Screening for Addison's disease in patients with type 1 diabetes mellitus and recurrent hypoglycaemia.

BACKGROUND: Addison's disease may present with recurrent hypoglycaemia in subjects with type 1 diabetes mellitus. There are no data, however, on the prevalence of Addison's disease presenting with recurrent hypoglycaemia in patients with diabetes mellitus. METHODS: Three year retrospective study of diabetic patients with "unexplained" recurrent hypoglycaemia investigated with a short Synacthen test to exclude adrenocortical insufficiency. RESULTS: 95 patients with type 1 diabetes mellitus were studied. Addison's disease was identified as the cause of recurrent hypoglycaemia in one patient with type 1 diabetes mellitus. CONCLUSION: Addison's disease is a relatively rare but remedial cause of recurrent hypoglycaemia in patients with type 1 diabetes mellitus. A low threshold for investigating patients with type 1 diabetes mellitus and recurrent hypoglycaemia to detect Addison's disease is therefore suggested.

The sweat test: effect of elution time on chloride and sodium concentrations.

BACKGROUND: The National Committee for Clinical Laboratory Standards guidelines and Guidelines for the Performance of the Sweat Test for the Diagnosis of Cystic Fibrosis in the United Kingdom recommend that sweat be eluted from filter paper for a minimum of 40 min. In the absence of published data, this recommendation is based on expert opinion. We therefore investigated the effect of elution time on chloride and sodium concentrations. METHODS: The effect of elution time (up to three hours) on chloride and sodium concentrations was studied as recommended for measurement of quality control samples using external quality assessment solutions. RESULTS: There were no significant differences in eluted chloride and sodium concentrations with time of elution up to 3 h. CONCLUSION: Elution time within 3 h had no effect on chloride and sodium concentrations when eluted from filter paper.

Comparison of original (2003) and revised (2008) national guidelines for reporting of cerebrospinal fluid spectrophotometric scanning for suspected subarachnoid haemorrhage against patient outcome.

BACKGROUND: National guidelines for cerebrospinal fluid (CSF) analysis and its reporting in suspected subarachnoid haemorrhage (SAH) were published in 2003, but revised in 2008 to give greater clarity in interpretation. It is not known whether the less ambiguous reporting of 2008 guidelines may lead to a false assurance and adversely affect patient outcome. We, therefore, re-interpreted scans reported under the 2003 guidelines, using the 2008 guidelines and compared these reports against final diagnosis and patient outcome obtained from a retrospective case-note review audit. METHODS: We identified requests for CSF xanthochromia studies from the laboratory system between September 2006 and August 2007. Spectroscopy scans were then retrieved and re-interpreted using the 2008 guidelines. The original reports and re-interpreted scans were compared against diagnosis and patient outcome using case-note review. RESULTS: We received 93 requests for CSF spectroscopy on 90 patients. Fourteen requests were not processed due to insufficient sample, but of these three patients had a repeat lumbar puncture (LP). Two further requests were not processed at the request of the clinician as they were no longer clinically indicated. Therefore, 77 spectroscopic scans were re-interpreted. The revised guidelines re-classified 11 previously equivocal scans into the not supportive of SAH category. On case-note review, one patient had a subsequent fatal SAH. The remaining 10 were given non-SAH final diagnoses and none had similar further inpatient episodes for at least 12 months and up to 18 months following LP. CONCLUSIONS: The revised (2008) national guidelines for the analysis of CSF in suspected SAH offer greater clarity in reporting without adversely affecting patient outcome.

Ethnic differences in umbilical cord blood vitamin D and parathyroid hormone--South Asians compared to Whites born in the UK.

Serum calcium, 25-hydroxyvitamin D (25OHD) and parathyroid hormone (PTH) were measured in umbilical cord blood samples taken from 54 White and 22 South Asian babies born in the UK during the summer months. South Asians had lower serum calcium (p < 0.0027) and 25OHD (p < 0.0002) than Whites. Serum PTH was low in all subjects, but South Asians had relatively higher concentrations of serum PTH (p < 0.001) than Whites. The lower vitamin D and calcium in South Asian newborns is not associated with secondary hyperparathyroidism as previously reported but may still explain their increased prevalence of neonatal hypocalcaemia and rickets.