Application of SWATH mass spectrometry in the identification of circulating proteins does not predict future weight gain in early psychosis

Weight change following diagnosis with psychosis: a retrospective cohort study in Greater Manchester, UK

INTRODUCTION

Weight gain in the months/years after diagnosis/treatment of severe enduring mental illness (SMI) is a major predictor of future diabetes, dysmetabolic profile and increased risk of cardiometabolic diseases. There is limited data on the longer-term profile of weight change in people with a history of SMI and how this may differ between individuals. We here report a retrospective study on weight change over the 5 years following an SMI diagnosis in Greater Manchester UK, an ethnically and culturally diverse community, with particular focus on comparing non-affective psychosis (NAP) vs affective psychosis (AP) diagnoses.

METHODS

We undertook an anonymised search in the Greater Manchester Care Record (GMCR). We reviewed the health records of anyone who had been diagnosed for the first time with first episode psychosis, schizophrenia, schizoaffective disorder, delusional disorder (non-affective psychosis = NAP) or affective psychosis (AP). We analysed body mass index (BMI) change in the 5-year period following the first prescription of antipsychotic medication. All individuals had taken an antipsychotic agent for at least 3 months. The 5-year follow-up point was anywhere between 2003 and 2023.

RESULTS

We identified 9125 people with the diagnoses above. NAP (n = 5618; 37.3% female) mean age 49.9 years; AP (n = 4131; 60.5% female) mean age 48.7 years. 27.0% of NAP were of non-White ethnicity vs 17.8% of AP individuals. A higher proportion of people diagnosed with NAP were in the highest quintile of social disadvantage 52.4% vs 39.5% for AP. There were no significant differences in baseline BMI profile. In a subsample with HbA1c data (n = 2103), mean HbA1c was higher in NAP at baseline (40.4 mmol/mol in NAP vs 36.7 mmol/mol for AP). At 5-year follow-up, there was similarity in both the overall % of individuals in the obese ≥ 30 kg/m2 category (39.8% NAP vs 39.7% AP), and % progressing from a normal healthy BMI transitioned to obese/overweight BMI (53.6% of NAP vs 55.6% with AP). 43.7% of those NAP with normal BMI remained at a healthy BMI vs 42.7% with AP. At 5-year follow-up for NAP, 83.1% of those with BMI ≥ 30 kg/m2 stayed in this category vs 81.5% of AP.

CONCLUSION

The results of this real-world longitudinal cohort study suggest that the changes in BMI with treatment of non-affective psychosis vs bipolar disorder are not significantly different, while 43% maintain a healthy weight in the first 5 years following antipsychotic prescription.

First episode psychosis and weight gain a longitudinal perspective in Cheshire UK: a comparison between individuals with nonaffective versus affective psychosis

Early weight gain following initiation of antipsychotic treatment predicts longer-term weight gain, with attendant long-term consequences including premature cardiovascular events/death. An important question is whether there is a difference in weight change over time between people with affective versus nonaffective psychosis. Here we describe the results of a real-world analysis of the BMI change in the months postdiagnosis with affective versus nonaffective psychosis.

Methods

We undertook an anonymised search across one Primary Care Network in Cheshire, UK with a total population of 32 301 individuals. We reviewed the health records of anyone who had been diagnosed over a 10-year period between June 2012 and June 2022 for the first time with first episode nonaffective psychosis versus psychosis associated with depression or bipolar affective disorder (affective psychosis).

Results

The overall % change in BMI was +8% in nonaffective psychosis individuals and +4% in those with a diagnosis of affective psychosis - however, the distribution was markedly skewed for nonaffective psychosis patients. Using caseness as >30% increase in BMI; affective = 4% cases and nonaffective = 13% cases, there was a three-fold difference in terms of increase in BMI. In regression analysis, the r² linking the initial BMI to % change in BMI was 0.13 for nonaffective psychosis and 0.14 for affective psychosis.

Conclusion

The differences observed here in the distribution of weight change over time between individuals with affective versus nonaffective psychosis may relate to underlying constitutional differences. The phenotypic and genetic factors underlying this difference remain to be defined.