Peripheral sensitivity to insulin in aged subjects

Insulin sensitivity has been studied in ten young patients (22 years old means) and in eleven elderly patients (72 years old means). They were free of family diabetes history, glucose intolerance, hypertriglyceridemia, hepatic or renal failure or factor of insulin resistance such as infectious diseases. A two hours hyperinsulinic euglycemic clamp was done with an artificial pancreas (Biostator GCIIS Miles). The ten young patients and the eleven old patients had a stable hyperinsulinic level (93.3 +/- 5 uu/ml and 90 +/- 8 uu/ml) they respectively required 8.08 +/- 0.73 and 5.5 +/- 2.5 mg/kg/min of glucose. Metabolic clearance of insulin does not seem altered with aging. For a same hyperinsulinic level the glucose requirement is less in old patients. So there is an apparent insulin resistance in aging.     

Low levels of serum thyroglobulin after withdrawal of thyroid suppression therapy in the follow up of differentiated thyroid carcinoma

We evaluated the reliability of very low serum thyroglobulin (Tg) levels (less than 3 ng/ml) obtained after withdrawal of thyroid suppression therapy in 224 patients without anti-Tg antibodies, who had undergone total thyroidectomy (125 patients) or thyroidectomy followed by 1 or more courses of 131I therapy (99 patients), by performing whole body scans after a therapeutic course of 131I given at the same time of Tg measurement. In 79 patients (35%) a positive scan, associated with a very low level of Tg, was noted. The 131I uptake was limited to the thyroid bed in 60 patients, but metastases were demonstrated in 19 patients (8.5%). These results are mainly explained by the much improved performance of scintigraphy after administration of therapeutic doses of 131I. In the majority of patients, especially those whose 131I uptake was limited to the thyroid bed, further scans were negative. Therefore, in these cases, negative Tg values can generally be considered an early indication of satisfactory evolution. However, in 8.5% of all cases, very low Tg levels were associated with metastases. Thus the follow up of thyroid cancer should not rely only upon Tg determination, even after suppression therapy withdrawal.     

Malaise and loss of consciousness in the elderly patient: prospective evaluation of methods of investigation

60 consecutive patients (mean age: 80,7 yrs; s.d.: 6,1 yrs; range 70-94 yrs) referred to a geriatric medicine department with syncope or dizziness were proposectively compared with 40 age and sex matched controls. A battery of non-invasive investigations including tilt-test, glycemia, 12 lead ecg., eeg, 24 hour ambulatory ecg recording,. M--mode echocardiogram and cervical Doppler velocimetry was applied blindly to patients and controls. The proportion of abnormalities was similar in both groups having sick sinus syndrom or complete atrio-ventricular block versus no control (p less than 0.05). By contrast history-case was of great predictive value: 6 of 13 patients reporting abrupt syncope had a 24 ecg recording showing sick sinus syndrom or complete atrio ventricular block, versus 2 of 47 other patients (p less than 0,01); 11 of 14 patients reporting orhostatic dizziness or syncope had a tilt-test consistent with orthostactic hypotension versus 6 of 46 other patients (p less than 0,01).     

Hypothyroid neuropathy

Two cases of polyneuropathy in patients with hypothyroidism are reported. In both cases, the polyneuropathy involved the lower limbs and was predominantly distal. It was sensorimotor in the first patient and purely sensory in the second one. Electrophysiological findings were consistent with an axonopathy. Symptoms and electrophysiological parameters improved with thyroid therapy. Neuropathy in such cases is probably related to the duration of hypothyroidism.     

Effect of LH-RH infusion on plasmatic testosterone level in normal man and in pathologic cases (author's transl)]

LH-RH INFUSION with 250 microgram in eight hours increases testosterone level in normal man by 40% (alpha less than 0,01). Results in hypogonadic patients and in pituitary tumours are presented. No correlation is found between LH-RH responses and pituitary enlargement.     

Thallium-201 imaging in the follow-up of differentiated thyroid carcinoma

Since thallium-201 imaging has been reported as a potential means of follow-up of patients with differentiated thyroid carcinoma (DTC) during ongoing thyroid suppression therapy, the authors evaluated the diagnostic sensitivity of this procedure in 31 patients known to have metastases or local recurrence. Among 51 tumor sites 201TI imaging had a detection rate of 45% whereas 84% was noted for imaging with 131I administered in therapeutic doses. Thus, even though the effectiveness of the two radionuclides is not strictly comparable due to the difference in the administered doses, Thallium imaging cannot be recommended as the only modality for the follow-up of patients with DTC. Six of the eight tumor sites negative with 131I were positive with 201TI (especially metastatic cervico-mediastinal lymph nodes). So 201TI imaging may particularly be helpful in localizing metastases or recurrences in patients with a negative 131I scan and abnormal levels of serum thyroglobulin.