Serum ferritin in a Greenlandic Inuit hunter population from the Thule district.

Serum (S-) ferritin was analyzed in 67 Greenlandic Inuit hunters from Thule (Qaanaaq), 35 males and 32 females with a median age of 39 years (range 17-77). S-ferritin was higher in males, median 211 micrograms/l (range 30-1040), than in females, median 87 micrograms/l (range 33-794) (p less than 0.01). None of the subjects had S-ferritin less than or equal to 20 micrograms/l (i.e. depleted iron stores); 5 of the 48 subjects less than or equal to 50 years old had S-ferritin 21-40 micrograms/l (i.e. small iron stores). All 19 subjects greater than 50 years old had S-ferritin greater than 40 micrograms/l (i.e. replete iron stores) and 8 showed values greater than 300 micrograms/l (i.e. increased iron stores). S-ferritin levels increased with the percent energy intake from traditional native hunter food (rs = 0.26, p less than 0.05). Inuit had higher S-ferritin than Danish Caucasian subjects. In Inuit of both sexes, S-ferritin displayed a correlation to age (rs = 0.63, p less than 0.0001 in the entire series), indicating gradually increasing S-ferritin levels during lifetime, without the plateaus seen in Caucasians. These findings suggest continued accumulation of iron reserves in elderly Inuit, due to consumption of large quantities of iron rich meat from marine mammals and/or genetic differences in the regulatory mechanisms for body iron stores.

Long-term bone loss in insulin-dependent diabetic patients with microvascular complications.

Insulin-dependent diabetic patients have an approximately 10% decreased bone mineral content (BMC) when they are studied a few years after clinical onset of diabetes. After that time, patients without diabetic microvascular complications have no, or only very little, further bone loss. The aim of the present study was to investigate if any substantial long-term bone loss occurs in diabetic patients with microvascular complications. We studied 19 insulin-dependent diabetic patients with neither physiologic nor pathologic conditions known to interfere with bone metabolism, other than diabetes. BMC was determined twice, with an interval of 11 years. At initial examination, no patient had diabetic microangiopathy, but at final examination 7 patients had developed diabetic microvascular complications while 12 patients had not. As compared with gender- and age-matched controls, both subgroups had significantly decreased BMC at the initial examination. During the study period, the patients with complications showed further bone loss, whereas the subgroup without complications had unchanged decreased BMC. At final examination, BMC was significantly lower in patients with microvascular complications than in patients without them. The biochemistry of bone metabolism showed a significantly increased fasting urinary excretion of calcium and hydroxyproline in patients with complications, but not in the group without complications, and there was a negative correlation between plasma BGP (osteocalcin) and hemoglobin A1C for all patients. These findings indicate that, in addition to a decreased BMC (before or shortly after clinical onset of diabetes), patients who develop microvascular complications also develop ongoing bone loss. This loss may be caused by an increased bone resorption, but decreased bone formation during periods of poor diabetic control may be involved as well.

Serum ferritin, iron status and plasma ascorbic acid in 40- to 49-year-old males in the Faroe Islands.

Iron status (haemoglobin, S-ferritin, S-iron, S-transferrin, and transferrin saturation) was evaluated in an epidemiological survey comprising a representative sample of 118 (4%) of the 40- to 49-year-old Faroese male population. All had normal haemoglobin, (mean +/- SD 153 +/- 9 g/l; 9.5 +/- 0.6 mmol/l). Median S-ferritin was 151 micrograms/l, 5-95 percentile 46-588 micrograms/l, observed range 33-1166 micrograms/l. None had depleted iron stores (S-ferritin less than or equal to 20 micrograms/l), 2.5% had 'small' iron stores (S-ferritin 21-40 micrograms/l), 80.5% had 'normal' iron stores (S-ferritin 41-300 micrograms/l) and 17% had 'increased' iron stores (S-ferritin greater than 300 micrograms/l). Transferrin saturation values were greater than 16% in all males; high values greater than 50% were found in 9.3%, and the combination of high transferrin saturation and S-ferritin greater than 300 micrograms/l was found in 3.4% of the males. Median P-ascorbic acid was 26 mumol/l, 5-95 percentile 7-67 mumol/l; significantly higher in subjects taking vitamin supplements (n = 35, median 50 mumol/l) than in those not taking supplements (n = 81, median 23 mumol/l) (p less than 0.0001). There was no correlation between P-ascorbic acid and iron status markers. The results indicate a high frequency of ample iron reserves in the Faroese male population.

