Dietary Fiber and Bone Density in Youth with Type 2 Diabetes

Abstract

Abstract Objectives Assess relationships between dietary fiber and bone density in youth with type 2 diabetes, obesity, and healthy weight. Methods Cross-sectional study of youth (56% African American, 67% female) ages 10–23 years with type 2 diabetes (n = 180), obesity (BMI >95th; n = 226), or healthy weight (BMI < 85th; n = 238). Total body bone mineral density (BMD) was assessed via DXA. BMD standard deviation scores (“Z-scores”) were computed using published reference data. Dietary fiber (total, soluble, and insoluble) and total calories were assessed via 3-day food diaries, which were analyzed using the Nutrition Data System for Research. Relationships between dietary fiber and BMD Z-score were assessed using linear regression. Separate analyses were performed for total, soluble, and insoluble fiber, and each regression model included age, sex, ancestry, total calories, group, and fiber (total, soluble, or insoluble), as well as group by fiber interactions. Results BMD Z-score was greater in the type 2 diabetes and obese compared to the healthy weight group (P < 0.001). Total, soluble, and insoluble fiber intakes were significantly greater in the healthy weight versus obese group (all P < 0.05), but only marginally greater than the type 2 diabetes group (all P = 0.06–0.10). Regression analyses demonstrated positive relationships between total, soluble, and insoluble fiber intakes and BMD Z-score (all P < 0.05). However, significant group by fiber interactions indicated that the positive relationships between dietary fiber intakes and BMD Z-score was evident only in the healthy weight group (all P < 0.005). Similar relationships were observed when considering BMD Z-score adjusted for height Z-score. Conclusions Prior studies have reported a favorable influence of dietary fiber on bone mineral accrual in healthy individuals and metabolic health in adults with insulin resistance. Dietary strategies promoting increased fiber consumption warrant investigation with respect to fracture prevention and glycemic control in youth with type 2 diabetes. Funding Sources NIH-NHLBI, American Diabetes Association, and Endocrine Fellows Foundation.