Using basal glucose at 180 minutes during minimal model analysis, patients with chronic heart failure showed a significant 30% reduction in insulin sensitivity compared to controls (p=0.0018).
Case-Control (n=30)
Does using the 180-minute plasma glucose concentration instead of fasting glucose improve the precision and discriminatory power of insulin sensitivity estimates in patients with chronic heart failure?
Using the plasma glucose concentration at 180 minutes as the basal glucose value in minimal model analysis of IVGTT improves the precision and discriminatory power for detecting insulin resistance in chronic heart failure patients.
Effect estimate: 30% reduction
Absolute Event Rate: 2.36% vs 3.36%
p-value: p=0.0018
BACKGROUND: Minimal model analysis of the intravenous glucose tolerance test (IVGTT) has been used successfully to demonstrate that patients with chronic heart failure (CHF) are insulin-resistant. Continuing experience in minimal model methodology has raised questions about how best to assign basal glucose concentrations during such analyses. METHODS AND RESULTS: IVGTT data from randomly selected patients with CHF (n = 15) and controls (n = 15) were analysed using the minimal model, with the basal glucose concentration (G (b)) assigned the value of fasting plasma glucose concentration (G (fast)), or the value of plasma glucose concentration 180 minutes after the start of the IVGTT (G (180)). Insulin sensitivity (S (I)) was significantly higher with G (b) = G (fast), than with G (b) = G (180) (controls: 5.60 +/- 0.78 vs. 3.36 +/- 0.25/min/muU/ml x 10 (4), p = 0.0017; patients 4.19 +/- 0.54 vs. 2.36 +/- 0.15/min/microU/ml x 10 (4), p = 0.0004). At G (b) = G (fast), CHF patients showed a non-significant 25 % reduction in S (I) in comparison to controls (p = 0.15). In contrast, at G (b) = G (180), CHF patients showed a significant 30 % reduction of S (I) in comparison to controls (p = 0.0018). S (I) estimates derived at G (b) = G (fast) exhibited twice the variability of those estimated using G (b) = G (180) (coefficients of variation of S (I) in patients with CHF were 50.0 % and 24.8 %, respectively). CONCLUSION: In studies of patients with CHF, greater precision and discriminatory power of insulin sensitivity estimates is obtained when the basal glucose concentration is taken as the plasma glucose concentration 180 minutes after the start of the IVGTT.
Doehner et al. (2005) conducted a case-control in Chronic heart failure (n=30). Chronic heart failure vs. Controls was evaluated on Insulin sensitivity (S_I) using basal glucose at 180 minutes (30% reduction, p=0.0018). Using basal glucose at 180 minutes during minimal model analysis, patients with chronic heart failure showed a significant 30% reduction in insulin sensitivity compared to controls (p=0.0018).