Trine Bjøro

Hormonal responses to high- and moderate-intensity strength exercise

Abstract The hormonal responses of nine male, strength athletes to strength exercise were examined. The athletes performed one moderate- and one high-intensity strength exercise workout. In the high-intensity workout, the load was 100% of each subjects three-repetition maximum (3-RM) for squats and front squats, and 100% of each subjects six-repetition maximum (6-RM) for leg extensions. In the moderate-intensity workout, the load was 70% of the high-intensity protocol. Rest periods between sets were 4–6 min for both workouts. Blood samples were taken before, 30 min into, and every 15 min for the 1st h after exercise, and then 3, 7, 11, 22 and 33 h after exercise, thus allowing examination of both the acute and prolonged hormonal responses. Blood samples were analyzed for testosterone, luteinizing hormone (LH), follicle stimulating hormone (FSH), cortisol, adrenocorticotrophic hormone (ACTH), growth hormone (GH), insulin-like growth factor (IGF-1), insulin, sex hormone binding globulin, creatine kinase, total protein, glucose and lactate. The acute responses of testosterone and cortisol were greater during the high-intensity protocol as compared to the moderate-intensity protocol. The cortisol response was associated with an increase in ACTH concentration. LH and FSH showed no response to either protocol. Acute GH responses were not different between protocols. There were great inter-individual differences in acute GH responses to both protocols. There were no significant differences between protocols with regard to prolonged responses for any hormone. In both trials, IGF-1 concentrations were significantly lower at 0800 hours the morning after exercise as compared to concentrations found at 0800 hours the morning before exercise. The mechanisms responsible for reducing IGF-1 concentration in these trials are unclear, and it is not known if this reduction observed 22 hours after exercise is of physiological significance.

Gonadal hormones in long-term survivors 10 years after treatment for unilateral testicular cancer

OBJECTIVE To investigate whether unilaterally orchiectomised testicular cancer survivors (TCSs) are more likely to display reduced Leydig cell function than healthy males. METHODS A national multi-centre survey of 1235 TCSs was performed in 1998-2000 (mean age: 44 years) treated between 1980 and 1994 (mean follow-up: 11 years). Serum hormone analyses were performed on 1183 TCSs, as 52 TCSs used androgen replacement (AR). TCSs were allocated to four treatment groups: Surgery only (251); Radiotherapy only (515); Chemotherapy 1, cisplatin </=850 mg (373); Chemotherapy 2, cisplatin >850 mg (96). The Controls were represented by 200 healthy blue-collar workers (mean age: 44 years). LH >12 IU/l and testosterone <8 nmol/l and the use of AR indicated hypogonadism. RESULTS Serum testosterone was similar in TCSs and Controls (16.9 vs.17.1 nmol/l), but TCSs had higher age-adjusted LH levels than the Controls (5.2 vs. 3.5 IU/l). LH increased with treatment intensity, but was elevated even in TCSs treated with surgery only. The age-adjusted odds ratio of hypogonadism was 3.8 (95%CI: 2.0-7.3) in TCSs, and increased with treatment intensity. CONCLUSION TCSs are at risk to develop pre-mature reduced Leydig cell function and hypogonadism. They may therefore be predisposed for the syndrome of androgen deficiency of aging males (ADAM).

An association between depression, anxiety and thyroid function – a clinical fact or an artefact?

Objective: The aim of the study was to examine the association between depression, anxiety and thyroid dysfunction.

Thyrotropin Levels and Risk of Fatal Coronary Heart Disease: The HUNT Study

BACKGROUND Recent studies suggest that relatively low thyroid function within the clinical reference range is positively associated with risk factors for coronary heart disease (CHD), but the association with CHD mortality is not resolved. METHODS In a Norwegian population-based cohort study, we prospectively studied the association between thyrotropin levels and fatal CHD in 17,311 women and 8002 men without known thyroid or cardiovascular disease or diabetes mellitus at baseline. RESULTS During median follow-up of 8.3 years, 228 women and 182 men died of CHD. Of these, 192 women and 164 men had thyrotropin levels within the clinical reference range of 0.50 to 3.5 mIU/L. Overall, thyrotropin levels within the reference range were positively associated with CHD mortality (P for trend = .01); the trend was statistically significant in women (P for trend = .005) but not in men. Compared with women in the lower part of the reference range (thyrotropin level, 0.50-1.4 mIU/L), the hazard ratios for coronary death were 1.41 (95% confidence interval [CI], 1.02-1.96) and 1.69 (95% CI, 1.14-2.52) for women in the intermediate (thyrotropin level, 1.5-2.4 mIU/L) and higher (thyrotropin level, 2.5-3.5 mIU/L) categories, respectively. CONCLUSIONS Thyrotropin levels within the reference range were positively and linearly associated with CHD mortality in women. The results indicate that relatively low but clinically normal thyroid function may increase the risk of fatal CHD.

