Menstrual cycle effects on insulin sensitivity and nutrient intake in women with type 1 diabetes

Women with type 1 diabetes face the constant challenge of trying to maintain normal blood glucose levels. While previous studies have suggested a relationship between luteal phase hormones and reduced insulin sensitivity, results have been inconsistent. Some studies suggest that premenstrual syndrome (PMS) may be a significant variable exacerbating possible menstrual cycle changes. Prior studies have also suggested that women will increase their dietary intake of carbohydrates during the luteal phase. The objective of this study was to evaluate possible differences in insulin sensitivity and nutrient intake between the follicular and luteal phases of the menstrual cycle in women with type 1 diabetes and in a non-diabetic group of women with PMS. This is the first study to evaluate insulin sensitivity in these populations with Minimal Model analysis of the frequently sampled intravenous glucose tolerance test (FSIGT). Although not statistically significant, there was a mean 24 percent decline in insulin sensitivity noted in the luteal phase in the group of women with type 1 diabetes. There was a statistically significant difference in glucose effectiveness between cycle phases in women with type 1 diabetes, with increased glucose effectiveness noted in the luteal phase. There were no differences in insulin sensitivity or glucose effectiveness in the luteal phase for the group of women with PMS. There were no significant differences noted in nutrient intake between cycle phases for either group