Héctor F. Escobar-Morreale

Thyroid hormone replacement therapy in primary hypothyroidism: a randomized trial comparing L-thyroxine plus liothyronine with L-thyroxine alone.

Context Studies comparing the outcomes of treatment of hypothyroidism with l-thyroxine alone versus with a combination of l-thyroxine and liothyronine have had conflicting results. Some experts believe the conflicting results occurred because some studies used supraphysiologic doses of liothyronine. Contribution This crossover trial compared l-thyroxine with a combina-tion of physiologic doses of l-thyroxine and liothyronine and found no objective advantages of combination therapy. Implications Treatment of hypothyroidism with l-thyroxine alone is sufficient. The Editors The recommended treatment for hypothyroidism is oral l-thyroxine sodium. This treatment is administered with the aim of restoring clinical euthyroidism and well-being and maintaining normal serum levels of thyroid-stimulating hormone (TSH) (1). However, triiodothyronine is the most active thyroid hormone because its affinity for the nuclear thyroid hormone receptor is 10- to 20-fold that of thyroxine (2, 3). The current practice of using l-thyroxine alone as replacement therapy for hypothyroidism assumes that peripheral conversion of thyroxine into triiodothyronine is able to restore normal triiodothyronine concentrations in target tissues. However, no experimental data support this assumption. On the contrary, we found that infusion of thyroxine alone into thyroidectomized rats was not able to restore euthyroidism (4); this was possible only by infusing combinations of thyroxine and triiodothyronine in proportions similar to those secreted by the rat thyroid gland (5). An early study in hypothyroid patients compared treatment with the usual daily l-thyroxine dose, consisting of two or three 100-g tablets, versus the same number of tablets, each containing 80 g of l-thyroxine and 20 g of liothyronine(6). Although patients were probably overtreated throughout the study, adverse events were more frequent during treatment with the l-thyroxineliothyronine combination (6), probably because of the excessive amount of liothyronine administered. More recently, several studies have evaluated combined levothyroxineliothyronine treatment using a triiodothyronine substitution approach, in which a small yet supraphysiologic amount of liothyronine, ranging from 10 g/d to 15 g/d, was substituted for 50 g of the total l-thyroxine dose (7-10). Bunevicius and colleagues (7, 8) reported that triiodothyronine substitution resulted in marked improvements in several items of the Profile of Mood States (POMS) and in a few indexes of psychometric function and quality of life, especially in athyreotic patients with thyroid cancer (8). Recent studies, however, have failed to confirm any beneficial effects of triiodothyronine substitution on quality of life (9, 10). Even in selected hypothyroid patients presenting with depressive symptoms despite normalization of serum TSH concentrations, substitution of 50% of the l-thyroxine dose with a variable amount of liothyronine did not improve self-rated mood or well-being (11). However, 2 of these studies had a parallel-group design (10, 11), and in the study that included a crossover design, serum TSH levels were higher after triiodothyronine substitution than after treatment with l-thyroxine alone (9), suggesting undertreatment with the former agent (12). These recent studies using triiodothyronine substitution had limitations. The ratios of l-thyroxine to liothyronine in the individual combinations administered to patients varied widely and differed from the physiologic ratio of thyroxine to triiodothyronine and from the absolute quantities of both hormones secreted by the human thyroid gland (5, 13). Moreover, these studies included men and women whose hypothyroidism varied in duration and severity. Some had subclinical hypothyroidism and might have retained some residual secretion of thyroxine and triiodothyronine. Prestudy l-thyroxine requirements also differed among patients. Therefore, the lack of beneficial effects of the combinations over l-thyroxine alone might depend not on the treatment itself but on these confounding factors. To avoid the limitations of previous studies, we examined l-thyroxineliothyronine combinations with fixed ratios based on human thyroid secretion (14) in women with overt hypothyroidism at diagnosis. Methods Study Objective and Participants We performed this study to evaluate whether combinations of l-thyroxine plus liothyronine matching the proportion present in the normal secretion of the human thyroid gland offer demonstrable advantages over standard treatment with l-thyroxine alone in patients with overt primary hypothyroidism. We included women who were between 18 and 70 years of age; who presented with overt primary hypothyroidism, as defined by increased TSH levels and decreased serum free thyroxine levels at diagnosis; and who had maintained normal serum TSH levels while receiving treatment with