Comparison of two carbohydrate intake strategies to improve glucose control during exercise in adolescents and adults with type 1 diabetes.

BACKGROUND AND AIMS: During aerobic physical activity (PA), hypoglycemia is common in people with type 1 diabetes (T1D). Few studies have compared the effectiveness of different carbohydrate (CHO) intake strategies to prevent PA-induced hypoglycemia. Our objective was to compare the efficacy of two CHO intake strategies, same total amount but different CHO intake timing, to maintain glucose levels in the target range (4.0-10.0 mmol/L) during PA in people with T1D. METHODS AND RESULTS: An open-label, randomized, crossover study in 33 participants (21 adults; 12 adolescents). Participants practiced 60 min PA sessions (ergocyle) at 60% VO2peak 3.5 h after lunch comparing an intake of 0.5 g of CHO per kg of body weight applied in a pre-PA single CHO intake (SCI) or in a distributed CHO intake (DCI) before and during PA. The percentage of time spent in glucose level target range during PA was not different between the two strategies (SCI: 75 ± 35%; DCI: 87 ± 26%; P = 0.12). Hypoglycemia (<4.0 mmol/L) occurred in 4 participants (12%) with SCI compared to 6 participants (18%) with DCI (P = 0.42). The SCI strategy led to a higher increase (P = 0.01) and variability of glucose levels (P = 0.04) compared with DCI. CONCLUSIONS: In people living with T1D, for a 60 min moderate aerobic PA in the post-absorptive condition, a 0.5 g/kg CHO intake helped most participants maintain acceptable glycemic control with both strategies. No clinically significant difference was observed between the SCI and DCI strategies. ClinicalTrials.gov Identifier: NCT03214107 (July 11, 2017).

Diet-induced obesity in young mice: Consequences on the pancreatic intrinsic nervous system control of insulin secretion.

INTRODUCTION: Obesity has become a pandaemic even in children. We aimed to investigate the impact of obesity in youth on later pancreatic intrinsic nervous system (PINS) phenotype and control of insulin secretion. METHODS: Young mice (5-week-old, T0 group) were fed either a normal diet (ND group) or a Western diet (WD group) for 12 weeks. Pancreas nervous system density, PINS phenotype and pancreas anatomy were analysed by immunohistochemistry at T0 and in adulthood (ND and WD groups). Insulin secretion was also studied in these 3 groups using a new model of ex vivo pancreatic culture, where PINS was stimulated by nicotinic and nitrergic agonists with and without antagonists. Insulin was assayed in supernatants by ELISA. RESULTS: Pancreas nervous system density decreased with age in ND (P < .01) but not in WD mice (P = .08). Western diet decreased the PINS nitrergic component as compared to normal diet (P < .01) but it did not modify its cholinergic component (P = .50). Nicotinic PINS stimulation induced greater insulin secretion in ND compared to WD mice (P < .001) whereas nitrergic stimulation significantly decreased insulin secretion in ND mice (P < .001) and tended to increase insulin secretion in WD mice (P = .08). Endocrine pancreas anatomy was not modified by the Western diet as compared to the normal diet (P = .93). CONCLUSIONS: Early Western diet induced neuronal density and phenotype changes in PINS that might be involved in the pancreas insulin secretion dysfunctions associated with obesity.

Blood Pressure, Heart Rate Variability, and Adiposity in Caribbean Pre-pubertal Children.

Childhood obesity prevalence has increased over the last 30 years. The Heart Rate Variability (HRV) studies performed in adults suggest a possible relation between abnormal autonomic regulation and hypertension in the situation of overweight or obesity. Objective: The aims of this study were to explore the early relationships between adiposity and blood pressure and HRV in pre-pubertal children. Methods: Data were collected during the medical examination of the follow-up at 7 years of the TIMOUN mother-child cohort in Guadeloupe. Body Mass Index z-score (zBMI), sum of tricipital and subscapular skinfold thickness, percentage of fat mass, and Waist-to-Height Ratio were measured. A global corpulence score was computed using a Principal Component Analysis (PCA). Systolic Blood Pressure (SBP) and HRV parameters (cardiac holter monitoring) were collected under 2 conditions (calm and tachycardial period). Relations between HRV, SBP, each adiposity indicator and the corpulence score were studied with restricted cubic splines models, and linear regression models. The age at adiposity rebound (AR) was estimated from the individual growth curves. Results: 575 children were included in the SBP study (mean age: 7.7 years, from 85 to 99 months). SBP was linearly correlated with the corpulence score and the zBMI. An increase of 1 in the zBMI was associated with an increase of 2.3 (±0.28) mmHg in SBP. The effect-size of zBMI on SBP was higher in children with early age at AR. Compared to children with normal BMI, children with a zBMI <™2SD had their RMSSD, SDNN, LF and HF indicators in tachycardial conditions significantly reduced by -30, -21, -37, and -48%, respectively. In boys with a zBMI >2SD, we observed a global increase in all HRV parameters (under tachycardial conditions), particularly the LF [ß = 0.43 (±0.18)]. Conclusion: In pre-pubertal period a positive correlation between adiposity excess and SBP was observed with significant changes of HRV in boys, arguing for an early abnormal autonomic regulation and for early preventive intervention in the infancy period, particularly in case of overweight or obesity. Thinness was associated with a reduction in almost all the HRV parameters studied, when compared to normal corpulence, suggesting a decrease in autonomic influence.