An earlier clinical study on Tocovid Suprabio had reported that its antioxidant, anti-hyperglycaemic and anti-inflammatory properties managed to ameliorate diabetes in diabetic rats.
The current study was a prospective, double-blinded phase II RCT designed to explore the impact of Tocovid Suprabio on diabetic nephropathy in type 2 diabetes patients.
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To E or not to E?
The researchers recruited 45 participants who had had the baseline parameters of glycated haemoglobin (HbA1c), advanced glycation end-products (AGEs, proteins or lipids that become glycated from exposure to sugars), soluble receptor for AGEs (sRAGE), Nε-Carboxymethyllysine (Nε-CML, an AGE), and cystatin C (a protein used mainly as a biomarker of kidney function) measured for correlation with diabetic nephropathy.
The participants were found to have either diabetic nephropathy, or high levels of the protein microalbumin in their urine (microalbuminuria, a sign of kidney problems), measured using the Urine Albumin to Creatinine Ratio (UACR).
They then divided them into two groups: 22 subjects were placed in the intervention group, each receiving 200mg of Tocovid Suprabio twice a day. The other 23 subjects were placed in the control group, and were each given a placebo twice a day.
After eight weeks, the researchers measured the changes in the subjects HbA1c, blood pressure, serum biomarkers, renal parameters such as UACR, and serum creatinine, and compared the measurements between the two groups.
They reported that the intervention group experienced a marked reduction in serum creatinine compared to the placebo group.
They also observed a significant correlation between serum Nε-CML and diabetic nephropathy (as opposed to more conventional risk factors like hyperglycaemia): for every 1ng/ml increase in serum Nε-CML, the odds of diabetic nephropathy rose 1.48 times.
The researchers wrote: "This is a new finding, as there are no other studies that have demonstrated a significant correlation between serum Nε-CML and diabetic nephropathy that is independent of HbA1c, blood pressure, age, and duration of diabetes."
At the same time, serum creatinine assessment revealed that Nε-CML was significantly associated with renal function, "despite controlling for HbA1c, blood pressure, and age".
This was consistent with previous studies that had reported a direct correlation between serum creatinine in diabetics, due to renal impairment impairing the kidneys' ability to remove serum creatinine and Nε-CML via urinary excretion.
This is especially common in patients with end-stage renal failure, who had three to four times the amount of serum Nε-CML than healthy subjects.
However, despite the significant reduction of serum creatinine in the intervention group after eight weeks of Tocovid Suprabio supplementation, the same subjects saw no change in their UACR, HbA1c, blood pressure, serum AGEs, sRAGE, Nε-CML, or cystatin C.
The study's small sample size was one of its limitations, as the ideal sample size would have been 52 participants. This meant that the statistical power of the study was reduced, making any significant change or impact of Tocovid Suprabio difficult to detect.
Another limitation was the study's short duration. Since AGEs, sRAGE and Nε-CML are long-term biomarkers, eight weeks of Tocovid Suprabio was likely insufficient for any noticeable decrease in these biomarkers to be observed, even with a particularly high dose of 200mg twice daily.
Finally, the researchers wrote that the study lacked newly diagnosed diabetes patients, as its focus was diabetic nephropathy, which takes years to develop.
They said future studies "should investigate the potential role of Tocovid (Suprabio) in preventing diabetic complications among patients who are newly diagnosed with type 2 diabetes", and "include measuring of serum vitamin E to investigate for confounding effects".
In conclusion, they wrote: "Diabetic nephropathy was significantly associated with serum Nε-CML, which highlights the potential clinical use of Nε-CML in assessing the odds of diabetic nephropathy at an early stage.
"Eight weeks of high-dose Tocovid (Suprabio) did not improve HbA1c, blood pressure, serum AGE, sRAGE, Nε-CML, and cystatin C in patients with diabetic nephropathy.
"Nevertheless, Tocovid (Suprabio) significantly reduced serum creatinine compared to placebo. Therefore, it may be a useful addition to the current treatment for diabetic nephropathy."
"Tocotrienol-Rich Vitamin E from Palm Oil (Tocovid) and Its Effects in Diabetes and Diabetic Nephropathy: A Pilot Phase II Clinical Trial"
Authors: Suzanne May Quinn Tan, et al.