Effect of short-term exposure to particulate air pollution on heart rate variability in normal-weight and obese adults

Abstract

Background The adverse effects of particulate air pollution on heart rate variability (HRV) have been reported. However, it remains unclear whether they differ by the weight status as well as between wake and sleep. Methods A repeated-measure study was conducted in 97 young adults in Beijing, China, and they were classified by body mass index (BMI) as normal-weight (BMI, 18.5–24.0 kg/m2) and obese (BMI ≥ 28.0 kg/m2) groups. Personal exposures to fine particulate matter (PM2.5) and black carbon (BC) were measured with portable exposure monitors, and the ambient PM2.5/BC concentrations were obtained from the fixed monitoring sites near the subjects’ residences. HRV and heart rate (HR) were monitored by 24-h Holter electrocardiography. The study period was divided into waking and sleeping hours according to time-activity diaries. Linear mixed-effects models were used to investigate the effects of PM2.5/BC on HRV and HR in both groups during wake and sleep. Results The effects of short-term exposure to PM2.5/BC on HRV were more pronounced among obese participants. In the normal-weight group, the positive association between personal PM2.5/BC exposure and high-frequency power (HF) as well as the ratio of low-frequency power to high-frequency power (LF/HF) was observed during wakefulness. In the obese group, personal PM2.5/BC exposure was negatively associated with HF but positively associated with LF/HF during wakefulness, whereas it was negatively correlated to total power and standard deviation of all NN intervals (SDNN) during sleep. An interquartile range (IQR) increase in BC at 2-h moving average was associated with 37.64% (95% confidence interval [CI]: 25.03, 51.51%) increases in LF/HF during wakefulness and associated with 6.28% (95% CI: − 17.26, 6.15%) decreases in SDNN during sleep in obese individuals, and the interaction terms between BC and obesity in LF/HF and SDNN were both statistically significant (p < 0.05). The results also suggested that the effects of PM2.5/BC exposure on several HRV indices and HR differed in magnitude or direction between wake and sleep. Conclusions Short-term exposure to PM2.5/BC is associated with HRV and HR, especially in obese individuals. The circadian rhythm of HRV should be considered in future studies when HRV is applied. Graphical abstract

Psychosocial Stress Modifies the Acute Cardiac Health Effects of Traffic-Related Air Pollution

“…Our study found that acute BC exposure was primarily associated with increased risks of ST-segment depression events. Similar to the present study, increased risk of ST-segment depression associated with acute BC exposure has been observed in two studies in the United States. , For HR and HRV variables, several studies in China showed that short-term BC exposure was associated with increased HR, declined SDNN , and LF, which are consistent with our results. We compared results from two studies (repeated-measure study and panel study), and the consistent results between these two studies highlight the robustness of the novel findings.…”

Evaluation of MERRA-2 Black Carbon Characteristics and Potential Sources over China

“…Then, the uptake of these toxic chemical species by the alveolar epithelium enters the bloodstream [13]. In fact, cardiovascular diseases and carcinogenesis, such as elevated systolic blood pressure, heart rate variability, and respiratory infections, have been confirmed to be partially associated with BC contamination [14][15][16]. The exposure to persistent BC tends to induce augmented premature mortalities and abated lung function [17][18][19].…”