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Biomedical subjects

R Pelkonen

Publications and source records attributed to R Pelkonen.

At least 37 records · Page 2Linked to original sources
PubMed1993

Serum sex hormone-binding globulin, cardiovascular risk factors, and adrenal cortisol responses to dexamethasone and corticotropin.

Basal cortisol levels and cortisol responses to dexamethasone (DXM) and corticotropin were studied in relation to serum levels of sex hormone-binding globulin (SHBG), testosterone (T), free T, estradiol (E2), insulin-like growth factor I (IGF-I), high-density lipoprotein cholesterol (HDLC), triglycerides (TG), and insulin in 30 men. SHBG was positively correlated to age (P < .01), HDLC (P < .05), and total T (P < .05) and negatively correlated to TG (P < .02) and insulin (P < .001). SHBG was inversely related to corticosteroid-binding globulin (P < .05), but was not significantly associated with IGF-I. Free T was positively related to TG (P < .05), insulin (P < .01), total T (P < .001), and basal (P < .01) and free cortisol (P < .05). Corticotropin-stimulated cortisol responses were negatively associated with SHBG (P < .001) and positively associated with insulin (P < .01). Multiple linear regression analyses with SHBG as the dependent variable indicated that cortisol response alone explained 34.0% and together with age 46.2% of the variation of SHBG levels. Only insulin and age, but not cortisol response, remained significant predictors of SHBG concentrations when entered simultaneously into the mathematical model; this model explained 55.1% of the variation of SHBG levels. Thus, in addition to insulin and age, cortisol reserves and secretion seem to have significant associations with serum SHBG and free T concentrations.

Adrenal Cortex↗
PubMed1993

Alcohol with a meal has no adverse effects on postprandial glucose homeostasis in diabetic patients.

OBJECTIVE: To examine the effect of moderate alcohol intake with a meal on glucose homeostasis in diabetic patients. RESEARCH DESIGN AND METHODS: Alcohol (1 g/kg, an aperitif before, wine during, and a drink after a meal) or an equal amount of mineral water was given during a dinner. Blood glucose and insulin concentrations were measured before, during, and after the meal until the next morning. This study was conducted at the Helsinki University Hospital Metabolic Ward and the Finnish Diabetes Association Education Center. The participants in the study included 10 type I diabetic patients treated with insulin and 16 type II diabetic patients treated with diet alone or with diet and oral drugs. In each subject, we examined hypoglycemic episodes or differences in blood glucose or serum insulin concentrations between alcohol and the control study. RESULTS: In type I diabetic patients, blood glucose and insulin concentrations were virtually identical in both studies. In type II diabetic patients, alcohol slightly enhanced the meal-induced insulin secretion resulting in lower blood glucose concentrations next morning. No hypoglycemic glucose concentrations were observed in either group after alcohol ingestion. CONCLUSIONS: Moderate alcohol intake with a meal does not lead to hypo- or hyperglycemia in diabetic patients.

Adult↗
PubMed1993

Seven years of remission in a type I diabetic patient.

OBJECTIVE: To analyze factors contributing to a long-term remission in a patient with type I diabetes. RESEARCH DESIGN AND METHODS: The patient was treated with cyclosporin for 16 mo after a short duration of symptoms. During the 7-yr follow-up, we tracked his glycemic control, oral glucose tolerance, insulin sensitivity, endogenous insulin secretion, and beta-cell immunology. The results are compared with those of matched diabetic patients and healthy control subjects. RESULTS: Insulin therapy was discontinued after 5 wk. Thereafter the patient had normal fasting and home blood glucose concentrations and near-normal HbA1c without insulin therapy for 7 yr. During this period, he maintained islet cell antibodies, although his basal and glucagon-stimulated C-peptide concentrations were normal. He participated in active physical training and had an insulin sensitivity higher than in sedentary control subjects or trained diabetic patients and equal to that in healthy athletes. His oral glucose tolerance decreased gradually and became diabetic during the last 3 yr. CONCLUSIONS: In this patient, an early start of cyclosporin therapy probably contributed to the maintenance of endogenous insulin secretion, and insulin sensitivity was high because of physical training. Consequently, the patient was able to maintain normoglycemia without exogenous insulin therapy for 7 yr.

Adolescent↗
PubMed1992

Cyclosporin reduces renal prostanoid excretion in type 1 diabetic patients.

