People with schizophrenia and diabetes at risk for excess mortality, study finds
Cardiovascular complications confer the highest relative mortality rate in patients with schizophrenia and diabetes. Hong Kong: Schizophrenia patients with diabetes are at increased risk of excess mortality compared to those with diabetes alone irrespective of complication burden levels, show results from a 16-year long study.
The results, published in the journal European Neuropsychopharmacology, indicate the need for the implementation of multilevel, targeted interventions to improve diabetes-related outcomes and reduce the mortality gap in this vulnerable population.
Schizophrenia is known to be associated with increased diabetes risk. However, not much is studied about the risk of diabetes complications, its impact of complication burden, and patterns on subsequent risk of mortality in schizophrenia patients with co-existing diabetes. To throw some light on the topic, Wing Chung Chang, State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, and colleagues conducted the population-based, propensity-score matched (1:10) cohort study.
The researchers identified 6991 patients with incident diabetes and pre-existing schizophrenia and 68,682 patients with incident diabetes only (comparison group) between 2001 and 2016 in Hong Kong, using a territory-wide medical-record database of public healthcare services. Using Diabetes Complications Severity Index (DCSI), the researchers measured complications. This stratified complication burden into 6 levels (DCSI score=0, 1, 2, 3, 4, or ≥5). Associations of diabetes complications, in terms of DCSI scores (complication burden), specific types and two-way combinations of complications (complication patterns), with all-cause mortality rate in schizophrenia were evaluated using Cox proportional-hazards models.
Key findings of the study include:
- Schizophrenia group had comparable macrovascular (adjusted OR 0.99) and lower microvascular (0.79) complication rates relative to comparison group.
- Mortality risk ratio for schizophrenia was elevated at all complication burden levels, which conferred incremental impact on excess mortality in both groups.
- Cardiovascular diseases (1.60) and cerebrovascular-metabolic diseases (2.74) were associated with the highest differential mortality in schizophrenia among various specific complications and complication combinations, respectively
The researchers concluded, "our results indicate that schizophrenia patients with co-existing diabetes are at increased risk of excess mortality relative to those with diabetes alone, regardless of complication burden levels."
The study titled, "Diabetes complication burden and patterns and risk of mortality in people with schizophrenia and diabetes: A population-based cohort study with 16-year follow-up," is published in the journal European Neuropsychopharmacology.