Childhood insulin level and BMI may predict psychosis, depression risk in later life

Cardiometabolic comorbidities associated with psychosis and depression may have distinct and disorder-specific early-life origins, with disrupted insulin sensitivity appearing to be a shared risk factor for comorbid cardiometabolic disorders and adult psychosis whilst an increase in puberty-onset body mass index (BMI) appears to be associated with adult depression, results of a recent study have shown.

“Although residual confounding maybe an issue, our results suggest that cardiometabolic markers could be among shared risk factors and indicators of adult cardiometabolic and psychiatric disorders. These markers may represent novel targets for prevention and treatment of cardiometabolic disorders in people with psychosis and depression,” said the authors. [JAMA Psychiatry 2021, doi: 10.1001/jamapsychiatry.2020.4180]

In the study, persistently high fasting insulin (FI) level trajectory was associated with 5.01-fold and 3.22-fold increase in risk of psychosis at-risk mental state (p=0.006) and psychotic disorder (p=0.05), respectively, but not with depressive episode (p=0.69).

On the other hand, puberty-onset major increase trajectory of BMI was associated with a 4.46-fold increase in risk of depressive episode (p=0.006), but not with psychotic disorder (p>0.99).

Subgroup analysis showed consistent associations of risks for psychiatric outcomes. Persistently high FI trajectory was associated with a 3.94-fold increase in risk of psychiatric disorder in males (95 percent confidence interval [Cl], 1.10 to 11.96), while puberty-onset major increase trajectory of BMI was associated with a 6.28-fold increase in risk of depressive episode (95 percent Cl, 2.14 to 18.44).

In the study, data of 5,790 participants (female, 54.1 percent) for FI levels and 10,463 participants (female, 51.0 percent) for BMI were extracted from the Avon Longitudinal Study of Parents and Children (ALSPAC), a prospective study that included 14,975 individuals aged 1–24 years representative of England’s population. FI measured at 9, 15, 18, and 24 years of age and BMI measured at 1, 2, 3, 4, 7, 9, 10, 11, 12, 15, 18 and 24 years of age were used for growth mixture modelling to delineate three FI and five BMI developmental trajectories, all of which were differentiated by mid-childhood.