Prostacyclin and thromboxane A2 are important regulators of kidney blood flow. To examine whether changes in their metabolism could be involved in the nephrotoxicity of cyclosporin, we determined urinary excretion of 6-keto PGF1a and dinor-6-keto PGF1a (prostacyclin metabolites) and dinor-TxB2 (thromboxane metabolite) in five newly diagnosed type 1 diabetic patients during and after stopping cyclosporin therapy. In the resting state, cyclosporin had no effect on prostanoid excretion. In response to exercise, urinary excretion of 6-keto PGF1a was reduced by 50% (P less than 0.02), dinor-6-keto PGF1a by 15% (P less than 0.05) and dinor-TxB2 by 45% (P less than 0.02), while albumin excretion increased 4.5-fold (P less than 0.05) during cyclosporin therapy. Simultaneously, there was a rise in serum creatinine concentration, and renal biopsy specimens obtained from three patients showed periglomerular and interstitial fibrosis and tubular atrophy. After the discontinuation of cyclosporin therapy, serum creatinine concentrations returned to normal, histological changes improved and there was an associated rise in urinary prostanoid excretion. These data suggest that a reduction in renal prostanoid synthesis by cyclosporin may diminish renal blood flow and function, and lead to histological changes in the kidney.

6-Ketoprostaglandin F1 alpha↗
PubMed1992

Normal renal sensitivity to atrial natriuretic peptide in Gordon's syndrome.

To test the hypothesis that renal sensitivity to atrial natriuretic peptide (ANP) is impaired in Gordon's syndrome (hypertension and hyperkalaemia with normal glomerular filtration rate) we infused alpha-hANP into two patients with this syndrome (a sister and a brother, 19 and 18 years of age). For comparison, 11 healthy volunteers were also examined. The infusion of alpha-hANP increased urinary volume and excretion of sodium similarly in the patients and controls. The excretion of potassium did not change in either the patients or the controls. The infusion of alpha-hANP had no effect on the serum potassium levels or the plasma CO2 content in the patients. The present results do not confirm the hypothesis of lack of sensitivity to ANP as a pathophysiological concept in Gordon's syndrome.

Adolescent↗
PubMed1992

Fuel and fluid homeostasis during long-term exercise in healthy subjects and type I diabetic patients.

OBJECTIVE: This study was designed to examine metabolic and hormonal effects of long-term exercise in healthy subjects and insulin-dependent (type I) diabetic patients. RESEARCH DESIGN AND METHODS: Two studies were performed. First, 16 healthy males (32 +/- 3 yr) were studied during a semitriathlon competition (2 km swimming, 90 km biking, and 21 km running). Second, 9 type I diabetic males (41 +/- 2 yr) and 17 healthy matched control subjects were studied during a 75 km cross-country skiing race. Blood samples were taken before and immediately after exercise, and also during the ski race. RESULTS: During the semitriathlon race, serum insulin, C-peptide, glucagon cortisol, growth hormone ACTH, prolactin, and plasma renin activity increased two- to ninefold, whereas serum testosterone fell. Apart from a fall in magnesium, serum electrolyte concentrations remained unchanged. Before long-term skiing, patients reduced their insulin dose by 30-40%. They were hyperglycemic during the initial part of the race, but near normoglycemic thereafter. There were large interindividual variations in the increments of counterregulatory hormones, whereas serum testosterone and luteinizing hormone fell quite uniformly. Plasma renin activity and aldosterone concentrations rose similarly in diabetic and healthy subjects, whereas the rise in antidiuretic hormone was slightly greater in diabetic patients. During the initial part of the race, serum atrial natriuretic peptide fell in both groups. CONCLUSIONS: Severalfold increments in hormone concentrations contribute to the maintenance of fuel and fluid homeostasis during long-term exercise. With an appropriate adjustment of insulin dose and diet, also type I diabetic patients can participate in competitive long-term exercise.

Adult↗
PubMed1991

Is the treatment of metastatic carcinoid tumor with interferon not as successful as suggested?

Eight patients with metastatic carcinoid tumor, seven of whom had symptoms of the carcinoid syndrome, were treated with either human leukocyte interferon (seven patients) or recombinant alpha-interferon (IFN alpha-2b) (one patient) at doses of 4.5 to 21 x 10(6) IU weekly for 1 to 21 (mean, 8.5) months. Tumor regression on computed tomography (CT) scan was found in one patient, the CT findings remained unchanged in three, and the tumor progressed in four patients. A clearcut and continuing decrease in urinary levels of 5-hydroxyindoleacetic acid (5-HIAA) was observed in one patient and a transient one in four patients. The symptoms improved in only two of seven patients. Four patients had leukopenia develop, which was circumvented by reducing the dose. The authors conclude that interferon therapy of the carcinoid tumor is not as successful as has been suggested in previous reports.

Adult↗
PubMed1991

Testosterone-secreting virilizing adrenal adenoma with human chorionic gonadotrophin receptors and 21-hydroxylase deficiency.

