Effect of Isomaltulose on Glycemic and Insulinemic Responses: A Systematic Review and Meta-analysis of Randomized Controlled Trials

Abstract

Evidence regarding the effect of isomaltulose on glycemic and insulinemic responses is still conflicting, which limits isomaltulose's application in glycemic management. The purpose of this study was to comprehensively evaluate its effectiveness and evidence quality. We systematically searched PubMed, Embase, and the Cochrane Library for randomized controlled trials (RCTs) prior to October 2021. RCTs were eligible for inclusion if they enrolled adults to oral intake of isomaltulose or other carbohydrates dissolved in water after an overnight fast and compared their 2-h postprandial glucose and insulin concentrations. The DerSimonian-Laird method was used to pool the means of the circulating glucose and insulin concentrations. Both random-effects and fixed-effects models were used to calculate the weighted mean difference in postprandial glucose and insulin concentrations in different groups. Subgroup, sensitivity, and meta-regression analyses were also conducted. Grading of Recommendations Assessment, Development, and Evaluation (GRADE) was used to assess the certainty of evidence. Finally, 11 RCTs (n = 175 participants) were included. The trials were conducted in 4 countries (Japan, Brazil, Germany, and the Netherlands), and all of the enrolled participants were >18 y of age with various health statuses (healthy, type 2 diabetes, impaired glucose tolerance, and hypertension). Moderate evidence suggested that oral isomaltulose caused an attenuated glycemic response compared with sucrose at 30 min. Low evidence suggested that oral isomaltulose caused an attenuated but more prolonged glycemic response than sucrose and an attenuated insulinemic response. Low-to-moderate levels of evidence suggest there may be more benefit of isomaltulose for people with type 2 diabetes, impaired glucose tolerance, or hypertension; older people; overweight or obese people; and Asian people. The study was registered on PROSPERO (International Prospective Register of Systematic Reviews) as CRD42021290396 (available at https://www.crd.york.ac.uk/prospero/).

Keywords: diabetes; glycemic and insulinemic response; isomaltulose; palatinose; systematic review and meta-analysis.

FIGURE 1

Flowchart of study identification and selection. RCT, randomized controlled trial.

FIGURE 2

Changes in blood glucose (A) and insulin (C) concentrations after ingestion, WMD in postprandial blood glucose (B) and insulin (D) concentrations between the 2 groups, and a summary plot of the GRADE assessment (E). Values are means in panel A and C. Panel B and D show the WMDs and corresponding 95% CIs (vertical lines around every point). GRADE, Grading of Recommendations, Assessment, Development, and Evaluation; WMD, weighted mean difference.

FIGURE 3

Subgroup analyses of the changes in blood glucose and insulin concentrations after ingestion. Comparisons of the changes in blood glucose and insulin concentrations to each carbohydrate are shown for participants with differing health status (A and B), age category (C and D), BMI category (E and F), and ethnicity (G and H). The numbers of included studies of 0, 30, 60, 90, 120, and 180 min for the healthy group are 6, 6, 6, 6, 6, and 3; for the unhealthy group are 5, 4, 5, 2, 5, and 5; for the age ≤50-y group are 6, 5, 6, 5, 6, and 4; for the age >50-y group are 4, 4, 4, 2, 4, and 4; for the normal-weight group are 5, 5, 5, 5, 5, and 3; for the overweight or obesity group are 5, 4, 5, 2, 5, and 5; for the Asian group are 5, 5, 5, 5, 5, and 2; and for the European group are 6, 5, 6, 3, 6, and 6. Values are means. *Significant difference between the subgroups.

FIGURE 4

Subgroup analyses of the weighted mean difference in postprandial blood glucose and insulin concentrations between the isomaltulose and sucrose arms. Comparisons of the WMDs of these two carbohydrates in people with differing health status (A and E), age category (B and F), BMI category (C and G), and ethnicity (D and H). Each panel shows the WDMs and corresponding 95% CIs (vertical lines around every point). The numbers of included studies of 0, 30, 60, 90, 120, and 180 min for the healthy group are 6, 6, 6, 6, 6, and 3; for the unhealthy group are 5, 4, 5, 2, 5, and 5; for the age ≤50-y group are 6, 5, 6, 5, 6, and 4; for the age >50-y group are 4, 4, 4, 2, 4, and 4; for the normal-weight group are 5, 5, 5, 5, 5, and 3; for the overweight or obesity group are 5, 4, 5, 2, 5, and 5; for the Asian group are 5, 5, 5, 5, 5, and 2; and for the European group are 6, 5, 6, 3, 6, and 6. *Significant difference between the subgroups. WMD, weighted mean difference.