The amino acid response to a mixed meal in patients with type 2 diabetes: effect of sitagliptin treatment.

AIMS: Amino acid (AA) metabolism is altered in type 2 diabetes (T2D), and fasting levels of α-hydroxybutyrate (α-HB), a biomarker for insulin resistance, have been suggested to track AA metabolism. We investigated the changes in AA and α-HB induced by a mixed-meal tolerance test (MTT) and the effects of sitagliptin treatment. METHODS: Forty-seven T2D patients [56 ± 7 years, body mass index (BMI) 29.9 ± 4.2 kg/m(2) ] were randomized to sitagliptin (100 mg/day, 6 weeks) or placebo. Seven age- and BMI-matched non-diabetic subjects served as control (CT). RESULTS: During a 5-h MTT, branched-chain AA (BCAA) peaked earlier in T2D than CT [75(25) vs. 62(3) mmol/l · h over 2 h, median(interquartile range), p = 0.05], and rose higher [5-h increment: 31(23) vs. 19(24) mmol/l · h, p = 0.05]. Fasting α-HB was higher [7.5(2.7) vs. 5.9(1.3) µg/ml, p = 0.04 T2D vs. CT], and its meal-induced increments were larger [24(99) vs. -41(86) µg/ml · h, p = 0.006]. Plasma non-esterified fatty acids (NEFA) declined during MTT, but their increments were greater in patients (53 ± 16 vs. 35 ± 10 mEq/l · h, p = 0.005). Compared to placebo, both BCAA [-6.4(21.1) vs. 0.0(48.0) mmol/l · h, p = 0.01] and α-HB increments [-114(250) vs. 114(428) µg/ml · h, p = 0.002] decreased with sitagliptin, and meal-induced NEFA suppression was improved. Changes in BCAA and α-HB were reciprocally related to changes in insulin sensitivity (ρ = -0.37 and -0.43, p ≤ 0.01). CONCLUSIONS: T2D is associated with a hyperaminoacidaemic response to MTT, which circulating α-HB levels track. Sitagliptin-induced glycaemic improvement was associated with reductions in BCAA and α-HB excursions and better NEFA suppression, in parallel with improved insulin sensitivity, confirming that α-HB is a readout of metabolic overload.

Direct effect of GLP-1 infusion on endogenous glucose production in humans.

AIMS/HYPOTHESIS: Glucagon-like peptide-1 (GLP-1) lowers glucose levels by potentiating glucose-induced insulin secretion and inhibiting glucagon release. The question of whether GLP-1 exerts direct effects on the liver, independently of the hormonal changes, is controversial. We tested whether an exogenous GLP-1 infusion, designed to achieve physiological postprandial levels, directly affects endogenous glucose production (EGP) under conditions mimicking the fasting state in diabetes. METHODS: In 14 healthy volunteers, we applied the pancreatic clamp technique, whereby plasma insulin and glucagon levels are clamped using somatostatin and hormone replacement. The clamp was applied in paired, 4 h experiments, during which saline (control) or GLP-1(7-37)amide (0.4 pmol min⁻¹ kg⁻¹) was infused. RESULTS: During the control study, plasma insulin and glucagon were maintained at basal levels and plasma C-peptide was suppressed, such that plasma glucose rose to a plateau of ~10.5 mmol/l and tracer-determined EGP increased by ~60%. During GLP-1 infusion at matched plasma glucose levels, the rise of EGP from baseline was fully prevented. Lipolysis (as indexed by NEFA concentrations and tracer-determined glycerol rate of appearance) and substrate utilisation (by indirect calorimetry) were similar between control and GLP-1 infusion. CONCLUSIONS/INTERPRETATION: GLP-1 inhibits EGP under conditions where plasma insulin and glucagon are not allowed to change and glucose concentrations are matched, indicating either a direct effect on hepatocytes or neurally mediated inhibition.

Metabolic effects of muraglitazar in type 2 diabetic subjects.