a stable l-thyroxine dosage of 100 g/d for at least the previous year. Exclusion criteria were mental illness; affective disorders or use of psychotropic drugs; cardiovascular, renal, or hepatic disease; or osteoporosis. For the external euthyroid control group, we selected healthy women who were similar to the patients in terms of age, postmenopausal status, ethnicity, social and cultural background, academic degrees, and current professional occupation. Patients and controls were not taking any drug known to influence thyroid function, other than l-thyroxine in the former group. The Ethics Committee of the Hospital Ramn y Cajal approved the study, and written informed consent was obtained from all patients and controls. Interventions We used a randomized, double-blind, crossover design to compare treatment with l-thyroxine, 100 g/d (standard treatment), and treatment with a combination of l-thyroxine, 75 g/d, plus liothyronine, 5 g/d (combination treatment), in periods of 8 weeks each (Figure 1). The latter combination was selected after we considered the 14-to-1 proportion of thyroxine to triiodothyronine in human thyroid secretion (14) and the intestinal absorption of both hormones. Because our previous experience in rats indicated that it is difficult to guess the correct l-thyroxineliothyronine combination, and because we feared that the combination we chose might result in undertreatment, all patients were also given a daily combination containing 87.5 g of l-thyroxine plus 7.5 g of liothyronine (add-on combination treatment) for a final 8-week add-on period (Figure 1). Figure 1. Flow of patients through the study. l On a daily basis, patients took one 50-g tablet of l-thyroxine (Euthyrox, Merck KgaA, Darmstad, Germany) from a red-tagged opaque box and another tablet from a yellow-tagged opaque box. The content of the yellow-tagged box differed during every 8-week period and contained 50-g l-thyroxine tablets (Levothroid, Aventis, Madrid, Spain) for standard treatment; Novothyral Mite tablets (Merck), containing 25 g of l-thyroxine plus 5 g of liothyronine, for combination treatment; or half-tablets of Novothyral 75 (Merck), containing 37.5 g of l-thyroxine plus 7.5 g of liothyronine, for the add-on combination treatment. Outcomes Primary outcomes included serum thyroid hormone levels, POMS, the Digit Symbol Substitution Test, the Digit Span Test, the Visual Scanning Test, and patients preference. Other tests of quality of life and psychometric function and multiple biological thyroid hormone end points were studied as secondary outcomes. We performed the same procedures in patients at 4 different times: when they were receiving their usual l-thyroxine treatment before the start of the study and at the end of each treatment period. Patients were evaluated while receiving usual treatment to avoid a placebo effect related to the fact of being evaluated; these data were not included in the final analysis. Controls were evaluated only once. Patients and controls reported to the hospital after fasting overnight for 12 hours. Patients took the study medication with water immediately after waking up. Body mass index, office blood pressure, waist-to-hip ratio, body composition (estimated by bioelectrical impedance [BF-300, Omron Healthcare Inc., Bannockburn, Illinois]), and body temperature were measured. Immediately afterward, a broad evaluation of biological thyroid hormone end points was performed. The sequence of this evaluation was the same for every participant and lasted for no more than 3 hours. Cardiovascular Evaluation A single investigator performed echocardiography in all participants as described previously (15). The following measurements were recorded: left atrial diameter, systolic and diastolic left ventricular diameter, posterior wall and septum thickness, shortening fraction, left ventricular ejection fraction, left ventricular mass index, early-phase and maximal late mitral valve flows and their ratio, isovolumic relaxation time, deceleration time, aortic velocity time integral, heart rate, and cardiac output. Systemic vascular resistance was calculated as the mean arterial blood pressure divided by cardiac output. Patients were asked to record their heart rate using an oscillometric ambulatory blood pressure monitor (A&D Company Ltd., Tokyo, Japan) for 24 hours to exclude liothyronine-induced tachycardia. Hormonal and Biochemical Measurements Blood samples were obtained 2 hours after ingestion of study medication. Serum levels of free thyroxine, free triiodothyronine, TSH, and sex hormonebinding globulin were determined by using immunochemiluminescent assays (Immulite 2000, Diagnostic Products Corp., Los Angeles, California). The normal ranges were 0.4 to 4.0 mU/L for serum TSH, 10.3 to 24.5 pmol/L for free thyroxine, and 2.8 to 6.5 pmol/L for free triiodothyronine, as reported by the Central Laboratory of Hospital Ramn y Cajal. An automated analyzer was used to perform a complete serum biochemistry analysis, including renal and liver function tests and lipid profiles, a

