The effects of disease severity and comorbidity on oxidative stress biomarkers in obstructive sleep apnea

PURPOSE

Ischemia-modified albumin (IMA), total oxidant status (TOS), and total antioxidant status (TAS) are biomarkers used to evaluate oxidative stress status in various diseases including obstructive sleep apnea (OSA). In this study, we investigated the effects of disease severity and comorbidity on IMA, TOS and TAS levels in OSA.

METHODS

Patients with severe OSA (no-comorbidity, one comorbidity, and multiple comorbidities) and mild-moderate OSA (no-comorbidity, one and multiple comorbidities), and healthy controls were included in the study. Polysomnography was applied to all cases and blood samples were taken from each participant at the same time of day. ELISA was used to measure IMA levels in serum samples and colorimetric commercial kits were used to perform TOS and TAS analyses. In addition, routine biochemical analyses were performed on all serum samples.

RESULTS

A total of 74 patients and 14 healthy controls were enrolled. There was no statistically significant difference between the disease groups according to gender, smoking status, age, body mass index (BMI), HDL, T3, T4, TSH, and B12 (p > 0.05). As the severity of OSA and comorbidities increased, IMA, TOS, apnea-hypopnea index (AHI), desaturation index (T90), cholesterol, LDL, triglyceride, AST, and CRP values increased significantly (p < 0.05). On the other hand, TAS, minimum desaturation, and mean desaturation values decreased significantly (p < 0.05).

CONCLUSIONS

We concluded that IMA, TOS, and TAS levels may indicate OSA-related oxidative stress, but as the severity of OSA increases and with the presence of comorbidity, IMA and TOS levels may increase and TAS levels decrease. These findings suggest that disease severity and presence/absence of comorbidity should be considered in studies on OSA.

Relation between serum ischemia-modified albumin levels and rectus abdominis muscle flap viability

Ischemia is a major cause of flap failure in reconstructive surgery. To detect circulatory compromise, many flap monitoring methods are used; however, there is no any optimal standard method. Ischemia-modified albumin (IMA) is an ischemia marker, which has recently been investigated in many studies and largely validated for early detection of ischemia. In this study, we investigated possible relationship between muscle flap viability and serum IMA levels in experimental flap model. The rectus abdominis muscle flap model was used in 18 New Zealand white rabbits. The study was planned using 3 groups. In group 1, the rectus abdominis muscle flap was harvested as a superior pedicle-based flap in which the inferior pedicle was sacrificed. In group 2, the flap was harvested by severing the superior pedicle. Both pedicles were harvested in group 3. Serum IMA levels were measured before the procedure and 1 hour, 6 hours, and 7 days postoperatively and then compared. In group 3, in which the ischemia was evident, and in group 1, IMA levels were significantly high 1 hour postoperatively (P < 0.05). There was no other significant difference in any of the other studied parameters between the groups. In conclusion, IMA can be used as a biochemical parameter for monitoring muscle flap viability.

Time-dependent variations in ischemia-modified albumin levels in mesenteric ischemia

OBJECTIVES

The objective was to determine the value of ischemia-modified albumin (IMA) in the diagnosis of mesenteric embolism. The authors investigated whether or not plasma IMA levels rose in the acute period in a rat model of mesenteric ischemia and the related time-dependent changes.

METHODS

In this randomized, controlled, nonblinded trial, 36 mature female Wistar rats were divided into six groups: three control (Groups I, III, and V) and three ischemia (Groups II, IV, and VI). In the control groups, blood was sampled at 30 minutes (Group I), 2 hours (Group III), and 6 hours (Group V) following a simple laparotomy. In the ischemia groups, following laparotomy, the superior mesenteric artery (SMA) was clamped using a bulldog clamp, and blood samples were taken at 30 minutes (Group II), 2 hours (Group IV), and 6 hours (Group VI).

RESULTS

Plasma IMA levels in the ischemia groups were significantly higher compared to those of the control groups (p < 0.004). In addition, levels were higher in the 6-hour blood samples of the ischemia group than in the 2-hour and 30-minute samples (p < 0.001). Serum IMA was also higher in the 2-hour blood samples of the ischemia group than in the 30-minute samples (p < 0.001).

CONCLUSIONS

These preliminary findings suggest that serum IMA levels may represent a significant parameter in the early diagnosis of acute mesenteric ischemia and that further studies are necessary.