AIM: To assess the effect of muraglitazar, a dual peroxisome proliferator-activated receptor (PPAR)γ-α agonist, versus placebo on metabolic parameters and body composition in subjects with type 2 diabetes mellitus (T2DM). METHODS: Twenty-seven T2DM subjects received oral glucose tolerance test (OGTT), euglycaemic insulin clamp with deuterated glucose, measurement of total body fat (DEXA), quantitation of muscle/liver (MRS) and abdominal subcutaneous and visceral (MRI) fat, and then were randomized to receive, in addition to diet, muraglitazar (MURA), 5 mg/day, or placebo (PLAC) for 4 months. RESULTS: HbA1c(c) decreased similarly (2.1%) during both MURA and PLAC treatments despite significant weight gain with MURA (+2.5 kg) and weight loss with PLAC (-0.7 kg). Plasma triglyceride, LDL cholesterol, free fatty acid (FFA), hsCRP levels all decreased with MURA while plasma adiponectin and HDL cholesterol increased (p < 0.05-0.001). Total body (muscle), hepatic and adipose tissue sensitivity to insulin and ß cell function all improved with MURA (p < 0.05-0.01). Intramyocellular, hepatic and abdominal visceral fat content decreased, while total body and subcutaneous abdominal fat increased with MURA (p < 0.05-0.01). CONCLUSIONS: Muraglitazar (i) improves glycaemic control by enhancing insulin sensitivity and ß cell function in T2DM subjects, (ii) improves multiple cardiovascular risk factors, (iii) reduces muscle, visceral and hepatic fat content in T2DM subjects. Despite similar reduction in A1c with PLAC/diet, insulin sensitivity and ß cell function did not improve significantly.

Metabolic normality in overweight and obese subjects. Which parameters? Which risks?

OBJECTIVES: The objective of this study was to define metabolic normality and to investigate the cardiometabolic profile of metabolically normal obese. DESIGN: Cross-sectional study conducted at 21 research centers in Europe. SUBJECTS: Normal body weight (nbw, n=382) and overweight or obese (ow/ob, n=185) subjects free from metabolic syndrome and with normal glucose tolerance, were selected among the Relationship between Insulin Sensitivity and Cardiovascular Disease study participants. MAIN OUTCOME MEASURES: Insulin sensitivity was assessed by the clamp technique. On the basis of quartiles in nbw subjects, the limits of normal insulin sensitivity and of normal fasting insulinemia were established. Subjects with normal insulin sensitivity and fasting insulin were defined as metabolically normal. RESULTS: Among ow/ob subjects, 11% were metabolically normal vs 37% among nbw, P<0.0001. Ow/ob subjects showed increased fasting insulin (P=0.0009), low-density lipoprotein cholesterol (LDL-cholesterol) (P=0.004), systolic (P=0.0007) and diastolic (P=0.001) blood pressure, as compared with nbw. When evaluating the contribution of body mass index (BMI), hyperinsulinemia and insulin resistance, BMI showed an isolated effect on high-density lipoprotein (P=0.007), high-sensitivity C-reactive protein (P<0.0001), systolic (P=0.002) and diastolic (P=0.008) blood pressures. BMI shared its influence with insulinemia on total cholesterol (P=0.04 and 0.003, respectively), LDL-cholesterol (P=0.003 and 0.006, respectively) and triglycerides (P=0.02 and 0.001, respectively). CONCLUSION: In obese subjects, fasting insulin should be taken into account in the definition of metabolic normality. Even when metabolically normal, obese subjects could be at increased risk for cardiometabolic diseases. Increased BMI, alone or with fasting insulin, is the major responsible for the less favorable cardio-metabolic profile.

Short-term acute hyperinsulinemia and prothrombotic factors in subjects with normal glucose tolerance.

