medwireNews: The prevalence of diabetes is increased in the unaffected relatives of patients with non-affective psychosis, results from a Dutch study show.
Hanneke van Welie (University Medical Centre Utrecht) and colleagues found that the first-, second-, and third-degree relatives of patients with non-affective psychotic disorders are 1.6 times more likely to have diabetes than the relatives of individuals without psychosis.
Furthermore, the associated risk was even higher among relatives over the age of 50 years.
As previous studies have shown an increased risk for diabetes among patients with schizophrenia, "our findings support the hypothesis of a familial, possibly genetic, link between DM [diabetes mellitus] and non-affective psychotic disorders," say the researchers.
The team assessed data on 1740 unaffected relatives of patients diagnosed with a non-affective psychotic disorder, according to DSM-IV criteria, and 1271 relatives of controls without a family history of psychosis who participated in the Genetic Risk and Outcome of Psychosis study.
The prevalence of diabetes was assessed using the Family Interview for Genetic Studies.
The researchers found that the prevalence of diabetes was significantly higher in the relatives of patients with psychosis than in those of controls, at 6.1% versus 3.6% (odds ratio [OR]=1.6).
Dividing the relatives into first-, second-, and third-degree categories did not significantly alter the association.
The greatest differences in the prevalence of diabetes between relatives of patients with psychosis and those of controls were in the age groups 50-59 years (4.8 vs 1.2%) and 60-69 years (5.4 vs 2.5%).
"In conclusion, we have shown that relatives of patients with non-affective psychotic disorders show an increased prevalence of DM," write van Welie et al in Schizophrenia Research.
They add: "The increased risk of DM in the absence of psychosis and antipsychotics suggests that familial, possibly genetic, factors play a role."
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