Earlier Age at Diagnosis Increases Risk of Adverse Outcomes in Diabetes

A recent study is providing new insight into the impact of age at diagnosis of diabetes on risk of multiple adverse outcomes, including risk of multiple comorbidities and all-cause mortality.

A propensity scored-matched analysis of data recorded within the Health and Retirement Study from 1995-2018, results of the study indicate risk of various outcomes differ among the age groups examined in the study, with those in younger age groups at an elevated risk of cardiovascular disease, stroke, disability, cognitive impairment, and all-cause mortality compared to those diagnosed later in life.

“In this cohort study using 23 years of longitudinal data for adults 50 years and older drawn from a national health interview survey, we provide evidence of the differential association of diabetes with incident distal outcomes across varying ages at diabetes diagnosis while accounting for diabetes duration,” wrote investigators. “Our use of an (matched control) group helped us separate the association of diabetes with these outcomes from the association with increasing age.”

Conducted by a team from Michigan Medicine and NYU Gross School of Medicine, the current study was designed with the intent of providing further insight into the associations of age at diagnosis and duration of diabetes with risk of negative health outcomes among older patients in real-world settings. To do so, investigators leveraged data from the 1995-2018 waves of the Health and Retirement Study, which was a population-based, biennial longitudinal health interview survey of older adults in the US.

Using data from the survey, investigators classified patients into 3 age-at-diagnosis groups, defined as 50-59, 60-69, and 70 years and older. The primary outcomes of interest were association of diabetes with incidence of disease, stroke, disability, cognitive impairment, and all-cause mortality. Investigators noted a propensity score-matched control group of individuals who never developed diabetes were created for each age-at-diagnosis group.

From survey waves occurring from 1995-2018, investigators obtained data from 36,060 adults aged 50 years or older without diabetes at entry. Of these individuals, 7739 developed diabetes during the follow-up and 28,321 did not develop diabetes. This cohort had a mean age of 67.4 (SD, 9.9) years at diagnosis and 55.1% were women. In terms of age at diagnosis distribution, 1866 were diagnosed at 50-59 years, 2834 were diagnosed at 60-69 years, and 3039 were diagnosed at 70 years or older.

Compared to matched controls, those with an age at diagnosis of 50-59 years had significantly greater risk for incident heart disease [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]) (P for all <.05), even when accounting for diabetes duration. Further analysis indicated these associations significantly decreased with advancing age at diagnosis, with those diagnosed at 70 years or older 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. Metabolic mechanisms, lifestyle and behaviors, social determinants of health, and diabetes management all affect age at diabetes diagnosis and aging with diabetes,” investigators added.

This study, “Associations of Age at Diagnosis and Duration of Diabetes With Morbidity and Mortality Among Older Adults,” was published in JAMA Network Open.