Some cytokines and proinflammatory mediators are considered markers of increased atherothrombotic risk. Few information is available on the effects of acute glucose and insulin variations on these markers of atherosclerosis. We assessed the acute effect of glucose and insulin on soluble CD40 ligand (sCD40L), IL-6, and P-selectin levels, evaluating their relationship with insulin sensitivity in normal glucose tolerance subjects (NGT). Twenty-four NGT subjects underwent a 3-h oral glucose tolerance test (OGTT) with measurements of sCD40L, IL-6, and P-selectin levels at 0, 90 and 180 min. Insulin sensitivity was assessed by the Oral Glucose Sensitivity Index (OGIS). To distinguish the role of glucose and insulin, eight subjects had the plasma glucose profile of the OGTT reproduced by a variable IV glucose infusion (ISO-G study) and nine underwent a euglycemic clamp. Lastly, a 3-h time-control (TC) study was performed in eleven subjects. A significant reduction of sCD40L was observed during OGTT and ISO-G study. This reduction was not due to time-related changes, since it was not observed in TC study. During the clamp, insulin induced a marked drop in sCD40L (from 4.89+/-1.34 to 1.60+/-0.29 ng/ml, p<0.05). In the pooled data from all studies, fasting sCD40L was indirectly related to LDL-cholesterol (r=-0.38; p=0.04), while IL-6 was directly related with BMI, fat mass, waist circumference, and P-selectin (p<0.05). sCD40L levels are downregulated during a short-term period of acute hyperinsulinemia, whether induced by oral or intravenous glucose administration or by insulin infusion, while it does not seem to affect P-selectin and IL-6.

Effects of glucose tolerance on the changes provoked by glucose ingestion in microvascular function.

AIMS/HYPOTHESIS: Hyperglycaemia and hyperinsulinaemia have opposite effects on endothelium-dependent vasodilatation in microcirculation, but the net effect elicited by glucose ingestion and the separate influence of glucose tolerance are unknown. METHODS: In participants with normal glucose tolerance (NGT), impaired glucose tolerance (IGT) or diabetic glucose tolerance, multiple plasma markers of both oxidative stress and endothelial activation, and forearm vascular responses (plethysmography) to intra-arterial acetylcholine (ACh) and sodium nitroprusside (SNP) infusions were measured before and after glucose ingestion. In another IGT group, we evaluated the time-course of the skin vascular responses (laser Doppler) to ACh and SNP (by iontophoresis) 1, 2 and 3 h into the OGTT; the plasma glucose profile was then reproduced by means of a variable intravenous glucose infusion and the vascular measurements repeated. RESULTS: Following oral glucose, plasma antioxidants were reduced by 5% to 10% (p < 0.01) in all patient groups. The response to acetylcholine was not affected by glucose ingestion in any group, while the response to SNP was attenuated, particularly in the IGT group. The ACh:SNP ratio was slightly improved therefore in all groups, even in diabetic participants, in whom it was impaired basally. A time-dependent improvement in ACh:SNP ratio was also observed in skin microcirculation following oral glucose; this improvement was blunted when matched hyperglycaemia was coupled with lower hyperinsulinaemia (intravenous glucose). CONCLUSIONS/INTERPRETATION: Regardless of glucose tolerance, oral glucose does not impair endothelium-dependent vasodilatation either in resistance arteries or in the microcirculation, despite causing increased oxidative stress; the endogenous insulin response is probably responsible for countering any inhibitory effect on vascular function.

Effect of pioglitazone on the metabolic and hormonal response to a mixed meal in type II diabetes.

We explored the mechanisms by which a 4-month, placebo-controlled pioglitazone treatment (45 mg/day) improves glycemic control in type II diabetic patients (T2D, n=27) using physiological testing (6-h mixed meal) and a triple tracer technique ([6,6-(2)H(2)]glucose infusion, (2)H(2)O and [6-(3)H]glucose ingestion) to measure endogenous glucose production (EGP), gluconeogenesis (GNG), insulin-mediated glucose clearance and beta-cell glucose sensitivity (by c-peptide modeling). Compared to sex/age/weight-matched non-diabetic controls, T2D patients showed inappropriately (for prevailing insulinemia) raised glucose production (1.05[0.53] vs 0.71[0.36]mmol min(-1) kg(ffm)(-1) pM, P=0.03) because of enhanced GNG (73.1+/-2.4 vs 59.5+/-3.6%, P<0.01) persisting throughout the meal, reduced insulin-mediated glucose clearance (6[5] vs 12[13]ml min(-1) kg(ffm)(-1) nM(-1), P<0.005), and impaired beta-cell glucose-sensitivity (27[38] vs 71[37]pmol min(-1) m(-2) mM(-1), P=0.002). Compared to placebo, pioglitazone improved glucose overproduction (P=0.0001), GNG and glucose underutilization (P=0.05) despite lower insulinemia. GNG improvement was quantitatively related to raised adiponectin. beta-cell glucose sensitivity was unchanged. In mild-to-moderate T2D, pioglitazone monotherapy decreased fasting and post-prandial glycemia, principally via inhibition of gluconeogenesis, improved hepatic and peripheral insulin resistance.

