Race is a major determinant of secondary hyperparathyroidism in uremic patients: comparative study of Blacks and Hispanics.

BACKGROUND

Racial differences in bone and mineral metabolism are characterized by higher circulating intact parathyroid hormone levels (iPTH) in Black vs. White patients with end-stage renal disease (ESRD). The susceptibility of Hispanic patients to secondary hyperparathyroidism is not known.

METHOD: This is a cross-sectional study that compares bone and mineral parameters of 48 Black and 61 Hispanic ESRD patients attending a single outpatient hemodialysis center.

RESULT: The mean iPTH level was significantly higher in Blacks vs. Hispanics, despite similar levels of serum bone-specific alkaline phosphatase (BSAP), calcium, phosphorus and similar dosages of vitamin D analogs. After adjusting for independent variables including age, diabetic status and plasma levels of C-reactive protein, phosphorus and albumin significant predictors of iPTH were race (p < 0.01), gender (p < 0.05), serum calcium (p < 0.05), BSAP (p < 0.0001) and doses of vitamin D analogs (p < 0.001). Adjusted predictors of serum BSAP were PTH (p < 0.0001), gender (p = 0.01) and serum albumin (p < 0.005), but not race. There was no significant difference in serum BSAP between Blacks and Hispanics despite 60% higher iPTH levels in Blacks.

CONCLUSIONS

Amongst ESRD patients, Blacks have higher iPTH levels compared with Hispanics despite similar BSAP levels, these finding support the emerging evidence of racial/ethnic differences in response of bone to PTH action.