Status of Bone Mineral Density in Children with Type 1 Diabetes Mellitus and Its Related Factors

Abstract

Background: Type 1 Diabetes mellitus (DM) causes changes in bone mineral density (BMD). Objectives: The aim of this study was to evaluate BMD in children with type 1 DM and predictive factors of BMD loss in these patients. Methods: This cross-sectional study was conducted on 112 children with type 1 DM referrtd to children’s medical center in Tehran, Iran during 2015 and 2016. Serum levels of hemoglobin A1c (HbA1c), Insulin-like growth factor 1 (IGF-1), 25-hydroxy vitamin D (25(OH) D), calcium, phosphorus, parathyroid hormone (PTH), alkaline phosphates (ALP), Fasting blood sugar (FBS) was recorded. Lumbar spinal BMD (L1-L4) was measured in all patients by dual energy X-ray absorptiometry (DEXA). A BMD Z-score of ≥ -1 was accepted as normal; between -1 and -2, in the low range of normality; and ≤ -2 , low BMD. Bone mineral content (BMC) was calculated by DEXA and recorded. Results: Median age was 12.5 (4 - 14) years. Low BMD and BMD in the low range of normality were diagnosed in 17 (15.2%) and 25 (22.3%) of patients, respectively. There was a significant correlation between BMD and patient age (P < 0.001), age of onset of diabetes (P < 0.001), IGF-1 (P = 0.002), HbA1c (P = 0.001) and PTH (P = 0.040) but only HbA1c increased level significantly predicted reduction of BMD. Conclusions: Glycemic control in children with type I diabetes is mainly predictor of changes in BMD and the changes in BMD were observed mainly in older ages and is independent of gender.