Bone health and hyperglycemia in pediatric populations

Risk factor analysis for tibial tubercle avulsion fractures in children

PURPOSE

Tibial tubercle avulsion fractures (TTAFs) are rare in children, particularly bilateral TTAFs. This study aimed to elucidate the associating factors of TTAF, and compare the risk factor profiles of unilateral and bilateral injuries, thus provide clinical theoretical basis for reducing the occurrence of TTAFs.

METHODS

TTAF paediatric patients who were hospitalized between April 2017 and November 2022 were retrospectively analysed. Children who presented for physical examination during the same period were randomly selected, and were age- and sex-matched as controls. A subgroup analysis based on endocrine function was also performed. A risk factor analysis for bilateral TTAF was performed as well. Data were collected via medical records and a questionnaire. All variables were assessed for association with TTAF using univariate and multiple logistic regression analyses.

RESULTS

A total of 64 TTAF patients and controls were respectively included. Multivariate analysis demonstrated BMI (P = 0.000，OR = 3.172), glucose (P = 0.016，OR = 20.878), and calcium (P = 0.034，OR = 0.000) as independent associating factors of TTAF. Subgroup analysis showed significant differences in oestradiol (P = 0.014), progesterone (P = 0.006) and insulin levels (P = 0.005) between the TTAF and control groups. Bilateral TTAF was found to significantly associate with a history of knee joint pain (P = 0.026).

CONCLUSION

High BMI, hyperglycaemia, and low calcium levels were found as independent risk factors for TTAF in children. In addition, decreased oestradiol, elevated progesterone, and insulin resistance were identified as potential risk factors for TTAF. A history of knee pain may be suggestive of bilateral TTAF.

Dietary Complex and Slow Digestive Carbohydrates Promote Bone Mass and Improve Bone Microarchitecture during Catch-Up Growth in Rats

Catch-up growth is a process that promotes weight and height gains to recover normal growth patterns after a transient period of growth inhibition. Accelerated infant growth is associated with reduced bone mass and quality characterized by poor bone mineral density (BMD), content (BMC), and impaired microarchitecture. The present study evaluated the effects of a diet containing slow (SDC) or rapid (RDC) digestible carbohydrates on bone quality parameters during the catch-up growth period in a model of diet-induced stunted rats. The food restriction period negatively impacted BMD, BMC, and microarchitecture of appendicular and axial bones. The SDC diet was shown to improve BMD and BMC of appendicular and axial bones after a four-week refeeding period in comparison with the RDC diet. In the same line, the micro-CT analysis revealed that the trabecular microarchitecture of tibiae and vertebrae was positively impacted by the dietary intervention with SDC compared to RDC. Furthermore, features of the cortical microstructure of vertebra bones were also improved in the SDC group animals. Similarly, animals allocated to the SDC diet displayed modest improvements in growth plate thickness, surface, and volume compared to the RDC group. Diets containing the described SDC blend might contribute to an adequate bone formation during catch-up growth thus increasing peak bone mass, which could be linked to reduced fracture risk later in life in individuals undergoing transient undernutrition during early life.

Relationships between Bone Turnover Markers and Factors Associated with Metabolic Syndrome in Prepubertal Girls and Boys

The associations between individual components of metabolic syndrome (MetS) and bone health in children are complex, and data on this topic are sparse and inconsistent. We assessed the relationship between bone turnover markers and markers of the processes underlying MetS (insulin resistance and inflammation) in a group of presumably healthy children aged 9–11 years: 89 (51 girls, 38 boys) presenting without any features of MetS and 26 (10 girls, 16 boys) with central obesity and two features of MetS. Concentrations of glucose, triglycerides (TG), HDL cholesterol (HDL-C), C-reactive protein (CRP), HbA1c, total 25-hydroxyvitamin D (25(OH)D), intact-P1NP (N-terminal propeptide of type I procollagen), CTX-1 (C-terminal telopeptide of type I collagen) were assayed and insulin resistance was assessed (HOMA-IR). BMI centile, waist circumference (WC) and blood pressure were measured. The presence of MetS in girls resulted in significantly lower concentrations of CTX-1 and a trend to lower CTX-1 in boys. The concentrations of bone formation marker i-P1NP were not affected. Among the features associated with MetS, HOMA-IR appeared as the best positive predictor of MetS in girls, whereas CRP was the best positive predictor in boys. A significant influence of HOMA-IR on the decrease in CTX-1 in girls was independent of BMI centile and WC, and the OR of having CTX-1 below the median was 2.8-fold higher/1SD increased in HOMA-IR (p = 0.003). A weak relationship between CTX-1 and CRP was demonstrated in girls (r = −0.233; p = 0.070). Although TG, as a MetS component, was the best significant predictor of MetS in both sexes, there were no correlations between bone markers and TG. We suggest that dyslipidemia is not associated with the levels of bone markers in prepubertal children whereas CRP is weakly related to bone resorption in girls. In prepubertal girls, insulin resistance exerts a dominant negative impact on bone resorption, independent of BMI centile and waist circumference.

