High prevalence of secondary hyperparathyroidism due to hypovitaminosis D in hospitalized elderly with and without hip fracture.
OBJECTIVE
To determine and compare the prevalence of secondary hyperparathyroidism (HPTH) in a population of community-dwelling and institutionalized older adults hospitalized with and without hip fracture, and to evaluate factors correlated with secondary HPTH in this population.


METHODS
Circulating concentrations of serum intact PTH, 25-hydroxyvitamin D [25(OH)D] total serum calcium and albumin were measured in 160 subjects with an osteoporotic fracture of the proximal femur and in 160 matched controls hospitalized for a disease unrelated to bone status. Patients with secondary causes of bone loss and taking medications affecting bone metabolism were excluded. Age, sex, place of residence and the ability to perform basic activities of daily living (BADL) two weeks before hospital admission were recorded at baseline.


RESULTS
Patients were comparable with regard to the baseline demographic, biochemical and functional characteristics. The overall prevalence of secondary hyperparathyroidism was 51.2%, without significant differences between hip fractured patients and controls (50.6 vs 51.9%, p=0.911). In bivariate analysis only the age and functional status (BADL) demonstrated a significant relationship with secondary HPTH, while sex and place of residence were not significant. These results were also confirmed in multivariate analysis. Particularly, the risk of secondary HPTH increased with age and with the number of functions lost in BADL: patients fully dependent showed a 3 times as high risk (odd ratio 3.07, 95% confidence interval 1.73 to 5.46, p=0.000) compared to patients independent in BADL, and subject aged >88 yr had a twice as high risk of developing secondary HPTH compared to younger ones (odd ratio 2.28, 95% confidence interval 1.20 to 4.32, p=0.012).


CONCLUSIONS
These results show that secondary HPTH due to hypovitaminosis D is a frequent disorder in hospitalized elderly, strongly correlated with the functional status, irrespective of sex and place of residence.
Giusti
A
A
Department of Gerontology and MusculoSkeletal Sciences, E.O. Galliera Hospital, 16100 Genoa, Italy.
Barone
A
A
Razzano
M
M
Pizzonia
M
M
Oliveri
M
M
Palummeri
E
E
Pioli
G
G
D000368:Aged; D000369:Aged, 80 and over; D000418:Albumins / Q000032:analysis; D002118:Calcium / Q000097:blood; D016022:Case-Control Studies; D005260:Female; D006620:Hip Fractures / Q000097:blood / Q000453:epidemiology* / Q000209:etiology; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000097:blood / Q000453:epidemiology* / Q000209:etiology*; D008297:Male; D015663:Osteoporosis, Postmenopausal / Q000097:blood / Q000150:complications / Q000453:epidemiology; D010281:Parathyroid Hormone / Q000097:blood; D015995:Prevalence; D012111:Residence Characteristics; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000150:complications* / Q000453:epidemiology
D000418:Albumins; C470125:PTH protein, human; D010281:Parathyroid Hormone; D014807:Vitamin D; C104450:25-hydroxyvitamin D; D002118:Calcium