Thyroid hormones influence serum leptin concentrations in the rat.

Leptin, the product of the ob gene, is secreted by adipocytes and has been shown to decrease appetite and increase energy expenditure. Leptin mRNA in adipocytes correlates with body wt, and serum leptin levels correlate with body fat. Alterations in thyroid status are frequently associated with changes in body wt. To evaluate the possible influence of thyroid status on the leptin system, we have measured serum leptin concentrations in thyroidectomized rats infused either with placebo, or with different doses of T4 (0.8 to 8.0 μg/100 g body wt per day) or T3 (0.25 to 2.0 μg/100 g body wt per day), covering a wide range of thyroid hormone concentrations, from overt hypothyroidism to hyperthyroidism. Intact animals infused with placebo were used as euthyroid controls. Infusion of T4 or T3 into thyroidectomized rats resulted in a decrease in serum leptin levels with respect to the thyroidectomized animals infused with placebo. When compared to the control group, serum leptin levels were decreased in the group...

Regulation of Iodothyronine Deiodinase Activity as Studied in Thyroidectomized Rats Infused with Thyroxine or Triiodothyronine

To provide new insights into the in vivo regulation of iodothyronine deiodinases in the different tissues of the rat, we have evaluated the effects on these enzymatic activities of T4 or T3 infusions into thyroidectomized rats. Thyroidectomized rats were infused with placebo, T4, or T3. Placebo-infused intact rats served as euthyroid controls. Plasma and samples of cerebral cortex, brown adipose tissue, pituitary, liver, and lung were obtained after 12–13 days of infusion. Plasma TSH, plasma and tissue T4 and T3, and iodothyronine deiodinase activities were determined. Type II 5′-deiodinase (DII) was increased in cortex, brown adipose tissue, and pituitary from animals infused with placebo. DII activity returned to normal only with T4 infusion, remaining elevated in the animals infused with T3 alone despite normal tissue T3 concentrations. Cortex type III 5-deiodinase was only increased when hyperthyroidism was induced by infusion of T3. Liver type I 5′-deiodinase (DI) paralleled the changes in plasma and...

Role of the pentanucleotide (tttta)n polymorphism in the promoter of the CYP11a gene in the pathogenesis of hirsutism

