, the observed associations between T2D and all outcomes decreased and remained lower after controlling for duration of disease, findings the authors say underscore the clinical heterogeneity of diabetes and the importance of tailoring interventions to account for potential “distal” risk.

Older adults with T2D very widely in age, age at diagnosis, and duration of disease, write investgiators from the University of Michigan, NYU Langone Health, and NYU Grossman School of Medicine in New York, in JAMA Network Open, however, treatment is often similar to T2D management pursued in a middle-aged population. Nor is there consensus on the optimal treatment course for older adults, they add.

The researchers set out to better characterize the association between age at diagnosis of T2D and health outcomes in a large group of community-dwelling adults using a matched-control design to help "separate the association of diabetes with these outcomes from the association with increasing age.”

The study cohort was drawn from participants in the 1995-2018 waves of the population-based, biennial, longitudinal Health and Retirement Survey (HRS) of older adults living in the community and in long-stay nursing facilities. Eligible respondents were free of T2D at study entry and self-reported incident diabetes with a diagnosis at age ≥50 years. Investigators classified these participants into 3 age-at-diagnosis groups: 50 to 59 years, 60 to 69 years, and ≥70 years.

Study authors write that the main exposure was the age at which diabetes was diagnosed. The 5 primary outcomes of interest among participants with incident T2D for each age-at-diagnosis group were: heart disease, stroke, disability, cognitive impairment, and all-cause mortality. A propensity score-matched control group of participants who never developed T2D was constructed for each T2D age-at-diagnosis group.

FINDINGS

From the ~40 000 HRS respondents between 1995-2018, the final cohort for analysis numbered 36 060; of those 7739 self-reported incident T2D diabetes and 28 321 never reported diabetes. The group was 55.1% women. Mean age at T2D diagnosis was 67.4 years with age-at-diagnosis groups as follows:

• Age 50 to 59 years 1866

• Age 60 to 69 years 2834

• Aged ≥70 years 3039

When age-at-diagnosis groups were compared to matched controls and even after investigators accounted for duration of diabetes, participants aged 50-59 years at T2D diagnosis were at significantly greater risk for incident heart disease (hazard ratio [HR], 1.66 [95% CI, 1.40-1.96]), stroke (HR, 1.64 [95% CI, 1.30-2.07]), disability (HR, 2.08 [95% CI, 1.59-2.72]), cognitive impairment (HR, 1.30 [95% CI, 1.05-1.61]), and mortality (HR, 1.49 [95% CI, 1.29-1.71]) (Pinteraction<.05 for all).

Additional analysis found that these associations decreased significantly as age at T2D diagnosis increased, with those diagnosed at age ≥70 years only exhibiting a significant association with increased risk of mortality (HR, 1.08 [95% CI, 1.01-1.17]).

“We believe this study provides a framework for future studies that can explore other key variables associated with diabetes-related health outcomes,” investigators write in conclusion. “Metabolic mechanisms, lifestyle and behaviors, social determinants of health, and diabetes management all affect age at diabetes diagnosis and aging with diabetes.”

Reference: Cigolle CT, Blaum CS, Lyu C, et al. Associations of age at diagnosis and duration of diabetes with morbidity and mortality among older adults. JAMA Netw Open. 2022;5(9):e2232766. doi:10.1001/jamanetworkopen.2022.32766