Effect of pine bark extract supplementation on metabolic status and serum vascular cell adhesion molecule-1 levels in patients with type 2 diabetes and microalbuminuria

Abstract

Introduction: Type 2 diabetes (T2DM) is the most common metabolic disease and public health problem. Abnormal changes associated with diabetes such as hyperglycemia and glycosylated end products, oxidative stress, cytokines and inflammatory agents lead to increased expression of adhesive molecules such as VCAM-1. French pine bark (PBE) extract is a standardized herbal supplement of water-soluble bioflavonoids, which according to previous studies has beneficial metabolic properties in various diseases. The aim of this study was to evaluate the effect of pine bark extract supplementation on metabolic status, serum VCAM-1 levels and anthropometric indices in patients with T2DM with microalbuminuria.

Materials and Methods: In this double-blind randomized controlled clinical trial, 46 patients with T2DM and microalbuminuria were divided into intervention and placebo groups (n = 23 in each group). The intervention group received capsules containing 50 mg PBE twice a day. The placebo group received capsules containing the same amount of corn starch for 8 weeks. Anthropometric indices including weight, height, waist circumference, hip circumference were measured at the beginning and end of the study and body mass index, waist to hip and waist to height were also calculated at the beginning and end of the study. Information about food intake was obtained using a 24-hour 3-day dietary recall method at the beginning, middle and end of the study, as well as the level of physical activity using the International Physical Activity Questionnaire (IPAQ) were ghathered at the beginning and end of the study. Fasting blood samples were taken from all participants after 12 hours of fasting to determine serum levels of lipid profile, insulin, glucose, HbA1c, insulin resistance index (HOMA-IR) and serum level of VCAM-1 at the beginning and end of the study. Also, to obtain the ratio of albumin to urinary creatinine (UACR), a random morning urine sample was collected from patients before and at the end of the study.

Results: There was no statistical difference in terms of all variables except the mean of triglyceride between the two group, at the beginning of the study. At the end of the study, HbA1c, TC and serum VCAM-1 levels, UACR, WC and WHtR in the group receiving PBE had a significant decrease compared to their baseline values (p <0.001, p = 0.005, p <0.001, P <0.001, p = 0.04 and p = 0.02, respectively). Changes in other variables in the intervention group were not significant. In the placebo group, a significant increase was observed in serum VCAM-1 after the intervention compared to its initial level (p = 0.02). Changes in other variables in the placebo group after the intervention were not significant compared to baseline values. There was a significant decrease in HbA1c (p <0.001), TC (p = 0.03), VCAM-1 (p <0.001), UACR (p <0.001), WC (p = 0.02) and WHtR (p = 0.01) in the intervention group compared with the placebo group, at the end of the study,

Conclusion: PBE supplementation improved HbA1c, TC, serum VCAM-1 levels, WC, WHtR and microalbuminuria in patients with T2DM.

Keywords: Type 2 diabetes, Pine bark extract, Glycemic indexes, Lipid profile, VCAM-1, Albumin to creatinine ratio, Anthropometric indices