Long-term interferon beta-1b therapy for MS: is routine thyroid assessment always useful?

BACKGROUND: The authors previously reported on the development of thyroid dysfunction and autoimmunity during 1-year treatment of patients with MS with interferon-beta 1b (IFN beta-1b). OBJECTIVE: To evaluate the evolution of incident thyroid disease and the possible development of more thyroid disease during longer term therapy. PATIENTS: The authors studied 31 patients (aged 34 +/- 7 years; 21 women) with relapsing-remitting MS during 3 years of IFN beta-1b treatment. Systematic thyroid assessment was performed every 3 or 6 months, depending on the development of thyroid disease. RESULTS: After the first year of IFN beta-1b treatment, no further cases of thyroid disease were observed. Among the six patients with early incident subclinical hypothyroidism, thyroid dysfunction persisted only in those with baseline autoimmune thyroiditis (n = 2). The three patients who developed transient hyperthyroidism remained euthyroid throughout the treatment course. A positive autoantibody titer was continually detected in only two out of five patients without baseline autoimmunity. CONCLUSIONS: The risk of thyroid disease seems related to IFN beta-1b treatment during the first year only, particularly in patients with preexisting thyroiditis. Furthermore, incident thyroid dysfunction is generally transient and mild in degree. Indeed, we recommend a routine systematic thyroid assessment only in patients with baseline thyroiditis. During the first year of therapy, serum thyroid-stimulating hormone measurement should suffice as first line test; a systematic thyroid assessment is only useful for those patients with incidental and persistent dysfunction. Further studies with many patients will be necessary to confirm our suggestions as broad clinical guidelines.

Effect of 1-year treatment with interferon-beta1b on thyroid function and autoimmunity in patients with multiple sclerosis.

OBJECTIVE: Interferon-beta (IFN-beta) is a widely used therapy for multiple sclerosis (MS), a demyelinating disease of the central nervous system. This study has evaluated the effect on thyroid function and autoimmunity of a 1-year treatment with IFN-beta1b in patients with MS. PATIENTS: We studied 31 patients (age 34+/-7 years, 21 women) with relapsing-remitting MS during IFN-beta1b treatment of 1 year duration. Systematic thyroid assessment and measurements of serum interleukin-6 (IL-6) levels were performed at baseline and every 3 months during treatment. RESULTS: Sixteen percent of the patients had autoimmune thyroiditis before IFN-beta1b, all positive for anti-peroxidase antibodies. The overall incidence of thyroid dysfunction was 33% over 1 year (10% hyperthyroidism, 23% hypothyroidism). Thyroid autoimmunity developed in 5/26 patients (19%), in one case without dysfunction. In addition to autoantibody positivity at baseline, female gender and the presence of an ultrasound thyroid pattern suggestive of thyroiditis were identified by multiple logistic regression as additional risk predictors for the development of thyroid dysfunction. During IFN-beta1b treatment, serum IL-6 levels rose in a consistent biphasic pattern; there was, however, no difference between patients with or without incident thyroid abnormalities. CONCLUSIONS: We conclude that IFN-beta1b therapy can induce multiple alterations in thyroid function, some of which are unrelated to thyroid autoimmunity. IL-6 measurement is not useful to identify patients prone to develop thyroid abnormalities. Though thyroid dysfunction is generally subclinical and often transient, systematic thyroid assessment should be performed during IFN-beta1b treatment.

