Diurnal and ultradian rhythms of plasma norepinephrine and epinephrine and their role in the regulation of cardiovascular parameters were investigated over 24 h of recumbency in a group of five men. Catecholamines were measured at 10 min intervals, and blood pressure and heart rate were recorded continuously. Norepinephrine and epinephrine rapidly fluctuated in each subject, with no obvious diurnal rhythm. Spectral analysis suggested two ultradian rhythms with periods of around 12 h and 50-100 min for both catecholamines. The pulse detection programs PULSAR and CLUSTER revealed 20-30 pulses/24 h for norepinephrine and epinephrine, with a significant correlation between the two rhythms (r = 0.63-0.80, P < 0.001). Neither the frequency nor the amplitude of these rapid fluctuations differed between day and night. Arousal in the morning caused a small increase in plasma catecholamines and getting out of bed a large increase. Thus changes in posture and activity are the main influences on the diurnal variations of plasma catecholamines reported previously, while the ultradian rhythms of sympathoadrenomedullary activity appear to be of intrinsic origin. Blood pressure and heart rate exhibited a diurnal rhythm with a nightly decrease. Arousal and rising from bed increased blood pressure and heart rate significantly. Although the amplitude of the rapid fluctuations of plasma catecholamines at times exceeded those caused by postural changes in the morning, when both plasma norepinephrine and epinephrine levels correlated highly with all cardiovascular parameters, correlations were not significant during recumbency. Thus the intrinsic ultradian fluctuations of plasma catecholamines appear not to be involved in the control of cardiovascular parameters during recumbency, and the increase in blood pressure and heart rate in the morning appears to be controlled by direct sympathetic neural input to the heart and vasculature in response to changes in activity and posture rather than by an endogenous surge of plasma catecholamines.
C Schofl, C Becker, K Prank, A von zur Muhlen and G Brabant
M Mohlig, J Spranger, M Osterhoff, M Ristow, AF Pfeiffer, T Schill, HW Schlosser, G Brabant and C Schofl
OBJECTIVE: The syndrome of polycystic ovaries (PCOS) is a known risk factor for type 2 diabetes. It is not known, however, whether the increase in diabetes risk is related to endocrine abnormalities associated with PCOS such as hyperandrogenemia, or whether it is a consequence of the anthropometric or metabolic alterations frequently observed in PCOS women. DESIGN: Since markers of inflammation are supposed to predict type 2 diabetes, interleukin-6 (IL-6) and C-reactive protein (CRP) in combination with parameters of obesity, insulin resistance and hyperandrogenism were determined in 57 PCOS women and in 20 age-matched healthy controls. In addition, the C-174G IL-6 promoter polymorphism was analyzed as a determinant in influencing IL-6, obesity, and androgen levels in women. RESULTS: Neither CRP nor IL-6 were significantly elevated in lean or obese PCOS women compared with age-matched lean or obese controls. In PCOS patients, variables of body composition (body mass index (BMI), waist to hip ratio, dual-energy X-ray-absorptiometry fat mass) and of insulin resistance were correlated with IL-6 or CRP, while parameters of hyperandogenism were not. Multivariate linear regression analysis revealed that obesity is the dominant force, thus explaining 18% and 24% of the IL-6 or CRP levels, respectively, in PCOS women. No association of IL-6 or BMI to a certain genotype at C-174G could be demonstrated in 50 PCOS patients. The heterozygous GC genotype, however, was associated with lower androstendione levels. Metformin treatment of 9 obese, insulin-resistant PCOS patients over a period of 6 months caused a significant decrease in body weight, body fat mass and total testosterone, but showed no significant decline in IL-6 or CRP concentrations. CONCLUSIONS: In PCOS women, plasma levels of IL-6 and CRP were not increased when compared with age- and BMI-matched controls. BMI was, however, the parameter most strongly related to IL-6 and CRP in PCOS; thus PCOS-related endocrine abnormalities do not appear to activate inflammatory parameters thereby enhancing the risk of diabetes. In PCOS, the type 2 diabetes risk may, therefore, be confined to those with obesity and/or metabolic alterations rather than affecting all women suffering from the syndrome.
