Hypovitaminosis D in medical inpatients.

BACKGROUND: Vitamin D deficiency is a major risk factor for bone loss and fracture. Although hypovitaminosis D has been detected frequently in elderly and housebound people, the prevalence of vitamin D deficiency among patients hospitalized on a general medical service is unknown. METHODS: We assessed vitamin D intake, ultraviolet-light exposure, and risk factors for hypovitaminosis D and measured serum 25-hydroxyvitamin D, parathyroid hormone, and ionized calcium in 290 consecutive patients on a general medical ward. RESULTS: A total of 164 patients (57 percent) were considered vitamin D-deficient (serum concentration of 25-hydroxyvitamin D, < or = 15 ng per milliliter), of whom 65 (22 percent) were considered severely vitamin D-deficient (serum concentration of 25-hydroxyvitamin D, <8 ng per milliliter). Serum 25-hydroxyvitamin D concentrations were related inversely to parathyroid hormone concentrations. Lower vitamin D intake, less exposure to ultraviolet light, anticonvulsant-drug therapy, renal dialysis, nephrotic syndrome, hypertension, diabetes mellitus, winter season, higher serum concentrations of parathyroid hormone and alkaline phosphatase, and lower serum concentrations of ionized calcium and albumin were significant univariate predictors of hypovitaminosis D. Sixty-nine percent of the patients who consumed less than the recommended daily allowance of vitamin D and 43 percent of the patients with vitamin D intakes above the recommended daily allowance were vitamin D-deficient. Inadequate vitamin D intake, winter season, and housebound status were independent predictors of hypovitaminosis D in a multivariate model. In a subgroup of 77 patients less than 65 years of age without known risk factors for hypovitaminosis D, the prevalence of vitamin D deficiency was 42 percent. CONCLUSIONS: Hypovitaminosis D is common in general medical inpatients, including those with vitamin D intakes exceeding the recommended daily allowance and those without apparent risk factors for vitamin D deficiency.

A comparison of lateral versus anterior-posterior spine dual energy x-ray absorptiometry for the diagnosis of osteopenia.

Because bone mineral density (BMD) measurements at various sites differ in the relative amounts of cortical and trabecular bone that they assess, they also differ in their sensitivity for detecting osteopenia. Lateral spine dual energy x-ray absorptiometry (DXA) allows measurement of BMD of the vertebral bodies, which contain mainly trabecular bone, without contribution from the posterior vertebral elements, which are rich in cortical bone. Thus, we hypothesized that lateral spine DXA would detect osteopenia more frequently than anterior-posterior (AP) spine DXA. To assess the ability of DXA to estimate trabecular bone mass, we compared AP and lateral DXA spine measurements with trabecular bone measurements by quantitative computed tomography (QCT) in 58 patients. We then compared AP vs. lateral spine DXA measurements in 1) 300 women referred for routine bone densitometry, 2) 30 glucocorticoid-treated women, and 3) 44 women with vertebral compression fractures. To compare short term reproducibility, we performed repeat AP and lateral DXA scans in 50 women. The association between QCT and DXA measurements was stronger when DXA measurements were made in the lateral (r = 0.784) or midlateral (r = 0.823) projection than in the AP (r = 0.571) projection. The association of BMD with age was stronger when DXA measurements were made in the lateral (r = 0.536) or midlateral (r = 0.536) projection than in the AP (r = 0.382) projection. The declines in BMD with age for AP, lateral, and midlateral DXA measurements were 0.48%, 0.60%, and 0.88%/yr, respectively. In the women referred for routine densitometry, lateral DXA measurements were significantly (P < 0.05) more abnormal than AP measurements compared with those in young women. This was also true in the women treated with glucocorticoids and women with vertebral compression fractures. Lateral DXA often detected osteopenia in patients whose AP DXA was normal. The 95% confidence limits for changes in BMD attributable to measurement error for AP, lateral, and midlateral DXA were 0.027, 0.038, and 0.057 g/cm2, respectively. These results indicate that lateral DXA measurements identify patients with osteopenia more often than AP DXA measurements, probably because lateral DXA more accurately estimates trabecular bone mass. Short term reproducibility of lateral DXA is nearly as good as that for AP DXA.

Diagnostic use of recombinant human thyrotropin in patients with thyroid carcinoma (phase I/II study).

Current diagnostic studies [radioiodine uptake and serum thyroglobulin (Tg) levels] for residual or metastatic thyroid tissue in patients with differentiated thyroid carcinoma require a hypothyroid status necessary for adequate endogenous TSH stimulation. However, almost all patients have symptoms of clinical hypothyroidism during this period. As shown in the present study, recombinant human TSH (rhTSH) allows stimulation of 131I uptake and Tg release from residual thyroid tissue in euthyroid patients. To assess safety, dosage, and preliminary efficacy, comparison was made of the stimulation of 131I uptake and Tg release after rhTSH administration and after T3 withdrawal in 19 patients after a recent thyroidectomy for differentiated thyroid carcinoma. Various doses (10-40 U) of rhTSH were injected im for 1-3 days in patients receiving suppressive doses of T3. Twenty-four hours after the last dose of rhTSH, 1-2 mCi 131I were administered, followed by a neck and whole body scan 48 h later. After discontinuing T3 for a median period of 19 days (range, 15-28), endogenous serum TSH levels were markedly elevated, and the patients were given a second dose of 131I and rescanned 48 h later. The injections of rhTSH were tolerated well. No major adverse effects were reported; nausea was reported in 3 (16%) and vomiting in 1 of the patients treated with high doses. The quality of life, as measured by two psychometric scales, was far better during rhTSH treatment than after T3 withdrawal. The peak levels of serum TSH (mean +/- SD) after a single dose of 10, 20, or 30 U were 127 +/- 19, 309 +/- 156, and 510 +/- 156 mU/L, respectively, and occurred 2-8 h after injection. Twenty-four hours after the injection, TSH levels decreased to 83 +/- 31, 173 +/- 73, and 463 +/- 148 mU/L in these treatment groups, respectively. The quality of the thyroid scans and the number of sites of abnormal 131I uptake were similar after rhTSH treatment and in the hypothyroid scans in 12 (63%) patients. Two additional sites of uptake in the chest and one in the thyroid bed, not visible on the hypothyroid scans, were identified in 3 (16%) patients after rhTSH. In 1 patient a focus of uptake was better visualized after rhTSH than after withdrawal. In 3 (16%) other patients, 1 lesion in the chest and 2 in the neck were seen only after T3 withdrawal.(ABSTRACT TRUNCATED AT 400 WORDS)