UBC Theses and Dissertations
Effects of feeding nutritional formulas high in carbohydrate or monounsaturated fat on parameters of carbohydrate and lipid metabolism of patients with non-insulin dependent diabetes mellitus Bowron, Elaine
Non-insulin dependent diabetes mellitus (NIDDM) is a common disorder of carbohydrate metabolism. The main characteristic of NIDDM is high blood glucose levels. People with NIDDM are at increased risk of microvascular (retinopathy, nephropathy and neuropathy) and macrovascular (coronary heart disease) complications. It has been found in insulin-dependent diabetic subjects that maintaining low blood glucose levels can reduce the risk of microvascular complications. Risk factors that have been identified in NIDDM subjects for heart disease have included high triglyceride levels, high levels of very-low density lipoprotein (VLDL) cholesterol and low levels of high-density lipoprotein (HDL) cholesterol. The current dietary recommendation for people with NIDDM is to consume a diet high in complex carbohydrate and fiber and low in fat. This recommendation has recently been challenged by some investigators who have suggested that high monounsaturated fat diets may be better. Sixteen people with NIDDM who were in moderate metabolic control and had low to moderate blood lipid levels were randomized to receive either Ensure with Fiber® (high carbohydrate) or Glucerna® (high monounsaturated fat). The diets were followed for 28 days, with an average of about 90% of energy corning from the formula. Subjects performed finger prick blood glucose monitoring at home before and 2 hours after each meal for two days each week. Fasting blood samples were taken from the subjects on days 0, 7 and 28, and were used to measure selected indices of carbohydrate and lipid metabolism. It was found that the consumption of Glucerna® resulted in lower postprandial rises in blood glucose when compared to Ensure with Fiber® (p=0.000). Statistical analysis using repeated measures ANOVA revealed significant time effects, in which a decrease in serum glucose (p=0.000), and plasma glucagon (p=0.002) were found. A different pattern of change between the groups was noted for plasma insulin levels (p=0.028) in which the Ensure with Fiber® group displayed a decrease in insulin over time. No significant effects were found for plasma triglycerides, total cholesterol or apo B cholesterol. There was a different pattern of change for HDL cholesterol between the two groups (p=0.004), explained by a significant decrease in the Glucerna® group. This result may be confounded by the significantly different baseline levels of HDL cholesterol between the two groups. Overall, this study found that the only advantage of the high monounsaturated fat, Glucerna® diet over the high carbohydrate, Ensure with Fiber® diet, was the lower rise in postprandial blood glucose levels. This study found no benefit of Glucerna® on other indices of carbohydrate metabolism or on indices of lipid metabolism. More research is needed to understand the metabolic effects of high carbohydrate and high monounsaturated fat diets in NIDDM subjects.
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