People with type 2 diabetes whose daily routine includes staying up late at night demonstrate more symptoms of depression than individuals who prefer to wake up and go to sleep earlier, according to research presented at ENDO 2017: The 99th Annual Meeting & Expo, April 1-4, in Orlando, Florida.
Sirimon Reutrakul, MD, an associate professor at Mahidol Universal Faculty of Medicine in Bangkok, Thailand, wanted to build upon the research proving that this late-wake cycle preference, referred to as a “chronotype,” by studying people with type 2 diabetes who demonstrate an increased risk of depression to determine whether a late chronotype was independently associated with greater depression symptoms.
Dr Reutrakul and her co-investigators also sought to clarify whether geographic location affected chronotype, with a greater morning chronotype occurring in individuals who live closer to the equator. “We aimed to explore the association between chronotype and depressive symptoms in T2D patients from 2 different geographic areas,” the researchers reported in their abstract.
To research this, the investigators studied patients with T2D in 2 distinct geographic locations: Chicago and Thailand. The Chicago group consisted of 194 patients, 70% of whom were women. The Thai group consisted of 282 patients with T2D, 67% of whom were women.
The participants answered questionnaires about symptoms of sleep quality (using the Pittsburgh Sleep Quality Index), depression (using the Center for Epidemiologic Studies Depression scale), and chronotype (the Morningness-Eveningness Questionnaire for the Chicago cohort and the Composite Score of Morningness in the Thailand cohort).
After adjusting for age, sex, sleep quality, and other factors that could affect depression incidence in both cohorts, patients with a late chronotype reported a higher number of depression symptoms than patients with a morning chronotype did.
“These data support an association [between] circadian regulation and psychological functioning in individuals with T2D,” Dr Reutrakul and colleagues stated. “Intervention studies targeting circadian timing should be explored to determine whether altering circadian functioning may improve depressive symptoms in T2D patients.”
Saetung S, Hood MM, Nimitphong H, Siwasaranond N, Crowley SJ, Reutrakul S. Later chronotype is associated with greater depressive symptoms in type 2 diabetes patients: A study in two different ethnic cohorts. Abstract OR11-3. Presented at: ENDO 2017: the 99th Annual Meeting & Expo. April 1-4, 2017; Orlando, Florida.