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N C Thalassinos

Publications and source records attributed to N C Thalassinos.

At least 19 recordsLinked to original sources
PubMed2006

Characterization of patients with an inadequate clinical outcome from osteoporosis therapy: the Observational Study of Severe Osteoporosis (OSSO).

BACKGROUND: Osteoporotic fractures remain a major public health problem. Currently available osteoporosis therapies significantly reduce the risk of fractures, but up to 50% of patients have an inadequate clinical outcome to therapy. AIM: To describe the clinical and quality of life (QOL) of a study population meeting a proposed definition of inadequate clinical outcome to osteoporosis therapy, recruited for the Observational Study of Severe Osteoporosis (OSSO). DESIGN: Cross-sectional, observational study. METHODS: Post-menopausal women with osteoporosis (n = 2314) were divided into Group 1 (those who had previously experienced a fragility fracture despite osteoporosis drug therapy for at least 12 months) (n = 1309, 57%), or Group 2 (those who had previously discontinued osteoporosis drug therapy due to non-compliance or side-effects) (n = 1005; 43%). Baseline clinical characteristics, quality of life (QOL) and osteoporosis/falls risk factors were analysed. RESULTS: The overall population had low BMD (mean +/- SD T-score at lumbar spine -3.1 +/- 1.1), and risk factors for fracture such as previous fractures (67.8%), family history (15.1%), and prolonged glucocorticoid use (17.5%). QOL was poor: total QUALEFFO and EQ-5D scores were 46.8 +/- 18.7, and 0.50 +/- 0.33, respectively. Patients in Group 1 had higher age and body mass index, fewer hours of exercise, more previous fragility fractures and falls, and poorer QOL scores. DISCUSSION: Our definition of inadequate clinical outcome from osteoporosis drug therapy identifies a severe osteoporosis cohort with poor QOL and increased fracture risk. Using such a definition may lead to earlier recognition of inadequate clinical outcome to osteoporosis therapy, and improved interventions and results.

Absorptiometry, Photon↗
PubMed2005

Evaluation of GH reserve in patients with adrenal incidentalomas and biochemical evidence of subclinical autonomous glucocorticoid hypersecretion.

OBJECTIVE: Although it is well established that overt hypercortisolism in patients with active Cushing's syndrome leads to a profound suppression of stimulated GH secretion, the role of subclinical autonomous glucocorticoid hypersecretion (SAGH), currently detected with increasing frequency in patients with adrenal incidentalomas, on GH secretory reserve has received little attention. The aim of the present study was to evaluate whether SAGH in patients presented with adrenal incidentalomas has a negative effect on GH secretory reserve. DESIGN AND PATIENTS: Sixteen patients with overt Cushing's syndrome (CS) and 36 patients with adrenal incidentalomas were investigated. The latter group was further divided in 23 patients who demonstrated an adequate suppression of cortisol levels (of < 70 nmol/l) following the low-dose dexamethasone suppression test (LDDST) and in 13 patients, who failed to suppress (cortisol levels post-LDDST > 70 nmol/l). The former group was defined as normocortisolaemic (NC) and the latter group as representing patients with SAGH. The combined pyridostigmine + GHRH test (PD + GHRH) was used to assess the GH secretory reserve of these patients. RESULTS: Peak GH levels following PD + GHRH administration were significantly lower in CS patients compared to both the NC and SAGH group of patients with adrenal incidentalomas (2.2 +/- 0.7 vs. 18.9 +/- 2.6 and 21.5 +/- 3.6 microg/l, respectively, P < 0.05); no difference was observed in peak GH responses between the NC and SAGH group of patients. A subnormal GH response (defined as GH(max) < 12.8 microg/l) was observed in all 16 patients with CS. However, only seven NC and three SAGH patients failed to respond adequately. Correlation analysis revealed a negative correlation between peak GH response to PD + GHRH and plasma cortisol concentrations in CS patients (R =-0.6, P = 0.012), while in patients with adrenal incidentalomas such a correlation was absent. Contrary to patients with CS in whom body mass index (BMI) was not correlated to peak GH, a significant negative correlation between peak GH response to PD + GHRH and BMI was disclosed in patients with adrenal incidentalomas (R =-0.49, P = 0.003). In these patients, again contrary to CS patients, a significant negative correlation was also found between peak GH post PD + GHRH and age (R = -0.46, P = 0.002). CONCLUSIONS: In conclusion, our results provide evidence that, contrary to patients with overt CS, SAGH does not affect the GH secretory response to provocative stimulation.