A 60-year-old woman was evaluated for persistently elevated serum testosterone concentrations after bilateral ovariectomy. Her serum cortisol, androstenedione, dehydroepiandrosterone sulphate and 17-hydroxyprogesterone levels were normal, and decreased after dexamethasone administration. Those of testosterone (17.8-18.4 nmol/l) were remarkably high (normal range 0.7-2.8 nmol/l), were not suppressed by dexamethasone, but clearly increased after hCG administration (up to 128 nmol/l). Computed tomography revealed an adenoma in the right adrenal gland and adrenal scintigraphy under dexamethasone suppression visualized this adenoma. A right adrenalectomy was performed. (1) The tumour was histologically and ultrastructurally adrenocortical adenoma of zona reticularis cell type. (2) The adenoma tissue contained hCG receptors (198 fmol/g). (3) During tissue culture both ACTH and hCG were capable of maintaining its testosterone production, which was attenuated with time without stimulation. (4) The adenoma tissue did not elaborate 21-hydroxylated steroids in contrast to normal adrenal tissue. Thus the aberrant endocrine behaviour of this gonadotrophin-responsive testosterone-secreting adenoma of adrenal zona reticularis cell origin can be explained by ectopic functional hCG receptors and the lack of 21-hydroxylase activity.

Adenoma↗
PubMed1991

Obstructive sleep apnoea syndrome in morbidly obese patients.

Twenty-seven morbidly obese patients (13 men and 14 women) with body mass index greater than or equal to 40 kg m-2 were examined. The mean age of the subjects was 36.9 +/- 8.2 years (range 23-51 years), and the mean BMI was 50.2 +/- 6.2 kg m-2 (range 40.0-62.9 kg m-2). A whole-night sleep recording was made for all patients with signs or symptoms indicative of possible obstructive sleep apnoea syndrome (OSAS). If the first nocturnal sleep recording was abnormal, it was controlled after 1 year. Eleven (10 men and one woman) of the 27 patients had an oxygen desaturation index (ODI) of 10 h-1. They were symptomatic with excessive daytime sleepiness or other daytime symptoms of OSAS. The occurrence of OSAS in men and women was 76.9 and 7.1%, respectively. Arterial hypertension was associated with OSAS, but not with smoking or the degree of obesity. Antihypertensive treatment was received by nine of the 27 patients; six of them had OSAS. Thus six of the 11 (54.5%) patients with OSAS and three of the 16 (18.8%) nonapnoeic patients were treated for arterial hypertension (Fisher exact test, P = 0.042). The odds ratio of OSAS for arterial hypertension is 5.2 (95% CI, 0.71-43.6). Vertical-banded gastroplasty was performed in 14 patients, three of whom had OSAS. The selection of patients for gastroplasty was made without taking into account the results of sleep recordings. In the three OSAS patients, a 30-38% reduction in BMI was achieved by surgery. Eight patients with OSAS were treated with an intensified dietary regimen, and the reduction in BMI ranged from -2.6 to 33%. OSAS was either cured or significantly improved in six (55%) patients, with a mean reduction in BMI of 27%, while in patients with persistent OSAS the mean reduction in BMI was only 7%.

Adult↗
PubMed1991

Hormonal changes in severely uncontrolled type 1 (insulin-dependent) diabetes mellitus.

To investigate endocrinological changes associated with severely uncontrolled type 1 (insulin-dependent) diabetes mellitus 27 patients (19 men, eight women) with ketoacidosis or severe ketonuria (= group 1) were examined on admission and after recovery. For comparison 13 non-ketotic patients (seven men, six women), admitted for adjustment of treatment because of poor diabetic control (= group 2), and 20 healthy controls were studied. On admission, the serum testosterone levels in men were lower in group 1 (15.1 +/- 2.0 nmol l-1) (mean +/- SEM) than in group 2 (27.2 +/- 2.8 nmol l-1) (p less than 0.01) and healthy controls (20.6 +/- 2.0 nmol l-1) (p less than 0.05). During treatment the testosterone levels in group 1 rapidly rose to the control level. The serum oestradiol levels in women were low in group 1 both on admission and discharge. The serum prolactin levels were low in female patients in group 1 (119 +/- 17 mIU l-1) compared with the women in group 2 (315 +/- 75 mIU l-1) (p less than 0.05). On admission the serum cortisol levels were higher and their response to 1 mg of dexamethasone was weaker in group 1 than in group 2 and healthy controls. After recovery the serum cortisol levels fell by 15% (p less than 0.01) and the response to 1 mg of dexamethasone returned to normal in group 1. In group 1 during treatment the serum free T4 and reverse T3 levels fell, and the T3 levels rose, whereas the thyroid stimulating hormone (TSH) levels and their responses to TRH remained unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