Clinical, immunological, and genetic features of autoimmune primary adrenal insufficiency: observations from a Norwegian registry

OBJECTIVE

Primary adrenal insufficiency [Addison's disease (AD)] is rare, and systematic studies are few, mostly conducted on small patient samples. We aimed to determine the clinical, immunological, and genetic features of a national registry-based cohort.

DESIGN

Patients with AD identified through a nationwide search of diagnosis registries were invited to participate in a survey of clinical features, health-related quality of life (HRQoL), autoantibody assays, and human leukocyte antigen (HLA) class II typing.

RESULTS

Of 664 registered patients, 64% participated in the study. The prevalence of autoimmune or idiopathic AD in Norway was 144 per million, and the incidence was 0.44 per 100,000 per year (1993-2007). Familial disease was reported by 10% and autoimmune comorbidity by 66%. Thyroid disease was most common (47%), followed by type 1 diabetes (12%), vitiligo (11%), vitamin B12 deficiency (10%), and premature ovarian insufficiency (6.6% of women). The mean daily treatment for AD was 40.5 mg cortisone acetate and 0.1 mg fludrocortisone. The mean Short Form 36 vitality scores were significantly diminished from the norm (51 vs. 60), especially among those with diabetes. Concomitant thyroid autoimmunity did not lower scores. Anti-21-hydroxylase antibodies were found in 86%. Particularly strong susceptibility for AD was found for the DR3-DQ2/ DRB1*0404-DQ8 genotype (odds ratio, 32; P = 4 x 10(-17)), which predicted early onset.

CONCLUSIONS

AD is almost exclusively autoimmune, with high autoimmune comorbidity. Both anti-21-hydroxylase antibodies and HLA class II can be clinically relevant predictors of AD. HRQoL is reduced, especially among diabetes patients, whereas thyroid disease did not have an impact on HRQoL. Treatment modalities that improve HRQoL are needed.

Endogenous sex hormones and the prospective association with cardiovascular disease and mortality in men: the Tromsø Study

OBJECTIVE

To study the impact of endogenous testosterone levels in community-dwelling men on later risk for myocardial infarction (MI) and all-cause, cardiovascular disease (CVD), and ischemic heart disease (IHD) mortality.

DESIGN

Population-based prospective cohort study.

METHODS

For the analyses, we used a cohort of 1568 randomly selected men, with sex-hormone data participating in the fourth Tromsø Study (1994-1995). Defined end points were first-ever MI (fatal or nonfatal), all-cause, CVD, and IHD mortality. A committee performed thorough ascertainment of end points, following a detailed protocol. Complete ascertainment of end points was until 30 September 2007 for all-cause mortality, until 31 December 2005 for CVD/IHD mortality, and until 31 December 2004 for first-ever MI. The prospective association between total and free testosterone and end points were examined using Cox proportional hazard regression, allowing for multivariate adjustment for age and cardiovascular risk factors.

RESULTS

During follow-up, there were 395 deaths from all causes, 130 deaths from CVD and 80 deaths from IHD, while 144 men experienced a first-ever MI. There was a significant increase in all-cause mortality risk for men with free testosterone in the lowest quartile (<158 pmol/l) compared with the higher quartiles after age adjustment hazard ratios (HR 1.24, 95% confidence interval, CI 1.01-1.53) and after multivariate adjustments (HR 1.24, 95% CI 1.01-1.54). Total testosterone was not associated with mortality risk. Likewise, there were no significant changes in risk for first-ever MI across different total or free testosterone levels.

CONCLUSION

Men with free testosterone levels in the lowest quartile had a 24% increased risk of all-cause mortality.

Glucocorticoid replacement therapy and pharmacogenetics in Addison's disease: effects on bone

Context Patients with primary adrenal insufficiency (Addison's disease) receive more glucococorticoids than the normal endogenous production, raising concern about adverse effects on bone.

OBJECTIVE

To determine i) the effects of glucocorticoid replacement therapy on bone, and ii) the impact of glucocorticoid pharmacogenetics.

DESIGN, SETTING AND PARTICIPANTS

A cross-sectional study of two large Addison's cohorts from Norway (n=187) and from UK and New Zealand (n=105).

MAIN OUTCOME MEASURES

Bone mineral density (BMD) was measured; the Z-scores represent comparison with a reference population. Blood samples from 187 Norwegian patients were analysed for bone markers and common polymorphisms in genes that have been associated with glucocorticoid sensitivity.

RESULTS

Femoral neck BMD Z-scores were significantly reduced in the patients (Norway: mean -0.28 (95% confidence intervals (CI) -0.42, -0.16); UK and New Zealand: -0.21 (95% CI -0.36, -0.06)). Lumbar spine Z-scores were reduced (Norway: -0.17 (-0.36, +0.01); UK and New Zealand: -0.57 (-0.78, -0.37)), and significantly lower in males compared with females (P=0.02). The common P-glycoprotein (ABCB1) polymorphism C3435T was significantly associated with total BMD (CC and CT>TT P=0.015), with a similar trend at the hip and spine.

CONCLUSIONS

BMD at the femoral neck and lumbar spine is reduced in Addison's disease, indicating undesirable effects of the replacement therapy. The findings lend support to the recommendations that 15-25 mg hydrocortisone daily is more appropriate than the higher conventional doses. A common polymorphism in the efflux transporter P-glycoprotein is associated with reduced bone mass and might confer susceptibility to glucocorticoid induced osteoporosis.

Endogenous sex hormone levels in men are not associated with risk of venous thromboembolism: the Tromso study

OBJECTIVES

Low testosterone levels in men have been associated with cardiovascular risk factors and atherosclerosis and lately also an increased risk of both cardiovascular disease (CVD) and all-cause mortality. As arterial CVDs and venous thromboembolism (VTE) have been shown to share common risk factors, the purpose of the present study was to determine the impact of endogenous sex hormone levels on the incidence of VTE in a cohort of men.

DESIGN

A prospective, population-based study.

METHODS

Sex hormone measurements were available in 1350 men, aged 50-84, participating in the Tromsø study in 1994-1995. First, lifetime VTE-events during the follow-up were registered up to September 1 2007.

RESULTS

There were 63 incident VTE-events (4.5 per 1000 person-years) during a mean of 10.4 years of follow-up. Age was significantly associated with increased risk of VTE; men 70 years or older had a 2.5-fold higher risk of VTE (HR 2.47, 95% CI 1.19-5.12), compared with those between 50 and 60 years of age. In age-adjusted analyses, endogenous sex hormones levels were not associated with risk of VTE; for each s.d. increase, hazards ratios (95% CI) were 1.06 (0.83-1.35) for total testosterone, 1.02 (0.79-1.33) for free testosterone, and 1.27 (0.94-1.71) for ln-estradiol. In dichotomized analyses comparing men in the lowest total and free testosterone quartile with men in the higher quartiles, hypoandrogenemia was not associated with risk of VTE.

CONCLUSIONS

In this population-based study of middle-aged and older men, endogenous sex hormone levels were not associated with 10-year risk of VTE.