Neuromuscular symptoms and dysfunction in subclinical hypothyroid patients: beneficial effect of L-T4 replacement therapy.

DESIGN, PATIENTS AND MEASUREMENTS: The presence of neuromuscular symptoms was ascertained by questionnaire in 33 consecutive patients with subclinical hypothyroidism (sHT) as compared to 44 age- and sex-matched controls. Blood was sampled for PTH, magnesium, phosphate, and total and ionized calcium determination. Patients reporting three or more symptoms were also studied by surface electromyography (sEMG). The study was repeated following a six-month L-T4 course. RESULTS: Neuromuscular symptoms were significantly more frequent in patients than in controls (P = 0. 0001), and correlated with TSH values (r = 0.52; P = 0.0001). Among patients showing three or more symptoms (n = 11), sEMG documented the presence of repetitive discharges in 8 patients. L-T4 therapy led to a significant improvement of symptoms (P = 0.0001); persistent repetitive discharges were no longer observed. Total and ionized calcium values, always within the normal limits, were significantly lower in patients than controls (P < 0.0001). An inverse relationship was observed between ionized calcium and: TSH values (r = -0.69, P = 0.0001); the number of neuromuscular symptoms (r = -0.53, P = 0.0001). L-T4 replacement induced a significant increase in both total and ionized calcium levels (P < 0.01 and P < 0.0001, respectively). CONCLUSIONS: Neuromuscular symptoms and dysfunction are rather common in subclinical hypothyroidism, and may be associated with abnormalities in serum calcium balance and surface electromyography. The ability of L-T4 treatment to reverse all these changes suggests that subclinical hypothyroidism patients may require early therapy not only to prevent progression to frank hypothyroidism, but also to improve their neuromuscular dysfunction.

Thyroid function and autoimmunity in Parkinson's disease: a study of 101 patients.

Thyroid disease is the endocrine dysfunction most frequently reported in association with idiopathic Parkinson's disease (PD). The aim of this study was to assess thyroid autoimmunity and function in PD, and to verify the effect of long term l-dopa and/or dopamine therapy on thyroid function. We studied 101 consecutive PD outpatients and seventy age- and sex-matched neurological non-PD patients as controls. They were evaluated for free thyroid hormones, TSH and thyroid autoantibodies. No significant difference in the prevalence of thyroid autoimmunity and dysfunction was found between PD patients and neurological controls (10.8% in PD patients vs 10% in neurological controls). Further, treatment with l-dopa and/or dopaminergic drugs and the stage of Parkinson's disease did not affect thyroid function. In conclusion, the prevalence of thyroid autoimmunity in PD patients appeared similar to that as described in the general population, though thyroid dysfunction was observed in over than 10% of PD patients. Indeed, neurologists should be alerted to the possible complications arising from thyroid dysfunction in Parkinson's disease, but thyroid function tests should be performed only when justified on clinical grounds.

Treatment of hyperfunctioning thyroid nodules with percutaneous ethanol injection: Eight years' experience.

The aim of our study was to define the long-term efficacy and safety of percutaneous ethanol injection (PEI) for the treatment of autonomous thyroid nodule (ATN), and to optimise the clinical usefulness of such a therapy. We treated 132 patients with ATN (30 M and 102 F, aged 47.5+/-12.9 years; mean+/-SD), in case other established treatments were refused or contraindicated. Eighty-five patients were affected by toxic adenoma and 47 suffered from pre-toxic nodules. Ethanol was administered weekly under sonographic control, in 7 sessions (range 2-16). During PEI treatment, 26 toxic elderly patients were treated with methimazole and propranolol. Three possible outcomes were identified for statistical analysis: failure (persistent suppression of extra nodular tissue uptake, along with elevated free thyroid hormone and undetectable TSH levels); partial cure (normal free thyroid hormone and low/undetectable TSH levels); complete cure (normal thyroid hormone and TSH levels; restored extra nodular uptake). The patients were followed for up to 8.5 years (median 76 months). PEI therapy was well tolerated by all patients though a mild to moderate local pain occurred in about 30% of sessions. Complete cure was achieved in all pre-toxic patients and in 60 (70.6%) patients with toxic adenoma, while partial cure was observed in 11 cases (12.9%) and failure in 14 (16.5%). A significant shrinkage of nodule volume was observed in all patients (p = 0.0001), while those with toxic nodules larger than 30 mL showed a significantly lower response rate to PEI (p < 0.05). At controls, only one patient developed subclinical hypothyroidism while, among partially cured patients, five relapsed. The administration of methimazole and/or propranolol did not modify PEI outcome. In conclusion, we suggest that PEI therapy may be the treatment of choice in patients with pre-toxic thyroid adenoma where therapy is least necessary- despite the nodule volume. Though ethanol injection therapy of toxic thyroid nodules may be troublesome for the need of multiple sessions, it appears an effective alternative procedure in patients at poor surgical risk, and in younger patients in whom radioiodine is contraindicated. Since a special technical skill in intervention procedures is required, PEI therapy may be suitable only for patients living nearby a trained centre.