Adenoma↗
PubMed1998

Megavoltage pituitary irradiation lowers but seldom leads to safe GH levels in acromegaly: a long-term follow-up study.

Radiotherapy (RT) has long been used in the treatment of acromegaly, but confusion regarding the definition of biochemical cure has hampered interpretation of previous reports on the outcome of this treatment. In the present study we present additional data using the currently accepted criteria of biochemical cure in a large group of patients followed up by our department. Forty-six acromegalic patients were treated with external beam megavoltage RT and followed up for a mean of 7.6 years (range 2-22 years). Only four patients had had previous surgical treatment by either transsphenoidal or transfrontal routes. Following RT, mean basal GH levels decreased from 30.9 ng/ml (5-96 ng/ml) to 11.5 ng/ml (1-36 ng/ml) at 10 years of follow up with a further fall to 6.1 ng/ml (1-29 ng/ml) in those patients followed up for more than 10 years. As a result, although mean GH levels of less than 5 ng/ml were achieved in 9/28 (30.1%) at 5 years, 6/19 (31.6%) at 10 years, and in 6/11 (54.5%) of those patients followed up for more than 10 years post-RT, only 0/28 (0%), 7/28 (25%), 4/19 (21%) and 1/11 (1%) achieved GH levels of <2.5 ng/ml at 2, 5. 10 and >10 years following RT. Thus, in the whole series only 10/48 (20.8%) patients showed a decrease of GH level to less than 2.5 ng/ml at their latest follow up. Hypopituitarism as a result of RT was only infrequently observed in this series; gonadal deficiency developed in 12 (26.6%) patients, thyrotrophin (TSH) deficiency in 3 (6.6%) and adrenocorticotrophin deficiency in 2 (4.4%). In conclusion, megavoltage RT is an effective treatment for the control of GH hypersecretion in acromegaly, with a continuing lowering effect for several years following RT but seldom leads to safe GH levels.

Acromegaly↗
PubMed1994

Does acromegaly really predispose to an increased prevalence of gastrointestinal tumours?

OBJECTIVE: The few published prospective studies suggest a strong association of colonic tumours with acromegaly, but include small numbers of patients. In addition, the upper gastrointestinal tract of these patients has never been prospectively studied. The aim of the present study was to investigate the incidence of gastric and colonic tumours in a large cohort of acromegalic patients. DESIGN: Acromegalic patients consecutively admitted to an Endocrinology Department for diagnosis and follow-up, were submitted to gastroscopy and colonoscopy, to identify those harbouring gastrointestinal tumours. PATIENTS: Over a 5-year period, 54 out of 61 patients (78% with active disease) received colonoscopy and 42 out of 61 gastroscopy. No patient had a past history of gastrointestinal malignancy. MEASUREMENTS: All polypoid lesions found at colonoscopy and gastroscopy were separately recorded and biopsied. RESULTS: No case of gastrointestinal cancer or gastric polyp was discovered. Nineteen patients (35%) had 1-8 colonic polyps, including 5 (9.3%) with adenomas. When compared to patients with a normal colon, those with polyps were significantly older (44.5 +/- 14.2 vs 52.1 +/- 10.9 years, P = 0.047), but the duration of acromegaly (10.8 +/- 8.4 vs 10.9 +/- 7.1 years, P = 0.9) and the number of patients with active disease were similar in both groups. CONCLUSIONS: Acromegalic patients do not have an increased incidence of gastric tumours. The observed significant variation in the prevalence of colonic adenomas (9-35%, P = 0.03) and cancer (0-15%, P = 0.017), between our patients and those of the published prospective studies with similar demographic characteristics, suggest that environmental and hereditary factors may be more important than the presence of acromegaly.

Acromegaly↗
PubMed1993

Effect of 131I treatment on the calcitonin response to calcium infusion in hyperthyroid patients.

OBJECTIVE: The objective was to evaluate the effect of 131I treatment for hyperthyroidism on calcitonin secretion by thyroid C-cells. DESIGN: Determination of basal calcitonin levels and calcitonin secretory reserve before and after 131I administration. PATIENTS: Seventeen hyperthyroid patients (15 female, two male) were studied before, and 2 months after 131I treatment, and 12 of these patients were restudied 8 months after 131I treatment. MEASUREMENTS: Calcitonin response was assessed by measuring basal and post calcium infusion calcitonin levels. Basal TSH, T3, and T4 levels were also determined at each study. RESULTS: The rise of plasma calcium resulted in statistically significant increase of plasma calcitonin levels before 131I treatment (10.9 +/- 2.4 pmol/l), while this response was significantly diminished 2 and 8 months after treatment (2.6 +/- 0.7 and 1.6 +/- 0.3 pmol/l, respectively). No correlation was found between the calcitonin response and age or plasma TSH. CONCLUSION: Our results demonstrate that 131I treatment for hyperthyroidism may seriously damage thyroid C-cells and cause calcitonin deficiency.

