Role of dietary interventions on microvascular health in South-Asian Surinamese people with type 2 diabetes in the Netherlands: A randomized controlled trial

Abstract

Background/objectives: We investigated whether dietary interventions, i.e. a fasting mimicking diet (FMD, Prolon®) or glycocalyx mimetic supplementation (Endocalyx^TM) could stabilize microvascular function in Surinamese South-Asian patients with type 2 diabetes (SA-T2DM) in the Netherlands, a patient population more prone to develop vascular complications.

Subjects/methods: A randomized, placebo controlled, 3-arm intervention study was conducted in 56 SA-T2DM patients between 18 and 75 years old, for 3 consecutive months, with one additional follow up measurement 3 months after the last intervention. Sublingual microcirculation was assessed with SDF-imaging coupled to the GlycoCheck^TM software, detecting red blood cell velocity, capillary density, static and dynamic perfused boundary region (PBR), and the overall microvascular health score (MVHS). Linear mixed models and interaction analysis were used to investigate the effects the interventions had on microvascular function.

Results: Despite a temporal improvement in BMI and HbA1c after FMD the major treatment effect on microvascular health was worsening for RBC-velocity independent PBR_dynamic, especially at follow-up. Glycocalyx supplementation, however, reduced urinary MCP-1 presence and improved both PBR_dynamic and MVHS_dynamic, which persisted at follow-up.

Conclusions: We showed that despite temporal beneficial changes in BMI and HbA1c after FMD, this intervention is not able to preserve microvascular endothelial health in Dutch South-Asian patients with T2DM. In contrast, glycocalyx mimetics preserves the microvascular endothelial health and reduces the inflammatory cytokine MCP-1.

Clinical study registration: NCT03889236.

Fig. 1. Study design and patient inclusion.

Study design (A) and CONSORT Flow diagram (B).

Fig. 2. Changes in microvascular parameters upon FMD treatment.

Comparison of changes within 3 months intervention between the diet and placebo group of A Capillary density, B Dynamic capillary blood volume (CBV_dynamic) and C Static perfusion boundary region (PBR_static), D Scatter dot plots and simple linear regression (slope) with 95% confidence intervals of PBR_static plotted against red blood cell velocity (V_RBC) in feed vessels. Comparison of changes after 3 months intervention between diet (continuous line) and placebo (dashed line) of E dynamic perfusion boundary region (PBR_dynamic) and F dynamic Microvascular Health Score (MVHS_dynamic). Box plot whiskers indicate 5th and 95th percentiles. Delta changes were compared between the diet and placebo group with an unpaired t-test. *P < 0.05, **P < 0.01.

Fig. 3. Changes in microvascular parameters upon supplement treatment.

Comparison of changes within 3 months intervention between the supplement and placebo of A Capillary density, B Dynamic capillary blood volume (CBV_dynamic) and C Static perfusion boundary region (PBR_static), D Scatter dot plots and simple linear regression (slope) with 95% confidence intervals of PBR_static plotted against red blood cell velocity (V_RBC) in feed vessels. Comparison of changes after 3 months intervention between supplement (continuous line) and placebo (dashed line) of E dynamic perfusion boundary region (PBR_dynamic) and F dynamic Microvascular Health Score (MVHS_dynamic). Box plot whiskers indicate 5th and 95th percentiles. Delta changes were compared between the supplement and placebo group with an unpaired t-test. *P < 0.05, **P < 0.01, ***P < 0.0001.