Physical activity increases bone mineral density in children with type 1 diabetes.

INTRODUCTION: Osteoporosis is a growing health problem in patients with type 1 diabetes mellitus (T1DM). The aim of this study was to determine the effects of a 9-month weight-bearing physical activity program on bone mineral density (BMD) and bone biomarkers in T1DM compared with healthy children. METHODS: This was a randomized controlled trial including 27 diabetic and 32 healthy children (mean age = 10.5 ± 2.5 yr). Both T1DM and healthy participants were randomized to either an exercise or a control group (i.e., four groups). At baseline and 9 months, total body (TB), lumbar spine (LS2-LS4), femoral neck, and greater trochanter areal BMD (aBMD) and serum bone biomarkers (osteocalcin, type 1 collagen cross-linking) were measured. The intervention consisted of two 90-min sessions per week of weight-bearing physical activity (ball games, jumping, rope skipping, and gymnastics). RESULTS: Baseline variables were similar among groups. At 9 months, changes in TB (T1DM = 0.035 ± 0.022 g·cm(-2), healthy = 0.031 ± 0.017 g·cm(-2)) and LS2-LS4 (T1DM = 0.046 ± 0.038 g·cm(-2), healthy = 0.063 ± 0.034 g·cm(-2)) aBMD were statistically significant in the intervention groups and of similar magnitude between T1DM and healthy subjects. The level of type 1 collagen cross-linking (T1DM = -0.12 ± 0.32 ng·mL(-1), healthy = -0.36 ± 0.11 ng·mL(-1)) decreased in the intervention groups but was not associated with TB aBMD changes. CONCLUSIONS: Regular weight-bearing physical activity (180 min·wk(-1), including ball games, jumping activities, and gymnastics) improves total and LS2-LS4 bone mineral accretion in children with T1DM, in a similar magnitude to healthy subjects. We conclude that children with T1DM should be encouraged to practice regular physical activity to enhance peak bone mass and prevent osteoporosis later in life.

Elevated E-selectin and diastolic blood pressure in diabetic children.

BACKGROUND: Cardiovascular risk markers are related to micro-angiopathy in children with type 1 diabetes (T1DM), but there is no information about their relationship with blood pressure (BP) and endothelial function. MATERIALS AND METHODS: This was a case-control study including 29 children with T1DM (mean age 10·5 ± 2·7 years, disease duration: 3·8 ± 2·2 years) and 39 healthy controls (mean age: 9·8 ± 2·7 years). We assessed 24-h ambulatory BP, vascular function and serum level of lipids, vascular cell adhesion molecule-1 (VCAM-1; ICAM) and selectins (E-selectin; P-selectin). RESULTS: The subject groups had similar physical characteristics and lipids level, except body mass index (BMI) which was higher in T1DM than in healthy children (18·6 ± 2·6 vs. 16·7 ± 2·5 kg/m(2), P = 0·003). Children with T1DM had increased 24 h diastolic BP z-score (0·62 ± 0·9 vs. -0·65 ± 0·8, P < 0·001), even after adjustment for BMI, as well as higher VCAM-1 concentration (492 ± 346 vs. 340 ± 225 ng/mL, P = 0·039) compared to healthy subjects. Diastolic BP z-scores were associated with disease duration, E-selectin and triglyceride levels in the T1DM group (P < 0·05). E-selectin was also related to triglycerides, otherwise there were no relationships between vascular function, markers and BP. CONCLUSION: E-selectin, an early atherosclerosis biomarker, is positively associated with diastolic BP values in children with T1DM, despite relatively short disease duration.

Long-term follow-up of cardiovascular risk factors after exercise training in obese children.

OBJECTIVE: We previously demonstrated beneficial effects of physical activity on cardiovascular disease (CVD) risk factors, body mass index (BMI) and fat mass in pre-pubescent obese children. The aim of this study was to determine whether these changes were maintained 2 years later. METHODS: Two years after the Randomised Controlled Trial, we performed a follow-up study with 20 of 38 subjects (11.4 ± 1.8 years). Outcomes included blood pressure (BP) by ambulatory monitoring; arterial function and structure using high-resolution ultrasound, BMI, body composition by dual-energy x-ray absorptiometry (DXA), physical activity using accelerometer, and biological markers. RESULTS: During the 2-year follow-up period, mean 24-hour diastolic BP z-score significantly decreased (1.4 ± 1.2 vs. 0.3 ± 1.4, p = 0.04), while systolic BP z-score was slightly reduced (2.4 ± 1.5 vs. 1.4 ± 1.7, p = 0.067). Blood pressure changes were greater in children who diminished their BMI z-score compared with the ones who did not. Systolic hypertension rates dropped from 50 to 28% and diastolic hypertension from 42 to 6%. In addition, arterial intima-media thickness (0.51 ± 0.03 vs. 0.51 ± 0.06, p = 0.79), BMI z-score (2.9 ± 0.8 vs. 2.9 ± 1.1 kg.cm(-2), p = 0.27), body fat (41.9 ± 6.9 vs. 42.8 ± 6.7%; p = 0.39) and physical activity count (703 ± 209 vs. 574 ± 244 cpm, p = 0.30) were stable. CONCLUSION: To our knowledge, this is the first study reporting that beneficial effects on adiposity and CVD risk factors of a physical activity centred intervention are sustained 2 years after the cessation of training in obese children. Subjects stabilized BMI z-score and maintained physical activity with further improvement of BP and stabilization of arterial wall remodelling. We conclude that it is important to encourage physical activity in this population. Effects of Aerobic Exercise Training on Arterial Function and Insulin Resistance Syndrome in Obese Children: A Randomised Controlled Trial: NCT00801645.

