Undernutrition may double risk of tuberculosis

A new Cochrane review highlights the significant association between undernutrition and tuberculosis (TB) disease, shedding light on its prognostic value in predicting TB incidence among adults, adolescents, and children.

The review, which analyzed data from 51 cohort studies involving over 27 million participants across diverse settings, reveals that undernutrition probably doubles the risk of TB disease. This association, particularly evident within 10 years from the onset of undernutrition, underscores the urgent need for targeted interventions to address undernutrition as part of broader TB prevention strategies.

Undernutrition, characterized by factors such as low body mass index (BMI) emerges as a key risk factor for TB infection and progression. Malnutrition compromises the immune system, reducing the body's ability to fight off infections, including TB. Individuals who are malnourished have weakened immune responses, making them more susceptible to the TB bacterium and less capable of containing latent infections. In 2022 alone, undernutrition contributed to an estimated 2.2 million TB cases worldwide, as documented in the World Health Organization's Global Tuberculosis Report.

Lead author of the review and lead of the Cochrane evidence synthesis group at Heinrich Heine University Düsseldorf, Juan Franco, says, “By quantifying this risk, we can more accurately estimate the burden of TB disease attributable to undernutrition. This information informs the planning of policies based on the burden of risk factors across different regions of the world.”

The impact of quantifying the relationship between undernutrition and TB provides evidence-based guidance for policymakers to allocate resources effectively, design targeted interventions, and implement comprehensive TB prevention strategies. For doctors and patients, it highlights the importance of nutritional assessments and interventions in TB care and prevention.

The findings from the review suggest that public health policies in countries with high TB burdens must prioritize nutritional support as a core component of TB control programs.

“By addressing undernutrition, these policies can reduce TB incidence, improve treatment outcomes, and contribute to overall health improvements in these populations,” Franco notes.

Despite the clear link between undernutrition and TB disease risk, challenges persist in standardizing diagnostic methods and accounting for confounding factors. The review emphasizes the importance of ongoing research, especially in low- and middle-income countries, to obtain accurate estimates of undernutrition's impact on TB across different populations and settings.

Juan Franco emphasizes the vital role of international organizations, such as the World Health Organization (WHO) and the WHO TB Programme, in implementing the review’s findings. "Evidence-based policies addressing food insecurity and malnutrition are urgently needed," he explains. 

"Undernutrition manifests differently worldwide, influenced by various social determinants of health. There is no one-size-fits-all solution, but addressing societal inequalities is always a good starting point. Treating undernutrition, along with reducing other TB risk factors, is essential not only to lower the TB burden but also to achieve overall well-being." 

By focusing on the dual burden of undernutrition and TB, this Cochrane review underscores the importance of integrating nutritional support into TB control programs to achieve better health outcomes globally.

Thursday, June 13, 2024