Plasma free tissue factor pathway inhibitor (TFPI) levels and TF-induced thrombin generation ex vivo in men with low testosterone levels

Low testosterone levels in men have been associated with cardiovascular risk factors, some prothrombotic factors, and lately also an increased risk of both cardiovascular disease and all-cause mortality. Experimental studies have shown increased synthesis and release of tissue factor pathway inhibitor (TFPI) by physiological levels of testosterone in endothelial cells. Our hypothesis was that elderly men with low testosterone levels would have lower plasma levels of plasma free TFPI with subsequent increased thrombin generation. Elderly men with low (n = 37) and normal (n = 41) testosterone levels were recruited from a general population, and tissue factor (TF)-induced thrombin generation ex vivo and plasma free TFPI Ag were measured. Elderly men with low testosterone levels had lower plasma free TFPI Ag (10.9 +/- 2.3 ng/ml vs. 12.3 +/- 3.0 ng/ml, p = 0.027) and shorter initiation phase of TF-induced coagulation assessed by lag-time (5.1 +/- 1.0 min vs. 5.7 +/- 1.3, p = 0.039). The differences between groups remained significant and were strengthened after adjustment for waist circumference and other cardiovascular risk factors. Lag-time increased linearly across quartiles of plasma free TFPI Ag (p<0.001). Multiple regression analysis revealed that total and free testosterone were independent predictors of plasma free TFPI Ag. Our findings suggest that low testosterone levels in elderly men is associated with low plasma free TFPI Ag and subsequent shortened initiation phase of TF-induced coagulation.

[Treatment practice in primary hyperparathyroidism]

BACKGROUND

A recent study found considerable regional differences in treatment of primary hyperparathyroidism in Norway. There is no consensus on specific indications for operation in these patients. We surveyed opinions among Norwegian endocrine surgeons and endocrinologists on the indications for surgical treatment of primary hyperparathyroidism.

MATERIAL AND METHODS

A questionnaire on preoperative evaluation, indications for surgery and treatment of patients with primary hyperparathyroidism was sent to the chief consultants of surgical departments that operated on parathyroid glands in 2005. The questionnaire was also sent to endocrinologists at the same hospitals.

RESULTS

In 2006, 415 parathyroid gland operations were performed in 17 Norwegian hospitals, with a median of 18 operations per hospital. A total of 46 surgeons operated on the parathyroid glands, with a median of two surgeons per hospital. Hospitals differed with respect to preoperative evaluations and indications for operative treatment; but these differences did not coincide with regional differences in the frequency of parathyroid surgery. There was a good correlation between endocrine surgeons and endocrinologists on the indications for surgery in primary hyperparathyroidism, but neither group adhered unconditionally to the international guidelines for surgical treatment of patients with primary hyperparathyroidism. Patients in the hospitals that operated most frequently were initially diagnosed in a surgical department.

INTERPRETATION

Our survey did not reveal differences that could explain the large regional variations in the frequency of parathyroid surgery.

Normal overall mortality rate in Addison's disease, but young patients are at risk of premature death

CONTEXT

Primary adrenal insufficiency (Addison's disease) is a rare autoimmune disease. Until recently, life expectancy in Addison's disease patients was considered normal.

OBJECTIVE

To determine the mortality rate in Addison's disease patients.

DESIGN AND METHODS

i) Patients registered with Addison's disease in Norway during 1943-2005 were identified through search in hospital diagnosis registries. Scrutiny of the medical records provided diagnostic accuracy and age at diagnosis. ii) The patients who had died were identified from the National Directory of Residents. iii) Background mortality data were obtained from Statistics Norway, and standard mortality rate (SMR) calculated. iv) Death diagnoses were obtained from the Norwegian Death Cause Registry.

RESULTS

Totally 811 patients with Addison's disease were identified, of whom 147 were deceased. Overall SMR was 1.15 (95% confidence intervals (CI) 0.96-1.35), similar in females (1.18 (0.92-1.44)) and males (1.10 (0.80-1.39)). Patients diagnosed before the age of 40 had significantly elevated SMR at 1.50 (95% CI 1.09-2.01), most pronounced in males (2.03 (1.19-2.86)). Acute adrenal failure was a major cause of death; infection and sudden death were more common than in the general population. The mean ages at death for females (75.7 years) and males (64.8 years) were 3.2 and 11.2 years less than the estimated life expectancy.

CONCLUSION

Addison's disease is still a potentially lethal condition, with excess mortality in acute adrenal failure, infection, and sudden death in patients diagnosed at young age. Otherwise, the prognosis is excellent for patients with Addison's disease.

Androgen receptor gene polymorphism and the metabolic syndrome in 60-80 years old Norwegian men

The metabolic syndrome (MS) includes a clustering of metabolic derangements. Low testosterone levels have been shown to be associated with both components of MS and MS per se. As most androgen-related effects are mediated thorough the androgen receptor (AR), we wanted to investigate to which degree the AR CAG and GGN repeat polymorphisms might be related to MS. Sixty-eight men, 60-80 years old, with subnormal total testosterone levels (<or=11.0 nmol/L) and 104 men with normal levels (>11.0 nmol/L), participating in a nested case-control study were investigated in this study. Body weight, height, waist circumferences and blood pressure were measured. Fasting blood samples were drawn and an oral glucose tolerance test (OGTT) was performed. The CAG and GGN polymorphisms in the AR gene were determined by direct sequencing of leucocyte DNA. Men with MS had lower CAG repeat number than healthy men (p = 0.007). There were, however, no difference in CAG or GGN repeats length between the groups with subnormal or normal testosterone concentrations. In cross-sectional analyses, men with CAG repeat lengths <or= 21 had significantly higher fasting glucose, C-peptide and glycosylated haemoglobin (HbA1c) levels (all p < 0.05). In multiple regression analyses, CAG repeat length was an inverse and independent predictor of glucose after an OGTT and of HbA1c levels. We also found that men with more than one component of MS had shorter CAG repeat number (p for trend 0.013) than those with only one component. In conclusion, there were no associations with GGN repeat length, while short CAG repeat length seems to be associated with increased risk of MS.

Effects of vitamin D supplementation on symptoms of depression in overweight and obese subjects: randomized double blind trial

OBJECTIVES

The objective of the present study was to examine the cross-sectional relation between serum 25-hydroxyvitamin D [25-(OH) D] levels and depression in overweight and obese subjects and to assess the effect of vitamin D supplementation on depressive symptoms.

DESIGN

Cross-sectional study and randomized double blind controlled trial of 20,000 or 40,000 IU vitamin D per week versus placebo for 1 year.

SETTING

A total of 441 subjects (body mass index 28-47 kg m(-2), 159 men and 282 women, aged 21-70 years) recruited by advertisements or from the out-patient clinic at the University Hospital of North Norway.

MAIN OUTCOME MEASURES

Beck Depression Inventory (BDI) score with subscales 1-13 and 14-21.

