For patients hospitalized for a wide range of medical conditions, type 2 diabetes (T2D) was found to be associated with an increased risk of hospital bed-days, according to a study published today in PLoS Medicine.

One group that saw a particularly higher risk of hospital bed-days was patients who received a T2D diagnosis before the age of 40 and have a mental health disorder.

The study included more than 1.5 million patients in Hong Kong, with data provided by the Hong Kong Hospital Authority. The study population was matched 1:1 by age, sex, and index year, with 758,254 patients with T2D and another 758,254 without T2D in the control group. The entire follow-up period lasted between 2002 and 2018, and hospital bed-day rate was defined as the total number of inpatient bed-days divided by follow-up time.

Over a median follow-up of 7.8 years, the study showed that 60.5% of patients with T2D and 56.5% of control patients had a hospital admission for any cause. The hospital bed-day rate was alarmingly higher for individuals with T2D, who had 3359 bed-days per 1000 person-years, compared with 2350 bed-days per 1000 person-years among patients without T2D.

Age played a different role in hospitalization patterns for each group. In the control group, the all-cause hospital bed-day rate increased with age. However, among those with T2D, the researchers observed a J-shaped relationship with age, indicating an increase in hospital bed-days for younger individuals as well.

Additionally, men with diabetes had a 1.75-fold increased risk, while women had a slightly higher 1.87-fold increased risk.

Aside from all-cause hospitalization, the study further revealed that T2D was associated with a higher risk of hospital bed-days for 7 broad disease categories: infections or parasites, neoplasms, mental health disorders, circulatory system, respiratory system, digestive system, and genitourinary system. Circulatory and respiratory conditions contributed to the largest number of inpatient bed-days in both the T2D and control groups.

Among 72 specific medical conditions within the 7 categories, the researchers found that pneumonia, ischemic stroke, chronic obstructive pulmonary disease, heart failure, and ischemic heart disease contributed to the highest hospital bed-day rates for both groups. Interestingly, sex-based risk varied depending on the age at diabetes diagnosis and the specific medical condition. The study also revealed a 4 to 5 times increased risk of bed-days for heart failure and pancreatic cancer among patients with T2D compared with controls.

“The discrepancy may be attributable to the choice of outcome measure, as hospital bed-days take into account factors leading to hospitalisation as well as those affecting the length of stay,” the researchers said. “Importantly, the association between type 2 diabetes and hospital bed-days extended to a broad range of medical conditions that had not been conventionally attributed to diabetes such as diseases of the respiratory and digestive systems.”

Notably, 38.4% of bed-days among people who received a T2D diagnosis before the age of 40 were attributed to mental health disorders, highlighting the pressing need for mental health support in young people with diabetes. The study showed that schizophrenia and bipolar disorder—of the 8 included mental disorders—contributed to the highest rate of inpatient bed-days for both male and female patients, and that mental health had a larger impact on bed-days for women than men.

According to the researchers, patients with comorbid diabetes and mental health disorders also had high prevalence of nonadherence to medication and self-care, which was associated with suboptimal glycemic control and frequent hypoglycemia.

“Although guidelines recommend screening for mental health disorders in people with type 2 diabetes and vice versa, their implementation in clinical practice is suboptimal,” the researchers said. “Up to 45% of cases of depression in people with diabetes and 70% of cases of diabetes in people with severe mental health disorders were undetected. The high rate of co-occurrence of mental health disorders and type 2 diabetes especially in young people extended previous findings in a register-based study and calls for urgent awareness program among all stakeholders to take actions.”

These findings emphasized the need to consider age and sex differences in designing preventive and therapeutic strategies for T2D, and highlighted the urgent requirement for effective control of risk factors.

“Effective control of risk factors with a focus on mental health disorders are urgently needed in young people with type 2 diabetes,” the researchers emphasized. “Healthcare systems and policymakers should consider allocating adequate resources and developing strategies to meet the mental health needs of young people with type 2 diabetes, including integrating mental health services into diabetes care.”

Reference

Wu H, Yang A, Lau ESH, et al. Age- and sex-specific hospital bed-day rates in people with and without type 2 diabetes: a territory-wide population-based cohort study of 1.5 million people in Hong Kong. PLoS Med. 2023;20(8):e1004261. doi:10.1371/journal.pmed.1004261