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30-05-2012 | Cardiology | Article

Noncommunicable diseases need more attention among prisoners

MedWire News: Prisons are not taking appropriate action to improve diet and increase physical activity levels to help prevent noncommunicable diseases (NCDs) among prisoners, say UK researchers in The Lancet.

Katherine Herbert (University of Oxford) and colleagues explain that, in 2008, 36 million of 57 million deaths worldwide were attributable to NCDs, such as heart disease, diabetes, and cancer. The burden of these diseases is disproportionately carried by low- and middle-income countries and disadvantaged sectors of society such as prisoners, they add.

The prevalence of two main modifiable NCD risk factors, tobacco and alcohol use, among prisoners has been assessed, but there are no data on the other two, namely diet and physical activity.

To address this, the researchers systematically searched online databases for relevant reports published between 1948 and 2011. They used population-based data to calculate age- and gender-adjusted prevalence ratios, which estimate the likelihood of insufficient physical activity and obesity prevalence in prisoners compared with the national population.

The team identified 31 eligible studies including more than 60,000 prisoners in 884 institutions in 15 countries.

A meta-analysis of body mass index data showed that male prisoners were less likely to be obese than men in the general population (prevalence ratios=0.33 to 0.87) in all but one study from the USA (prevalence ratio=1.02).

Even so, the prevalence of overweight and obesity was "unacceptably high" in developed world countries (UK, USA, Australia), where it ranged from 38% to 65%, and was increasing in low- and middle-income countries.

By contrast, female prisoners were more likely to be obese than nonimprisoned women in the USA (prevalence ratio=1.18) and Australia (prevalence ratios=1.15 to 1.20), but less likely to be obese than nonimprisoned women in the UK (prevalence ratio=0.70).

The gender differences may be explained by diet, say the researchers. They found that, while male diets in high-income countries provided an appropriate calorie intake, female diets provided a substantial excess of total energy. "The evidence suggests that female prisoners are simply supplied with a diet designed for males," Herbert et al remark.

The researchers also found that sodium intake was about two to three times the recommended intake for all prisoners.

Data on physical activity were only available for Australia and the UK, and showed contrasting situations. In Australia, male and female prisoners were more likely to achieve sufficient activity levels (150 minutes of moderate exercise per week) than the general population, whereas UK prisoners were less likely than the general UK population to achieve sufficient activity levels.

"Prisons present a unique public health opportunity for health promotion among vulnerable groups who are difficult to engage with in community settings," say Herbert and co-authors.

"However, the data from this systematic review suggest that the opportunity is not being seized by prison authorities," they add.

The team concludes: "Improved monitoring and further research is essential to inform appropriate targeting of public health interventions."

MedWire ( is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2012

By Laura Cowen

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