Food insecurity – limited or unreliable food supplies due to
poverty – was associated with an increased risk of death in US adults with non-alcoholic
fatty liver disease (NAFLD) or advanced fibrosis caused by NAFLD, an analysis of
a large US cohort study has shown.
Dr Ani Kardashian, Assistant Professor of Clinical Medicine
at the University of Southern California, presenting the findings to the
International Liver Congress last week, said that one in five deaths in adults
with advanced fibrosis living in poverty could be prevented if food insecurity were
Food insecurity is defined by nutritional researchers as the
limited or uncertain availability of nutritionally adequate foods or the inability
to acquire food in socially acceptable ways. It disproportionally affects
low-income and socially marginalised adults. Food insecurity tends to be
accompanied by a reduction in the quality and variety of foods, followed by a
reduction in food intake.
Approximately 35 million adults in 18 million households in
the US were experiencing some degree of food insecurity before the COVID-19
pandemic. Job losses during the pandemic may have pushed the number of people who are food insecure
towards 50 million over the past year, Dr Kardashian said.
Foods high in fat and sugar often predominate in the diets
of people who are food insecure, as these may be cheaper and provide energy. However,
food insecurity is linked to high blood pressure, cardiovascular disease, type
2 diabetes, obesity, chronic kidney disease and NAFLD.
Diets high in fat and sugar also lead to fat accumulation in
the liver and eventually to liver damage, or advanced fibrosis. Understanding
the impact of food insecurity on mortality from NAFLD
is critical for influencing policies regarding food assistance and the availability
of healthy food for people living in poverty.
To investigate the long-term outcomes of people with fatty liver
disease and food insecurity, Prof. Kardashian and colleagues at the University
of Southern California in Los Angeles carried out a retrospective cohort study
of participants in the National Health and Nutrition Examination Survey
(NHANES) from 1999 to 2014.
Food insecurity in NHANES participants was established by an
18-item questionnaire on individual and household experiences of food affordability,
adequacy of diet and hunger during the previous year.
NHANES participants aged 20 or over were included in the
analysis if they had NAFLD (US Fatty Liver Index of 30 or above without viral
hepatitis or significant alcohol use) or advanced fibrosis (defined as an NAFLD
fibrosis score greater than 0.675, an APRI score greater than 1.5 or a FIB-4
score greater than 2.67. Participants with missing mortality, liver enzyme or
food insecurity data were excluded, as were pregnant women.
Investigators identified 4816 participants with NAFLD and
1654 with advanced fibrosis. Twenty-eight per cent of those with NAFLD were
food insecure, as were 21% of those with advanced fibrosis. Food insecure people
were less likely to be non-Hispanic White, more likely to be living in poverty
and more likely to lack public or private health insurance. Food insecure
participants were also more likely to be diabetic and obese.
During a median follow-up period of 85 months, food-insecure
participants had a higher rate of all-cause mortality (p < 0.001) and multivariate
analysis adjusted for gender, ethnicity, other socio-demographic and metabolic
risk factors, showed that food insecurity was associated with a 46% higher risk
of death in adults with NAFLD (hazard ratio 1.46, 95% CI 1.08-1.97, p = 0.01).
All-cause mortality was also elevated in publicly insured participants (HR
1.36, 95% CI 1.06-1.73, p = 0.02) and participants with a history of smoking (HR
1.45, 95% CI 1.16-1.81, p = 0.001).
Food insecurity was also associated with an increased risk
of death in participants with advanced fibrosis during a median follow-up
period of 56 months (p = 0.04). Multivariate analysis adjusted for gender, ethnicity,
other socio-demographic and metabolic risk factors showed that food insecurity
was associated with a 37% higher risk of death in adults with advanced fibrosis
(95% CI 1.01-1.86, p = 0.04). The risk of death was also raised in publicly
insured participants (HR 1.27, 95% CI 1.02-1.5, p = 0.03).
The researchers also calculated the population-attributable
risk percentage, or the percentage of deaths that would be averted if food
insecurity were eliminated. Three per cent of deaths would be averted if food
insecurity were eliminated in participants with NAFLD, rising to 7% of deaths
in participants with advanced fibrosis and 22% of deaths in participants with
advanced fibrosis living in poverty.
Speaking to a press briefing on the study, Prof. Kardashian
said that the impact on mortality of interventions to reduce food insecurity
should be investigated. Screening for food insecurity, referral to food counselling
and linkage to food assistance should be considered in any clinical practice
treating patients with NAFLD, she suggested. Partnering with food banks to
improve nutrition for people with NAFLD should also be explored. “It’s
important that we expand food assistance for our at-risk patients,” Dr