Older adults with type 2 diabetes have an increased risk for higher depressive symptoms with greater variability in glycemic control whereas mean HbA1c does not affect depressive symptoms, according to study findings published in Diabetes Care.
Ramit Ravona-Springer, MD, an instructor at The Joseph Sagol Neuroscience Center at Sheba Medical Center and Sackler Faculty of Medicine at Tel Aviv University, both in Israel, and colleagues evaluated data from the Israel Diabetes and Cognitive Decline study on 837 adults (mean age, 72.74 years) with type 2 diabetes (mean HbA1c, 6.82%) to determine the relationship of variability in HbA1c since 1998 with subsequent depressive symptoms.
The 15-item version of the Geriatric Depression Scale was used to assess symptoms of depression, and the Mini-Mental State Examination was used to evaluate cognitive function. All participants were members of a diabetes registry (mean number of years in the registry, 8.7 years), and HbA1c measurements were collected through the registry (mean number of measurements, 17.83). Variability in glycemic control was measured as the standard deviation of HbA1c measurements.
The mean Mini-Mental State Examination score was 28.02, which is consistent with normal cognitive status; mean Geriatric Depression Scale score was 2.16, and 10% of participants had a score consistent with clinically significant depression ( 6).
Variability in glycemic control was significantly correlated with mean HbA1c (P < .0001). The number of depressive symptoms was not associated with mean HbA1c in any models, but a larger number of depressive symptoms was significantly associated with greater variability in glycemic control. The number of depressive symptoms increased by 29% with each additional 1% increase in glycemic control variability (P = .0078) in the basic model adjusted for age, number of years in the diabetic registry, years of education and sex. In the fully adjusted model, the number of depressive symptoms increased by 31% with each additional 1% increase in glycemic control variability (P = .03).
“Though long-term effects of initially uncontrolled diabetes on brain biology and mood cannot be ruled out, our results suggest that long-term variability in glycemic control, rather than initial variability after type 2 diabetes diagnosis, is associated with symptoms of depression,” the researchers wrote. “These results stress the potential value of HbA1c variability, which may better reflect the course of type 2 diabetes over time, in predicting depression.” – by Amber Cox
Disclosures: The researchers report no relevant financial disclosures.