RESULTS

Subjects with serum 25(OH)D levels < 40 nmol L(-1) scored significantly higher (more depressive traits) than those with serum 25(OH)D levels > or = 40 nmol L(-1) on the BDI total [6.0 (0-23) versus 4.5 (0-28) (median and range)] and the BDI subscale 1-13 [2.0 (0-15) versus 1.0 (0-29.5)] (P < 0.05). In the two groups given vitamin D, but not in the placebo group, there was a significant improvement in BDI scores after 1 year. There was a significant decrease in serum parathyroid hormone in the two vitamin D groups without a concomitant increase in serum calcium.

CONCLUSIONS

It appears to be a relation between serum levels of 25(OH)D and symptoms of depression. Supplementation with high doses of vitamin D seems to ameliorate these symptoms indicating a possible causal relationship.

Preoperative octreotide treatment in newly diagnosed acromegalic patients with macroadenomas increases cure short-term postoperative rates: a prospective, randomized trial

CONTEXT

Surgery is the primary treatment of acromegaly. However, it often fails to cure the patient. New strategies that improve surgical outcome are needed.

OBJECTIVE

Our objective was to investigate whether 6-month preoperative treatment with octreotide improves the surgical outcome in newly diagnosed acromegalic patients.

PATIENTS

During a 5-yr period (1999-2004), all newly diagnosed acromegalic patients between 18 and 80 yr of age in Norway were screened and invited to participate in the study. A total of 62 patients was included in the Preoperative Octreotide Treatment of Acromegaly study.

RESEARCH DESIGN AND METHODS

After a baseline evaluation, patients were randomized directly to transsphenoidal surgery (n = 30) or pretreatment with octreotide (n = 32) 20 mg im every 28th day for 6 months before transsphenoidal surgery. Cure was evaluated 3 months postoperatively primarily by IGF-I levels.

RESULTS

According to the IGF-I criteria, 14 of 31 (45%) pretreated patients vs. seven of 30 (23%) patients with direct surgery were cured by surgery (P = 0.11). In patients with microadenomas (< or = 10 mm), one of five (20%) pretreated vs. three of five (60%) with direct surgery were cured (P = 0.52). In patients with macroadenomas, 13 of 26 (50%) pretreated vs. four of 25 (16%) with direct surgery were cured (P = 0.017).

CONCLUSIONS

Six-month preoperative octreotide treatment might improve surgical cure rate in newly diagnosed acromegalic patients with macroadenomas. These results have to be confirmed in future studies.

Postprandial triglyceride metabolism in elderly men with subnormal testosterone levels

AIM

To investigate the level of postprandial triglycerides (TG)s in elderly men with subnormal testosterone level (< or = 11.0 nmol/L) compared to men with normal testosterone level (> 11.0 nmol/L).

METHODS

Thirty-seven men with subnormal and 41 men with normal testosterone aged 60-80 years underwent an oral fat load and TG levels were measured fasting and 2, 4, 6 and 8 h afterwards.

RESULTS

Men with subnormal testosterone had significantly higher body mass index (BMI) and waist circumference (P < 0.001) than men with normal testosterone. They had significantly higher area under curve (AUC, P = 0.037), incremental area under curve (AUCi, P = 0.035) and TG response (TGR, P = 0.014) for serum-TG and significantly higher AUC (P = 0.023), AUCi (P = 0.023) and TGR (P = 0.014) for chylomicron-TG compared to men with normal testosterone level. Adjusting for waist circumference erased the significant differences between the groups in postprandial triglyceridemia.

CONCLUSION

Men with subnormal testosterone have increased postprandial TG levels indicating an impaired metabolism of postprandial TG-rich lipoproteins (TRL), which may add to an unfavourable lipid profile and promote development of atherosclerosis.

Low serum testosterone in men is inversely associated with non-fasting serum triglycerides: the Tromsø study

OBJECTIVE

To study the relationships between endogenous testosterone, sex hormone-binding globulin (SHBG) and serum lipids in non-fasting men.

METHODS

We performed a cross-sectional study in 1274 men without known cardiovascular disease who participated in a population-based study, the 1994/1995 Tromsø study. Anthropometric characteristics were measured and questionnaires regarding lifestyle and medical history were completed. Non-fasting blood samples were drawn between 08.00 and 16.00h, and total testosterone, SHBG, triglycerides (TG), total cholesterol (TC) and high-density lipoprotein (HDL) were analyzed.

RESULTS

In stratified analyses based on sampling time, a linear increase in serum TG levels was found in men with total testosterone levels below the 50th percentile during the day (p for trend=0.004). In contrast, serum triglycerides did not change during the day in men with testosterone levels above the 50th percentile. In regression analyses, total testosterone and SHBG were inversely and independently associated with TG (p<0.001 and p<0.001 respectively), and positively and independently associated with HDL (p=0.005 and p<0.001, respectively). Men with an unfavorable lipid profile (HDL <0.90 and TG >1.8) had significantly lower levels of total testosterone and SHBG (p=0.004 and p<0.001, respectively) in age and BMI adjusted analyses, compared to men with a normal lipid profile.

CONCLUSIONS

Low serum total testosterone was associated with a linear increase in serum TG during the day, and was independently associated with an unfavorable lipid profile. Our findings may indicate that low total testosterone is associated with impaired TG metabolism in men.

Radiotherapy for rectal cancer is associated with reduced serum testosterone and increased FSH and LH

PURPOSE

It is known that scattered radiation to the testes during pelvic radiotherapy can affect fertility, but there is little knowledge on its effects on male sex hormones. The aim of this study was to determine whether radiotherapy for rectal cancer affects testosterone production.

METHODS AND MATERIALS

All male patients who had received adjuvant radiotherapy for rectal cancer from 1993 to 2003 were identified from the Norwegian Rectal Cancer Registry. Patients treated with surgery alone were randomly selected from the same registry as control subjects. Serum levels of follicle stimulating hormone (FSH), luteinizing hormone (LH), testosterone, and sex hormone binding globulin (SHBG) were analyzed, and free testosterone was calculated (N = 290). Information about the radiotherapy treatment was collected from the patient hospital charts.

RESULTS

Serum FSH was 3 times higher in the radiotherapy group than in the control group (median, 18.8 vs. 6.3 IU/L, p <0.001), and serum LH was 1.7 times higher (median, 7.5 vs. 4.5 IU/l, p <0.001). In the radiotherapy group, 27% of patients had testosterone levels below the reference range (8-35 nmol/L), compared with 10% of the nonirradiated patients (p <0.001). Irradiated patients had lower serum testosterone (mean, 11.1 vs. 13.4 nmol/L, p <0.001) and lower calculated free testosterone (mean, 214 vs. 235 pmol/L, p <0.05) than control subjects. Total testosterone, calculated free testosterone, and gonadotropins were related to the distance from the bony pelvic structures to the caudal field edge.

CONCLUSIONS

Increased serum levels of gonadotropins and subnormal serum levels of testosterone indicate that curative radiotherapy for rectal cancer can result in permanent testicular dysfunction.

Associations between the metabolic syndrome and bone health in older men and women: the Rancho Bernardo Study

We examined the associations of metabolic syndrome (MS) with BMD, osteoporosis, and osteoporotic fractures in 417 men and 671 women from the Rancho Bernardo Study. After adjusting for BMI, MS was associated with lower, not higher BMD. Incidence of osteoporotic non-vertebral fractures was higher in participants with MS. MS may be another risk factor for osteoporotic fractures.

