Parathormone--25(OH)-vitamin D axis and bone status in children and adolescents with type 1 diabetes mellitus

Pediatr Diabetes. 2011 Sep;12(6):536-46. doi: 10.1111/j.1399-5448.2010.00739.x. Epub 2011 Mar 22.

Abstract

Background: Skeletal involvement in patients with type 1 diabetes mellitus (T1DM) has complex pathogenesis and despite numerous researches on this problem, many questions remain unanswered.

Objective: This study aimed to assess bone status by measurement parathormone (PTH), 25-hydroxy vitamin D [25(OH)D] serum levels in children and adolescents with T1DM and its relation to insulin-like growth factor-1 (IGF-1), disease duration, puberty stage, and metabolic control.

Patients and methods: This study included 36 children and adolescents with T1DM and 15 apparently healthy controls. Serum levels of 25(OH)D, PTH, IGF-1 measured using enzyme-linked immunosorbent assay (ELISA), while glycosylated hemoglobin (HbA1c), calcium (Ca), inorganic phosphorus (PO(4) ) using autoanalyzer. Bone quality assessed using dual energy X-ray absorptiometry (DEXA).

Results: Diabetic patients showed significant increase in PO(4) and PTH levels, while significant decrease in Ca, IGF-1, and 25(OH)D serum levels. As much as 52.8% of patients showed reduced 25(OH)D, and 30.65% showed elevated PTH serum levels. In diabetic patients, abnormal bone status (osteopenia-osteoporosis) found mostly in total body (94.40%) then lumber-spine (88.90%), ribs (88.90%), pelvis (86.10%), thoracic-spine (80.60%), arms (80.60%) and legs (77.80%), while head bones showed no abnormalities. Long diabetic duration had negative; meanwhile PTH, onset age, and puberty age had positive impact on bone status.

Conclusions: Children and adolescent with T1DM have abnormal bone status mostly in axial skeleton which may be contributed to impairment of formation of 25(OH)D and IGF-1. Physical activity, calcium and vitamin D supplement seem important in T1DM. Elevated serum PTH level in diabetic patients is not uncommon and its positive correlation with bone status needs further investigations.

MeSH terms

  • Absorptiometry, Photon
  • Adolescent
  • Body Mass Index
  • Bone and Bones / metabolism*
  • Calcium / blood
  • Child
  • Child, Preschool
  • Diabetes Mellitus, Type 1 / metabolism*
  • Female
  • Glycated Hemoglobin / analysis
  • Humans
  • Hypoglycemic Agents / therapeutic use
  • Insulin / therapeutic use
  • Insulin-Like Growth Factor I / analysis
  • Male
  • Parathyroid Hormone / blood*
  • Phosphates / blood
  • Vitamin D / blood*

Substances

  • Glycated Hemoglobin A
  • Hypoglycemic Agents
  • Insulin
  • Parathyroid Hormone
  • Phosphates
  • hemoglobin A1c protein, human
  • Vitamin D
  • Insulin-Like Growth Factor I
  • Calcium