This study aimed to determine differences in the rates of growth, endocrine- and
calcium-related abnormalities in the various
thalassemia syndromes in North America treated with current
therapies. Medical history, physical examinations and blood and urine collections were obtained from patients with all
thalassemia syndromes age 6 years and older in the
Thalassemia Clinical Research Network. 361 subjects, 49% male, mean age 23.2 years (range 6.1-75 years) were studied. Approximately 25% of children and adults, regardless of the
thalassemia syndrome, had short stature. Overall growth in children was mildly affected. Final height was close to midparental height (z = -0.73 +/- 1.24). Patients with
beta thalassemia major (TM) had higher rates of
hypogonadism, multiple endocrinopathies, worse hyperglycaemia, subclinical
hypoparathyroidism and
hypercalciuria.
Hypogonadism remained the most frequent endocrinopathy and was frequently under-treated. 12.8% of the subjects had 25
vitamin D concentrations less than 27 nmol/l and 82% less than 75 nmol/l, regardless of the
thalassemia syndrome. Adolescents had lower 25
vitamin D levels than children and adults. Compared to patients with other
thalassemia syndromes, those with beta TM suffered from higher rates of multiple endocrinopathies, abnormal
calcium metabolism and
hypercalciuria.
Vitamin D abnormalities were high among adolescents.