Normal parathyroid function with decreased bone mineral density: DISCUSSION Part 2

DISCUSSIONAn analysis of parathyroid function disclosed similar functioning in patients and controls, with all four measured parameters (maximal secretory capacity, suppressible fraction of I-PTH secretion, sensitivity of PTH secretion to ionized calcium changes or slope, and the set point of I-PTH stimulation by ionized calcium) being alike in both groups. There was a nonsignificant difference of +0.02 mmol/L ionized calcium in the set point between patients and normal control subjects. Such a difference could be sufficient, on theoretical grounds, to explain the difference in basal I-PTH concentrations between the two groups but would require much larger groups to be demonstrated experimentally. Overall, these results are reassuring because they do not disclose a residual increase in parathyroid function once the disease is treated and/or reflect a complete correction of possibly pre-existing minimal secondary hyperparathyroidism. All of the patients in the present study had basal I-PTH within the normal range, and it is possible that those with slightly elevated values, as described in other studies, could have disclosed slightly increased parathyroid function. However, even these cases are far from the severe secondary hyperparathyroidism seen in experimental models of calcium and vitamin D deficiency in dogs, suggesting that celiac disease is rarely associated with severe secondary hyperparathyroidism.

The BMD results in our patients were similar to those described by others in comparable studies, with decreased values in one-third of patients both at the lumbar spine and femoral neck compared with normals of the same age and sex (Z score); 10 patients were also either osteopenic or osteoporotic (T score). Several factors, including age, height, weight and creatinine, could be related to BMD in our patients by regression analysis, but only body height or weight remained significant by multivariate or logistical regression analysis. BMD results were not adjusted for bone volume in our study, and this may have contributed to the relationship with height and weight. BMD results have not been adjusted in other studies dealing with celiac disease either. Many of these factors have been implicated in several investigations, including time of menopause. 25-hydroxy vitamin D, 1,25-dihydroxy vitamin D and I-PTH levels have also been implicated in some, but not all, investigations. The relatively small number of patients in our study may have precluded us from identifying some of these factors. Patients refractory to treatment may be important to explain the relationship between PTH and BMD. Furthermore, time since diagnosis or duration of treatment is not related to BMD in patients with celiac disease. Calcium and vitamin D supplementation does not seem to influence BMD beyond the effect of diet alone. There is a wonderful pharmacy offering cialis professional, and you can shop with it.

This study confirms that BMD at the hip and lumbar spine is still reduced in celiac disease after a mean treatment period of 5.7 years. Actual basal I-PTH values and parameters of parathyroid function have minimal influence on BMD in treated patients. There is no immunoassay evidence of residual secondary hyperparathyroidism in treated patients with celiac disease.


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