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Øyvind Skadberg

Publications and source records attributed to Øyvind Skadberg.

3 recordsLinked to original sources
PubMed2005

Albumin-corrected or ionized calcium in renal failure? What to measure?

BACKGROUND: Secondary hyperparathyroidsm is frequently observed in patients with chronic renal failure, and clinical treatment guidelines have been published. Despite this, a large proportion of patients do not reach the target levels for calcium, phosphorus, calcium x phosphorus product, or intact parathyroid hormone. The use of albumin-corrected calcium is recommended as calcium measurement, but it is the concentration of ionized calcium that is biologically active. We hypothesized that in clinical practice, the use of ionized calcium rather than albumin-corrected calcium would influence the calcium classification of the individual patient. METHODS: Blood samples from 34 patients in chronic haemodialysis were analysed for evaluation of mineral metabolism according to K/DOQI guidelines. Blood for analysis of total and ionized calcium was drawn simultaneously. As ionized calcium is pH dependent, samples were analysed at the actual pH of the individual patient. RESULTS: For both methods, a similar number of patients were characterized as normocalcaemic. The use of albumin-corrected calcium caused one patient (3%) to be classified as hypocalcaemic, and 10 patients (26%) as hypercalcaemic whereas with ionized calcium, five (15%) and three patients (9%) were classified as hypo- and hypercalcaemic, respectively. CONCLUSIONS: According to present guidelines, the difference in calcium classification of patients might have clinical implications for the prescription of vitamin D, and on the choice of phosphate binders.

Adolescent↗
PubMedDate not supplied

Haplotype analysis of Norwegian and Swedish patients with acute intermittent porphyria (AIP): Extreme haplotype heterogeneity for the mutation R116W.

Acute intermittent porphyria (AIP), the most common of the acute porphyrias, is caused by mutations in the gene encoding hydroxymethylbilane synthase (HMBS) also called porphobilinogen deaminase (PBGD). The mutation spectrum in the HMBS gene is characterized by a majority of family specific mutations. Among the exceptions are R116W and W198X, with high prevalence in both the Dutch and Swedish populations. These two mutations were also detected in unrelated Norwegian patients. Thus, Norwegian and Swedish patients were haplotyped using closely linked flanking microsatellites and intragenic single nucleotide polymorphisms (SNPs) to see if the high frequency of these two mutations is due to a founder effect. Twelve intragenic SNPs were determined by a method based on fluorescent restriction enzyme fingerprinting single-strand conformation polymorphism (F-REF-SSCP). W198X occurred exclusively on one haplotype in both Norwegian and Swedish patients, showing that it has originated from a common gene source. In contrast, R116W was found on three different haplotypes in three Norwegian families, and in five Swedish families on four or five haplotypes. This extreme haplotype heterogeneity indicates that R116W is a recurrent mutation, maybe explained by the high mutability of CpG dinucleotides. This can also explain why it is the only AIP mutation reported to occur in seven different populations (Norway, Sweden, Finland, Netherlands, France, Spain and South Africa).

Founder Effect↗