Effect of Cinnamon Powder on Random Blood Glucose Among Type 2 Diabetes Patients: A Nonequivalent Control Group Quasi-Experimental Study

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disorder characterized by persistently elevated blood glucose due to insulin resistance and impaired pancreatic β-cell function. Cinnamon (Cinnamomum sp.), which contains polyphenols and cinnamaldehyde, has been suggested to influence biological pathways related to glucose regulation. This study aimed to assess the short-term effect of cinnamon powder supplementation on random blood glucose levels in adults with type 2 diabetes mellitus. A quasi-experimental study with a non-randomized, nonequivalent control group design was conducted among 32 participants. The intervention group consumed Cinnamos sp. daily for three consecutive days. The control group continued usual diabetes management without additional supplementation. Two-hour postprandial (random) blood glucose was measured at baseline and on each of the three study days using a digital glucometer. Blood glucose levels declined significantly over time in both the intervention and control groups during the three-day observation period (p < 0.001). On day 3, mean blood glucose was 193.31 mg/dL in the intervention group and 167.31 mg/dL in the control group, yielding a mean difference of 26.00 mg/dL (p < 0.05). These findings suggest that short-term cinnamon powder administration is associated with changes in random blood glucose relative to standard therapy alone, although the direction of effect between groups was not consistent with an added benefit. Causal inference should be made cautiously given the non-randomized design, brief exposure period, and baseline imbalances between groups, and larger randomized controlled trials are warranted.