Family studies of hereditary hemochromatosis in Denmark and the Faroe Islands.

Pedigree studies were performed based on one Faroese and four Danish probands with overt idiopathic hemochromatosis (IH). The study consisted of HLA typing and determination of biochemical iron status indicators (serum transferrin saturation, serum ferritin). In total, 130 persons were evaluated. The screening identified 6 homozygous (h/h) subjects with preclinical IH, 46 heterozygous (h/n), and 8 normal (n/n) subjects, while 39 subjects were classified as normal or heterozygous (n/h?). One family demonstrated both a homozygous x heterozygous as well as a heterozygous x heterozygous mating. Recombination between the HLA region and IH locus occurred possibly in three subjects in three different families. The significance of detailed screening in families with probands with IH is discussed.

[Meningococcal disease in the Faroe Islands during the period 1978-1985]. / Meningokoksygdom på Faerøerne 1978-1985.

On the Faroe Islands (45,000 inhabitants), a total of 203 cases of meningococcal disease (MD) were recorded during the period 1978-1985. The peak incidence was 95/100,000 in 1981. MD mainly attacked children, 30% were below two years and 75% were below 11 years of age. The lethality rate was 5.4% (11 deaths). In 1981, rifampicin was introduced as a prophylactic treatment against secondary cases and at the same time, a decrease in incidence occurred. The decrease was more pronounced in the part of the country where the number of prescribed prophylactic doses per case of MD was greatest. These observations indicate that the introduction of rifampicin may have modified the course of the epidemic. None of the MD-patients had received prophylactic treatment with rifampicin. Of 132 examined, one patient with complement deficiency was identified, indicating that complement deficiencies were not a major risk factor in the epidemic of MD on the Faroe Islands.

Long-term bone loss in insulin-dependent diabetes mellitus.

The bone mineral content (BMC) in patients with insulin-dependent diabetes is reduced by 10% early in the disease, but due to a lack of long-term longitudinal studies it is unknown whether this diabetic osteopenia develops further through life. Over a time period of 11 years we examined the BMC in a group of seven adult insulin-dependent diabetics, in whom physiological and pathological factors affecting bone metabolism had been excluded; the patients were well regulated without diabetic complications. The BMC was not significantly decreased at the initial examination. The longitudinal study revealed a small but statistically significant fall in BMC, mainly in trabecular bone. The narrow (95%) confidence interval of median end value (93.3-99.0% of initial BMC) indicates that the annual decrease in BMC in such patients is of the order of 0.5%, a reduction that is probably clinically insignificant.

[Polyglandular autoimmune syndrome type II]. / Polyglandulaert autoimmunt syndrom type II.

The polyglandular autoimmune syndrome type II, (Schmidts syndrome), is defined as coexistence of two of the diseases: Addison's disease, insulin dependent diabetes mellitus and autoimmune thyroid disease. The first endocrine deficiency state typically develops after the age of twenty and in most cases it is Addison's disease. The prevalence is approximately 5 per 100,000. The syndrome occurs within families in half of the cases. The immunological mechanism is not finally determined, but both the humoral and cellular systems seem to be involved and furthermore there is an association with the major histocompatibility complex. Whereas treatment of the components in polyglandular autoimmune syndrome is straightforward, diagnosis may be troublesome: Patients with Addison's disease may be biochemically hypothyroid the first months of corticosteroid treatment. Patients with myxedema show decreased urine excretion of 17-ketosteroids until thyroid substitution treatment is sufficient. A decreased insulin requirement or increased frequency of hypoglycaemic attacks may be the first sign of an adrenocortical hypofunction in diabetic patients. Patients with one autoimmune disease and their relatives are predisposed to (other) autoimmune diseases.

[The accuracy and reproducibility of clinical examination of adenoma of the thyroid--corrected for randomness with iota and kappa]. / Rigtighed og reproducerbarhed ved klinisk undersøgelse for adenomer i glandula thyreoidea--korrigeret for tilfaeldighed med "iota" og "kappa".

