Irregular sleep schedule doubles the risk of cardiovascular complications

The main finding was that the negative effects of irregular sleep patterns are selective. The risk of developing pathologies is doubled in individuals whose average sleep duration is less than 7 hours and 56 minutes (the median value for the study group). For individuals who sleep longer than this threshold, there was no statistically significant association between irregular sleep patterns and the risk of cardiac events. This suggests that sufficient sleep duration may partially compensate for the negative effects of disrupted circadian rhythms.

Statistical analysis revealed certain population groups that were most at risk. In the study cohort, 128 cases of MACE were recorded, accounting for 4% of the total number of participants. The researchers noted the following patterns:

• Gender factor: Men were more likely to experience serious heart complications compared to women;
• Socioeconomic indicators: The risk level was higher among unemployed participants, which may be attributed to increased stress levels and concomitant lifestyle disturbances;
• Physiological markers: individuals who had experienced a cardiac event had higher levels of body mass index (BMI), blood pressure, glycated hemoglobin, and LDL cholesterol.
  Notably, the study did not find a link between irregular wake-up times and cardiovascular risk. The most significant parameters were the time of bedtime and the “mid-sleep” (the middle point between falling asleep and waking up).

The researchers attribute these findings to the impact of circadian rhythms on physiological recovery. Constant shifts in the time of falling asleep disrupt the internal regulation of the cardiovascular system and metabolic processes. If a person sleeps less than the recommended amount, the compensatory mechanisms fail, leading to systemic inflammation and vascular damage. These findings are supported even after adjusting the data for factors such as age, smoking, physical activity, and cholesterol levels.

The study utilized accelerometers to capture movements and accurately measure sleep time, providing an accuracy of up to 20 minutes compared to subjective diaries. However, the authors point out that the study was limited by its sample size, as it was conducted on an ethnically and age-homogeneous group (middle-aged residents of Northern Finland). This means that additional research is needed to generalize the findings to other racial and ethnic groups, taking into account genetic and cultural diversity.

Maintaining a consistent bedtime, especially when it is not possible to sleep for the recommended 8 hours, is an important and accessible strategy for preventing cardiovascular diseases. By maintaining a consistent sleep schedule, the body’s internal biological clock can function synchronously, allowing for optimal recovery of the heart and blood vessels during nighttime rest.