Early signs of cardiovascular dysregulation in young adult binge drinkers

Abstract

Binge drinking is widespread on American college campuses, but its effects on the cardiovascular system are poorly understood. This study sought evidence of preclinical cardiovascular changes in binge drinking young adults (n = 24) compared to nondrinking (n = 24) and social drinking (n = 23) peers during baseline, paced sighing (0.033 Hz), and paced breathing (0.1 Hz) tasks. Binge drinkers showed consistent but often statistically nonsignificant evidence of greater sympathetic activation and reduced baroreflex sensitivity. Interestingly, the structure of group-averaged baseline heart rate spectra was considerably different between groups in the low frequency range (0.05-0.15 Hz). In particular, the binge drinking group-averaged spectra showed several spectral peaks not evident in the other groups, possibly indicating two functionally distinct subranges (0.05-0.08 and 0.08-0.15 Hz) that reflect vascular tone baroreflex activity and heart rate baroreflex activity, respectively. Vascular tone baroreflex gain and power in two peaks in the 0.05-0.08 Hz range were associated with years of drinking in the binge drinking group. Vascular dysfunction may be an early indicator of drinking-related change in the cardiovascular system.

Keywords: alcohol; baroreflex; college; heart rate variability; vascular tone.

Conflict of interest statement

Conflicts of Interest: The authors declare no conflicts of interest.

© 2017 Society for Psychophysiological Research.

Figures

Figure 1

Average (+/− standard error) cardiovascular parameters at rest and in response to challenge in the binge drinking and social drinking groups. (A) R-R interval from the ECG, (B) stroke volume, (C) pulse transit time, and (D) systolic arterial pressure were averaged within group during a low-demand baseline task (B1), a paced sighing sympathetic challenge (PS), and a paced breathing parasympathetic challenge (PB). b significant effect of task.

Figure 2

Interrelation of Average Heart Rate (HR), Stoke Volume (SV), Vascular Tone (VT), and Systolic Arterial Pressure (SAP) in the nondrinking, social drinking, and binge drinking groups. Solid lines denote significant positive relationships; dashed lines denote significant negative relationships. R2 values are presented on each line to demonstrate the strength of the relationship between cardiac and vascular parameters. The binge drinking group showed considerable differences from both the nondrinking and social drinking groups, which were only negligibly different from one another.

Figure 3

Average (+/− standard error) heart rate variability (HRV) indices at rest and in response to challenge in the binge drinking and social drinking groups. (A) Total HRV, (B) high frequency (HF) HRV, (C) low frequency (LF) HRV, and (D) the root mean square of the standard deviation (RMSSD) showed task differences when compared across a low-demand baseline task (B1), a paced sighing sympathetic challenge (PS), and a paced breathing parasympathetic challenge (PB). The overall pattern suggested a tendency for reduced vagus activity in the BD group compared to the SD group, although the interactions were not statistically significant. b significant effect of task.

Figure 4

Group-averaged baseline RRI spectra. The average spectra of the (A) nondrinking group, (B) social drinking, and (C) binge drinking groups are presented with the mean shown in red and the standard error shown as dashed lines around the mean. In the low frequency range (green + gray shaded region) of the RRI spectra, peaks at 0.066 Hz, 0.081, and ~ 0.1 Hz were noted in the binge drinking (C) group. These peaks are thought to reflect activity of vascular tone branch of the baroreflex (0.066 and 0.081 Hz; green shaded region) and the HR branch of the baroreflex (~ 0.1 Hz; gray shaded region).

Figure 5

The association of baseline RRI spectra peak powers at (A) 0.066, (B) 0.081, and (C) ~ 0.1 (0.098) Hz with self-reported years of alcohol use in binge drinking young adults. The number of years of drinking was measured as the difference between age at the laboratory session and the self-reported age of first use. Significant associations were noted at 0.066 Hz and 0.081 Hz. * p < .05.

Figure 6

Normalized baseline RRI spectra of six binge drinking young adults that varied in the years of alcohol use. Male binge drinking young adults who reported drinking for 1 year, 3 years, and 9 years are shown on the left. Female binge drinking young adults who reported drinking for 2 years (no 1 year duration reported), 3 years, and 9 years are shown on the right. The power at the 0.066 Hz peak appeared to be lowest in the two individuals who self-reported 9 years of drinking.

Figure 7

Average (+/− standard error) baroreflex gain in the heart rate (HR, top), stroke volume (SV, middle), and vascular tone (VT, bottom) branches in binge and social drinking groups. BL - Baseline task. PS - Paced Sighing at 0.033 Hz task. PB - Paced Breathing at 0.1 Hz task. b significant effect of task.

Figure 8

Association of vascular tone baroreflex gain in binge drinking young adults with self-reported years of alcohol use. Gain in the vascular tone branch of the baroreflex during (A) baseline, (B) paced sighing, and (C) paced breathing tasks was regressed on the number of years of drinking as measured as the difference from age at the laboratory session and the self-reported age of first use. Significant associations were noted in response to paced sighing and paced breathing, but not at baseline. * p < .05.