Advanced Bone Disease as the Most Common Clinical Presentation of Primary Hyperparathyroidism In Iranians: Clinical And Laboratory Features of 62 Patients from North-Western Iran

The original studies of Albright and Reifenstein characterized primary hyperparathyroidism as a disease of bones and stones”. The disease at present is recognized most frequently as a totally asymptomatic condition, detection being based on the finding of hypercalcemia in the routine screening of serum calcium levels. The purpose of this cross sectional clinical case study was to analyze the clinical, biochemical, radiological, and pathological features of the disease in Irani- ans and to compare these features with those of patients from western countries. Materials and Methods: From 1985 through 2002, sixty-two patients with primary hyperparathy- roidism were studied from the north-western part of Iran. In addition to routine studies, the following evaluations were conducted; 1) meas- urements of serum calcium, phosphorous, alka- line phosphatase, creatinine and electrolytes; 2) X-rays of skull, hands, clavicles, pelvis, vertebral bones, abdomen, long bones, and dental film of lamina dura, and 3) Intravenous pyelogram and/or ultrasonography of kidneys. PTH was measured in only 29 patients because of lack of reliable laboratory methods during the earlier Correspondence: Amir Bahrami; Departments of In- ternal Medicine and Surgery Tabriz University of Medical Sciences, Tabriz, Iran, Address: P. O. Box 51335 – 1896, Tabriz, I.R.Iran E-mail: t.u.end.d@tbzmed.ac.ir years of the study. Surgery was performed in all subjects and they were followed postoperatively. Results: There were 52 females and 10 males, with a female to male ratio of 5.2:1, and an age range of 13 to 71 years with a mean age of 38/6 years. The peak incidence in both sexes was in the 4th decade. The vast majority of patients in this series presented with symptoms referable to skeletal involvement. Fifty-eight (93.5%) patients suffered from bone pains, deformities, patho- logic fractures, and localized bone tumors. Renal colic was a less frequent complaint; only in 4 pa- tients (6.4%) clinical renal disease led to the di- agnosis of hyperparathyroidism. No patient was asymptomatic. Fifty-four patients had persistent hypercalcemia. In 3 patients hypercalcemia was intermittent and 5 patients were normocalcemic. Mean serum calcium concentration was 11.2 mg/dl (range 9.3-15.6 mg/dl). A high proportion of the patients, 49 of 62, had low serum phospho- rus level. Mean serum phosphate concentration was 2.1 mg/dl (range 1.4-3.6 mg/dl). Interestingly, all 5 normocalcemic patients were hypophos- phatemic. Serum alkaline phosphatase level was elevated in 56 patients, and PTH concentration was high in all the 29 patients in whom it was measured. All patients displayed some ra- diologic changes. Subperiosteal resorption of phalanges and/or distal clavicles was the most frequent (43/62) radiologic finding. Salt and pepper appearance on skull x- rays, brown tumor 20 A. Bahrami et al. in pelvis, metacarpals, and long bones were other common radiologic features. Pathologic fractures were found in 32 patients, including vertebral collapse in 3 patients. The pathologic findings were single adenoma in 54 patients, double adenoma in 3 subjects, hyperplasia in 4 patients (2 patients with MEN –1 and one with MEN-2), and parathyroid carcinoma in 1 patient. Conclusion: This study shows that advanced bone disease is the most frequent clinical pres- entation of hyperparathyroidism in Iranians. Routine serum calcium measurement is recom- mended at least in high-risk patients, in particu- lar for females in their 4th – 5th decades of life.