Basal glucometabolic status has an impact on long-term prognosis following an acute myocardial infarction in non-diabetic patients.

OBJECTIVES: Patients with diabetes are known to have a worse prognosis after an acute myocardial infarction (AMI) compared with non-diabetic patients. The primary aim of this study was to investigate the effect of glucometabolic status on long-term prognosis in non-diabetic patients with an AMI. The second aim was to evaluate the extent to which blood glucose levels at admission depended on acute stress, assessed as serum cortisol, previous glucometabolic status, measured as haemoglobin A1c (HbA1c), or both. DESIGN: In a prospective study of patients with an AMI, blood glucose, HbA1c and cortisol were measured at admission. Fasting blood glucose was determined before discharge and also afterwards, if necessary, for classification. Patients were followed-up for 5.5 years. SUBJECTS: Of the 305 consecutive patients 24% were diagnosed as diabetic and 76% as non-diabetic. MAIN OUTCOME MEASURES: Death or non-fatal myocardial re-infarction. RESULTS: In non-diabetic patients, a Cox regression model was used. With death or re-infarction as endpoint, the following prognostic factors had an impact on event-free survival: age (P<0.001), HbA1c (P=0.002), cortisol (P<0.001) and thrombolytic treatment (P=0.001). There was a correlation between cortisol and blood glucose at admission (r=0.44, P<0.001). Fasting blood glucose day 5 showed no association with event-free survival. CONCLUSIONS: In non-diabetic patients with AMI, admission HbA1c and cortisol were predictors for 5.5-year survival without recurrent non-fatal myocardial infarction. The glucometabolic status of importance for prognosis was detected by HbA1c but not by fasting blood glucose or admission blood glucose, of which the latter was influenced by cortisol.

[Laboratory diagnosis of gastrinoma. Nordic collaboration can improve the quality]. / Laboratoriediagnostik av gastrinom. Nordiskt samarbete kan ge ökad säkerhet.

Measurement of gastrin in serum or plasma in patients with gastrinoma may be complicated by the presence of circulating biosynthetic intermediates which may not be detected by commonly available immunoassays. In contrast, the "processing-independent analysis" of gastrins developed by professor Jens Rehfeld et al in Copenhagen detects gastrin forms irrespective of their size. The authors review gastrinoma pathophysiology, the biochemistry of gastrin and other biomarkers of gastrinoma, the differential diagnosis of hypergastrinemia as well as other methods currently employed in the workup of gastrinoma patients, and illustrate with a clinical case.

[How reliable is the laboratory? Increased needs of patient-related quality assurance]. / Kan man lita på laboratoriet? Okat behov av patientrelaterad kvalitetssäkring. Expertgruppen för endokrinologi inom EQUALIS.

Recent developments in medical care and research involve the increased use of immunochemical assays for hormones, tumour markers, vitamins and drugs. External quality assurance programmes using pooled human sera usually fail to detect analytical interference due to substances (e.g. anti-immunoglobulin or anti-ligand antibodies) present in individual serum specimens. The article reports on experience gained during a three-year period when specimens from individual patients attending a thyroid unit were distributed to hospital laboratories in Sweden for analysis. Specimen selection criteria were based on contradictory findings at the initial clinical or laboratory evaluation. The programme has given rise to the formation of a network of the laboratories involved, under the co-ordination of EQUALIS (External quality assurance in laboratory medicine in Sweden).

Is a more active attitude warranted in patients with subclinical thyrotoxicosis?

In 1985 one of the new sensitive thyroid stimulating hormone (TSH) assays was introduced as part of our laboratory routine for thyroid function testing. Consequently, we now routinely identify a small but not insignificant group of patients with 'subclinical thyrotoxicosis', i.e. a low serum TSH in conjunction with a normal serum free T4. We here present the results of a 2-year follow-up investigation, which includes 40 patients with subclinical thyrotoxicosis and 40 euthyroid control patients. The group with subclinical thyrotoxicosis was characterized by a mean age of 65 years and a high prevalence of nodular goitre. Twelve (30%) of the patients but none of the individuals in the control group were treated during the follow-up period because of clinical thyroid disease. Atrial fibrillation was found in 11 (28%) patients compared to four (10%) of the controls. Therapy should be considered more often than previously in patients with nodular goitre and subclinical thyrotoxicosis, particularly in conjunction with atrial fibrillation.

Influence of endogenous T3-autoantibodies on thyroid hormone measurements in a woman with transient postpartum thyroiditis.

Unreliable estimates of serum total T3 due to the presence of autoantibodies against T3 were observed in a woman who developed thyrotoxicosis followed by transient hypothyroidism after childbirth (postpartum thyroiditis). The T3 autoantibody levels changed during the postpartum period in a similar way to the thyroid microsomal antibodies. The total T3 values were constantly low, whereas the measurement of free T3 by the Amerlex analogue method deviated from the expected only at the time of maximal antibody levels. Thus, evaluation of thyroid function may be complicated by the simultaneous presence of thyroid hormone autoantibodies and transient postpartum thyroiditis.

Free thyroxin index and direct measurements of free thyroxin compared for evaluating postpartum autoimmune thyroid dysfunction.

Measurement of free thyroxin (FT4) by a recently introduced commercial assay (Amerlex Free T4 RIA) was compared with the calculated free thyroxin index (FT4I) for serum from 104 postpartum women. Of these, 63 had transient thyroid dysfunction due to autoimmune thyroiditis, six had transient Graves' thyrotoxicosis, and 35 were euthyroid with no signs of autoimmune thyroid disease. The correlation between results for FT4 and the calculated FTI for 95 serum samples from women with no signs of autoimmune thyroiditis (r = 0.941; p = 0.0001) was almost identical to that for 270 serum samples from women with thyroid microsomal autoantibodies characteristic of autoimmune thyroiditis (r = 0.937; p = 0.0001). Furthermore, we observed no difference when the autoimmune group was subdivided according to low or high titers of thyroid microsomal antibodies. In no case did autoantibodies to thyroxin interfere with the FT4 assay. However, one woman had a spuriously low value for FT4I owing to interference by autoantibodies to triiodothyronine with the triiodothyronine resin uptake test. We conclude that the FT4 RIA assay provided diagnostic information in this group of postpartum women equivalent to that of the more elaborate procedure of determining FT4I.