INTRODUCTION

The metabolic syndrome (MS) is a cluster of risk factors, including abdominal obesity, high glucose, triglycerides, hypertension and low HDL levels, associated with cardiovascular disease morbidity. The association between components of the MS and bone mineral density (BMD) has been researched, but results are contradictory.

METHODS

We used multivariate regression models to examine the cross-sectional associations of MS defined by NCEP-ATP III criteria with BMD and osteoporosis, and the longitudinal association of MS with fractures in 420 men and 676 women from the Rancho Bernardo Study.

RESULTS

Prevalence of MS at baseline was 23.5% in men and 18.2% in women. In age-adjusted analyses, men and women with MS had higher BMD at total hip when compared to those without MS (p < 0.001 and p = 0.01, respectively). Men but not women with MS also had higher BMD at femoral neck (p = 0.05). After adjusting for BMI, these associations were reversed, such that MS was associated with lower and not higher BMD.

CONCLUSION

Incidence of osteoporotic non-vertebral fractures was higher in participants with MS. MS may be another risk factor for osteoporotic fractures. The association of MS with higher BMD was explained by the higher BMI in those with MS.

Measuring gonadotropins is of limited value in detecting hypogonadism in ageing men: the Tromsø study

Testosterone levels decrease with age. The mechanisms responsible for the age-related decrease in testosterone concentration are still being debated, and probably involve all three levels of the hypothalamo-pituitary-testicular axis. Luteinizing hormone (LH) concentration is often measured in combination with testosterone, but its value is questionable when considering the testosterone levels of older men. The objective of the present study was to examine the associations of endogenous gonadotropin and testosterone levels both in a cross-sectional cohort of 3447 men participating in the fifth Tromsø study and longitudinally in a cohort of 1352 men participating in both the fourth and the fifth Tromsø study. Total testosterone, LH, follicle-stimulating hormone and sex hormone-binding globulin levels were measured with immunoassay while free testosterone levels were calculated. Total testosterone and LH were independently and positively associated in the cross-sectional analyses (p < 0.001). In the longitudinal study, however, LH levels did not predict changes in total and free testosterone levels. Thus, in clinical practice, measuring gonadotropins seems to be of limited value in detecting hypogonadism in ageing men.

Components of the metabolic syndrome in long-term survivors of testicular cancer

BACKGROUND

A possible explanation of the excess cardiovascular risk in testicular cancer (TC) survivors is development of metabolic syndrome. The association between metabolic syndrome and TC treatment is examined in long-term survivors.

PATIENTS AND METHODS

In a national follow-up study (1998-2002), 1463 TC survivors (diagnosed 1980-1994) participated. Patients >60 years were excluded in the present study, leaving 1135 patients eligible. The patients were divided in four treatment groups: surgery (n = 225); radiotherapy (n = 446) and two chemotherapy groups: cumulative cisplatin dose (Cis) <or=850 mg (n = 376) and Cis >850 mg (n = 88). A control group consisted of 1150 men from the Tromsø Population Study. Metabolic syndrome was defined according to a modified National Cholesterol Education Program definition.

RESULTS

Both chemotherapy groups had increased odds for metabolic syndrome compared with the surgery group, highest for the Cis >850 group [odds ratio (OR) 2.8, 95% confidence interval (CI) 1.6-4.7]. Also, the Cis >850 group had increased odds (OR 2.1, 95% CI 1.3-3.4) for metabolic syndrome compared with the control group. The association between metabolic syndrome and the Cis >850 group was strengthened after adjusting for testosterone, smoking, physical activity, education and family status.

CONCLUSION

TC survivors treated with cisplatin-based chemotherapy have an increased risk of developing metabolic syndrome compared with patients treated with other modalities or with controls.

Reduced pulmonary function is associated with lower levels of endogenous total and free testosterone. The Tromsø study

Men with chronic obstructive pulmonary disease have reduced endogenous testosterone levels. Little is known, however, about the relationship between pulmonary function and endogenous testosterone levels in a general population. In the present study we have examined the cross-sectional associations between sex hormones measured by immunoassay and pulmonary function assessed with spirometry and oxygen saturation in 2,197 men participating in the fifth Tromsø study. The data were analyzed by univariate correlations, multiple linear regression analyses and analyses of variance and covariance. Total and free testosterone were positively and independently associated with forced vitality capacity, FVC (% of predicted) (P = 0.001 and P = 0.006, respectively) and forced expiratory volume in 1 second, FEV(1 )(% predicted) (P = 0.033 and P = 0.002, respectively), and men with severe pulmonary obstruction (FEV(1) % of predicted < 50) had lower free testosterone levels (P = 0.005). In this cross-sectional data from Tromsø, a reduction in pulmonary function was associated with lower levels of total and free testosterone. We suggest that the reduction of total and free testosterone could be due to an alteration of the hypothalamic-pituitary response.

Endogenous testosterone levels and smoking in men. The fifth Tromsø study

Smoking is a risk factor of coronary heart disease (CHD), while the role of testosterone in the development of CHD is controversial. The reported effects of cigarette smoking on testosterone levels in men are conflicting, and smoking may be an important confounding factor when evaluating the relationship between testosterone levels and CHD. Thus, the objective of the present study was to examine the associations of smoking status and number of cigarettes smoked per day with total and free testosterone levels in a cross-sectional population-based study of 3427 men participating in the fifth Tromsø study. Total testosterone, luteinizing hormone, follicle-stimulating hormone and sex hormone-binding globulin levels were measured with immunoassay while free testosterone levels were calculated. Waist circumference was also measured and two standardized questionnaires were completed, including smoking status and number of cigarettes smoked. The data were analysed with analysis of variance and covariance and multiple regression analysis. Smoking men had significantly higher levels of total and free testosterone compared with men who never smoked (p < 0.001 and <0.01 respectively). Both total and free testosterone levels increased significantly with increasing number of cigarettes smoked daily (p < 0.001). Smoking men had 15% higher total and 13% higher free testosterone levels compared with men who never smoked. Thus, smoking seems to be an important confounding factor when evaluating testosterone levels, and could possibly mask borderline hypogonadism.

Epidemiology: testosterone and the metabolic syndrome

Low levels of testosterone, hypogonadism, have several common features with the metabolic syndrome. In the Tromsø Study, a population-based health survey, testosterone levels were inversely associated with anthropometrical measurements, and the lowest levels of total and free testosterone were found in men with the most pronounced central obesity. Total testosterone was inversely associated with systolic blood pressure, and men with hypertension had lower levels of both total and free testosterone. Furthermore, men with diabetes had lower testosterone levels compared to men without a history of diabetes, and an inverse association between testosterone levels and glycosylated hemoglobin was found. Thus, there are strong associations between low levels of testosterone and the different components of the metabolic syndrome. In addition, an independent association between low testosterone levels and the metabolic syndrome itself has recently been presented in both cross-sectional and prospective population-based studies. Thus, testosterone may have a protective role in the development of metabolic syndrome and subsequent diabetes mellitus and cardiovascular disease in aging men. However, clinical trials are needed to confirm this assumption.

