VITAMIN-A (RETINOL) STATUS OF FIRST-NATION ADULTS WITH NON-INSULIN-DEPENDENT DIABETES-MELLITUS

Objective: Poorly controlled insulin-dependent diabetes mellitus (IDDM ) has been reported to be associated with an impaired metabolic availa bility of vitamin A. The purpose of this study was to examine vitamin A status in a select group with non-insulin dependent diabetes mellitu s (NIDDM). Methods: Participants included 106 (male, female, >40 years ) Plains Cree adults residing in central Alberta, with NIDDM (n = 59) and non-diabetic controls (n = 47). Non-fasting plasma samples were co llected and concentrations of retinol, zinc, alpha-tocopherol, total p rotein, albumin, retinol binding protein (RBP), transthyretin (TTR), c holesterol, triglycerides, glucose, insulin, and fructosamine were det ermined. Multiple linear regression was used to identify predictors of plasma REP concentration. Three repeated 24-hour recalls and a food f requency questionnaire were used to determine vitamin A intakes. Resul ts: Diabetic subjects had similar intake and plasma concentration of v itamin A compared to controls. Factors such as alpha-tocopherol, zinc, total protein, albumin, and TTR, which are known to influence vitamin A metabolism, also remained unaffected in subjects with diabetes. Pla sma levels of vitamin A carrier protein (RBP), however, were elevated in diabetic subjects, possibly as a result of hyperinsulinemia. The su bjects with diabetes had many characteristics of the insulin resistant syndrome, including central obesity, hypertension, and hypertriglycer idemia. Poor metabolic control, based on plasma glucose, was a signifi cant predictor of REP concentration in diabetic subjects. Conclusions: The plasma concentration of REP was elevated in diabetic subjects and was associated with normal circulatory availability of retinol. The s ubjects with NIDDM, characterized by insulin resistance without insuli n deficiency, thus, appear to be associated with normal vitamin A stat us.