CAROTENOIDS, RETINOL AND TOCOPHEROLS IN PATIENTS WITH INSULIN-DEPENDENT DIABETES-MELLITUS AND THEIR IMMEDIATE RELATIVES

1. Patients with insulin-dependent diabetes mellitus are classified am ong the groups at risk for low vitamin status, and recent studies sugg est that some degree of supplementation with antioxidants may be benef icial in helping to prevent certain long-term complications of diabete s mellitus. Our objective was to compare the status of the fat-soluble vitamins and antioxidant-related compounds in patients with well-defi ned insulin-dependent diabetes mellitus with that of their first-degre e relatives, controlling seasonal and analytical variability as factor s influencing the interpretation of the data. 2. Fifty-four patients w ith insulin-dependent diabetes mellitus, 214 non-diabetic, first-degre e relatives (controls) and 236 unrelated controls were analysed for re tinol, tocopherols (alpha and gamma) and main carotenoids in serum (be ta-carotene, alpha-carotene, beta-cryptoxanthin, lutein, zeaxanthin an d lycopene) by means of a validated HPLC method. 3, Insulin-dependent diabetes mellitus was associated with lower retinol levels and higher levels of beta-carotene, alpha-carotene and beta-cryptoxanthin than se x-matched, first-degree relatives, alpha-Tocopherol, the alpha-tocophe rol/cholesterol ratio, gamma-tocopherol, lutein, zeaxanthin and lycope ne showed no differences. Retinol and beta-carotene were the variables most closely associated with diabetes. 4. Patients with insulin-depen dent diabetes mellitus showed lower serum retinol status together with higher concentrations of provitamin-A carotenoids. Serum fat-soluble antioxidant levels were greater than or equal to those in controls. Ac cording to the serum status observed, individuals with diabetes do not require supplementation with alpha-tocopherol or carotenoids, althoug h the need for retinol supplementation in patients with marginal serum levels should be evaluated.