Low testosterone levels are associated with carotid atherosclerosis in men

OBJECTIVE

To study the relationship between endogenous sex hormone levels and intima-media thickness (IMT) of the carotid artery measured by ultrasonography.

DESIGN

Population-based cross-sectional study.

METHODS

Sex hormone levels measured by immunoassay, anthropometric measurements and IMT was studied in 1482 men aged 25-84 years participating in the 1994-1995 Tromsø study. The data were analysed with partial correlation, multiple linear regression and logistic regression analysis.

RESULTS

Linear regression models showed that total testosterone and sex hormone-binding globulin levels, but not calculated free testosterone, serum oestradiol or dehydroepiandrosterone sulphate levels were inversely associated with the age-adjusted IMT (P = 0.008 and P < 0.001 respectively). These associations were independent of smoking, physical activity, blood pressure and lipid levels, but were not independent of body mass index (BMI). Excluding men with cardiovascular disease (CVD) did not materially change these results. In a logistic regression model adjusted for the confounding effect of CVD risk factors, men with testosterone levels in the lowest quintile (<9.0 nmol L(-1)) had an independent OR = 1.51 (P = 0.015) of being in the highest IMT quintile.

CONCLUSIONS

We found an inverse association between total testosterone levels and IMT of the carotid artery in men that was present also after excluding men with CVD, but was not independent of BMI. The clinical relevance of this, however, is uncertain and needs to be investigated in a clinical setting.

The relationship between blood pressure and serum parathyroid hormone with special reference to urinary calcium excretion: the Tromsø study

The aim of the present cross-sectional epidemiological study from Tromsø, Northern Norway, was to evaluate the relation between blood pressure and serum PTH, and to examine whether this relation can be explained by a blood pressure-induced increase in urinary calcium. Ten thousand-four hundred and nineteen subjects were invited to participate and 8,128 attended. Those with serum calcium outside the reference range (2.20-2.60 mmol/l), with increased serum creatinine (upper limit 120 micromol/l for men and 100 micromol/l for women) and those using antihypertensive medication were excluded. Three thousand- six hundred and twenty subjects had complete data on outcome measures. Height, weight, blood pressure, serum calcium, PTH, and creatinine were measured and smoking status recorded. A morning urine sample was collected and urinary calcium, sodium and creatinine measured. The urinary calcium/urinary creatinine ratio (Uca/Ucr) and urinary sodium/urinary creatinine ratio (Una/Ucr) were calculated. There was a significant association between both systolic and diastolic blood pressure and serum PTH. The Uca/Ucr increased with increasing blood pressure. However, the Uca/Ucr did not affect the association between blood pressure and serum PTH in a multiple linear regression model. The relationship between blood pressure and serum PTH was also seen in subjects with similar Uca/Ucr, and a negative association between serum PTH and the Uca/Ucr was found. In conclusion, blood pressure and serum PTH are associated. This association cannot be explained by the urinary calcium excretion alone.

[Endogenous Cushing's syndrome]

BACKGROUND

Untreated endogenous Cushing's syndrome is a serious condition with high morbidity and mortality. New diagnostic procedures make today's assessment more accurate. We describe which tests should be done when there is suspicion of the syndrome. Treatment options are mentioned.

MATERIAL AND METHODS

The paper is based on current international literature and reflects the experience of the authors.

RESULTS AND INTERPRETATION

Endogenous Cushing's syndrome is caused by elevated cortisol levels. The reason can be overproduction of ACTH or an adrenocortical pathology. It should be considered when combinations of symptoms like central obesity, proximal muscle weakness, striae and menstrual irregularities are seen. Osteoporosis and impotence are other important symptoms. Diagnosis of Cushing's syndrome is often challenging. Measurement of urinary free cortisol or overnight dexamethasone suppression test has usually been performed initially. Midnight salivary cortisol seems promising as an alternative. The final diagnosis is often made after a combined evaluation of dynamic tests. The first-line treatment of endogenous Cushing's syndrome is surgery.

Neuropsychological function in relation to serum parathyroid hormone and serum 25-hydroxyvitamin D levels. The Tromsø study

There are receptors for parathyroid hormone (PTH) and 1,25-dihydroxyvitamin D in the brain, and there are clinical and experimental data indicating that PTH and vitamin D may affect cerebral function. In the present study 21 subjects who both in the 5th Tromsø study and at a follow-up examination fulfilled criteria for secondary hyperparathyroidism (SHPT) without renal failure (serum calcium < 2.40 mmol/L, serum PTH > 6.4 pmol/L, and normal serum creatinine) and 63 control subjects were compared with tests for cognitive and emotional function. Those in the SHPT group had significantly impaired performance in 3 of 14 cognitive tests (Digit span forward, Stroop test part 1 and 2, and Word association test (FAS)) as compared with the controls, and also had a significantly higher depression score at the Beck Depression Inventory (BDI) (items 1-13). In a multiple linear regression model, a high serum PTH level was significantly associated with low performance at the Digit span forward, Stroop test part 1 and 2, and Digit Symbol tests. A low level of serum 25-hydroxyvitamin D was significantly associated with a high depression score. In conclusion, a deranged calcium metabolism appears to be associated with impaired function in several tests of neuropsychological function.

Serum parathyroid hormone as a predictor of increase in systolic blood pressure in men

BACKGROUND

In cross-sectional studies there appears to be a link between calcium metabolism and blood pressure, and most studies have found a positive association between serum parathyroid hormone (PTH) and hypertension.

OBJECTIVE

To determine the prognostic value of serum PTH regarding a future increase in blood pressure.

DESIGN

A prospective cohort study.

SUBJECTS

A total of 1784 individuals who had measurements of PTH in serum samples from both the fourth (1994) and fifth (2001) Tromsø studies, who did not use blood pressure medication during the observation period, and had serum calcium less than 2.61 mmol/l, were included.

MAIN OUTCOME MEASURE

Delta blood pressure (blood pressure from 2001 minus blood pressure from 1994).

RESULTS

The mean delta systolic blood pressure in the men and women during these 7 years was 5.8 and 8.1 mmHg, respectively. In a sex-specific linear regression model correcting for age, body mass index (BMI), and smoking status, serum PTH from 1994 was a significant predictor of delta systolic blood pressure in men (P < 0.01), but not in women. The difference in delta systolic blood pressure between those in the highest and those in the lowest PTH quartile was 3.5 mmHg. Similarly, delta serum PTH (serum PTH from 2001 minus serum PTH from 1994) was a significant predictor of delta systolic blood pressure in men (P < 0.05).

CONCLUSIONS

Although these findings do not prove a causal relationship between PTH and blood pressure, it adds to the growing number of indications that PTH is involved in the development of hypertension.

