Infectious Diseases in Children and Body Mass Index in Young Adults

Gina Suh

, Catherine Ley, and Julie Parsonnet

Author affiliations: Stanford University School of Medicine, Stanford, California, USA

Abstract

In a cohort of 1,863 Filipinos, diarrhea, fever, and unsanitary conditions in infancy were associated with a decreased body mass index in adulthood; upper respiratory tract infection was associated with an increased body mass index. These finding support the hypothesis that infections early in life play a role in body habitus in adulthood.

Obesity rates are increasing globally, particularly in countries transitioning from a state in which mortality rates are driven primarily by infectious disease to a state in which mortality rates are driven by chronic diseases. In the Philippines, a shift in obesity rates occurred between 1985 and 2005, with weight increasing in 40-year-old women by 9.6 kg (1). By 2011, 24.6% of Filipino men and 28.4% of women were overweight (2).
Rapid changes in population health historically have been caused by the elimination or introduction of infectious pathogens. In the last 3 decades, infectious diseases among humans have been disappearing from society because of vaccines and improved vaccination practices (3), widespread antimicrobial drug use, expanded medical care access, and improved sanitation (4). Infections cause alterations in inflammatory cytokines and adipocytokines and raise metabolic rates, and they may influence the colonizing microbiota, which vary with the colonized person’s weight (5). Childhood infections may thus affect a person’s long-term weight. We sought to determine whether infectious disease prevalence in infancy predicted body mass index (BMI) in adulthood.