Metabolic Syndrome (MetS) is a constellation of risk factors that includes abdominal obesity, high triglyceride levels, low HDL cholesterol (HDL-C), elevated blood pressure, and high fasting glucose levels. MetS is associated with chronic diseases such as accelerated atherosclerotic cardiovascular disease, hyperuricemia/gout, chronic kidney disease, and obstructive sleep apnea¹.

The diagnosis of MetS varies according to the criteria applied and the total number of risk factors considered by different institutions. Therefore the prevalence of MetS may differ. With this in mind, data from the National Health and Nutrition Examination Survey (NHANES) estimated that 35% of adults in the United States and up to 50% of the population over 60 years old have a diagnosis of MetS. In addition, the Metabolic Syndrome and Arteries Research (MARE) study, which applies the ATP III criteria, established a MetS prevalence of 23.9% in men and 24.6% in women in Europe². In Spain, according to WHO criteria, the prevalence of MetS is 32% in men and 29% in women. Furthermore, the COVID-19 pandemic lockdown has increased the global prevalence of MetS and its risk factors due to changes in dietary and physical activity habits and the use of antipsychotics.

An increase in non-communicable chronic pathologies, specifically in metabolic syndrome risk factors, has been observed amongst the prison population in recent years, especially in high-income countries. However, studies on this topic are very scarce³ and/or provide partial information showing when they show the prevalence of cardiovascular risk factors or related situations and conditions that incarcerated individuals experience to a greater extent than the general population, such as the prevalence of metabolic syndrome observed in the prison population with mental illness and substance use disorders, infectious diseases including HIV, tuberculosis, and hepatitis, non-communicable diseases such as obesity, diabetes, hypertension, etc., and cognitive disability such as stress and post-traumatic stress disorder^4-6.

In the case of women, the scarcity of data and studies exacerbates the situation⁷.

The main reasons for the increased prevalence of metabolic syndrome in this population are the same as the ones that were published in 2016⁸, and include progressive aging, low socioeconomic status of much of the incarcerated population from low-income countries, higher global morbidity load among inmates, frequent smoking habits amongst inmates in Spain where 3 out of 4 smoke, and the widespread use of second-generation antipsychotics, which are associated with weight gain and the risk of dyslipidaemia or diabetes mellitus.

Numerous studies in the literature show that the primary therapeutic strategy for the prevention, treatment, and management of metabolic syndrome and its risk factors are nutritional and dietary interventions, exercise, reduced tobacco and alcohol consumption, and overall modifications to establish a healthy lifestyle⁵. Most studies conducted in correctional facilities report improvements in metabolic syndrome following dietary and exercise interventions or combined approaches. However efforts to prevent smoking seem to have had less successful results, especially among women and young people⁴.

The main lifestyle strategies and interventions observed relate to caloric and simple carbohydrate restriction, lipid modification, and exercise and physical activity activation programs.

A novel area for exploration is related to the role and importance of intestinal microbiota in human health, which is currently better understood. Recent studies^9,10 have reported a strong impact by antipsychotics on the composition of intestinal microbiota, which may impact adiposity. Experimental models suggest that treatment with prebiotics may be effective in limiting weight gain following antipsychotic treatment.

The health of the prison population is also a public health issue, as the global prison population has increased by 24% since 2000, with over 10.77 million people detained worldwide in 2021¹¹.

At the latest WHO international meeting in Lisbon in 2017 on prisons and health, the importance of recognizing “the role of prisons as important settings to address health inequalities and to recognize the status of people in prison as a disadvantaged group in terms of health and well-being” was emphasized. Providing healthcare to inmates is an international policy norm that includes health restoration and disease prevention¹².

Healthcare in the prison setting is a crucial component of public health, and proper management of healthcare in prisons is essential to reduce health inequalities amongst the population. However, there is very little published evidence on current governance systems in prison healthcare or on the impact of different intervention policies on health outcomes¹¹.

The study of health, incidence, and prevalence of non-communicable diseases, particularly metabolic syndrome, and the exploration of lifestyle strategies and interventions in this population are necessary due to the scarcity of evidence and the special circumstances they present.