Type 2 Diabetes Onset at Younger Age Tied to Worse Complications, Mortality
Complications include more severe neuropathy and albuminuria.
Patients who experienced onset of type 2 diabetes between ages 15 and 30 years had worse complications than those who experienced disease onset between ages 40 and 50, researchers reported in Diabetes Care.
More adolescents are being diagnosed with type 2 diabetes, they noted, with recent data suggesting that this age group accounts for 45% of new cases in the United States.
“The net result is a widening of the clinical spectrum, with age of diabetes onset increasingly recognized as an important factor in the heterogeneity of risk within this diagnosis,” the researchers wrote.
Even so, few studies have evaluated whether or not age at disease onset affects complications.
For this study, the researchers investigated how age of onset impacts diabetes complications after controlling for diabetes duration in 354 patients with type 2 diabetes diagnosed between ages 15 and 30 and a duration-matched cohort of 1062 patients diagnosed with diabetes between ages 40 and 50. They also assessed standardized mortality ratios according to age of onset among 15 238 patients.
Complication status was evaluated according to standard protocol and extracted from the researchers' electronic database. Survival status was determined via data linkage with the Australian National Death Index.
After the same duration of type 2 diabetes, about 11 years, patients diagnosed between ages 15 and 30 had more severe albuminuria (P=.004) and neuropathy scores (P=.003), as compared with those diagnosed at an older age, according to the data.
Patients diagnosed at a younger age were also less likely to be treated with a statin or antihypertensive agent despite having more obesity and higher cholesterol and triglyceride levels vs those diagnosed at an older age (P<.0001), the researchers noted.
Data indicated that macrovascular complications were less apparent clinically in those diagnosed at a younger age (P<.0001), but vascular deaths predominated and the percentages in the younger-age-at-onset group were comparable to those diagnosed at an older age. For patients diagnosed between ages 15 and 30, age of death was lower by about 15 years, as compared with those diagnosed between ages 40 and 50.
There was a total of 156 804 person-years of follow-up for the 15 238 patients, which translates to an average follow-up time of 10 years until death or date of censure, in the standardized mortality ratio analysis.
Over a 25-year period, 4169 deaths occurred. Age of diabetes onset was inversely associated with standardized mortality ratio, according to the study results. Data indicated that the ratio was 3 times higher for patients with a younger age at onset than the general population (standardized mortality ratio=3.4; 95% CI, 2.7-4.2).
After adjustment for duration, standardized mortality ratio plots revealed that those for patients diagnosed with type 2 diabetes between ages 15 and 30 were the highest at any chronological age — peaking at more than 6 in early midlife. Mortality for those who were diagnosed after age 50, however, is at most 2-fold higher and decreases with aging compared with that of the background population, the researchers noted.
“In the context of rising rates of obesity largely driving type 2 diabetes in younger age groups, research into effective and diverse strategies, including modifying in utero glycemic exposure, public health policy, addressing social disadvantage, and urban planning, are needed to tackle this,” they wrote.
“There is now some urgency to develop an evidence base in this regard and to determine the optimal timing of such interventions more closely. Our results highlight the growing imperative to prevent diabetes in youth and, if not possible, at least to delay the development of diabetes to an older age.”