OBJECTIVEnTo determine if the (tttta)(n) repeat polymorphism in the promoter region of CYP11a gene is associated with hirsutism and hyperandrogenism in women from Spain.nnnDESIGNnControlled clinical study.nnnSETTINGnTertiary-care institutional hospital.nnnPATIENT(S)nNinety-two hirsute women and 33 healthy control women.nnnINTERVENTION(S)nBasal and adrenocorticotropin-stimulated serum samples and genomic DNA extracted and purified from whole-blood samples were obtained during the follicular phase of the menstrual cycle.nnnMAIN OUTCOME MEASURE(S)nCYP11a (tttta)(n) repeat-polymorphism genotype and serum ovarian and adrenal androgen levels.nnnRESULT(S)nNone of the CYP11a (tttta)(n) polymorphic alleles was associated with hirsutism. The absence of the four-repeat-units allele (4R-- genotype), which has been reported by other authors to be associated with polycystic ovary syndrome (PCOS), was found in 22.4% of the women studied here and was equally distributed among patients and controls, independently of the presence of PCOS and/or ovarian or adrenal hyperandrogenism. No differences were observed in serum hormone concentrations in 4R-- individuals as compared with subjects with at least one four-repeat-units allele.nnnCONCLUSION(S)nThe (tttta)(n) repeat polymorphism in the promoter region of CYP11a does not appear to play any significant role in the pathogenesis of hirsutism and hyperandrogenism in women from Spain.

The presence of the 21-hydroxylase deficiency carrier status in hirsute women: phenotype-genotype correlations

OBJECTIVEnTo determine the role of heterozygosity for mutations in the 21-hydroxylase gene (CYP21) in the pathogenesis of hyperandrogenism.nnnDESIGNnControlled clinical study.nnnSETTINGnTertiary care institutional hospital.nnnPATIENT(S)nForty hirsute women and 13 healthy control women.nnnINTERVENTION(S)nThe source of androgen excess was determined by the changes in serum testosterone levels in response to a single 3.75-mg i.m. dose of triptorelin.nnnMAIN OUTCOME MEASURE(S)nCYP21 molecular genetic analysis and serum 17-hydroxyprogesterone levels.nnnRESULT(S)nEight patients and one control were heterozygous carriers of CYP21 mutations. Two patients with adrenal hyperandrogenism and one patient with ovarian hyperandrogenism, who carried the V281L mutation had an increased ACTH-stimulated 17-hydroxyprogesterone level (>4.1 ng/mL) that persisted during gonadal suppression. Another patient with adrenal hyperandrogenism carried the V281L mutation, and her ACTH-stimulated 17-hydroxyprogesterone level was elevated only during gonadal suppression. Four patients (three with idiopathic hirsutism, one with ovarian hyperandrogenism) and one control were carriers of CYP21 mutations typically associated with classic congenital adrenal hyperplasia but had normal basal and ACTH-stimulated 17-hydroxyprogesterone levels. Nine patients without CYP21 mutations had increased ACTH-stimulated 17-hydroxyprogesterone levels; these decreased to normal in six of the patients during gonadal suppression.nnnCONCLUSION(S)nThe response of serum 17-hydroxyprogesterone to ACTH does not predict CYP21 carrier status. No clear concordance was found between the CYP21 genotype and the functional origin of androgen excess.

Treatment of hirsutism with ethinyl estradiol–desogestrel contraceptive pills has beneficial effects on the lipid profile and improves insulin sensitivity

OBJECTIVEnTo evaluate the effects on the lipid pattern and insulin sensitivity of hirsute women of an oral contraceptive pill containing 30 microg of ethinyl estradiol and 150 microg of desogestrel.nnnDESIGNnProspective clinical study.nnnSETTINGnTertiary care institutional hospital.nnnPATIENT(S)n16 hirsute women.nnnINTERVENTION(S)nWomen were evaluated at baseline and after receiving six cycles of oral contraceptive therapy.nnnMAIN OUTCOME MEASURE(S)nBody mass index (BMI); hirsutism score (nine body areas); serum levels of total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, triglycerides, apolipoprotein B, lipoprotein(a), and serum adrenal and ovarian androgens; and fasting glucose and insulin concentrations.nnnRESULT(S)nThe mean serum total, HDL, and LDL cholesterol levels increased after six cycles of oral contraceptive therapy. Levels of HDL cholesterol were < 50 mg/dL in 7 of the 16 patients at baseline; these levels normalized in 4 patients after treatment. Serum total and LDL cholesterol remained within the normal range in all patients before and after therapy. No significant changes were observed in serum triglyceride, apolipoprotein B and lipoprotein(a) concentrations. Fasting insulin levels and insulin resistance as analyzed by homeostasis model assessment were reduced significantly after therapy. No changes in BMI were observed. Administration of oral contraceptive pills signifiCantly reduced the hirsutism score and hyperandrogenemia.nnnCONCLUSION(S)nOral contraceptive pills containing low-dose ethinyl estradiol and desogestrel are effective in controlling hyperandrogenism and hirsutism and ameliorate the abnormal metabolic profile of women with hirsutism.