Appearance of Graves' disease after percutaneous ethanol injection for the treatment of hyperfunctioning thyroid adenoma.

In this report we describe an unusual patient with hyperfunctioning thyroid adenoma in whom percutaneous ethanol injection (p.e.i.) therapy was followed by typical Graves' disease. His history revealed the presence of a sister with Hashimoto's thyroiditis. 99-mTc thyroid scintiscan showed focal uptake in the nodule, with suppression of extranodular parenchyma. P.e.i. therapy was followed by the development of severe hyperthyroidism. One month after a second p.e.i. cycle, recurrence of hyperthyroidism associated with diffuse 99-mTc uptake by the gland was observed. TSH-receptor and thyroglobulin autoantibodies were undetectable before p.e.i. therapy, appeared during the first cycle, and showed a further increase after the second p.e.i. therapy cycle. Though spontaneous switch to Graves' disease cannot be excluded in patients with toxic nodules, the massive release of thyroid materials from follicular cells, among these TSH-receptor antigenic components partially denatured by ethanol, may indeed trigger an autoimmune response to the TSH-receptor, thus accounting for this observation. Patients with possible autoimmune disposition, as selected by familiar history and/or laboratory markers should be carefully monitored during p.e.i. treatment.

Five-year follow-up of percutaneous ethanol injection for the treatment of hyperfunctioning thyroid nodules: a study of 117 patients.

UNLABELLED: Percutaneous ethanol injection (PEI) has been suggested as an alternative to radioiodine and surgery for the treatment of autonomous thyroid nodules (ATN). OBJECTIVE: In this study we have defined the long-term efficacy and safety of PEI for the treatment of ATN, and we have attempted to optimize the clinical usefulness and improve the technical approach to PEI treatment. PATIENTS: One hundred and seventeen patients with ATN, 26 males and 91 females, aged 48 +/- 12.9 years (mean +/- SD), were offered PEI when other established treatments were refused or contraindicated. Seventy-seven patients were affected by toxic adenoma (60 with a single nodule, 17 with a multinodular goitre); 40 patients suffered from a pretoxic single nodule. METHODS: Sterile 95% ethanol was administered weekly under sonographic control by a 20-22 gauge needle without anaesthesia or pharmacological sedation. During PEI treatment, 26 toxic elderly patients were treated with methimazole and propranolol. According to hormone and scintigraphic data, three possible outcomes were identified for statistical analysis: failure (persistent suppression of extra-nodular tissue uptake, along with elevated free T4 (FT4) and free T3 (FT3) and undetectable TSH levels); partial cure (normalization of FT4 and FT3 levels, with low/ undetectable TSH levels; persistent suppression of extra-nodular uptake); complete cure (normal thyroid hormone and TSH levels; restored extra-nodular uptake). RESULTS: The patients were followed for up to 5 years (median 2.5). PEI therapy was well tolerated by all patients. Complete cure was achieved in all pretoxic patients and in 60 (77.9%) patients with toxic adenoma, while partial cure was observed in 7 cases (9.1%) and failure in 10 (13%). PEI treatment proved similarly effective in toxic patients with a single nodule or with multinodular goitre (87 vs 88.2%, respectively). At the end of treatment, a significant shrinkage of nodule volume was observed in all patients (P = 0.0001). Toxic patients with pretreatment volume > 40 ml (n = 8) did not show a significant difference in treatment response rate as compared to those with volume < 40 ml. Recurrence of hyperthyroidism was never observed during follow-up, independently of thyroid status before treatment. Only one patient with significant thyroid autoantibody serum levels before PEI treatment, developed sub-clinical hypothyroidism at 3 years. The administration of methimazole and/or propranolol did not modify PEI outcome. CONCLUSION: Our data confirm the efficacy and safety of percutaneous ethanol injection for the therapy of autonomous thyroid nodules. The very low incidence of hypothyroidism along with the absence of recurrence of hyperthyroidism suggests that percutaneous ethanol injection is the treatment of choice in patients with pretoxic thyroid adenoma. Percutaneous ethanol injection appears an effective alternative procedure in toxic patients with a high surgical risk even if they have large nodules, and in younger ones in whom radioiodine is contraindicated. Patients may be submitted to anti-thyroid drug and/or beta-blocker therapy if it is necessary, but this does not affect percutaneous ethanol injection treatment outcome. Finally, not only single autonomous thyroid nodules but also toxic multinodular goitre may be successfully treated by percutaneous ethanol injection.

