The clinical respiratory journal 2018 01 13() doi 10.1111/crj.12765
Chronic intermittent hypoxia, inflammation and oxidative stress are involved in resultant obstructive sleep apnea syndrome (OSAS), which may affect numerous regulatory mechanisms that play a role in the regulation of blood pressure. Gamma glutamyl transferase (GGT) is a novel marker in the prediction of cardiovascular risk.
The objective of this study was to investigate the correlation of serum levels of GGT with hypertension and the degree of the upper airway obstruction in subjects with OSAS.
A total of 270 subjects that met the inclusion criteria were enrolled in the study. The subjects were divided into 4 separate groups according to the apnea-hypopnea index (AHI) scores as the control group (AHI <5), mild OSAS group (AHI 5-15), moderate OSAS group (AHI 16-30), and severe OSAS group (AHI >30). A further classification of the OSAS subjects was made in two groups based on the presence of hypertension.
The study included 43 control individuals and 59 subjects with mild, 54 moderate, and 114 severe OSAS. The serum levels of GGT were found to be significantly correlated with OSAS severity (control group;18±3.3, mild OSAS;23.6±7.3, moderate OSAS;26.4±7.5 and severe OSAS;39.8±12). Serum levels of GGT were found to be significantly higher in OSAS subjects with concomitant hypertension than in the group without associated hypertension (p< 0.05). The results showed that the adjusted mean GGT under OSA without hypertension (Madj =28.76, SE=0.71) was significantly lower than in cases with OSA with hypertension (Madj =42.79, SE=1.19). CONCLUSION
The present study indicated a strong correlation between high serum levels of GGT and concomitant hypertension in subjects with obstructive sleep apnea. This biomarker may be helpful in grading the severity of obstructive sleep apnea and correlated with hypertension in this population. This article is protected by copyright. All rights reserved.