U J Knappe, D Petroff, M Quinkler, S M Schmid, C Schöfl, J Schopohl, M R Stieg, A Tönjes and the participants of the German Acromegaly Registry
If biochemical control of acromegaly is not achieved by operation and medication, radiotherapy may be indicated.
To describe fractionated radiotherapy (FRT) and stereotactic radiosurgery (SRS) regarding excess of IGF-1 and pituitary function.
Design and methods
A retrospective analysis of 352 patients (4126 patient-years) from the German Acromegaly Registry was performed. Follow-up was 1.0–45.1 years after radiotherapy. Therapeutic success was defined by low or normal IGF-1 according to center-specific reference ranges without (= remission) or on (= controlled disease) suppressive medication.
Time between radiotherapy and last follow-up was 13.0 ± 8.2 years for FRT (n = 233) and 8.9 ± 5.0 years for SRS (n = 119, P < 0.001). Median (IQR) basal growth hormone before radiotherapy was 6.3 (2.9–16.2) ng/mL for FRT and 3.5 (1.8–6.9) ng/mL for SRS (P < 0.001). Mean time in uncontrolled state was 3.0 years after FRT and 2.1 years after SRS (95% CI for the difference is 0.1 to 1.6 years, P = 0.021). The 10-year calculated remission rate was 48% for FRT and 52% for SRS (95% CI for the difference is −18 to 26% age points, P = 0.74) and the respective controlled disease rate was 23 and 26%. The odds ratio for adrenocorticotropic or thyreotropic insufficiency was 0.54 (95% CI: 0.30–1.00, P = 0.049) in SRS compared to FRT patients.
Both after FRT and SRS about 75% of patients with acromegaly are in remission or controlled after 10 years. A slightly faster achievement of target values was observed after SRS. The rate of pituitary insufficiency in FRT patients is significantly higher.
Fabrice Bonneville, Louis-David Rivière, Stephan Petersenn, John S Bevan, Aude Houchard, Caroline Sert, Philippe J Caron and the PRIMARYS Study Group
Pituitary adenoma MRI T2 signal intensity associates with tumor characteristics including responsiveness to somatostatin analogs (SSAs). These analyses determined whether baseline T2 signal intensity predicts response to primary medical treatment with long-acting SSA.
Post hoc analyses of the prospective multicenter, open-label, single-arm PRIMARYS study in which patients with treatment-naïve GH-secreting pituitary macroadenomas received fixed-dose lanreotide autogel (120 mg) every 4 weeks for 48 weeks.
Associations were investigated between adenoma T2-signal hypo/iso/hyperintensity and treatment responses at week 48/last visit: hormonal control (GH ≤2.5 μg/L and IGF-1 normalization); tumor response (tumor volume reduction (TVR) ≥20%); separate GH/IGF-1 control and change from baseline in GH/IGF-1 and tumor volume.
Adenomas were hypointense at baseline in 50/85 (59%) patients using visual assessment. Of these, 40% achieved hormonal control and 76% achieved a tumor response. Significant univariate associations arose for hypo- vs isointensity with tumor response and achievement of GH ≤2.5 μg/L, but not IGF-1 normalization or overall hormonal control. In multivariate analysis, tumor response was six times more likely for hypo- vs iso-intense tumors (= 6.15; 95% CI: 1.36–27.88). In univariate change-from-baseline analyses, hypo- vs isointensity was associated with greater TVR and IGF-1 reduction but not change in GH. In multivariate analysis, IGF-1 decreased by an estimated additional 65 μg/L (P = 0.0026)) for hypo- vs isointense.
Patients with hypointense vs isointense GH-secreting macroadenomas had greater reductions in IGF-1 following primary treatment with lanreotide autogel and were more likely to achieve tumor response. Assessment of T2 signal intensity at baseline may help to predict long-term responses to primary treatment with SSAs.