201307_Determination of Frequency

Determination of Frequency of Vitamine D deficiency in Acromegalic
patients compared to control healthy subjects
Lídia Freire Abdalla², Daniel Higor Barros¹, Cyra Mesquita de Araújo², Anderson Rodrigues²,
Gabriella Soares Mota¹, Sandra Santana Soares Costa², Luciana Ansaneli Naves¹,².
¹Endocrine Unit, University of Brasilia, ²Laboratório Sabin de Analises Clinicas
BACKGROUND
Acromegaly is a rare endocrine disorder, related to hypersecretion of growth hormone (GH) and insulin like growth fator-1 (IGF-1), with important effects on bone and articular diseases. These tissues are very sensitive to
calcium metabolism, and the role of PTH, and vitamin D on osteoarthicular disorders is not clear. Recent studies suggested that rises on IGF-1 can influence 25 (OH) vitamine D plasma levels. The first line medical treatment for
Acromegaly concerns the somatostatin analogs, that may be related to lipossoluble vitamin bowel loss.
OBJECTIVE
Evaluate the relation between activity of Acromegaly and calcium metabolism.
SUBJECTS AND METHODS
We recruited 37 patients with active acromegaly, recruited from neuroendocrine outpatient clinics of Hospital of University of Brasilia. They were submitted to venopunction, and blood samples were collected to evaluate 25OHD
(chemiluminescence, Diasorin), Calcium, PTH 1,25 (OH) vitamine D GH and IGF-1 (chemiluminescence, Immulite), and D-xilose test. The patients were submitted to a washout of three months from medical treatment (group 1)
and group 2 was composed by the same patients treated by somatostatin analogs for three months. The data was compared to a control group of 200 healthy subjects paired for age and gender.
RESULTS
The mean age was 49 + 12 years, 48.5% were men. Most of patients presented elevated IGF-1 levels, and upper limit normal variation was 143.0±86.5 % (36.4-450.5). PTH was 52.5±27.1 (19.2-137), Calcium 9.2±0.46 (7.710.2), 25(OH) vitamine D 22.9±11.7 (8.8-34.6). Vitamine D< 30 ng/ml was observed in 82,8% of Acromegalic patients, and 76% of healthy subjects. 25(OH) vitamine D < 20ng/ml, was observed in 54.2% of Acromegalic patients,
compared to 32.1% of control patients (p<0,02). Only 28.6% of patients presented levels 20-30 ng/ml and 17,6% of patients were considered sufficient, with 25 (OH) vitamine D> 30 ng/ml.
Table 1: Acromegalic patients Group 1(three months of washout) and Group 2 (three months of treatment with somatostatin analogs)
Vitamin D
Ca++
PTH
D-xilose
Group 1
27,7±8,2 (13,7-49,4)
9,5±0,36(9-10,3)
54,2±61,0(15,1-333)
40,0±7,0(30-53)
Group 2
28,78±9,28(15,1-47,9)
9,4±0,39(8,9-10,2)
68,1±53,1(26-295)
35,4±10,7(21-54)
0,61
0,27
0,0125*
0,0463*
P
Figure 1: Comparison between IGF-1 levels before and after Somatostatin Analogs Treatment.
Figure 2: Comparison between D-Xylose test levels before and after Somatostatin Analogs Treatment.
DISCUSSION AND CONCLUSION
The frequency of vitamine D deficiency in Acromegalic patients was high, but no association was found with IGF-1 levels and type of treatment. Other studies have to be done to determinate the impact of vitamine D deficiency on
acromegalic ostheoarthicular disease. The treatment with somatostatin analogs may be involved in intestinal loss of vitamin D, and the adequate replacement should be considered in these group of patients.
REFERÊNCIA
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