OBJECTIVE: To characterize cardiac structure and function and cardiac autonomic control in patients with subclinical and overt hyperthyroidism. DESIGN: Thirty patients with subclinical hyperthyroidism and 30 with overt disease were selected from patients never previously treated for endocrinological disease in the outpatient clinic of our institution. Twenty normal individuals were studied as control group. METHODS: Left ventricular structure and function and cardiac autonomic control were evaluated, respectively, by two-dimensional Doppler echocardiography and by 24-h Holter recording with heart rate variability analysis. RESULTS: Patients with overt hyperthyroidism showed greater values of left ventricular end-diastolic volume (P<0.05) and left ventricular mass (P<0.05) than patients with subclinical disease. In addition, the mean velocity of left ventricular fibre shortening (P<0.05) and left ventricular ejection fraction (P<0.05) were greater in patients with overt hyperthyroidism than in patients with subclinical disease. No difference in any of these parameters was detectable between normal subjects and patients with subclinical disease. The isovolumic relaxation period was shorter in patients with subclinical hyperthyroidism than in control individuals (P<0.05) and in patients with overt hyperthyroidism (P<0.05). As regards cardiac autonomic control, all time and frequency domain measures decreased progressively from control individuals to patients with subclinical hyperthyroidism and those with overt disease (P<0.001). CONCLUSIONS: Thyrotoxic patients show changes in left ventricular structure and increased echocardiographic indexes of myocardial contractility, whereas the only echocardiographic feature detectable in patients with subclinical hyperthyroidism is an increased velocity of left ventricular relaxation. Cardiac parasympathetic withdrawal is evident in patients with overt hyperthyroidism and in patients with subclinical disease.
M Petretta, D Bonaduce, L Spinelli, ML Vicario, V Nuzzo, F Marciano, P Camuso, V De Sanctis and G Lupoli
V Nuzzo, L Tauchmanova, F Fonderico, R Trotta, MR Fittipaldi, D Fontana, R Rossi, G Lombardi, B Trimarco and G Lupoli
OBJECTIVE: Despite the increasing evidence that primary hyperparathyroidism (PHPT) contributes to greater risk of cardiovascular morbidity and mortality, its exact role in the development of cardiovascular changes and its clinical significance are still controversial. Given the multiple influence of PHPT on the cardiovascular system, this study aimed to assess the effects of PHPT on blood pressure profile, and on features of the heart and arterial vessels in normotensive symptomless patients. DESIGN: Twenty patients (8 males and 12 females) with a median age of 51.5 years (range 44 to 65 years) were evaluated and the results were compared with those of 20 controls matched for age, gender and body mass index. Patients' parathyroid hormone levels ranged from 172 to 454 pg/ml and Ca levels ranged from 11.4 to 13.5 mg/dl. Fasting levels of glucose, insulin, total and high density lipoprotein cholesterol and triglycerides were within the normal range in all subjects recruited. METHODS: Twenty-four-hour blood pressure profile, left ventricle (LV) dimension and carotid artery anatomy were investigated, the latter two by ultrasonography. RESULTS: No difference was found between the patients and controls in blood pressure profile, when the following parameters were considered: supine systolic/diastolic pressure, average 24-h systolic, diastolic and mean arterial pressure, day-time mean arterial pressure and fall in nocturnal blood pressure (-17% and -18% respectively). Heart rate and all parameters of LV mass were similar in patients and controls. The only alteration found in patients was in significantly greater carotid intimal-medial thickness (IMT) (P<0.001). Atherosclerotic plaques were more frequent in patients than in controls, with a difference reaching a trend (40% vs 10%, chi(2)=4.8; P=0.091). Considering that the carotid IMT is considered to be a marker of systemic atherosclerosis, our finding suggests early atherosclerotic changes in PHPT. No correlation was found between the severity and cardiovascular manifestation of PHPT. CONCLUSIONS: Vascular changes may occur due to a combination of structural and functional impairments in PHPT patients, likely as a result of altered calcium metabolism and impaired equilibrium of other factors regulating vascular function. Both extent and duration of PHPT can play a relative role in the development of cardiovascular complications. Considering that PHPT is now recognized as a quite common and often symptomless endocrine disorder, the evidence of cardiovascular manifestation in normotensive patients, found by this morphological study, suggests a possible implication for the management of such patients. In this light, screening for abnormalities in cardiovascular system function should be recommended in all PHPT subjects.
L Tauchmanova, R Rossi, V Nuzzo, A del Puente, A Esposito-del Puente, C Pizzi, F Fonderico, G Lupoli and G Lombardi
OBJECTIVE: Glucocorticoid excess is widely recognized as one of the most important causes of bone loss. The mechanism of glucocorticoid-induced osteoporosis is presumably multifactorial, and consists of the loss of organic and non-organic compounds. Efforts have been made to develop simple physical methods for the assessment of bone tissue for the screening of subjects at high risk of osteoporosis, without the use of radioactive sources or ionizing radiation. Quantitative ultrasonometry (QUS) has been suggested as a useful method for monitoring patients undergoing glucocorticoid therapy, which is the most common cause of glucocorticoid excess. QUS appears to detect more structural bone changes than the traditional methods and allows assessment of bone density and elasticity, both characteristics influenced by organic and non-organic bone compounds. However, the use of QUS has not yet been extensively investigated in subjects with endogenous cortisol excess. The aim of this study was to evaluate the usefulness and predictive power of QUS in assessing bone loss in subjects with differing degrees of endogenous cortisol excess due to adrenal mass. DESIGN: Thirty-four patients (20 women and 14 men) aged between 21 and 59 years were evaluated; fifteen (9 women and 6 men; median age, 42 years) were affected by overt Cushing's syndrome (CS) and nineteen (11 women and 8 men; median age, 44 years) by subclinical CS, defined as lacking clinical signs of hormone excess despite the presence of at least two abnormalities in hypothalamic-pituitary-adrenal axis function, as assessed by routine endocrine tests. All women included were eumenorrhoic. METHODS: QUS measurement of amplitude-dependent speed of sound was performed on the 2nd to 5th proximal phalanges of the non-dominant hand using a DBM Sonic 1200R bone profiler (Igea S.r.l, Italy). The results were compared with bone density assessed on lumbar vertebrae (L1-L4) and femoral neck sites by dual-energy X-ray absorptiometry (DEXA). RESULTS: A strongly significant bone loss was detected by finger QUS measurement when the patients were considered either all together or as two subgroups (P<0.001, all). The bone density decrease in the fingers was similar to that found at the lumbar spine and femoral neck by the DEXA technique. Lumbar and finger Z-scores correlated inversely with 24 h urinary free cortisol (UFF) excretion (P<0.01, both). Finger Z-scores also correlated inversely with the estimated duration of subclinical CS (P<0.05). Concerning disease activity, only UFF was confirmed by multivariate analysis to be an independent factor influencing bone loss (P<0.05). A positive correlation between the results of the two techniques was found in controls (P<0.05) but not in patients. The lack of correlation between the two techniques in patients can probably be attributed to the different parameters of bone alteration measured by the techniques. CONCLUSIONS: The detection of bone loss in subclinical CS similar to that in overt CS suggests that all subjects with endogenous cortisol excess should be evaluated for bone mass. QUS measurement appears to be a reliable, radiation-free, simple and fast tool for the identification of bone alteration in subjects with endogenous cortisol excess.