Hyperparathyroidism secondary to hypovitaminosis D in hypoalbuminemic is less intense than in normoalbuminemic patients: a prevalence study in medical inpatients in southern Brazil

• Published in: Endocrine Vol. 24; no. 1; pp. 47 - 53
• Main Authors: Premaor, Melissa Orlandin, Alves, Gustavo Vasconcelos, Crossetti, Ligia Beatriz, Furlanetto, Tania Weber
• Format: Journal Article
• Language: English
• Published: United States 01-06-2004
• Subjects: Albumins - analysis; Brazil - epidemiology; Calcium - blood; Cross-Sectional Studies; Female; Humans; Hyperparathyroidism, Secondary - blood; Hyperparathyroidism, Secondary - epidemiology; Hyperparathyroidism, Secondary - etiology; Hypoalbuminemia - blood; Hypoalbuminemia - complications; Hypoalbuminemia - epidemiology; Luminescent Measurements; Male; Middle Aged; Parathyroid Hormone - blood; Phosphorus - blood; Prevalence; Radioimmunoassay; Vitamin D - blood; Vitamin D Deficiency - blood; Vitamin D Deficiency - complications; Vitamin D Deficiency - epidemiology; Brazil
• ISSN: 1355-008X
• DOI: 10.1385/ENDO:24:1:047

Hypovitaminosis D has been reported in tropical countries, but this hormone has seldom been studied in Brazil. Our purpose was to study the prevalence of hypovitaminosis D in patients hospitalized in internal medicine wards in Southern Brazil. Possible associated factors were studied. We studied 81 adult patients in early spring. Mean serum 25(OH)D was 12 +/- 8.57 ng/mL; hypovitaminosis D was severe (< 10 ng/mL) in 27 (33.3%) patients, and moderate (> or = 10 ng/mL and < 20 ng/mL) in 36 (44.5%) patients. Clinical evaluation did not yield any data associated with hypovitaminosis D. Serum 25(OH)D levels of up to 20 ng/mL were associated with decreased mean serum total calcium (p = 0.001), ionized calcium (p = 0.01), and phosphorus (p = 0.044) levels, and increased mean serum PTH level (p = 0.001). In a multiple regression model, serum PTH level was independently affected by serum total calcium (p = 0.01), phosphorus (p = 0.009), and albumin (p = 0.009) levels. Hypovitaminosis D patients had lower mean serum albumin levels (p = 0.004), and serum 25(OH)D levels were directly correlated to serum albumin levels (p < 0.0001). Albumin influenced independently PTH response to hypovitaminosis D; normoalbuminemic hypovitaminosis D patients had higher mean serum PTH than hypoalbuminemic patients.
Hypovitaminosis D prevalence was very high in medical inpatients in Southern Brazil, in early spring. Nevertheless, secondary hyperparathyroidism was less intense in hypoalbuminemic hypovitaminosis D patients suggesting that in these patients free serum 25(OH)D was closer to normal.