Preclinical noninvasive markers of atherosclerosis in children and adolescents with type 1 diabetes are influenced by physical activity.

OBJECTIVES: To measure preclinical noninvasive markers of atherosclerosis in youth with type 1 diabetes (T1DM), and to determine their associations between physical activity level and cardiorespiratory fitness (maximal oxygen consumption [VO2max]). STUDY DESIGN: This was a cross-sectional study including 32 patients with T1DM and 42 healthy subjects aged 6 to 17 years. Main outcome measures included arterial flow-mediated dilation (FMD) and intima-media thickness with high-resolution ultrasonography; physical activity by accelerometer (valid 26 patients with T1DM, 35 healthy subjects) and VO2max. RESULTS: Compared with healthy control subjects, patients with T1DM had higher intima-media thickness (mean 0.50 mm [0.48-0.52, 95% CI] vs 0.48 [0.47-0.49], P=.02) and reduced FMD (4.9% [4.1%-5.7%] vs 7.3 [6.4-8.1], P=.001), VO2max (45.5 mL/kg/min [43.0-48.0] vs 48.7 [46.7-50.6], P

Reduced physical activity level and cardiorespiratory fitness in children with chronic diseases.

UNLABELLED: We aimed to compare physical activity level and cardiorespiratory fitness in children with different chronic diseases, such as type 1 diabetes mellitus (T1DM), obesity (OB) and juvenile idiopathic arthritis (JIA), with healthy controls (HC). We performed a cross-sectional study including 209 children: OB: n = 45, T1DM: n = 48, JIA: n = 31, and HC: n = 85. Physical activity level was assessed by accelerometer and cardiorespiratory fitness by a treadmill test. ANOVA, linear regressions and Pearson correlations were used. Children with chronic diseases had reduced total daily physical activity counts (T1DM 497 +/- 54 cpm, p = 0.003; JIA 518 +/- 28, p < 0.001, OB 590 +/- 25, p = 0.003) and cardiorespiratory fitness (JIA 39.3 +/- 1.7, p = 0.001, OB 41.7 +/- 1.2, p = 0.020) compared to HC (668 +/- 35 cpm; 45.3 +/- 0.9 ml kg(-1) min(-1), respectively). Only 60.4% of HC, 51.6% of OB, 38.1% of JIA and 38.5% of T1DM children met the recommended daily 60 min of moderate-to-vigorous physical activity. Low cardiorespiratory fitness was associated with female gender and low daily PA. CONCLUSION: Children with chronic diseases had reduced physical activity and cardiorespiratory fitness. As the benefits of PA on health have been well demonstrated during growth, it should be encouraged in those children to prevent a reduction of cardiorespiratory fitness and the development of comorbidities.

Physical activity reduces systemic blood pressure and improves early markers of atherosclerosis in pre-pubertal obese children.

