Passive smoking ups risk of fatty liver in midlife

Exposure to secondhand smoke in childhood and adulthood appears to elevate the risk of adult nonalcoholic fatty liver, reveals a study, noting that the prevention of passive smoking should begin as early as possible and be maintained throughout lifetime.

“Identifying early life risk factors remains key to the prevention of nonalcoholic fatty liver in adulthood,” the investigators said, but the longitudinal association of childhood passive smoking with adult fatty liver has not been previously examined.

To address this limitation, the association of childhood and adulthood passive smoking with fatty liver in midlife was assessed in this 31-year prospective cohort study involving a total of 1,315 participants.

The investigators obtained information regarding childhood passive smoking (parental smoking) in 1980 (aged 3–18 years) and 1983, as well as adulthood passive smoking in 2001, 2007, and 2011. Fatty liver was diagnosed by ultrasound in 2011 (aged 34–39 years).

A 16.3-percent prevalence of fatty liver was observed. Both childhood (relative risk [RR], 1.41, 95 percent confidence interval [CI], 1.01–1.97) and adulthood passive smoking (RR, 1.35, 95 percent CI, 1.01–1.82) resulted in an increased risk of fatty liver, adjusting for potential confounders such as age, sex, childhood socioeconomic status, and adulthood physical activity and alcohol consumption.

Persistent exposure to secondhand smoke between childhood and adulthood was associated with the highest risk (RR, 1.99, 95 percent CI, 1.14–3.45) compared with nonexposure to passive smoking in either childhood or adulthood.