HbA1c was measured in 3240 healthy non-diabetic adult individuals in a working population. There was no difference in HbA1c between sexes. The distribution of HbA1c was approximately normal with a slight difference between mean and median values at all ages in both sexes. HbA1c increased with deterioration of glucose tolerance and with all the known risk factors for diabetes (age, obesity, family history of diabetes, history of a large newborn delivery); age but not body mass index appeared as a factor influencing HbA1c independently. In women, HbA1c levels rose particularly at the age of menopause but the use of oral contraceptives or oestrogens made no difference. In both sexes, HbA1c was higher in smokers than in non-smokers. No consistent seasonal variation was observed. Haematologic factors had a negligible influence on HbA1c level. HbA1c was more highly correlated with fasting plasma glucose than with 2 h-plasma/glucose (r = 0.20 vs 0.11). In a stepwise multiple regression analysis, age followed by fasting plasma glucose were the only two significant factors associated with the level of HbA1c. These data indicate that HbA1c is influenced only by factors closely linked to diabetes.

Neuropeptides such as vasoactive intestinal peptide, LHRH, or TRH have been found in rat pituitary tissue and could act via paracrine or autocrine actions in this tissue. In this study we investigated whether normal human pituitary tissue and GH-secreting human pituitary adenomas could release somatostatin (SRIH) and GHRH. Fragments from three human pituitaries and dispersed cells from six GH-secreting adenomas (four adenomas were studied for GHRH release and five for SRIH release) were perifused using a Krebs-Ringer culture medium, and the perifusion medium was collected every 2 min (1 mL/fraction for 5 h). GH, GHRH, and SRIH were measured by RIA under basal conditions and in the presence of 10(-6) mol/L TRH or SRIH. Both normal pituitaries and GH-secreting pituitary adenomas released SRIH and GHRH. SRIH release commenced 90-180 min after initiation of the perifusion, at which time GH secretion had decreased significantly. TRH stimulated SRIH release from normal pituitary tissue and inhibited SRIH release from adenoma tissue. GHRH was present at the start of the perifusion, but rapidly disappeared. However, SRIH stimulated GHRH release from normal pituitary tissue, but not from adenoma tissue. Significant amounts of GHRH and SRIH were released during the experiments, suggesting their local synthesis. These results indicate that pituitary cells can release hypothalamic peptides. The liberation of these neuropeptides is regulated, and moreover, their regulation differs between normal and adenomatous pituitaries.

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Dose-response relationship in the treatment of hypopituitary children with human growth hormone: a retrospective survey. Acta Paediatr Scand [Suppl] 337:93, 1987.During the past 15 years, dose-response studies of hGH have been limited to prepubertal patients with complete somatotrophic deficiency, who have usually been treated with hCH three timeslweek within a dose range of 10-40 IU/kg/year. In such studies a weak positive correlation has been found (r = 0.429, p < 0.001) with marked important individual variations. Very few or no data have been published regarding the dose-response relationship after the first year of hGH treatment, or when the dose is increased because the growth rate is waning, or during puberty. The present paper reports some data on these issues. A group of 32 young hGH deficient children, whose hone age was 0-4 years, was followed up for at least