Increased Adolescent Height, Body Weight Linked to NHL

Individuals with increased height or body mass index (BMI) during adolescence showed an increased association with a diagnosis of non-Hodgkin lymphoma (NHL), according to the results of a large Israeli study published in Cancer.

More specifically, study results showed that an increased BMI was linked with marginal zone lymphoma, primary cutaneous lymphoma, and diffuse large B-cell lymphoma; increased height was linked with diffuse large B-cell lymphoma and primary cutaneous lymphoma.

“The potential role of height and obesity in NHL etiology is of public health relevance, and some of it (excess weight) may be preventable,” wrote researcher Merav Leiba, MD, of Sheba Medical Center in Tel Hashomer, Israel, and colleagues. “Further studies are needed to elucidate the biological mechanisms through which weight and height in adolescence influence the future risk of developing specific NHL subtypes.”

The researchers used data on more than 2 million Israeli adolescents age 16 to 19 years collected from 1967 to 2011 and linked it to cancer data from the Israel National Cancer Registry. They identified 4,021 cases of NHL. From there, they explored if excess BMI or increased height was linked with NHL diagnosis.

The mean age at examination was 17.3 years. About 9% of the participants were classified as overweight (BMI, 95th percentile or greater), and obesity was noted in 3.8% of participants.

The researchers conducted a multivariable analysis adjusting for sex, year of birth, and age at examination, and found that both height and weight were positively associated with an NHL diagnosis. Participants who were overweight or obese had a 25% increased risk for NHL diagnosis (hazard ratio [HR], 1.25 [95% CI, 1.13–1.37]) compared with normal weight participants.

To examine height, participants were grouped into eight categories based on their height. The data showed that compared with participants categorized as mid-range height, those that were the tallest had a 28% increased risk for NHL (HR, 1.28 [95% CI, 1.04–1.56]) and those that were shortest had a decreased risk (HR, 0.75 [95% CI, 0.65–0.87]).

“Previous studies have reported height as a risk factor for NHL,” wrote the researchers. “However, in an analysis that combined 18 studies from 13 countries, the tallest men were found to have a minimally greater risk in comparison with men of mid-range height.”

Leiba and colleagues then looked at whether or not certain subtypes of NHL were associated with overweight/obesity or increased height. Being overweight or obese during adolescence was significantly associated with marginal zone lymphoma (HR, 1.70), primary cutaneous lymphoma (HR, 1.44), and diffuse large B-cell lymphoma (HR, 1.31). Height had the strongest positive associations with diffuse large B-cell lymphoma (HR, 1.005) and primary cutaneous lymphoma (HR, 1.005).

The researchers proposed several possible causes for the link between increased height/weight and NHL.

“Impaired immune function, known to be of paramount importance in the etiology of NHL, can be related to both undernutrition and overnutrition,” they wrote. “Obesity is associated with chronic inflammation, insulin resistance, compensatory hyperinsulinemia, and increased insulin-like growth factor 1 (IGF-1) levels. In addition, oxidative stress, crosstalk between tumor cells and surrounding adipocytes, migrating adipose stromal cells, obesity-induced hypoxia, and shared genetic susceptibility may factor into the mechanism linking overweight and tumorigenesis.”