People with schizophrenia are known to have a lower life expectancy than people without this disorder, largely driven by an increased risk of cardiovascular disease. Some studies have suggested that the relationship between schizophrenia and cardiovascular disease may be due to shared etiology—that is, people who are genetically at risk of schizophrenia are also genetically at risk for cardiovascular disease. A study published in Schizophrenia Bulletin now suggests shared genetics likely does not explain this schizophrenia-cardiovascular association.
“The lack of evidence for genetic correlation between schizophrenia and [cardiovascular disease] is striking, given … the fact that a considerable amount of the risk variants for schizophrenia are located in genes relevant for cardiological functioning,” wrote Rada Veeneman and Jorien L. Treur, Ph.D., of the University of Amsterdam and colleagues. “This implies that effective treatment and intervention in early psychosis is important to decrease excess cardiovascular mortality.”
Veeneman and colleagues used data from seven genome-wide analyses (involving more than 1 million people) that identified genetic variants associated with coronary artery disease and heart failure, as well as other adverse cardiovascular outcomes including high systolic and diastolic blood pressure, highly variable heart rate, prolonged QT interval, early repolarization, and dilated cardiomyopathy. Another genome-wide analysis involving more than 130,000 people with schizophrenia and controls to identify genetic variants for schizophrenia risk was also included in the study. The researchers examined whether the people who had high genetic risk for one of these cardiovascular disease traits were more likely to develop schizophrenia and vice-versa (whether people who had high genetic risk for schizophrenia were more likely to have an adverse cardiovascular outcome).
The researchers found almost no evidence that an increased genetic risk of cardiovascular disease was associated with a similarly increased risk of developing schizophrenia, except for a weak association between high systolic blood pressure and schizophrenia risk. In contrast, people at an increased genetic risk of schizophrenia had higher odds of heart failure or early repolarization (an ECG pattern that resembles a heart attack and is considered a risk factor for cardiac arrest).
“Our findings are in line with the notion that schizophrenia is characterized by a systemic dysregulation of the body, including inflammation and oxidative stress, which promotes cardiac alterations and ultimately heart failure,” the authors wrote. “More thorough screening throughout psychiatric treatment must become a priority, in order to decrease the stark mortality gap between schizophrenia patients and individuals from the general population.”
To read more on this topic, see the Psychiatric News article “Cardioprotective Treatments After Heart Attack Can Help Patients With Schizophrenia Live Longer.”
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