Frequency of hyperprolactinaemia due to large molecular weight prolactin (150-170 kD PRL)

Of 605 hyperprolactinaemic sera (prolactin > 1000 mU l-1 determined with PRL DELFIA, Wallac) in the routine diagnostic (PRL was measured in 10,737 sera) 26% had an increased amount of PRL with molecular weight (MW) = 150-170 kD (150-170 kD PRL or bigbig PRL). In a series of serum samples from 660 healthy subjects, only one female with hyperprolactinaemia due to increased 150-170 kD PRL was found. The 150-170 kD PRL constituted less than 1% of the total PRL found in 11 patients with prolactinoma (macroprolactinoma, PRL 8800-500,000 mU l-1). When determined with five different commercially available immunometric assays, the PRL values in the sera with large amounts of 150-170 kD were increased in all sera in four of five assays, although they varied widely. The clinical implications of hyperprolactinaemia due to increased 150-170 kD PRL are still uncertain.

Gonadal dysfunction and fertility problems in cancer survivors

Gonadal dysfunction and fertility problems are adverse effects of cancer treatment or may be associated with specific malignancies. This review focuses on these problems in the young cancer survivors, where methods of protecting or restoring endocrine function and fertility need to be considered. In females, treatment adverse effects can result in infertility, but premature ovarian failure (POF) is probably relevant for more female cancer survivors, affecting also those who do not wish post-treatment parenthood. POF affects present and future health, especially through oestrogen deficiency symptoms and an increased risk of developing osteoporosis. A lower risk of developing POF has been considered in young females than in older due to a larger pool of oocytes. However, a recent long-term follow-up study reported a prevalence of POF in young females with Hodgkins lymphoma of 37% showing that young age at time of treatment only delays the development of POF. In male gonads, germ cells are much more sensitive to irradiation and chemotherapy than Leydig cells. Thus, infertility is a more common adverse effect than hypogonadism. Some malignancies are particular relevant. Persistent azoospermia was formerly common after treatment for Hodgkins lymphoma, but currently, most patients recover spermatogenesis. Modern treatment of childhood acute lymphoblastic leukemia is also unlikely to cause infertility. Norwegian testicular cancer survivors diagnosed in 1980–1994 who attempted conception had an overall 15-year actuarial post-treatment paternity rate of 71% (range 48–92% depending on the treatment). However, the rate was significantly higher among men diagnosed in1989–1994 (over 80%) than in 1980–1988 (about 63%). Patients at risk for hypogonadism and infertility should be defined prior to treatment, and available methods for gonadal preservation should maximally be utilised. During follow-up, oncologists should routinely address these issues.

Thyroid Function and Cancer Risk: A Prospective Population Study

Background: It has been hypothesized that thyroid function may influence cancer risk, but few studies with adequate statistical power have investigated this question, and the results have not been consistent. Methods: In a prospective study of 29,691 people (19,710 women and 9,981 men) without previously known thyroid disease, thyrotropin was measured at baseline, and cancer incidence was recorded during 9 years of follow-up. Using Cox regression analysis, we studied the associations (hazard ratios) of thyrotropin categories with total cancer risk, and specifically, with risk of lung, colon, prostate, and breast cancer adjusted for age, sex, and smoking status. Results: Low thyrotropin levels (<0.50 mU/L) were associated with increased cancer risk [adjusted hazard ratio (HR), 1.34; 95% confidence interval (CI), 1.06-1.69] compared with the euthyroid reference group. The higher risk was driven by lung cancer (adjusted HR, 2.34; 95% CI, 1.24-4.40) and prostate cancer (adjusted HR, 1.97; 95% CI, 1.04-3.76). After excluding the first 2 years of follow-up, the associations were strengthened to 2.91 (1.49-5.70) for lung cancer and 2.60 (1.36-4.99) for prostate cancer. Conclusion: Thyrotropin levels suggestive of hyperthyroid function are associated with increased cancer risk, and specifically, with increased risk of lung and prostate cancer, whereas hypothyroid function does not seem to be associated with cancer risk. (Cancer Epidemiol Biomarkers Prev 2009;18(2):570–4)

