A slight decrease in renal function further impairs bone mineral density in primary hyperparathyroidism.
BACKGROUND
The impairment of renal function can affect the clinical presentation of primary hyperparathyroidism (PHPT), increasing cardiovascular morbidity, fracture rate, and the risk of mortality.


OBJECTIVE
The aim of the study was to assess the differences in bone status in a series of consecutive patients affected by PHPT without overt renal failure at diagnosis grouped according to creatinine clearance (Ccr).


METHODS
A total of 161 consecutive patients with PHPT were studied. They were divided into two groups based on Ccr. Group A had Ccr 70 ml/min or less (n = 49), and group B had Ccr greater than 70 ml/min (n = 112). PTH, total and ionized serum calcium; urinary calcium and phosphate; serum 25-hydroxyvitamin D3; serum and urinary bone markers; lumbar, forearm, and femoral bone mineral density (BMD) were evaluated.


RESULTS
Patients in group A were older than those in group B (P < 0.0001). PTH levels did not differ in the two groups, whereas both urinary calcium and phosphorus were lower in group A than group B (P < 0.01). Lower BMD was evident in group A at lumbar spine (P < 0.002), forearm (P < 0.0001), and femur (P < 0.01). In asymptomatic PHPT, those with Ccr 70 ml/min or less had lower forearm BMD than patients with higher Ccr (P < 0.00001). When adjusting for age and body mass index in PHPT, BMD at each site persisted being lower (P < 0.05) in group A than group B. In all PHPT subjects, Ccr (beta = 0.29, P < 0.0005), age (beta = -0.27, P < 0.00001), and PTH levels (beta = -0.27, P < 0.0005) were all independently associated with forearm BMD.


CONCLUSIONS
In PHPT a slight decrease in renal function is associated with more severe BMD decrease, independent of age, body mass index, and PTH levels. This association is also present in asymptomatic PHPT and strengthens the National Institutes of Health recommendations for surgery in patients with mild PHPT.
Gianotti
Laura
L
Division of Endocrinology and Metabolism, Department of Internal Medicine, S. Croce and Carle Hospital, Via M. Coppino 26, 12100 Cuneo, Italy.
Tassone
Francesco
F
Cesario
Flora
F
Pia
Anna
A
Razzore
Paola
P
Magro
Giampaolo
G
Piovesan
Alessandro
A
Borretta
Giorgio
G
D000328:Adult; D000368:Aged; D015992:Body Mass Index; D015519:Bone Density; D002112:Calcifediol / Q000097:blood; D002118:Calcium / Q000097:blood / Q000652:urine; D003404:Creatinine / Q000378:metabolism; D005260:Female; D005269:Femur; D005340:Fibrinogen / Q000032:analysis; D005542:Forearm; D005919:Glomerular Filtration Rate; D006801:Humans; D049950:Hyperparathyroidism, Primary / Q000503:physiopathology*; D007668:Kidney / Q000503:physiopathology*; D008159:Lumbar Vertebrae; D008297:Male; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood; D010710:Phosphates / Q000652:urine; D012044:Regression Analysis
D010281:Parathyroid Hormone; D010710:Phosphates; D005340:Fibrinogen; D003404:Creatinine; D002112:Calcifediol; D002118:Calcium