But obesity appeared protective
CHICAGO -- Food insecurity was linked to childhood hypertension in a nationally representative dataset, according to a research group that also found that obesity moderates the association between the two in low-income settings.
One in five children ages 8-17 reportedly lived in a household with limited availability of nutritious food in 2007-2014, data from the National Health and Nutrition Examination Survey (NHANES) showed.
High blood pressure (BP) was more likely among these kids (14.4% versus 11.6% for "food-secure" peers, OR 1.25, 95% CI 1.04-1.50), said Andrew South, MD, and colleagues of Wake Forest School of Medicine in Winston-Salem, N.C., at a poster presented at Hypertension 2018, which is jointly sponsored by the American Heart Association and the American Society of Hypertension.
"We found that food insecurity was associated with an increased likelihood of high BP in a large, nationally representative cohort of U.S. children and adolescents, independent of obesity. Food insecurity likely has a significant impact on health and cardiovascular disease during childhood, so efforts to address food insecurity will also help reduce the burden of cardiovascular disease in children and in later adulthood," South suggested.
There were 7,125 children included in the study. Hypertension was defined as systolic or diastolic BP in at least the 90th percentile (age <13 years) or at least 120 mm Hg (if older); in NHANES, BP was an average of three measurements. Food security was evaluated using the U.S. Department of Agriculture Food Security Survey Module.
"It is well established that food insecurity is linked to health disparities in children and adults. While the relationship between food insecurity and hypertension is well known in adults, it had never previously been shown in children and adolescents," South told MedPage Today.
He said it is "very important" that clinicians understand what food insecurity is and who is at risk: "Clinicians should have honest conversations with their patients and their patients' families about their access to nutritionally adequate foods," South urged, noting that his center is one of several that have developed programs to support food-insecure individuals -- facilitating access to nutritionists and social workers, for example, or helping with applications to food assistance programs.
"Our study supports the idea of increasing access to nutritionally adequate food and educating healthcare providers and families as to the importance of adequate nutrition in order to prevent or attenuate disease."
Separately, a single-center study showed that food insecurity was associated with lower odds of hypertension in overweight and obese children, South's group showed.
The overall association between food insecurity and childhood hypertension that was found in the NHANES-based analysis was not replicated in a retrospective chart review of 2,688 children from a low-income population who visited a pediatric residency continuity clinic in 2016-2017. Similarly, living in a "food desert" had no impact on hypertension regardless of the child's body mass index.
On multivariable analysis, however, food insecurity was associated with lower odds of having high BP in overweight and obese children (beta coefficient -0.09, 95% CI -0.18 to -0.001), according to South and colleagues in another poster at the meeting. No such relationship existed in children of healthy weight.
Overweight and obese children in food-insecure households "may have different dietary intake than children in food-secure households, and this may decrease their risk for hypertension," the authors suggested. "More research is needed to investigate why children with obesity and food insecurity have less hypertension than children with obesity who are food secure."
What was different about the team's second study was that food insecurity was assessed with the two-item Hunger Vital Sign and that children ages 2-17 were included. In the end, food insecurity was reported among 9% of the group.
The rates of overweight and obesity were 18% and 26%, respectively, and the hypertension rate was 11%.
"The most likely reason that we did not exactly replicate our findings from the larger national cohort study is that we had a smaller sample size in the local cohort study," South said. Other possibilities include having a predominantly Hispanic (70%) local cohort, "so the factors that contribute to food insecurity as well as high blood pressure may have differed between the two study groups.
"The results of these two studies speak to the complex nature of food insecurity and how its effects on health disparities is multifaceted," he continued. "There are biological and social aspects to food insecurity, including genetic contributions, chronic physiologic stress, nutritional intake, physical activity, and geographic limitations."
What the local cohort study suggests, South said, is that nutritional impact also plays a role, as subjects without obesity demonstrated a stronger link between food insecurity and high BP.
South reported having no conflicts of interest.