Original Contribution Heart Rate Variability, Ambient Particulate Matter Air Pollution, and Glucose Homeostasis: The Environmental Epidemiology of Arrhythmogenesis in the Women’s Health Initiative

Metabolic neuropathophysiology underlying the prediabetic state may confer susceptibility to the adverse health effects of ambient particulate matter <10 lm in diameter (PM10). The authors therefore examined whether impaired glucose homeostasis modifies the effect of PM10 on heart rate variability in a stratified, random sample of 4,295 Women’s Health Initiative clinical trial participants, among whom electrocardiograms and fasting blood draws were repeated at 3-year intervals from 1993 to 2004. In multilevel, mixed models weighted for sampling design and adjusted for clinical and environmental covariables, PM10 exposure was inversely associated with heart rate vari-ability. Inverse PM10–heart rate variability associations were strongest for the root mean square of successive differences in normal-to-normal RR intervals (RMSSD). Among participants with impaired fasting glucose, ther