Habitually Higher Dietary Glycemic Index During Puberty Is Prospectively Related to Increased Risk Markers of Type 2 Diabetes in Younger Adulthood

OBJECTIVE-Carbohydrate nutrition during periods of physiological insulin resistance such as puberty may affect future risk of type 2 diabetes. This study examined whether the amount or the quality (dietary glycemic index [GI], glycemic load [GL], and added sugar, fiber, and whole-grain intake) of carbohydrates during puberty is associated with risk markers of type 2 diabetes in younger adulthood. RESEARCH DESIGN AND METHODS-The analysis was based on 226 participants (121 girls and 105 boys) from the Dortmund Nutritional and Anthropometric Longitudinally Designed Study (DONALD) with an average of five 3-day weighed dietary records (range 2-6) during puberty (girls, age 9-14 years; boys, age 10-15 years) and fasting blood samples in younger adulthood (age 18-36 years) (average duration of follow-up 12.6 years). Multivariable linear regression was used to analyze the associations between carbohydrate nutrition and homeostasis model assessment insulin resistance (HOMA-IR) as well as the liver enzymes alanine aminotransferase (ALT) and gamma-glutamykransferase (GGT) (n = 214). RESULTS-A higher dietary GI was prospectively related to greater values of HOMA-IR (P-trend = 0.03), ALT (P-trend = 0.02), and GGT (P-trend = 0.04). After adjustment for sex, adult age, baseline BMI, and early life and socioeconomic factors as well as protein and fiber intake, predicted mean HOMA-IR values in energy-adjusted tertiles of GI were 2.37 (95% Cl 2.16-2.60), 2.47 (2.26-2.71), and 2.59 (2.35-2.85). The amount of carbohydrates, GL, and added sugar, fiber, and whole-grain intake were not related to the analyzed markers. CONCLUSIONS-Our data indicate that a habitually higher dietary GI during puberty may adversely affect risk markers of type 2 diabetes in younger adulthood.