Surviving extreme hypercalcaemia--a case report and review of the literature

We report a case of extreme hypercalcaemia associated with a parathyroid adenoma in a young man. The patient presented with classical symptoms of a hypercalcaemic syndrome, and serum calcium and parathyroid hormone levels were 6.92 mmol L(-1) and 70.2 pmol L(-1) respectively. After stabilizing the patient and reducing the calcium level, a parathyroidectomy was performed. The postoperative course was uneventful with rapidly resolving clinical symptoms. Hypercalcaemic crisis is a rare but life-threatening complication of primary hyperparathyroidism. It should be suspected in acutely ill patients complaining of muscular weakness, gastrointestinal and cerebral symptoms. To reduce mortality, it is essential to correctly diagnose the condition without delay and provide appropriate emergency management correcting hypercalcaemia and dehydration. Successful parathyroidectomy quickly relieves symptoms and prevents recurrence.

[Should older men be treated with testosterone?]

BACKGROUND

Male hypogonadism is a clinical situation characterised by a low serum testosterone level in combination with a diversity of symptoms and signs such as reduced libido and vitality, decreased muscle mass, increased fat mass and depression. Similar symptoms in combination with subnormal testosterone levels are seen in some elderly men. Several publications have suggested that testosterone treatment in hypogonadal men may have beneficial effects, but it is still uncertain whether testosterone substitution in the aging man is indicated. Despite this uncertainty the sale of testosterone have increased enormously over the last few years, hence it seems important to discuss what we now know about such treatment.

MATERIAL AND METHODS

Review of recent literature studying testosterone substitution in older men.

RESULTS AND INTERPRETATION

The result from placebo-controlled studies of testosterone substitution in elderly men differ substantially, but it seems to improve, among other things, bone mineral density, body composition, perception of physical strength, and maybe libido. In the short term there have been few problems or complications with testosterone treatment, but effects on the cardiovascular system and the prostate over the long term remain uncertain. Before any general recommendation could be given, big prospective studies have to be performed. Treatment should, however, be considered in men with testosterone in the hypogonadal range accompanied by clinical symptoms. Treatment needs to be individualized and should preferably be initiated by specialists in andrology, endocrinology or urology.

[Primary adrenal failure--causes, diagnostics and therapy]

BACKGROUND AND METHODS

An overview of primary adrenal failure with emphasis on replacement therapy is presented. The article is based on a review of recent literature and authors' personal experience.

RESULTS AND CONCLUSIONS

Addison's disease is usually caused by an autoimmune destruction of the adrenal cortex. It is relatively rare (prevalence 14 per 100,000 inhabitants), but often considered as a differential diagnosis when evaluating fatigue, tiredness and loss of weight. Addison's disease is treated by repletion of glucocorticoids and mineralocorticoids. The recommended starting dose is 25 mg cortisone acetate per day divided into three (12.5 + 6.25 + 6.25 mg) or two doses (12,5 mg x 2). Mineralocorticoid replacement is given as fludrocortisone 0.05 - 0.2 mg in one dose per day. Treatment with 20 - 50 mg dehydroepiandrosterone has been studied in adrenal failure, but the evidence for positive effects is weak, and it can not be recommended as standard treatment in primary adrenal failure.

Waist circumference and testosterone levels in community dwelling men. The Tromsø study

To examine the relationship of total and free testosterone and sex hormone-binding globulin (SHBG) with central obesity in men, we studied 1548 men aged 25-84 years that took part in the 1994--1995 survey of the Tromsø study. Total testosterone and SHBG were measured by immuno-assay and the free testosterone fraction was calculated. These measurements were analyzed in relation to anthropometric data and lifestyle factors. The age-adjusted correlation between waist circumference (WC) and total testosterone was -0.34 (p < 0.001), between WC and free testosterone -0.09 (p < 0.001) and, between WC and SHBG -0.44 (p < 0.001). Adjusting for BMI and lifestyle factors weakened, but did not eliminate these associations. All hormone and SHBG associations were stronger for WC than for waist-hip ratio or BMI. In age- and BMI-adjusted analyses men with a WC > or = 102 cm had significantly lower levels of total testosterone and SHBG compared to men with an optimal WC, defined as < 94 cm (12.3 vs. 13.9 nmol/l; p < 0.01 and 48.5 vs. 55.1 nmol/l; p < 0.001, respectively). The lowest levels of total and free testosterone were observed in men with relatively high WC despite relatively low overall obesity (BMI), suggesting that WC should be the preferred anthropometric measurement in predicting endogenous testosterone levels.

Release of TNF-alpha from in vitro-stimulated monocytes is negatively associated with serum levels of apolipoprotein B in patients with type 2 diabetes

Impaired course of inflammation is a likely mechanism behind a number of diabetic complications. The present study was undertaken to investigate lipopolysaccharide-induced production of tumour necrosis factor (TNF)-alpha in monocytes from patients with type 2 diabetes and to assess its relationship with diabetes-associated metabolic abnormalities. Monocytic TNF-alpha mRNA production was lower in the diabetic participants compared to their corresponding controls. Diabetic subjects who had been receiving simvastatin treatment had TNF-alpha mRNA production similar to that of the healthy participants. The release of TNF-alpha from diabetic cells correlated negatively with serum levels of apolipoprotein B (apoB) (R = -0.755, P = 0.001), total plasma cholesterol (R = - 0.702, P = 0.002) and the presence of retinopathy (R = -0.572, P = 0.021). No such associations were found in the control subjects. In a multiple linear regression model, only the level of apoB and diabetes duration demonstrated significant effects on the release of TNF-alpha, with apoB alone accounting for 57% of the variation. We conclude that production of TNF-alpha mRNA in response to the bacterial stimulant is compromised in poorly controlled type 2 diabetes. Lipid abnormalities are associated with the observed defect. Impaired cytokine production represents a significant defect in the functioning of the immune system and may contribute to aberrations in the course of inflammation in the diabetic state.

Endogenous sex hormones in relation to age, sex, lifestyle factors, and chronic diseases in a general population: the Tromsø Study

The role played by endogenous hormones in many diseases makes it important to understand factors influencing their levels. This study examined the distribution of total and free estradiol, FSH, and dehydroepiandrosterone sulfate (DHEAS) by age and sex and associations of these hormones with body mass index (BMI), lifestyle factors, and chronic diseases. Plasma samples taken from 1555 men and 1952 women 25-84 yr of age in 1994-1995 Tromsø Study were analyzed in 2001. Total estradiol increased with age among men (P < 0.001), with or without adjustment for BMI and lifestyle factors. FSH increased with age both in men (P < 0.001) as well as pre- (P < 0.001) and postmenopausal women (P = 0.01) after similar adjustment, and DHEAS decreased with age in both sexes (P < 0.001). With increasing BMI, free estradiol increased in men (P = 0.004), total and free estradiol increased in postmenopausal women (P < 0.001), and FSH decreased in men (P = 0.03) and postmenopausal women (P < 0.001). Men with chronic diseases had lower levels of DHEAS, compared with healthy men (P < 0.001). Smokers had higher DHEAS levels than nonsmokers. Further studies are needed to confirm these hormonal changes with age and disease.

Could seasonal variation in testosterone levels in men be related to sleep?

