Prevention of Metabolic Syndrome in forensic mental health patients: Generating knowledge to improve future prevention of Metabolic Syndrome

Background: Forensic mental health patients (FMHPs) have higher mortality than the general population. Metabolic syndrome (MetS) is a condition of central obesity, insulin resistance, dyslipidaemia, and hypertension, and it contributes to the higher mortality in FMHPs. The risk of developing MetS is affected by, among other things, obesity and the health behaviours diet, smoking, alcohol consumption, and physical activity. Thus, improvement in these health behaviours could reduce the risk of MetS and subsequently reduce mortality.

Aim: The overall aim of this PhD project was to generate knowledge that can contribute to improve future MetS prevention. The project consisted of three sub-studies with the following objectives:

1) To review existing research, in order to investigate the characteristics of, and factors that influence FMHPs’ smoking, alcohol consumption, physical activity, and dietary behaviours 

2) To investigate the associations between hospitalisation time and change in body weight, waist circumference, blood pressure, blood glucose, and blood lipids, respectively, in FMHPs

3) To explore FMHPs’ perceptions of factors influencing their physical activity, smoking and dietary behaviours during their hospital stay

Methods: The first objective was investigated in a mixed methods systematic review. The electronic databases PubMed, CINAHL, PsycInfo, and Scopus were searched for primary research on FMHPs’ health behaviours in regard to smoking, alcohol consumption, physical activity, and dietary behaviours, and factors that influence these health behaviours. 

The second objective was investigated in a retrospective cohort study using data from medical records. All FMHPs with schizophrenia or bipolar disorder who were prescribed antipsychotics, and treated between January 1st, 2016 and April 6th, 2020 in the Region of Southern Denmark were included. Using linear regression, associations between proportional hospitalisation time (PHT) and, respectively, primary and secondary outcomes were analysed. PHT was determined between each measurement of the analysed outcome as the total number of days hospitalised divided by the total number of days between the measurements. The primary outcome was change in body weight and secondary outcomes were change in waist circumference, blood pressure, blood lipids, and estimated average glucose.

The third objective was investigated in hospitalised FMHPs. This sub-study was an interview study, and 18 hospitalised FMHPs participated. The transcribed interviews were analysed inductively using thematic analysis.

Results: In the review, 13 eligible studies were found. The studies consistently showed the presence of unfavourable health behaviours in FMHPs: High prevalence of smoking, problematic alcohol consumption in a considerable proportion of the FMHPs, low level of physical activity, and a high-calorie diet of poor nutritional value. Changing smoking and dietary habits was perceived by the FMHPs to be difficult, but they suggested that nicotine replacement and practical advice would be helpful to change health behaviours.

In the cohort study, 490 FMHPs were included of which 440 were diagnosed with schizophrenia. The analysis of weight change showed a statistically significant positive dose-response association with PHT (β=+0.040 kg/year/percent-point increase in PHT, 95% CI: 0.018 – 0.062), and the association interacted with baseline body mass index. The association between PHT and change in waist circumference was also statistically significant (β=+0.030 cm/year/percent-point increase in PHT, 95% CI: 0.004 – 0.056), whereas the associations with PHT were statistically non-significant for the remaining secondary outcomes.

The interview study showed that the respondents perceived the following four factors to have influence on their physical activity, smoking and dietary behaviours: Predisposing factors (consisting of wish for good health or fitness and experience and knowledge); motivation for health-promoting behaviours; mental health-related factors (consisting of mental health state and psychotropic drugs); and hospitalisation-related factors (consisting of boredom, other patients, staff, availability, facilities, and rules and restrictions). These factors and the health behaviours were shown to be interrelated and, furthermore, the health behaviours had mutual influence on each other.

Conclusion: The review showed unfavourable smoking, alcohol consumption, physical activity, and dietary behaviours among FMHPs. Thus, it seems likely that these health behaviours contribute to the increased risk of MetS in FMHPs, and it is suggested that future MetS prevention be targeted to all of these health behaviours. Furthermore, hospitalised FMHPs should be prioritised to receive prevention of weight gain and thereby prevention of MetS, given that FMHPs gained more weight during hospitalisations compared to when they were treated outside hospitals. In the implementation of MetS prevention, several factors must be considered: Predisposing factors, motivation for health-promoting behaviours, mental health-related factors, and hospitalisation-related factors.