Effect of Porang (Amorphophallus muelleri Blume) Flour Diet on Postprandial Blood Sugar Rates and Insulin Resistance in Male Wistar Rats (Rattus norvegicus) Diabetes Mellitus

Medical nutrition therapy is essential in diabetes management, especially as diabetes is often linked with aging. Porang tuber flour contains glucomannan, a compound with potential glucose-lowering effects. This study aimed to evaluate the effect of porang flour feeding frequency on 2-hour postprandial blood glucose (2hPPBG) and HOMA-IR in diabetic rats. Using a quasi-experimental pre-test and post-test control group design, 21 male Wistar rats were induced with diabetes via streptozotocin and nicotinamide, then randomly assigned to three groups: G0 (control, given aquadest), G1 (porang flour 300 mg/kg BW daily), and G2 (porang flour 300 mg/kg BW every two days). Five rats died during treatment. Wilcoxon test results showed a difference in 2hPPBG levels between each group before and after treatment. There was no decrease in G0 (p = 0.893), but a decrease in G1 (p = 0.043) and G2 (p = 0.028). The difference between HOMA-IR before and after treatment did not decrease in groups G0 (p = 0.345), G1 (p = 0.138), and G2 (p = 0.249). Post hoc test for 2hPPBG levels between groups showed a significant difference between G0 and G1 (p<0.001), a significant difference between G0 and G2 (p<0.001), and no significant difference between G1 and G2 (p = 0.135). One-way ANOVA test of HOMA-IR showed no significant difference between G0, G1, and G2 (p = 0.148). It was concluded that porang flour can reduce 2hPPBG, but not HOMA-IR. There was no difference in 2hPPBG levels between administering porang flour daily and every other day.