Association of Serum TSH with High Body Mass Differs between Smokers and Never-Smokers

CONTEXT Recent studies have suggested that the association of low thyroid function with high body mass is restricted to nonsmokers. OBJECTIVE The aim was to study the association of thyroid function with body mass separately for smokers and never-smokers. DESIGN AND SETTING We conducted a cross-sectional, population-based study. SUBJECTS We studied 27,097 individuals older than 40 yr of age who were without previously known thyroid disease. MAIN OUTCOME MEASURES We measured mean body mass index (BMI) and odds ratio for obesity (BMI > or = 30.0 kg/m(2)) according to categories of thyroid function, in women and men, and separately for current smokers and never-smokers. We also studied the association with BMI within the reference range of TSH (0.50-3.5 mU/liter). RESULTS TSH within the reference range was positively associated with BMI (P for trend < or = 0.001 in all groups) and with the prevalence of obesity (P for trend < 0.005 in all groups). Among women, the association did not differ between current smokers and never-smokers, but in men the association was stronger for current smokers. Hypothyroid function was associated with higher BMI and higher prevalence of obesity in women (subclinical and overt hypothyroidism) and men (subclinical hypothyroidism), both in current smokers and in never-smokers. CONCLUSION The association of low thyroid function with high body mass was as least as strong in current smokers as in never-smokers, and our results clearly show that the association is not limited to nonsmokers, as previously suggested.

Self-reported health and use of health care services in long-term cancer survivors

Owing to an increasing number of long‐term cancer survivors, the use of health care services and somatic health problems were compared between cancer survivors and a noncancer population. Data from the Nord‐Trøndelag Health Survey 2 (HUNT 2, 1995–1997) was merged with the Cancer Registry of Norway. Six cancer subgroups were constructed with diagnosis 5 years prior HUNT 2: testicular cancer (n= 59), colorectal cancer (n= 175), prostate cancer (n= 87), breast cancer (n= 258), gynaecological cancer (n= 153) and lymphoma/leukaemia (n= 83). For each cancer survivor 3 matched noncancer controls were selected from the HUNT 2 survey. The prevalence of common health problems, use of health care services and unfavourably life style parameters were compared between the 2 groups. Cancer survivors used health care services and received social welfare benefits more often than the controls. There was an increased risk of perceiving poor health after a history of cancer. Common health problems and/or unfavourable life style parameters could not explain poor health or the increased use of health care services among cancer survivors. Further studies are needed to investigate the reasons for increased use of health care services and perceived poor health in cancer survivors.

CHANGES IN HUMAN SKELETAL MUSCLE CONTRACTILITY AND HORMONE STATUS DURING 2 WEEKS OF HEAVY STRENGTH TRAINING

Abstract To examine neuromuscular and hormone changes during 2 weeks of heavy strength training, 18 weight-trained male students were recruited either into a heavy training group (HT, n=11) or into a control group (Ctr, n=7). The heavy training protocol consisted of leg-extensor workouts performed daily, while workouts were performed twice a week in the Ctr group. A test of one repetition maximum (1 RM) was performed before heavy training and on the 2nd day after heavy training. Isokinetic knee extensions, electrical stimulation, and squat jumps were performed before, on the 8th day of heavy training, and on the 4th day after heavy training. Morning blood samples (0800 hours) were drawn before, on the 8th day of heavy training, and on the 4th day after heavy training. Before, and on the 5th day after heavy training, 24 h urine samples were collected. The 1 RM leg press increased by 6 (SEM 2)% in the HT group. Testosterone and insulin-like growth factor-1 concentrations were respectively 12 (SEM 5)% and 11 (SEM 3)% lower than baseline on the 8th day of heavy training; however, hormone levels were back to baseline on the 4th day after heavy training. A significant correlation between individual changes in 1 RM leg press and changes in testosterone concentrations was observed in the HT group (r=0.69). In the HT group, 24 h urinary catecholamine excretion increased by 26 (SEM 12)%, 3-methylhistidine excretion increased by 21 (SEM 6)% and creatinine excretion increased by 11 (SEM 5)%. There were no significant changes in the Ctr group. This work addresses the role of changes in basal hormone status (morning samples) for skeletal muscle adaptation to heavy strength training.