Effects of Polycystic Ovary Syndrome (PCOS), Sex Hormones, and Obesity on Circulating miRNA-21, miRNA-27b, miRNA-103, and miRNA-155 Expression

CONTEXTnMicroRNAs (miRNAs) are small, noncoding RNA sequences that negatively regulate gene expression at the post-transcriptional level. miRNA-21, miRNA-27b, miRNA-103, and miRNA-155 have been associated with metabolic disorders such as obesity and diabetes, which are also associated with polycystic ovary syndrome (PCOS).nnnOBJECTIVEnWe aimed to evaluate the effects of sex, sex hormones, and PCOS and their interactions with obesity on the expression in the circulation of these miRNAs.nnnDESIGNnThis was a case-control study.nnnSETTINGSnThe setting was an academic hospital.nnnPARTICIPANTSnWe included 12 control women, 12 patients with PCOS, and 12 men selected as to have similar body mass index (BMI) and age. Six subjects per group had normal weight (BMI < 25 kg/m(2)), and six subjects per group were obese (BMI ≥ 30 kg/m(2)).nnnINTERVENTIONSnBlood samples were collected early in the morning after a 12-hour fast.nnnMAIN OUTCOME MEASURESnWe measured whole blood expression of miRNA-21, miRNA-27b, miRNA-103, and miRNA-155.nnnRESULTSnObesity significantly reduced the expression of miRNA-21, miRNA-27b, and miRNA-103. However, there was a significant interaction between obesity and the group of subjects in the expression of miRNA-21, miRNA-27b, miRNA-103, and miRNA-155 consisting of obesity reducing the expression of these miRNAs in control woman and men, but tending to increase their expression in women with PCOS. These differences paralleled those observed in serum T concentrations.nnnCONCLUSIONSnThe present results suggest that miRNAs that play an important role in metabolic and immune system processes are influenced by obesity and circulating androgen concentrations.

Body iron stores and glucose intolerance in premenopausal women: role of hyperandrogenism, insulin resistance and genomic variants related to inflammation, oxidative stress and iron metabolism

OBJECTIVE Increased serum ferritin levels and iron stores may be involved in the development of abnormal glucose tolerance in women presenting with obesity and/or polycystic ovary syndrome (PCOS). We aimed to study the determinants of serum ferritin levels in premenopausal women among indexes of insulin resistance, adiposity, hyperandrogenism, and genotypes pertaining to inflammation, oxidative stress, and iron metabolism. RESEARCH DESIGN AND METHODS A total of 257 premenopausal women, classified depending on the presence or absence of PCOS, obesity, and/or abnormal glucose tolerance, underwent a complete metabolic evaluation, serum ferritin, haptoglobin, and C-reactive protein (CRP) measurements, and genotyping for proinflammatory and prooxidant variants and mutations in the HFE gene. RESULTS Serum ferritin concentrations were increased in women presenting with PCOS and/or abnormal glucose tolerance, independent of obesity. A stepwise multivariate linear regression analysis (R2 = 0.18, P < 0.0001) retained menstrual dysfunction (β = 0.14, P = 0.035), free testosterone (β = 0.14, P = 0.052), insulin sensitivity index (β = −0.12, P = 0.012), the His63Asp variant in HFE (β = 0.16, P = 0.008), and abnormal glucose tolerance (β = 0.15, P = 0.015) as significant predictors of the logarithm of ferritin levels, whereas CRP, haptoglobin, waist-to-hip ratio, or variants in the TNFα, TNFRSF1B, IL6, IL6ST, IL6Rα, PON1, and HFE Cys282Tyr mutation exerted no influence. CONCLUSIONS Androgen excess (partly because of hyperandrogenemia and partly because of menstrual dysfunction), insulin resistance, abnormal glucose tolerance, and the HFE His63Asp variant correlate with ferritin levels in premenopausal women.

