The onset of type 2 diabetes before age 40 years was associated with significantly increased risk of hospitalization, especially for mental illness, compared to later onset, a study found.
The prospective study looked at hospitalization rates among adults with type 2 diabetes ages 20 to 75 years in Hong Kong: 422,908 in a population-based cohort and 20,886 in a registry-based cohort. Patients were considered to have young-onset type 2 diabetes if they were diagnosed between the ages of 10 years and 40 years; there were 21,032 and 3,566 such patients in the cohorts, respectively. Results of the study were published by Annals of Internal Medicine on Jan. 15.
The patients with young-onset diabetes had higher hospitalization rates by age than patients with later onset. The increased risk was found for all-cause hospitalizations (adjusted risk ratio, 1.8; 95% CI, 1.7 to 2.0), as well as for specific causes: renal, 6.7 (95% CI, 4.2 to 10.6); diabetes, 3.7 (95% CI, 3.0 to 4.6); cardiovascular, 2.1 (95% CI, 1.8 to 2.5); and infectious, 1.7 (95% CI, 1.4 to 2.1) (P<0.001 for all). The study found that 36.8% of the young-onset patients' days spent in the hospital were due to mental illness.
The risk of hospitalization was reduced in patients with better risk factor control (HbA1c level <6.2%, systolic blood pressure <120 mm Hg, LDL cholesterol level <2.0 mmol/L [<77.3 mg/dL], triglyceride level <1.3 mmol/L [<115.1 mg/dL], waist circumference of 85 cm [men] or 80 cm [women], and smoking cessation). Using a model, the study authors estimated that risk-factor control would reduce the cumulative bed-days of patients with young-onset diabetes by a third (bed-days from diabetes onset to age 75, 97 days vs. 65 days).
“We found a previously unknown burden of serious mental illness before age 40 years, and understanding its causes is imperative to improving mental health care in young adults,” the authors said. The association cannot be explained by the risk of diabetes posed by antitypical antipsychotics, according to the authors. They suggested that hyperglycemia might cause neuroinflammation or that diabetes might alter brain connectivity.
“Improving outcomes in this vulnerable population will require team-based, holistic, and integrated care approaches that are shown to improve health, increase patient satisfaction, and reduce hospitalizations,” the authors said. Limitations of the study include the possibility of residual confounding.