Decreased Frequency of HbA1c Testing in People With Youth-Onset Type 1 and Type 2 Diabetes

The odds of individuals with youth-onset type 1 diabetes undergoing glycated hemoglobin (HbA_1c) testing decrease with older age at diagnosis, longer disease duration, not having a personal physician, and lapses in health insurance; for those with type 2 diabetes, not seeing an endocrinologist decreased the odds of testing, according to study findings published in Diabetes Care. These findings corroborate previous research results that suggest a substantial proportion of younger patients do not receive regular HbA_1c testing, an issue that may have significant implications in long-term glycemic management.

In the SEARCH for Diabetes in Youth study, a team of US researchers examined data collected from patients who received a diabetes diagnosis before the age of 20 years. Data were collected at 8 years (type 1: n=1885; type 2: n=230) and 13 years (type 1: n=649; type 2: n=84) of diabetes duration. In addition to identifying correlates of reporting at least 3 HbA_1c tests per year, the researchers also examined associations between testing and HbA_1c levels and microvascular complications.

In the cross-sectional sample taken at 8 years’ diabetes duration, the mean ages at diagnosis were 9.5 years for patients with type 1 diabetes and 14.1 years for patients with type 2 diabetes. In the longitudinal subsample, the mean ages at diagnosis were 9.6 years for patients with type 1 diabetes and 14.4 years for patients with type 2 diabetes.

From 8 to 13 years of diabetes duration, patients with type 1 diabetes had lower odds of reporting at least 3 HbA_1c tests per year if they were older at diagnosis (odds ratio [OR], 0.91; 95% CI, 0.88-0.95), had a longer diabetes duration (OR, .90; 95% CI, 0.82-0.99), did not have a personal physician (OR, 0.44; 95% CI, 0.30-0.65), or experienced lapses in health insurance (OR, 0.51; 95% CI, 0.27–0.96).

There was a significant association between HbA_1c testing at least 3 times per year and lower levels of HbA_1c (OR -0.36%; 95% CI, -0.65 to -0.06) and lower odds of microvascular complications (OR, 0.64; 95% CI, 0.43–0.97) at 13 years’ diabetes duration. These associations, however, were attenuated following adjustment for HbA_1c testing correlates (OR, -0.17; 95% CI, -0.46 to 0.13 and OR, 0.70; 95% CI, 0.46-1.07, respectively).

The odds of reporting at least 3 HbA_1c tests per year over time in patients with type 2 diabetes decreased in those who did not see an endocrinologist (OR 0.19; 95% CI, 0.06-0.63). In these patients, the frequency of testing was not associated with HBA_1C levels or microvascular complications.

Limitations of this study included the small sample size for type 2 diabetes as well as the inability to examine microvascular complications individually because of relatively low prevalence.

Despite these limitations, the researchers conclude that the findings affirm “the recommendations for frequent HbA_1c testing in type 1 diabetes to facilitate reaching glycemic goals and potentially to reduce microvascular complications as the disease progresses.”

Disclosure: One study author reported personal fees from Amgen and KCI outside of the submitted work. Please refer to the original article for a full list of disclosures.

Reference

Sauder KA, Stafford JM, Ehrlich S, et al. Disparities in hemoglobin A_1c testing during the transition to adulthood and association with diabetes outcomes in youth-onset type 1 and type 2 diabetes: The SEARCH for Diabetes in Youth Study. Diabetes Care. Published online August 10, 2021. doi:10.2337/dc20-2983