PURPOSE: Obstructive sleep apnoea (OSA) is a common sleep disorder problem in obese people. Inflammation has been shown to play a significant role in OSA. Tumor necrosis factor alpha (TNF-α), a marker of inflammation is an important predictor of cardiovascular events. The relationship of TNF-α levels with OSA is conflicting and there is no data in Asian Indians. The purpose of the current study was to investigate the relationship between serum TNF-α levels in obese Asian Indians with and without OSA.
METHODS: We studied 141 obese subjects (BMI > 25 kg/m2). Polysomnography was done in all subjects and on the bases of Apnoea-Hypopnea index, patients were distributed in two categories (I) cases (obese with OSA; n=78) and (II) controls (obese without OSA; n=63). Both groups had comparable age and percentage body fat. Level of TNF-α was estimated in the serum sample of all subjects.
RESULTS: TNF-α levels (Mean±S.D) were significantly higher in obese subjects with OSA (31.55±16.59 pg/ml) than in obese subjects without OSA (23.96±9.41 pg/ml, p<0.05). No significant difference was seen in percentage body fat in cases (36.8±10.4), when compared with controls (35.6±9.6). TNF-α levels also showed an association with severity of OSA. There was a significant difference between hip circumference [(100.22±6.58)cm vs (105.84±12.32)cm] and neck circumference [(38.33±3.26)cm vs (39.96±4.40)cm] in cases as compared to controls.
CONCLUSION: In obese Asian Indians with OSA, significantly elevated serum TNF-α levels were seen as compared to the obese subjects without OSA. TNF-α levels also correlated with severity of OSA. This is the first study showing the association of TNF-α levels in obese Asian Indians having OSA.
CLINICAL IMPLICATIONS: Inflammation, as assessed by TNF-α level, is an important component of OSA. This may have therapeutic and prognostic implications in these patients.
DISCLOSURE: Randeep Guleria, No Financial Disclosure Information; No Product/Research Disclosure Information