Plasma concentrations of vitamins A and E in healthy and diabetic individuals [abstract]

ABSTRACT

Type 2 diabetes mellitus is highly prevalent in Trinidad and Tobago and is associated with severe morbidity. It is possible that poor antioxidant status, such as low levels of plasma vitamin E and A, may increase the clinical complications of diabetes mellitus. The present study assessed the adequacy of antioxidant protection in Type 2 diabetics by quantitating plasma levels of vitamins A and E. Blood was taken in EDTA tubes from 11 diabetic patients and from 9 healthy individuals, who served as controls. Plasma obtained was stored in Butylated hydroxy toluene at -70§C until susequently assayed for the antioxidants vitamins A and E, using a reverse-phase high pressure liquid chromoatography. Additionally, in the diabetics HbA1c levels were measured by immunoassay, using the DCA 2000 Analyser (Bayer Corporation, USA). In the diabetics HbA1c values ranged from 4.3 percent to 11.3 percent with the mean ñ SEM being 7.79 ñ 0.81 percent. The mean ñ SEM vitamin E concentration in the diabetics was 26.32 ñ 3.14 umol/L; this was not significantly different from the controls (27.39 ñ 1.66 umol/L). Plasma vitamin A in the diabetic group (1.99 ñ 0.19 æmol/L), was significantly higher (p< 0.001) than in controls (1.14 ñ 0.12 æmol/L). The interassay coefficient of variation for the high pressure liquid chromatography method was 4.3 percent and 1.15 percent for vitamins A and E, respectively. In the diabetic group there was a good relationship between vitamin A and HbA1c (r= -o.522; p= 0.099); however, this was not significant. Similarly, the relationship between vitamin A and HbA1c (r= 0.230; n= 11) was not significant. In conclusion, it was found that glycaemic control as measured by HbA1c varied amongst diabetics. The difference in vitamin E status between diabetics and non-diabetics was not significant. However, vitamin A levels for non-diabetics were significantly lower than for diabetes. (AU)