Relationship between Sleep Quality and Metabolic Syndrome and Infl ammatory Markers in Middle-aged Men in Korea

Abstract

Background: As many studies revealed that sleep restriction is associated with obesity and insulin resistance and blood pressure elevation, the relationship between sleep and metabolic syndrome has been concerned. But little information exists on correlation between sleep quality and metabolic syndrome. In this study, we investigated the relationship between sleep quality measured by Pittsburgh Sleep Quality Index (PSQI) and metabolic syndrome. Methods: A total of 100 middle-aged male adults were included in this study from March to May 2008 at a health promotion center. The subjects were divided into two groups of poor sleeper group (N = 47) vs. good sleeper group (N=53) by PSQI global score. The components of metabolic syndrome and infl ammatory markers were measured. The metabolic syndrome criterion of the AHA/NHLBI 2005 was adopted. Results: There was no significant differences in baseline characteristics between the two groups. HDL-cholesterol was signifi cantly lower in the poor sleeper group compared to the good sleeper group (P < 0.05). The negative correlation was noted between subjective sleep quality score with HDL-cholesterol (P < 0.05). There was a positive correlation between sleep latency and triglyceride and a negative correlation with HDL-cholesterol (P < 0.05). The longer sleep latency, the higher level of white blood cell count was observed (P = 0.001). Conclusion: The above data suggest that a possible causal interaction between poor sleep quality and lower HDLcholesterol of metabolic syndrome components and higher level of white blood cell counts. Further prospective studies regarding the change in the components of metabolic syndrome and the risk factors of cardiovascular diseases after relieving sleep disturbance seem to be warranted.