Effects of methylphenidate on height, weight and blood biochemistry parameters in prepubertal boys with attention deficit hyperactivity disorder: an open label prospective study

Background: Adverse effects of stimulants on growth in children have long been studied, but the results remain to be clarified, because metabolic changes or predictors accompanying the growth deviations were not sufficiently studied. Objective: This open label-prospective study investigated the effects of methylphenidate (MPH) on weight, height, blood biochemistry in children with attention deficit hyperactivity disorder (ADHD). Method: Prepubertal boys treated with MPH in Child and Adolescent Psychiatry Clinic at Antalya Training and Research Hospital in Health Sciences University, Turkey were recruited. Height and weight z-scores and fasting blood samples were taken at baseline and 6^th month. Changes were compared by paired-samples t-test or Wilcoxon signed-rank test. Any association between the changes in growth and biochemical values was analyzed by Spearman's Rank-Order Correlation. The statistical significance threshold was p<0.01. Results: 31 boys aged 74 to 104 months were enrolled in the study sample (mean=87.6, Standard Deviation (SD)=9.2). Osmotic release oral system-MPH (18 mg/day) was used in 77.4% (N=24) and immediate release-MPH (5 mg three times a day) in 22.5% (N=7). Average daily drug dose was 0.66 mg/kg (SD=0.12). Baseline weight z-score was 0.63 (SD=1.12), decreased significantly at 6 months (0.24 [SD=1.04]) (Z=-4.44, p=0.000, r=0.5) (median z-score was 0.53 at baseline, -0.11 at 6 months). Baseline height z-score (0.23[SD=0.87]) was not suppressed significantly at 6 months (0.28[SD=0.85])(t(30) = ‒1.50, p=0.14). Glucose (t(30) = -4.33, p=0.000, r=0.6), creatinine (t(30)=-3.28, p=0.003, r=0.5) and 25OH-VitD (N=29, Z=-3.98, p=0.000, r=0.5) increased but alkaline phosphatase (ALP) decreased (t(28)=3.63, p=0.001, r=0.5). The differences in W-SDS and ALP were positively correlated (r=0.47, p=0.009). Conclusions: Our results indicate the importance of monitoring blood variables that may accompany growth changes early in MPH treatment and should be further assessed in larger samples.

Rethinking Fragility Fractures in Type 2 Diabetes: The Link between Hyperinsulinaemia and Osteofragilitas

Patients with type 2 diabetes mellitus (T2DM) and/or cardiovascular disease (CVD), conditions of hyperinsulinaemia, have lower levels of osteocalcin and bone remodelling, and increased rates of fragility fractures. Unlike osteoporosis with lower bone mineral density (BMD), T2DM bone fragility "hyperinsulinaemia-osteofragilitas" phenotype presents with normal to increased BMD. Hyperinsulinaemia and insulin resistance positively associate with increased BMD and fragility fractures. Hyperinsulinaemia enforces glucose fuelling, which decreases NAD+-dependent antioxidant activity. This increases reactive oxygen species and mitochondrial fission, and decreases oxidative phosphorylation high-energy production capacity, required for osteoblasto/cytogenesis. Osteocytes directly mineralise and resorb bone, and inhibit mineralisation of their lacunocanalicular space via pyrophosphate. Hyperinsulinaemia decreases vitamin D availability via adipocyte sequestration, reducing dendrite connectivity, and compromising osteocyte viability. Decreased bone remodelling and micropetrosis ensues. Trapped/entombed magnesium within micropetrosis fossilisation spaces propagates magnesium deficiency (MgD), potentiating hyperinsulinaemia and decreases vitamin D transport. Vitamin D deficiency reduces osteocalcin synthesis and favours osteocyte apoptosis. Carbohydrate restriction/fasting/ketosis increases beta-oxidation, ketolysis, NAD+-dependent antioxidant activity, osteocyte viability and osteocalcin, and decreases excess insulin exposure. Osteocalcin is required for hydroxyapatite alignment, conferring bone structural integrity, decreasing fracture risk and improving metabolic/endocrine homeodynamics. Patients presenting with fracture and normal BMD should be investigated for T2DM and hyperinsulinaemia.