Prevalence and associations of impaired awareness of hypoglycemia in a pediatric type 1 diabetes population - The Norwegian Childhood Diabetes Registry.

AIMS: To determine the prevalence and associations of impaired awareness of hypoglycemia (IAH) in pediatric type 1 diabetes. METHODS: Nationwide, population-based cross-sectional study with 51 % participation. Participants (n = 1329; 53 % males) aged 2-19 years (median 13.3) with type 1 diabetes ≥ 6 months (median 4.6 years) self-assessed hypoglycemia awareness with a validated questionnaire ('Clarke'). Parents responded for children aged < 9 years (n = 235). We estimated associations between IAH and clinical data in the Norwegian Childhood Diabetes Registry. RESULTS: The overall prevalence of IAH was 22 %, but gradually decreased from 53 % in preschoolers to 12 % in adolescents aged ≥ 16 years. IAH was associated (adjusted OR; 95 %CI) with episodes of severe hypoglycemia (6.0; 3.04, 11.8) and diabetic ketoacidosis (3.45; 1.37, 8.68) the preceding year, increased fear of hypoglycemia (highest quartile vs. lowest: 2.27; 1.51, 3.40), female sex (1.41; 1.05, 1.90), and HbA1c ≥ 8.5 % (69 mmol/mol) vs. 7.5-8.4 % (58-68 mmol/mol) (1.48; 1.01, 2.18), but not with disease duration, use of insulin pump or continuous glucose monitoring, or HbA1c < 7.5 % (58 mmol/mol). CONCLUSIONS: IAH is prevalent in pediatric diabetes and more likely reported in young children. IAH is associated with severe hypoglycemia and fear of hypoglycemia, but good metabolic control seems achievable without increased risk of IAH.

Assessing awareness of hypoglycemia in children and adolescents with type 1 diabetes: Evaluation of established questionnaires.

OBJECTIVE: To evaluate the use of two questionnaires assessing awareness of hypoglycemia, in a pediatric type 1 diabetes (T1D) population. METHODS: Prospective observational study with children (aged 9-18 years) and parents (for children aged 2-11 years) answering the Gold and Clarke questionnaires assessing awareness of hypoglycemia. Psychometric properties of the questionnaires were evaluated, and the most appropriate cut-off score to classify participants as having normal vs impaired awareness of hypoglycemia (IAH) was determined by ability to recognize subsequent hypoglycemia and hypoglycemia severity, documented in a 4-week blood glucose diary. Questionnaires were readministered at follow-up assessment approximately 1.5 years later. RESULTS: In total, 112 participants (51% male) with median (IQR) age 13.7 (11.1-15.8) years, T1D duration 4.7 (2.2-7.8) years, and HbA1c 62 (57-73) mmol/mol (7.8%) were included. Both questionnaires demonstrated acceptable psychometric properties. Using score ≥3 to classify IAH gave a prevalence of IAH of 41% (Gold) and 22% (Clarke). When classified using the Gold questionnaire, IAH participants had higher incidences of mild asymptomatic hypoglycemia, whereas with the Clarke questionnaire, they had higher incidences of clinically significant and severe hypoglycemia. Subgroup analyses confirmed these associations only in participants aged ≥9 years. Follow-up was completed in 90% of the participants, and a change of awareness status was observed in 22% to 36%. CONCLUSIONS: The Gold and Clarke questionnaires may be used to assess awareness of hypoglycemia in pediatric T1D in those ≥9 years of age, but the more detailed Clarke questionnaire has higher specificity and is superior in predicting risk of clinically significant hypoglycemia.

Effect of 24 sessions of high-intensity aerobic interval training carried out at either high or moderate frequency, a randomized trial.

PURPOSE: The training response of an intensified period of high-intensity exercise is not clear. Therefore, we compared the cardiovascular adaptations of completing 24 high-intensity aerobic interval training sessions carried out for either three or eight weeks, respectively. METHODS: Twenty-one healthy subjects (23.0±2.1 years, 10 females) completed 24 high-intensity training sessions throughout a time-period of either eight weeks (moderate frequency, MF) or three weeks (high frequency, HF) followed by a detraining period of nine weeks without any training. In both groups, maximal oxygen uptake (VO2max) was evaluated before training, at the 9(th) and 17(th) session and four days after the final 24(th) training session. In the detraining phase VO2max was evaluated after 12 days and thereafter every second week for eight weeks. Left ventricular echocardiography, carbon monoxide lung diffusion transfer factor, brachial artery flow mediated dilatation and vastus lateralis citrate maximal synthase activity was tested before and after training. RESULTS: The cardiovascular adaptation after HF training was delayed compared to training with MF. Four days after ending training the HF group showed no improvement (+3.0%, p = 0.126), whereas the MF group reached their highest VO2max with a 10.7% improvement (p<0.001: group difference p = 0.035). The HF group reached their highest VO2max (6.1% increase, p = 0.026) twelve days into the detraining period, compared to a concomitant reduction to 7.9% of VO2max (p<0.001) above baseline in the MF group (group difference p = 0.609). CONCLUSION: Both HF and MF training of high-intensity aerobic exercise improves VO2max. The cardiovascular adaptation following a HF programme of high-intensity exercise is however delayed compared to MF training. TRIAL REGISTRATION: ClinicalTrials.gov NCT00733941.

Telomere length and long-term endurance exercise: does exercise training affect biological age? A pilot study.

BACKGROUND: Telomeres are potential markers of mitotic cellular age and are associated with physical ageing process. Long-term endurance training and higher aerobic exercise capacity (VO(2max)) are associated with improved survival, and dynamic effects of exercise are evident with ageing. However, the association of telomere length with exercise training and VO(2max) has so far been inconsistent. Our aim was to assess whether muscle telomere length is associated with endurance exercise training and VO(2max) in younger and older people. METHODS: Twenty men; 10 young (22-27 years) and 10 old (66-77 years), were studied in this cross-sectional study. Five out of 10 young adults and 5 out of 10 older were endurance athletes, while other halves were exercising at a medium level of activity. Mean telomere length was measured as telomere/single copy gene-ratio (T/S-ratio) using quantitative real time polymerase chain reaction. VO(2max) was measured directly running on a treadmill. RESULTS: Older endurance trained athletes had longer telomere length compared with older people with medium activity levels (T/S ratio 1.12±0.1 vs. 0.92±0.2, p = 0.04). Telomere length of young endurance trained athletes was not different than young non-athletes (1.47±0.2 vs. 1.33±0.1, p = 0.12). Overall, there was a positive association between T/S ratio and VO(2max) (r = 0.70, p = 0.001). Among endurance trained athletes, we found a strong correlation between VO(2max) and T/S ratio (r = 0.78, p = 0.02). However, corresponding association among non-athlete participants was relatively weak (r = 0.58, p = 0.09). CONCLUSION: Our data suggest that VO(2max) is positively associated with telomere length, and we found that long-term endurance exercise training may provide a protective effect on muscle telomere length in older people.