OBJECTIVES: The aim of this study was to determine the effects of physical activity on systemic blood pressure (BP) and early markers of atherosclerosis in pre-pubertal obese children. BACKGROUND: Hypertension and endothelial dysfunction are premature complications of obesity. METHODS: We performed a 3-month randomized controlled trial with a modified crossover design: 44 pre-pubertal obese children (age 8.9 + or - 1.5 years) were randomly assigned (1:1) to an exercise (n = 22) or a control group (n = 22). We recruited 22 lean children (age 8.5 + or - 1.5 years) for baseline comparison. The exercise group trained 60 min 3 times/week during 3 months, whereas control subjects remained relatively inactive. Then, both groups trained twice/week during 3 months. We assessed changes at 3 and 6 months in office and 24-h BP, arterial intima-media thickness (IMT) and stiffness, endothelial function (flow-mediated dilation), body mass index (BMI), body fat, cardiorespiratory fitness (maximal oxygen consumption [VO(2)max]), physical activity, and biological markers. RESULTS: Obese children had higher BP, arterial stiffness, body weight, BMI, abdominal fat, insulin resistance indexes, and C-reactive protein levels, and lower flow-mediated dilation, VO(2)max, physical activity, and high-density lipoprotein cholesterol levels than lean subjects. At 3 months, we observed significant changes in 24-h systolic BP (exercise -6.9 + or - 13.5 mm Hg vs. control 3.8 + or - 7.9 mm Hg, -0.8 + or - 1.5 standard deviation score [SDS] vs. 0.4 + or - 0.8 SDS), diastolic BP (-0.5 + or - 1.0 SDS vs. 0 + or - 1.4 SDS), hypertension rate (-12% vs. -1%), office BP, BMI z-score, abdominal fat, and VO(2)max. At 6 months, change differences in arterial stiffness and IMT were significant. CONCLUSIONS: A regular physical activity program reduces BP, arterial stiffness, and abdominal fat; increases cardiorespiratory fitness; and delays arterial wall remodeling in pre-pubertal obese children. (Effects of Aerobic Exercise Training on Arterial Function and Insulin Resistance Syndrome in Obese Children: A Randomized Controlled Trial; NCT00801645).

Associations among obesity, blood pressure, and left ventricular mass.

OBJECTIVES: To measure resting and ambulatory systemic blood pressure (BP) and left ventricular mass (LVM) in prepubertal obese and lean children and to determine their relationships. STUDY DESIGN: Cross-sectional study including 44 obese and 22 lean prepubertal children (mean age 8.8 +/- 1.5 years). We measured casual and 24-hour ambulatory BP, LVM and LVM index (LVMI) by echocardiography, and whole body lean tissue and fat mass by dual-energy X-ray absorptiometry. RESULTS: Mean 24-hour systolic BP (124.8 +/- 14.2 vs 105.5 +/- 8.8 mm Hg), diastolic BP (72.8 +/- 7.3 vs 62.7 +/- 3.8 mm Hg), and LVMI (36.1 +/- 5.8 vs 30.9 +/- 5.7, g x m(-2.7)) were significantly higher in obese than in lean subjects. Systolic ambulatory hypertension was present in 47.6% of obese children, and casual BP was normal in 55% of those cases. Body fatness, lean tissue mass, and 24-hour BP correlated positively with LVMI. When adjusted for body fatness, LVMI was only associated with 24-hour systolic BP (adjusted R(2) = 15.9%; P = .001). CONCLUSIONS: Ambulatory systemic hypertension and increased LVM are found in obese children. Left ventricular mass is partially determined by systemic BP. We conclude that prevention and treatment of childhood obesity should be initiated as early as possible to prevent the premature development of hypertension and end-stage organ damage.

Impaired endothelial and smooth muscle functions and arterial stiffness appear before puberty in obese children and are associated with elevated ambulatory blood pressure.

AIMS: To determine whether impaired brachial endothelial (flow-mediated dilation, FMD) and smooth muscle function (nitroglycerin-mediated dilation, NTGMD), and remodelling of the common carotid artery (CCA) develop before puberty in obese children. METHODS AND RESULTS: Arterial intima-media thickness (IMT), FMD and NTGMD were measured by high-resolution ultrasound in 48 obese and 23 lean pre-pubertal children (8.8 +/- 1.5 years old). We assessed central pulse pressure, incremental elastic modulus (Einc), casual and ambulatory systolic (SBP) and diastolic blood pressure (DBP), and body fatness by DXA. Obese children had significantly lower FMD (4.5 +/- 4.0 vs. 8.3 +/- 1.7%), NTGMD (19.0 +/- 9.0 vs. 25.8 +/- 6.1%), and increased Einc (13.9 +/- 5.2 vs. 10.4 +/- 5.2 mmHg/10(2)), ambulatory SBP (121.3 +/- 12.6 vs. 106.6 +/- 7.1, mmHg), and DBP (69.1 +/- 5.7 vs. 63.7 +/- 4.5) than lean subjects, whereas IMT was not augmented. Ambulatory systolic hypertension was present in 47% of obese subjects. FMD, NTGMD, and Einc were correlated with body fatness, body mass index, and blood pressure (BP). CONCLUSION: Impaired endothelial and smooth muscle functions and altered wall material develop before puberty in obese children, however remodelling of the CCA is not yet present. Arterial dysfunction may be considered as the first marker of atherosclerosis and is associated with elevated BP. Ambulatory blood pressure monitoring may be a potential tool to improve risk stratification in obese children.