Association between insulin resistance and BMI with FEV 1 in non-hypoxemic COPD out-patients

This study was conducted to determine the impact of insulin resistance using Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) score and BMI in non-hypoxemic out-patients with COPD on FEV using linear and polynomial regressions and to determine their correlation. COPD patients of both genders were included after informed consent. Fasting blood sugar and serum insulin were done to calculate HOMA-IR, which were segregated into two groups of ≥ 3 and < 3 labeled insulin resistance present and absent, these were compared with BMI. Patients were segregated into GOLD Grade 1-4 per GOLD Guidelines and compared with HOMA-IR and BMI. Curve and linear regressions, multivariate and univariate analysis of HOMA-IR with BMI, FVC, and FEV were done. A total of 273 subjects were inducted after informed consent. There was a linear correlation between HOMA-IR and BMI (r 0.498, P < 0.001) and nonlinear correlation between HOMA-IR and FEV1 (r 0. 617, P < 0.001) which showed little evidence of association above FEV1 > 60 predicted, but a clear negative association below that. Significant increase in HOMA-IR was seen from GOLD-2 to 3 and from GOLD-3 to 4 classes. The impact of HOMA-IR on FEV1 was 49.9% (P