We have previously reported seasonal variations in both total and free testosterone in men living in north Norway. The aim of this cross-sectional study was to determine whether seasonal variation in testosterone also occurs in men living in geographical areas with less extreme seasonal variation in sunlight and temperature. In 915 men aged 24-91 years from Rancho Bernardo, a suburb of San Diego in southern California, we found that neither total nor bioavailable testosterone varied by season, with or without adjustments for age and anthropometric measurements. Of all examined covariates, only physical activity showed a seasonal variation, with a peak in August (p < 0.001), and adjusting for physical activity did not change the lack of seasonal variation in testosterone. In addition, there was no association between testosterone and mean air temperature, or testosterone and possible hours of sunshine. We conclude that men living in southern California show no seasonal variation in testosterone levels. One possible explanation, besides the difference in climate, for the diverging findings between our previous study and the present study is different sleep patterns.

Testosterone treatment improves body composition and sexual function in men with COPD, in a 6-month randomized controlled trial

The aim of this study was to assess the effect of a low-dose testosterone on body composition and pulmonary function, as well as on quality of life, sexuality, and psychological symptoms in patients with chronic obstructive pulmonary disease (COPD). Twenty-nine men with moderate to severe COPD were allocated to receive either 250 mg of testosterone or placebo intra-muscularly, every fourth week, during the 26 weeks study period. Fat-free mass increased in the treatment group (P<0.05), and a significant difference between the treatment and the control group was seen after 26 weeks (P<0.05). Fat mass decreased in the treatment group (P<0.05), and there was a significant difference between the treatment and the control group after 12 weeks (P<0.01). A significantly better erectile function was reported in the treatment group at the final visit (P<0.05), and the overall sexual quality of life was significantly better in the treatment group after 12 weeks (P<0.05). No improvement in pulmonary function was found. In conclusion, administration of a low-dose testosterone to men with COPD for 26 weeks was associated with improvement of body composition, better erectile function and sexual quality of life. Furthermore, there were no clinical or biochemical side effects.

The associations of endogenous testosterone and sex hormone-binding globulin with glycosylated hemoglobin levels, in community dwelling men. The Tromsø Study

OBJECTIVES

Low levels of endogenous testosterone have been associated with increased risk of cardiovascular disease and atherosclerosis in men. Long-term hyperglycemia, as measured by glycosylated hemoglobin (HbA1c), is related to cardiovascular mortality, and HbA1c across its normal range is also positively related to coronary heart and cardiovascular disease mortality in men. We therefore undertook an analysis of the cross-sectional associations of total testosterone and SHBG levels with HbA1c levels, in a general population of 1419 men aged 25-84.

METHODS

Total testosterone, sex hormone-binding globulin (SHBG) and HbA1c were measured by immuno-assay. Partial correlation and multiple regression analyses were used to estimate the associations between total testosterone and SHBG with HbA1c. Analyses of variance and covariance were used to compare men with or without diabetes.

RESULTS

In age-adjusted partial correlation HbA1c was inversely associated with total testosterone (p<0.01) and SHBG (p<0.001). HbA1c was positively associated with body mass index (BMI) and waist circumference (WC) (p<0.001). In multiple regression analyses total testosterone, SHBG, age, number of cigarettes smoked, BMI and WC were independently associated with HbA1c levels. Men with a history of diabetes had lower levels of total testosterone in age-adjusted analyses (p<0.05) and lower levels of SHBG in both age- and WC-adjusted analyses (p<0.001 and p<0.01, respectively).

CONCLUSION

Lower levels of total testosterone and SHBG were associated with increased HbA1c levels and diabetes independent of concomitant variations in obesity and body fat distribution.

Association of endogenous testosterone with blood pressure and left ventricular mass in men. The Tromsø Study

OBJECTIVE

To test the hypothesis that lower endogenous testosterone levels are associated with higher blood pressure, left ventricular mass, and left ventricular hypertrophy.

DESIGN

Population-based cross-sectional study.

METHODS

Sex hormone levels, measured by immunoassay, anthropometric measurements and resting blood pressure were studied in 1548 men aged 25-84 Years; echocardiography was completed in 1264 of these men. Partial correlations and multiple regressions were used to estimate the associations between sex hormones, blood pressure and left ventricular mass by height. Analyses of variance and covariance were used to compare men with categorical hypertension and left ventricular hypertrophy.

RESULTS

In age-adjusted partial correlations, total testosterone and sex hormone-binding globulin (SHBG) were each inversely associated with systolic blood pressure (SBP) (P<0.001). Men with categorical hypertension (SBP> or =140 or diastolic blood pressure (DBP)> or =90 mmHg) had lower levels of total and free testosterone and SHBG before (P<0.001, P=0.011 and P<0.001, respectively) and after (P<0.001, P=0.035 and P=0.002, respectively) adjusting for body mass index (BMI). Total testosterone and SHBG were each inversely associated with left ventricular mass (P<0.001), and men with left ventricular hypertrophy had significantly lower levels of total testosterone (P=0.042) and SHBG (P=0.006); these associations were no longer significant after adjusting for BMI.

CONCLUSION

The results of the present study are consistent with the hypothesis that lower levels of testosterone in men are associated with higher blood pressure, left ventricular mass, and left ventricular hypertrophy. The reduced associations after adjusting for BMI suggest that the association of low testosterone levels with blood pressure and left ventricular mass is mediated by obesity.

[Hormonally inactive pituitary adenomas]

BACKGROUND

This paper surveys hormonally inactive pituitary tumours on the basis of the current international literature; it also reflects the experience of the authors.

INTERPRETATION

Pituitary tumours are frequently diagnosed and usually show a low potential for growth. Although benign they may invade adjacent structures such as the cavernous and sphenoid sinuses. The diagnosis is usually made on the basis of pituitary failure or visual problems, or incidentally. Tumour debulking or removal, usually by transsphenoidal surgery, is indicated if there is a compression of the optic chiasm or if the tumour shows signs of growth on consecutive MRI scans. Surgery is an effective treatment of these tumours, with little risk of complications. Repeated surgery, either transsphenoidally or by craniotomy, is indicated if chiasmal decompression is not achieved initially. Fractionated single beam irradiation or stereotactic radiosurgery is indicated in cases where there is a residual of growing tumours that may not be removed surgically.

The associations of age, lifestyle factors and chronic disease with testosterone in men: the Tromsø Study

OBJECTIVE

To study whether lifestyle factors and/or chronic disease are associated with the age-related decline of total and free testosterone in men, or if these factors might be associated with the variation of total and free testosterone but not with their age-related decline.

DESIGN

A population-based, cross-sectional study was used.

METHODS

Total testosterone and sex hormone binding globulin (SHBG) levels were analyzed and free testosterone levels were calculated in 1563 men participating in the Tromsø study in 1994/1995. Anthropometric characteristics were also measured and two standardized questionnaires completed, including lifestyle factors and medical history. The data were analyzed with multiple linear regression analysis of covariance, and logistic regression.

RESULTS

Total and free testosterone were inversely associated (P=0.001 and P<0.001), while SHBG was positively associated (P<0.001) with age. Body mass index (BMI) was inversely associated with total (P<0.001) and free (P=0.016) testosterone and SHBG (P<0.001). Both total and free testosterone were positively associated with tobacco consumption (P<0.001 and P=0.004) and total testosterone was positively associated with coffee consumption (P<0.001). SHBG was positively associated with smoking (P=0.004) and coffee consumption (P<0.001). Men who reported having had a stroke or having a cancer diagnosis had lower levels of total testosterone (P<0.001 and P<0.01) and free testosterone (P<0.01).

