Early onset of type 2 diabetes increased hospitalization rates in early adulthood, especially for serious mental illness, Hong Kong researchers found.
In a large cohort of Chinese adults with young-onset type 2 diabetes (YOD) — prior to age 40 — mental illness was the largest driver of hospitalization compared with a usual age of onset type 2 diabetes, reported Juliana C.N. Chan, MD, of the Chinese University of Hong Kong, and colleagues.
Specifically, mental illness accounted for nearly 37% of all bed-days for those with young-onset diabetes before age 40, the group wrote in the Annals of Internal Medicine.
This was largely comprised of psychotic disorders — making up over half of mental illness-related hospitalizations — and mood disorders, which contributed to a third of these hospitalizations.
“This could not be explained by antipsychotic medications, miscoding, or secular effects,” the authors noted, adding that “a bidirectional association between T2D [type 2 diabetes] and depression has been reported previously, the burden of serious mental illness early in the course of YOD has never been described.”
They pointed out that the findings suggested the link between depression or diabetes-related distress in YOD may be “severe” in young adulthood.
However, after age 60, cardiovascular disease overtook mental health as the largest driver of hospitalizations, regardless of the onset age of diabetes. Among those who had YOD, cardiovascular disease contributed to over a quarter of hospitalized bed-days after age 60, while it contributed to 20% of bed-days for those with usual-onset diabetes.
By age 60, those with YOD had a significantly elevated risk for all-cause hospitalization compared with those with a usual-onset on diabetes (risk ratio 1.8, 95% CI 1.7-2.0). This association also held true when looking across a number of different causes of hospitalization (P<0.001 for interaction for all):
- Renal: RR 6.7 (95% CI 4.2-10.6)
- Diabetes: RR 3.7 (95% CI 3.0-4.6)
- Cardiovascular: RR 2.1 (95% CI 1.8-2.5)
- Infection: RR 1.7 (95% CI 1.4-2.1)
“On the basis of the observed hospitalization rates, we estimated that a patient diagnosed with YOD would spend nearly 100 days in the hospital by his or her 75th birthday,” the researchers calculated.
Chan’s group emphasized the importance of modifiable risk factors to attenuate for this hospitalization risk, determining that intensified risk factor control for those with YOD slashed the cumulative number of in-hospital bed days prior to age 75 by one-third.
This intensified risk factor control included well-controlled diabetes with a target HbA1c <6.2%, a target systolic blood pressure <120 mmHg, LDL cholesterol level <77.3 mg/dL (2.0 mmol/L), and triglyceride level <115.1 mg/dL (<1.3 mmol/L). This also included abstaining from smoking and a waist circumference of <33.5 in (85 cm) for men and 31.5 in (80 cm) for women.
Some limitations to this cohort study included the exclusively Chinese population, which potentially limits generalizability. Also, the study drew upon a population-based and registry-based type 2 diabetes cohorts, and the registry cohort may have been biased towards healthier YOD survivors, the researchers noted.
Chan’s group called this link between mental health and YOD a “costly burden” and “an urgent call for policymakers, payers, patients, and health care providers to take action and address this unmet need.”
They recommended “An integrated system is needed to identify patients with YOD for comprehensive assessment of physical and psychological health, followed by optimization of cardiometabolic risk factors and individualized care to improve quality of life and reduce the effects of long-term complications on patients, their families, employers, and the health care system.”
The study was funded by the Asia Diabetes Foundation.
Chan and co-authors disclosed no relevant relationships with industry. One co-author disclosed support from the Canadian Institutes of Health Research Canada Graduate Scholarship and Michael Smith Foreign Study Supplements, the University of Toronto Clinician Investigator Program, the Canadian Society of Endocrinology and Metabolism Dr. Fernand Labrie Fellowship Research Grant, and the Royal College of Physicians and Surgeons of Canada Detweiler Travelling Fellowship.