The aim of this study was to evaluate the reliability (accuracy and observer variability) of the clinical examination of the thyroid gland for adenomatous changes. All patients (n = 105) admitted for scintigraphic examination of the thyroid gland were examined by three observers and the thyroid scintigraphy was performed. The study population consisted of the patients (n = 84), where the result of the scintigraphic examination could be classified as either "normal" (n = 24), "solitary adenoma" (n = 32) or "nodular goitre" (n = 28), with scintigraphy used as golden standard. The accuracy was evaluated using each observer's sensitivity, specificity and total agreement with the golden standard for each diagnosis and the observer variability by the overall agreement between each pair of observers. After random agreement was eliminated by calculation of iota and kappa, the results showed a fair reliability of the clinical diagnoses "normal" and "solitary adenoma" (iota between 0.20 and 0.62; kappa between 0.33 and 0.46), but poor reliability for "nodular goitre", (iota between 0.00 and 0.50, kappa between 0.00 og 0.46). Calculation of the newly introduced iota is discussed in the appendix.

An evaluation of the accuracy of clinical diagnosis at admission in a population with epidemic meningococcal disease.

The accuracy (sensitivity and positive predictive value) of the clinical diagnosis given by the general practitioner before admission to hospital was evaluated retrospectively in a population with epidemic meningococcal disease. The study population consisted of approximately 32,000 subjects. In a 12-year period, 344 patients were discharged from hospital with CNS infections, 274 of whom were admitted with a diagnosis suspecting a CNS infection. A further 401 patients were admitted with suspicion for, but discharged without a CNS infection. Overall, the sensitivity was 79.7% and the positive predictive value was 40.6%. There were no significant changes in the accuracy during the study. The sensitivity differed significantly between the age groups (P less than 0.001) and was lowest among the adults (15+ years, 67.9%) and the 0-2-year-old children (72.7%). Also among the 0-2 year-olds, the positive predictive value was low (34.1%) and not significant, indicating that it was more difficult to obtain the correct clinical diagnosis in this group.

[Vibration-induced inactivation of insulin]. / Vibrationsinduceret insulin-inaktivering.

A case of diabetic ketoacidosis precipitated by employment of flocculated, and thus inactivated, insulin is presented. The flocculation is presumed to have been produced by vibrations which are presumed to make slow-action insulin form insoluble fibrils at room temperature. This mechanism is recognized in rapid-action insulin.

[Life-threatening hypokalemia during a weight reducing regimen in a woman with hypertension treated with diuretics]. / Livstruende hypokaliaemi under affedningsforsøg hos diuretikabehandlet hypertensionspatient.

A case of hypokalaemia and metabolic alkalosis precipitated by a self-composed slimming diet in a woman treated with diuretics is presented. Cardiac stimulation and respirator treatment were required in addition to electrolyte therapy. Patients treated with diuretics should be warned against starting slimming cures without simultaneous frequent control of serum potassium.

Screening for complement deficiencies in patients surviving from epidemic meningococcal disease.

Sera from 132 patients surviving from meningococcal disease during the high-endemic period 1 January 1980 to 31 December 1984 on the Faroe Islands were screened for deficiencies of the complement (C) system by measuring hemolytic complement function in serum. Samples from 12 patients with reduced C function were further investigated by immunochemical quantification of individual C proteins. One patients was identified with C3-deficiency (C3-concentration 6% of normal) due to the presence of C3 nephritic factor (C3NeF) in serum. In addition, eight patients had minor aberrations in one or several complement proteins. It is concluded, that C deficiency is not an important risk factor during epidemics of meningococcal disease. The C3NeF activity could not be absorbed with Neisseria meningitidis group B, type 15, indicating absence of crossreactivity between neisserial antigens and C3NeF.

An epidemic outbreak of group B meningococcal disease on the Faroe Islands.

An epidemic of group B meningococcal disease on the Faroe Islands is described. A peak annual incidence of 95 cases/100,000 was reached in 1981. The time at which the epidemic commenced cannot be determined due to inadequate diagnostic facilities, but was presumably around the end of the 1970s. The incidence fell to 29 cases/100,000 in 1985, which indicates that the Faroe Islands are still a high incidence area. A total of 203 cases of meningococcal disease were recorded during the period 1978-1985 with 11 deaths (lethality rate 5.4%). After rifampicin was introduced in 1981 as prophylactic treatment against secondary cases, 1,892 persons were treated with this agent and none of these appeared in the study population. Before rifampicin prophylaxis was introduced, the number of cases were distributed with an evenly increasing incidence in the capital and in the provinces. Following the introduction of rifampicin as prophylactic agent, a fall in the incidence in both areas was observed. This fall was more pronounced in the capital, where the number of prescribed prophylactic doses per case of meningococcal disease was higher than in the province.