CONCLUSIONS

BMI and smoking are independent contributors to the variation of total and free testosterone and SHBG levels, and coffee consumption to the variation of total testosterone and SHBG. Thus, lifestyle factors can have a direct effect on circulating levels of free endogenous sex hormones and to total levels due to the effect on SHBG levels.

Seasonal variation of testosterone and waist to hip ratio in men: the Tromsø study

Studies of seasonal variation in male testosterone levels show contradictory results. We report here a cross-sectional study of the seasonal variation in total and free testosterone, LH, and SHBG levels in 1548 men living in north Norway, a population exposed to a wide seasonal variation in temperature and daylight. Total testosterone showed a bimodal seasonal variation (P < 0.001) with a small peak in February, the nadir in June, and a more prominent peak in October and November. Free testosterone also showed a significant seasonal pattern (P < 0.001), with the peak in December and the nadir in August. These patterns persisted after adjusting for age and waist to hip ratio (P < 0.001). Lowest testosterone levels occurred in months with the highest temperatures and longest hours of daylight. Waist to hip ratio paralleled the change in daylight and temperature, with the highest values during the summer and was thus inversely related to the seasonal testosterone variation. The variations in hormone levels were large, with a 31% difference between the lowest and highest monthly mean level of free testosterone. Prospective studies are needed to establish the direction of the association and its etiology.

[Hyperprolactinemia and prolactinemia--investigation and treatment]

BACKGROUND

Prolactinoma represents the most commonly occurring hormone-secreting pituitary adenoma. The majority of prolactinomas are small, only rarely do we find larger prolactinomas, so-called macroadenomas. They are almost exclusively benign. The symptoms are mainly caused by elevated prolactin levels and result in changes to the reproductive and sexual function. In cases of macroprolactinomas, symptoms caused by local mass effects can be seen. A variety of other conditions may also cause hyperprolactinaemia; the goal of the examination is to identify the cause.

MATERIAL AND METHODS

We have reviewed recent literature and compared findings with current management of hyperprolactinaemia and prolactinoma in Norwegian university hospitals.

RESULTS AND INTERPRETATION

The primary treatment is medical, intended to normalize prolactin levels, restore gonadal function, and reduce tumour size. With the new selective dopamine agonists, the treatment is often simple and efficient, but not all patients are in need of treatment.

[Anemia and neutropenia in primary empty sella syndrome]

BACKGROUND

A 64-year-old man was admitted to our hospital with significant weight loss and symptoms of fatigue. He had normocytic anaemia and absolute neutropenia in peripheral blood.

MATERIAL AND METHODS

Further haematological and endocrinological investigations were performed.

RESULTS

Bone marrow aspiration and biopsy showed dysplastic signs. Immunophenotyping and cytogenetics did not provide evidence of primary haematological disease. Endocrinological testing demonstrated secondary adrenal insufficiency. Magnetic resonance imaging of the sella turcica showed an empty sella. Cortisol substitution eliminated the symptoms of the patient and normalised his peripheral blood values. The disturbed maturity and hypoplasia of the bone marrow were also normalised.

INTERPRETATION

Normalisation of haematopoiesis after cortisol substitution indicates that cortisol plays an important role in the regulation of haematopoiesis. Primary empty sella syndrome with isolated ACTH cortisol deficiency is a very rare cause of disturbed haematopoiesis.

Antidiabetogenic action of glucagon-like peptide-1 related to administration relative to meal intake in subjects with type 2 diabetes

OBJECTIVE

To establish the antidiabetogenic effect of glucagon-like peptide-1 (GLP-1) when differently administered relative to meal intake in subjects with type 2 diabetes.

DESIGN

The study was a placebo-controlled comparison with random assignment to treatment sequence. A 3-h stepwise infusion of GLP-1 (17 nmol) was started either at the onset of a standard meal (550 kCal) (A) or at 30 min (B) or 60 min (C) after the start of the meal.

SETTING

The study was conducted at a university hospital.

SUBJECTS

Eight patients with type 2 diabetes (four women and four men), age 62 +/- 3.9 years (range 47-74 years), weight 79.8 +/- 5.4 kg (range 62-104 kg), BMI 26.2 +/- 1.3 kg m(-2) (range 21-31 kg m(-2)), diabetes duration 10.5 +/- 2.0 years (range 3-19 years) and HbA1c levels 6.1 +/- 0.3% (range 4.7-7.7%) participated in the study. All patients were treated with oral sulphonylureas.

RESULTS

Glucagon-like peptide-1 significantly lowered postprandial glycaemia by a similar degree in all three situations versus the control meal (P < 0.05). Postprandial insulin levels were not different in the four experimental series, whereas the postprandial glucagon levels were significantly lowered by GLP-1 in (A) and (B) (P < 0.03) but not in (C). Gastric emptying, as determined by the paracetamol test, was retarded by GLP-1 only in (A) (P < 0.01), but not affected in (B) or (C).

CONCLUSIONS

GLP-1 reduced postprandial hyperglycaemia in subjects with type 2 diabetes regardless of administration at the onset of meal intake or at 30 or 60 min after start of meal intake, although the mechanism of the antidiabetogenic action of GLP-1 depended on administration versus meal intake. Thus, when administered at the start of a meal, GLP-1 was antidiabetogenic mainly through retarding gastric emptying, whereas when given at 30 or 60 min after meal ingestion, changes in islet hormone secretion seem to be predominant.

The ethanol augmentation of glucose-induced insulin secretion is abolished by calcium antagonism with nifedipine: no evidence for a role of glucagon-like peptide-1 (GLP-1)

We studied the effect of ethanol and calcium antagonism (nifedipine) on insulin- (n = 8) and glucagon-like peptide-1 (GLP-1) (n = 6) secretion in healthy subjects. Four experiments in random order were performed (control, ethanol, nifedipine, and combination). Intravenous glucose tolerance tests were performed with and without pretreatment with oral ethanol and nifedipine. Ethanol pretreatment was followed by increased insulin (ethanol vs. control; p < 0.01) and C-peptide (ethanol vs. control; p < 0.05) areas after intravenous glucose (0-20 min), indicating that ethanol augments insulin secretion. Calcium antagonism with nifedipine abolished the ethanol augmentation of insulin secretion (insulin area 0-20 min, ethanol vs. combination, p < 0.05; and C-peptide area 0-20 min, ethanol vs. combination, p < 0.01). The GLP-1 response (area 0-90 min) was not significantly affected by ethanol.

Tumour-induced hypoglycaemia in a patient with insulin-dependent diabetes mellitus

We report on a case of malignant insulinoma occurring in a patient with genuine insulin-dependent diabetes mellitus (IDDM). A review of cases concerning patients with diabetes mellitus and insulinomas is presented, and reveals only patients with non-insulin-dependent diabetes mellitus (NIDDM). Our case appears to be the first in showing the combination of IDDM and a functioning malignant insulinoma.