Urinary phthalate metabolites and heart rate variability: A panel study.

Area of Science:

• Environmental Health
• Cardiovascular Science
• Toxicology

Background:

• Phthalate exposure is a growing concern for public health.
• Decreased heart rate variability (HRV) is an early sign of cardiac autonomic imbalance and cardiovascular disease risk.

Purpose of the Study:

• To investigate the longitudinal associations between individual and mixed phthalate exposures and heart rate variability (HRV) in Chinese adults.
• To identify specific phthalates and their mixtures that impact HRV.

Main Methods:

• A longitudinal panel study involving 127 Chinese adults with three repeated visits.
• Quantification of 10 urinary phthalate metabolites using GC-MS/MS.
• Measurement of 6 HRV indices using digital Holter monitors.
• Analysis using Linear Mixed-Effect (LME) and Bayesian Kernel Machine Regression (BKMR) models.

Main Results:

• Urinary mono-ethyl phthalate (MEP), mono-iso-butyl phthalate (MiBP), and mono-n-butyl phthalate (MBP) were inversely associated with low-frequency power (LF) and total power (TP) of HRV.
• Phthalate mixtures showed negative overall associations with LF and TP, with MiBP identified as a major contributor.
• The inverse relationship between MiBP exposure and HRV indices (LF, TP) was more pronounced in individuals over 50 years old.

Conclusions:

• Exposure to individual and mixtures of phthalates, especially MiBP, is associated with decreased heart rate variability.
• These findings highlight the potential cardiovascular risks associated with phthalate exposure, particularly in older adults.