Secondary hyperparathyroidism and bone turnover in elderly blacks and whites

This study was undertaken to describe the prevalence of secondary hyperpara thyroidism in African-American and Caucasian participants in the Boston Low -Income Elderly Osteoporosis Study and to examine and compare associations of hyperparathyroidism with biochemical markers of bone turnover and bone d ensity in the two racial groups. Serum osteocalcin and serum cross-linked N -telopeptides of type I collagen, and calcaneal bone mineral density were m easured in February or March in 255 men and women, 64 yr of age and older. Subjects were categorized as normal or as having hyperparathyroidism, based on a serum PTH concentration below or above the top of the normal range (6 .9 pmol/liter), respectively. The prevalence of hyperparathyroidism was 38% in the 144 black subjects and 20% in the Ill white subjects. Serum osteoca lcin and cross-linked N-telopeptides of type I collagen were significantly higher in both black and white hyperparathyroid subjects (P < 0.05), and th e hyperparathyroid-related difference in osteocalcin was greater among blac k than white subjects. Hyperparathyroidism was significantly associated wit h reduced heel bone mineral density in blacks (P = 0.008) but not in whites . This study provides evidence that secondary hyperparathyroidism is preval ent in elderly adults, both black and white, and that it should not be view ed as a benign condition in either group. Recent public health efforts to p romote higher calcium and vitamin D intakes, targeted predominantly to olde r Caucasians, should also be directed to older African-Americans.