PREVIEW (Prevention of Diabetes Through Lifestyle Intervention and Population Studies in Europe and Around the World) study in children aged 10 to 17 years: Design, methods and baseline results

Abstract

Insulin resistance (IR) in adolescence is associated with type 2 diabetes mellitus [T2DM]. The PREVIEW (Prevention of Diabetes Through Lifestyle Intervention and Population Studies in Europe and Around the World) study assessed the effectiveness of a high-protein, low-glycaemic-index diet and a moderate-protein, moderate-glycaemic-index diet to decrease IR in insulin-resistant children who were overweight or obese. Inclusion criteria were age 10 to 17 years, homeostatic model assessment of IR (HOMA-IR) ≥2.0 and overweight/obesity. In 126 children (mean ± SD age 13.6 ± 2.2 years, body mass index [BMI] z-score 3.04 ± 0.66, HOMA-IR 3.48 ± 2.28) anthropometrics, fat mass percentage (FM%), metabolic characteristics, physical activity, food intake and sleep were measured. Baseline characteristics did not differ between the groups. IR was higher in pubertal children with morbid obesity than in prepubertal children with morbid obesity (5.41 ± 1.86 vs 3.23 ± 1.86; P = .007) and prepubertal and pubertal children with overweight/obesity (vs 3.61 ± 1.60, P = .004, and vs 3.40 ± 1.50, P < .001, respectively). IR was associated with sex, Tanner stage, BMI z-score and FM%. Fasting glucose concentrations were negatively associated with Baecke sport score (r = -0.223, P = .025) and positively with daytime sleepiness (r = 0.280, P = .016) independent of sex, Tanner stage, BMI z-score and FM%. In conclusion, IR was most severe in pubertal children with morbid obesity. The associations between fasting glucose concentration and Baecke sport score and sleepiness suggest these might be possible targets for diabetes prevention.

Effect of a high protein/low glycaemic index diet on insulin resistance in adolescents with overweight/obesity—A PREVIEW randomized clinical trial

“…The PREVIEW study in adolescents was a multicentre, 104-week parallel-group, gender-stratified block-randomized (10:10) trial between December 2013 and December 2018, as described previously. 28 The first 8 weeks aimed at weight stabilization during growth. All participants received sample menus based on their estimated energy requirements, consisting of 15/55/30 energy percent (En%) protein/carbohydrate/ fat.…”

“…The PREVIEW study in adolescents was a multicentre, 104‐week parallel‐group, gender‐stratified block‐randomized (10:10) trial between December 2013 and December 2018, as described previously 28 . The first 8 weeks aimed at weight stabilization during growth.…”

“…Adolescents were recruited from three study sites (Maastricht University, the Netherlands; University of Navarra, Spain and Swansea University, UK) between December 2013 and December 2016 by ED, NS and SNC. Inclusion criteria were overweight/obesity (BMI z‐score >1.0 SDS), increased IR (defined as HOMA‐IR >2.0 for adolescents Tanner G/M stages ≥3 or any HOMA‐IR for adolescents at Tanner stages 1‐2) and signed informed consent from both parents and adolescents ≥12 years 28 . Exclusion criteria included medical conditions or use of medication that might influence study outcomes (eg, T2DM, bariatric surgery and use of metformin) or compromise study adherence (eg, severe food intolerances or musculoskeletal diseases).…”

“…Power calculations were performed using G*power (Dusseldorf University, Dusseldorf, Germany) and adjusted for an estimated 25% drop‐out. With an α of .05, effect size of .37 for HOMA‐IR and sample size of 100, a power of 0.96 could be achieved 28 . To remain sufficient power for analyses at 2 years despite drop‐out, intention‐to‐treat analyses were performed on the complete dataset after multiple imputation.…”

“…With an α of .05, effect size of .37 for HOMA-IR and sample size of 100, a power of 0.96 could be achieved. 28 Tables 1 and 2. No significant differences between the groups were observed in gender, BMI z-score, HOMA-IR or other glucose metabolism or lifestyle parameters.…”