Is percutaneous ethanol injection a useful alternative for the treatment of the cold benign thyroid nodule? Five years' experience.

We describe our 5-year experience with percutaneous ethanol injection (PEI) for the treatment of cold benign thyroid nodules and report its efficacy and side effects. Fifty-four euthyroid outpatients (aged 44.8+/-12.7 years, mean+/-SD) were divided into two groups matched for sex, age, and nodule volume: 27 patients treated only by PEI and 27 patients treated additionally with levothyroxine-suppressive therapy (median follow-up: 24 months, range 6-48). Mean pretreatment nodule volume was 21.0 mL (range 5.4-54.6). Ethanol (1.3+/-0.6 mL/mL nodule volume) was injected under sonographic control in 4 to 13 weekly sessions (mean 7.4). PEI therapy was well tolerated by all patients. At the end of treatment, nodule volume was 7.7+/-5.7 mL (p = .0001). A further significant shrinkage was obtained at 1-year follow-up (4.4+/-3.8 mL; p < .05). No significant differences in nodule reduction were observed between the levothyroxine treated or untreated group and between patients with pretreatment nodule volume smaller or larger than 15 mL. Our study confirms the efficacy and safety of PEI in inducing volume shrinkage of cold benign thyroid nodules. Overall our data suggest that PEI may become an interesting alternative for patients with surgical indications, if they refuse surgery or are poor surgical risks, or eventually demand treatment for aesthetic purposes. It may also be considered when levothyroxine therapy is contraindicated or ineffective.

Age-related modifications in the regulation of the hypothalamic-pituitary-thyroid axis.

We studied the hypothalamic-pituitary-thyroid function in two groups of healthy elderly subjects: group A (n = 23, age range 65-80 years), and group B (n = 11, age range 81-92 years), and in 32 controls, aged 20-60. A TRH test for TSH and prolactin was performed in all subjects, while the TSH circadian modulation was evaluated in elderly subjects only. Group B showed significantly lower fT3 and TSH, and higher fT4 levels with respect to controls (fT3: 4.4 +/- 0.2 vs. 5.2 +/- 0.2 pmol/l, p < 0.05; fT4: 13.1 +/- 0.9 vs. 11.4 +/- 0.4 pmol/l, p < 0.05; TSH: 1.07 +/- 0.21 vs. 1.46 +/- 0.13 mIU/l, p < 0.05). Morning TSH showed an inverse correlation with age (r = -0.42; p < 0.02) among the 34 elderly subjects, but not among controls. Evidence for TSH circadian modulation was found only in group A (nighttime TSH: 1.60 +/- 0.17, vs. daytime: 1.25 +/- 0.13 mIU/l, p < 0.001). The TRH-stimulated TSH peak was reduced among all elderly subjects with respect to controls (A: 6.26 +/- 0.64 mIU/l, p = 0.01; B: 5.02 +/- 0.58 mIU/l, p < 0.01). The maximal PRL response was also blunted (A: 25.7 +/- 2.6 micrograms/l, B: 27.7 +/- 5.2 micrograms/l, p < 0.0005). In conclusion, a resetting of the pituitary threshold of the TSH feedback suppression, along with complex alterations in peripheral thyroid hormone levels, may progressively develop in older people, becoming apparent only with extreme senescence. Moreover, the TSH nocturnal surge may be lost with increasing age, thus providing evidence also for hypothalamic dysfunction.

