PURPOSE: Obstructive sleep apnea (OSA) occurs commonly in obese individuals and it has been linked to increased risk of cardiovascular and cerebrovascular disease. Studies on the association of subclinical inflammation and severity of OSA have shown conflicting results. However, there is no data in Asian Indians in this regard. C-reactive protein (CRP) is an important marker of inflammation and has been associated with increased risk of cardiovascular disease. The purpose of the current study was to evaluate the relationship between serum levels of CRP and OSA in obese Asian Indian subjects.
METHODS: In this ongoing study, the data on 40 obese subjects (BMI > 25 kg/m2) has been analyzed. All the subjects underwent polysomnography and the data on 20 obese subjects with newly diagnosed OSA and 20 obese controls matched for age and body mass index without OSA has been analyzed. We analyzed high-sensitivity CRP (hs-CRP) levels in all the subjects.
RESULTS: Serum CRP levels were significantly higher in obese patients with OSA than in obese not having OSA (Mean 6.22 mg/dl versus 3.55 mg/dl, P<0.01). This conducted study was univariate as BMI was comparable in cases and controls (Mean 29.7 Kg/m2 versus 31.9 Kg/m2, P>0.1). Both groups were clearly demarcated by apnea hypopnea index (AHI). Mean AHI in cases was 51.6/hr and in controls was 2.41/hr (P<0.001).
CONCLUSION: OSA is associated with elevated levels of CRP, a marker of inflammation and of cardiovascular risk. CRP level was not significantly higher in obese cases, not having OSA but was significantly higher in obese subjects having OSA suggesting that high level of CRP might be independently associated with OSA. This is the first study showing association of C-reactive protein level in obese Asian Indians having OSA.
CLINICAL IMPLICATIONS: This conducted study shows that CRP can be considered as a diagnostic and therapeutic marker for OSA. However, to validate these findings, mentioned study shall be conducted on a larger population size.
DISCLOSURE: Bharat Bhushan, None.