Exercise-induced desaturation in patients with chronic obstructive pulmonary disease on six-minute walk test.

BACKGROUND AND OBJECTIVES: Exercise-induced desaturation (EID) is associated with increased mortality in chronic obstructive pulmonary disease (COPD). However, the relationship of EID with anthropometric and clinical parameters of resting pulmonary function test and six-minute walk test (6MWT) in COPD remains unclear. The study was designed to assess the correlate of EID and to identify various possible predictors of EID in stable normoxemic patients of COPD. MATERIALS AND METHODS: Sixty patients with stable COPD diagnosed and staged as per the Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines underwent 6MWT. A drop in standard pulse oximetry (SpO2) of ≥4% or nadir up to ≤88% was defined as EID. Based on EID during 6MWT, two groups were formed: desaturators (DS) and nondesaturators (NDS). DS and NDS were compared for baseline and clinical characters by the Student's t-test while Pearson and Spearman rho correlation coefficient assessed strength of the association of anthropometric and clinical variables with EID. The predictors of EID were identified by logistic regression and receiver operator curve analysis. RESULT: Out of 60 patients with stable COPD, 33 patients desaturated on exercise (n = 33/60). DS had significantly lower values of FEV1 (P < 0.001), FVC (P < 0.01) FEV1/FVC (P < 0.01) compared to NDS. EID had significant negative correlation with FEV1 (r = 0.31, P < 0.01), resting oxygen saturation (r = 0.549, P < 0.001) and 6MWD (r = 0.511, P < 0.001). Resting SpO2 ≤93% was found to a predictor of EID with a sensitivity and specificity of 83% and 78%, respectively. INTERPRETATION AND CONCLUSION: The 6MWT is a safe and sensitive test to recognize EID in normoxic stable COPD patients. Resting oxygen saturation is a good predictor of EID.

Glucose tolerance in overweight and obese North Indian adolescents.

The present analytic study was planned to study the impact of overweight and obesity on glucose tolerance in adolescents. Thirty overweight (BMI analogue ≥ 25-29.9 kg/m(2)) and 30 obese (BMI analogue ≥ 30 kg/m(2)) adolescents were included as cases and 30 healthy age and sex matched adolescents comprised the control group. All the study participants were subjected to oral glucose tolerance test (OGTT) as a measure of glucose tolerance.Means of fasting blood glucose levels in normal, overweight and obese groups were 84.5 mg/dl, 86.7 mg/dl and 94.8 mg/dl respectively. Means of two hourly blood glucose levels in normal, overweight and obese groups were 105.8 mg/dl, 117 mg/dl and 127.1 mg/dl respectively. Oral Glucose tolerance test (OGTT) was normal in all the participants from control group but was impaired in four overweight adolescents. In obese group, OGTT was impaired in eight subjects and one obese child had fasting and 2 hourly blood glucose levels in diabetic range.