Adult↗
PubMed1993

Calcium metabolism in diabetes mellitus: effect of improved blood glucose control.

Reduced bone mass occurring with increased frequency in diabetes mellitus has been attributed to poor blood glucose control but the pathogenetic mechanisms remain unknown. To evaluate the role of calcium metabolism, 59 patients with diabetes and normal renal function (22 Type 1, 37 Type 2) were studied. In all patients plasma calcium (Ca), serum phosphate (PO4), serum parathyroid hormone (PTH), and 24-h urinary calcium (uCa) were determined under both poor and improved control (for at least 7 days) as ascertained by four blood glucose determinations daily. Improvement of blood glucose control (p = 0.001) was associated with reduction of uCa both in Type 1 (6.9 +/- 1 vs 4.9 +/- 0.9 mmol day-1, mean +/- SEM, p = 0.02) and in Type 2 patients (4.2 +/- 0.4 vs 3.2 +/- 0.4 mmol day-1, mean +/- SEM, p = 0.002). Considerably more Type 1 patients (10 out of 22) had PTH values below the detection limit (1.5 pmol l-1) during poor than during improved control (2 out of 22). Comparison between the two types of diabetes showed that in Type 1 under poor control, Ca and PTH were lower (p = 0.03), while uCa was higher (p = 0.003), and after improved control, only uCa continued to be higher (p = 0.035). These findings suggest that increased uCa excretion in association with 'functional hypoparathyroidism' (especially in Type 1 diabetes) is observed during poor blood glucose control, and may be one of the factors leading to reduced bone mass in diabetes mellitus.

Adult↗
PubMed1982

Calcium balance in osteoporotic patients on long-term oral calcium therapy with and without sex hormones.

1. The effect of a high calcium intake (1 mmol day-1 kg-1) alone or with the concomitant administration of oestradiol and testosterone derivatives was monitored by serial calcium balances in 48 patients with osteoporosis of various types. 2. On high calcium alone there was an increase (P less than 0.001) in both total calcium balance and net calcium absorption as compared with values on a simulated home intake. This effect was sustained for periods up to 10 years (mean 3.5 years) by the addition of the hormones. 3. Discontinuation of the hormones (only) produced a significant decrease in both calcium balance and nett absorption but both were still increased when compared with the initial values under simulated home calcium intake. 4. No significant change in the urinary calcium output was observed under any of the regimens.

Adult↗
PubMed1979

Effect of digitalis on diminished baroreceptor sensitivity in diabetics.

The baroreceptor sensitivity was estimated in 50 normal controls (Group A) and in 50 diabetics of comparable age (Group B). The technique used was infusion of angiotensin (0.5 microgram/min) and measurement of the bradycardic response resulting from the increase of blood pressure. The slope was used as an index of baroreceptor sensitivity. Diabetics had significantly lower baroreceptor sensitivity and a higher resting heart rate. Sensitivity decreased with age in both groups. The reproducibility of the method was excellent. Deslanoside-C (0.8 mg) significantly increased the baroreceptor sensitivity in 11 normal controls and 9 diabetics. Very low sensitivity was found in 26 diabetics who had no evidence of orthostatic hypotension, neuropathy, or retinopathy. However all 17 patients with the above findings had very low sensitivity.

Adolescent↗
PubMed1970

Secondary hyperparathyroidism in osteomalacia.

Twenty-one patients with histologically proved osteomalacia from various causes were investigated for biochemical and radiological evidence of osteomalacia and secondary hyperparathyroidism. Among the 15 who maintained a normal serum calcium, seven had a raised phosphate excretion index, seven had a raised serum alkaline phosphatase, and six had phalangeal erosions. On the other hand, six patients had a subnormal serum calcium; of these, none showed a raised phosphate excretion index, one had a raised serum alkaline phosphatase, and one had erosions. The phosphate excretion index and the alkaline phosphatase were strongly correlated (r = +0.84). It is concluded that this absence of manifest secondary hyperparathyroidism in some patients with osteomalacia is due to failure of an increase in the release of parathyroid hormone. Measurement of phosphaturia does not appear to be a useful means of detecting osteomalacia. Subsequently, the 24-hour (stable) strontium space measurement was found to be the most sensitive single biochemical screening test for osteomalacia.

Adult↗