The lumbar bone mineral density is affected by long-term poor metabolic control in adolescents with type 1 diabetes mellitus.
OBJECTIVE
To analyze whether bone mineral density (BMD) and bone resorption status are influenced by long-term metabolic control and duration of disease in adolescents with long-standing type 1 diabetes mellitus.


METHODS
Twenty-seven adolescents (age 13.1 +/- 1.7 years, duration of diabetes 6.9 +/- 3.0 years) were studied. The BMD, expressed as z score, was measured at the lumbar spine (L1-L4) using dual-energy X-ray absorptiometry, while the urinary excretion of total deoxypiridinoline (Dpyd), a marker of bone resorption, was measured by immunoassay and was corrected by creatinine (Cr). Linear and multivariate correlations between lumbar BMD z score or Dpyd/Cr excretion and age and disease variables [short-term (Hb A(1c latest)) or long-term (Hb A(1c whole duration)) metabolic control, duration, 'diabetes impact index' (mean Hb A(1c whole duration) x duration of disease in months)] were sought.


RESULTS
In diabetic subjects the mean BMD z score was -0.44 +/- (SD) 1.02 (95% CI: -0.03; -0.84), and the Dpyd/Cr excretion was not increased. A negative correlation was found between lumbar BMD z score and age (r -0.59; p = 0.001), duration (r -0.39; p = 0.04), and the diabetes impact index (r -0.4; p = 0.04). The Dpyd/Cr ratio correlated negatively with age (r -0.40; p = 0.04) and positively with height velocity (r 0.42; p = 0.04). By using multiple linear regression, age showed a significant inverse correlation with lumbar BMD z score (beta = -0.39; p = 0.0005). A negative correlation was found between lumbar BMD z score and Hb A(1c whole duration) (beta = -0.40; p = 0.02) or diabetes impact index (beta = -0.001; p = 0.01).


CONCLUSIONS
Poor metabolic control may expose adolescents with long-standing type 1 diabetes to the risk of developing osteopenia in adult age. Optimization of metabolic control in growing diabetic children may prevent osteoporosis in later life.
Valerio
Giuliana
G
Faculty of Motoric Science, Parthenope University, Naples, Italy. giuliana.valerio@libero.it
del Puente
Antonio
A
Esposito-del Puente
Antonella
A
Buono
Pietro
P
Mozzillo
E
E
Franzese
Adriana
A
D015502:Absorptiometry, Photon; D000293:Adolescent; D015415:Biomarkers; D001786:Blood Glucose / Q000378:metabolism*; D001827:Body Height; D001835:Body Weight; D015519:Bone Density / Q000502:physiology*; D001862:Bone Resorption / Q000209:etiology / Q000652:urine; D002648:Child; D003922:Diabetes Mellitus, Type 1 / Q000188:drug therapy* / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D008297:Male; D011726:Pyridinium Compounds / Q000652:urine; D013131:Spine / Q000000981:diagnostic imaging / Q000473:pathology*
D015415:Biomarkers; D001786:Blood Glucose; D006442:Glycated Hemoglobin; D011726:Pyridinium Compounds