RESUMO
The vitamin D status of 181 elderly Irish community-dwelling and institutionalized subjects was studied during Winter-Spring. The mean serum 25-hydroxyvitamin D level was 10 nmol/L (95% range less than 5.0-59 nmol/L); values were below 25 nmol/L in 79 percent of subjects. A significant seasonal variation of serum 25-hydroxyvitamin D levels was noted in elderly community-dwelling subjects. The previously documented age-related increase in serum alkaline phosphatase activity was significantly less in vitamin D replete subjects than in vitamin D deplete subjects in this study (P less than 0.005). The higher serum alkaline phosphatase values found in the vitamin D deplete subjects may represent mild secondary hyperparathyroidism or osteomalacia. The relationship of vitamin D status to both dietary intake and effective sunlight (latitude) is examined.
Assuntos
Fosfatase Alcalina/sangue , Deficiência de Vitamina D/epidemiologia , Idoso , Calcifediol/sangue , Feminino , Humanos , Irlanda , Masculino , Pessoa de Meia-Idade , Estações do Ano , Luz Solar , Deficiência de Vitamina D/sangue , Deficiência de Vitamina D/enzimologiaRESUMO
Data from a retrospective study in 41 patients is used to suggest an index of bone disease. This is designed as a means of collating available results, clarifying the significance of each in diagnosing either osteomalacia or osteoporosis, and reducing the significance of a single abnormal finding--for example, a raised alkaline phosphatase activity or low serum 25 hydroxy vitamin D, when the overall index score is low. Index scores above 35% would be diagnostic of osteomalacia; scores below 15% if associated with collapsed vertebrae suggest osteoporosis. Scores between 15% and 35% would indicate the need for a bone biopsy to discriminate between osteoporosis and osteomalacia.
Assuntos
Osteomalacia/diagnóstico , Osteoporose/diagnóstico , Adolescente , Adulto , Idoso , Diagnóstico Diferencial , Estudos de Avaliação como Assunto , Feminino , Humanos , Masculino , Métodos , Pessoa de Meia-Idade , Probabilidade , Estudos RetrospectivosRESUMO
We studied six patients with renal stone disease, hypercalciuria, cystinuria and/or hyperuricosuria, during variations in dietary Na and Cl intake. Switching between equimolar NaCl and NaHCO3 intakes reduced urinary Ca (UCa) during the NaHCO3 phase, despite steady-state urinary Na. Switching between equimolar NaCl and KCl did not change UCa, despite a sharp fall in UNa. The results suggest a predominant role for Cl rather than Na ions during sodium-chloride-induced changes in UCa. In stone disease of mixed aetiology, where alkalinization of the urine as well as reduction in UCa may be desirable, treatment with NaHCO3 loading is not accompanied by a rise in UCa, provided that dietary Cl is maintained moderately low at 80-100 mmol/day. The mechanism whereby Cl intake influences UCa remains undefined. Plasma PTH and calcitriol levels showed no significant alteration, and atrial natriuretic peptide levels in one patient remained unchanged.
Assuntos
Cálcio/urina , Cálculos Renais/metabolismo , Cloreto de Sódio na Dieta/metabolismo , Cloretos/urina , Cistinose/metabolismo , Humanos , Cálculos Renais/terapia , Bicarbonato de Sódio/administração & dosagem , Cloreto de Sódio na Dieta/administração & dosagem , Ácido Úrico/urinaRESUMO
The relationship of ionised calcium measurement to changes in serum total protein and albumin were studied both in vivo and in vitro. During venostasis serum ionised calcium was determined in 10 control subjects using an Orion SS20 analyser. A slight but significant increase in ionised calcium occurred only after prolonged venostasis (15 min), when gross changes in total protein and albumin were seen. The effect of albumin concentration on serum ionised calcium was studied in vitro by the dialysis technique of Payne. The increase in ionised calcium in 40 sera was 0.0198 mmol/l per 10 g albumin change. We conclude that albumin-related variation in serum ionised calcium determination required such gross changes that correction is rarely necessary in clinical practice. When gross albumin alteration occurs, the appropriate correction for the analyser used should be determined and applied.
Assuntos
Cálcio/sangue , Albumina Sérica/análise , Adulto , Cátions Bivalentes , Eletrodos , HumanosRESUMO
In this prospective study we examined 100 consecutive in-patients found to have a blood urea concentration greater than 13.3 mmol/l (80 mg/dl) or a serum creatinine concentration greater than 176 µmol/l (2 mg/dl).Pre-renal causes were responsible in 32 of these patients and there was a 40% mortality rate in this subgroup of patients after one month follow up.In 14 cases inappropriate administration of diuretics was a major cause of blood urea elevation.