[Tolerance of long-term protirelin tartrate treatment]. / Tollerabilità del trattamento a lungo termine con protirelina tartrato.

Synthetic TRH (TRH-T) has recently been used for the treatment of chronic and acute neurologic disorders. We studied the effects of long-term (30 days) refracted daily intramuscular administration of 4 mg TRH-T on neuroendocrine and cardiovascular system and on glucose and fat metabolism in 22 patients (mean age 62.7 +/- 10.9) with chronic cerebrovascular disease. All subjects were submitted to ECG and arterial blood pressure determination and were assayed for TSH, thyroid hormone, PRL, glucose, creatinine, nitrogen, glutamine transaminase, cholesterol and triglycerides plasma levels before therapy (T0), after 30 treatment days (T30) and after a 15 days washout (T45). Thyroid hormone, TSH and PRL serum levels were detected also after 15 days of TRH-T therapy (T15). In addition, TSH and PRL response to 200 micrograms iv TRH was assessed at T0, T30 and T45. TRH-T administration did not cause significant alterations of neuroendocrine balance. Furthermore, we observed no changes in lipid metabolism, renal and liver function, arterial blood pressure, and ECG. In conclusion, TRH-T may be safely used in elderly patients with chronic cerebrovascular disease, independently to cardiovascular disorders.

Percutaneous ethanol injection therapy of autonomous nodule and amiodarone-induced thyrotoxicosis.

A patient with amiodarone-induced thyrotoxicosis and autonomous nodule was treated with percutaneous ethanol injection (PEI) in 8 sessions. Preinjection thyroid hormone levels showed a marked elevation, peaking before the third session. The thyroid hormone increments following each procedure never exceeded 20% of the preinjection levels. FT4 plasma levels thereafter declined to within the normal range by the sixth session (day 21), while FT3 levels, though markedly reduced, were still slightly elevated; also, the thyroid hormone increments following ethanol injection were not observed after the fifth session. These findings suggest that a significant, but not sustained, increase in thyroid hormone levels is induced by PEI and may account for the lack of acute deterioration of clinical status, which remained under control with medical treatment alone. Normal serum thyroid hormone levels were observed at the 3 and 12 month follow-up. The use of percutaneous ethanol injection therapy for amiodarone-induced hyperthyroidism should be restricted to patients with preexisting thyroid hyperfunctioning nodule, and it may be a practical alternative to surgery in addition to medical treatment. Special caution should be exercised with patients with severe underlying heart disorders, since their clinical status might seriously worsen in case of acute elevations of serum thyroid hormones following ethanol injection. To this purpose, a close monitoring of serum thyroid hormones is recommended in order to institute a prompt adjustment in their medical therapy and/or in their PEI protocol.

[Biologic action of promestriene on the genital tract of the castrated rat]. / Attività biologica del promestriene sul tratto genitale della ratta castrata.

The study assessed the activity of promestrien administered by a local vaginal route in 16 rats castrated 60 days previously. The dose used was 5 mg per day for 10 days. Following treatment, animals were sacrificed and histological analyses revealed a remarkable proliferation of the vaginal epithelium, inhibition and restored trophism of the strome, whereas no estrogen stimulus was observed at the level of uterine mucous. This confirms the exclusively local action of promestrien which does not provoke undesirable side effects on other segments of the genital tract, and allows the therapeutic use of the hormone in different gynaecological pathologies.