Insulin gene variable number of tandem repeats regulatory polymorphism is not associated with hyperandrogenism in Spanish women

OBJECTIVEnTo determine if the insulin gene variable number of tandem repeats (VNTR) regulatory polymorphism is associated with hyperandrogenism in a population of Spanish women.nnnDESIGNnControlled clinical study.nnnSETTINGnTertiary institutional hospital.nnnPATIENT(S)nNinety-six hyperandrogenic patients and 38 healthy control women.nnnINTERVENTION(S)nWhole blood and serum samples were collected during the follicular phase of the menstrual cycle.nnnMAIN OUTCOME MEASURE(S)nInsulin gene VNTR regulatory polymorphism genotypes (classes I/I, I/III, and III/III alleles) and serum androgen levels. Insulin resistance was estimated from fasting glucose and insulin levels by using the homeostatic model assessment.nnnRESULT(S)nThe frequencies of VNTR genotypes were 45.5%, 43.3%, and 11.2% for I/I, I/III, and III/III alleles considering patients and controls as a whole. These frequencies were not statistically different in controls (47.4%, 34.2%, and 18.4%) and in patients (44.8%, 46.9%, and 8.3%).nnnCONCLUSION(S)nHyperandrogenism and the insulin gene VNTR regulatory polymorphism are not associated in Spanish women.

Prospective randomized study comparing the long-acting gonadotropin-releasing hormone agonist triptorelin, flutamide, and cyproterone acetate, used in combination with an oral contraceptive, in the treatment of hirsutism

OBJECTIVEnTo compare triptorelin, cyproterone acetate (CPA), and flutamide, in combination with an oral contraceptive, in the treatment of hirsutism.nnnDESIGNnProspective randomized study.nnnSETTING(S)nTertiary care hospital.nnnPATIENT(S)nThirty-nine hirsute women with idiopathic or functional ovarian hyperandrogenism.nnnINTERVENTION(S)nPatients were randomly assigned to receive triptorelin (3.75 mg IM every 28 days), CPA (100 mg/d orally on days 1-10 of the menstrual cycle), or flutamide (250 mg orally twice daily). All the patients also received a triphasic oral contraceptive.nnnMAIN OUTCOME MEASURE(S)nBefore and after 3 and 9 months of treatment, the Ferriman-Gallwey score, hepatic function, and gonadal and adrenal steroid profiles were evaluated.nnnRESULTSnThirty-three patients completed the 9-month study period. The Ferriman-Gallwey score decreased in all the groups. In the patients treated with CPA or flutamide, a decrease in the hirsutism score was noted as soon as after 3 months of treatment. This decrease was more pronounced after 9 months of treatment, especially in the patients who received flutamide, who had lower hirsutism scores compared with the other treatment groups. None of the patients had abnormal liver function test results. There was a mild increase in serum lipid concentrations, mostly in the group treated with triptorelin.nnnCONCLUSION(S)nTriptorelin, CPA, and flutamide are effective drugs for the treatment of hirsutism. Flutamide results in a greater reduction in the hirsutism score, but CPA also offers satisfactory results at a much lower cost. Triptorelin has no advantages over flutamide and CPA, and is the most expensive of the three drugs tested.