[Eucaloric substitution of medium chain triglycerides for dietary long chain fatty acids improves body composition and lipid profile in a patient with human immunodeficiency virus lipodystrophy]

BACKGROUND

Lipodystrophy is a frequent disorder among patients with human immunodeficiency virus (HIV) infection, characterized by a loss of adipose tissue from the extremities, gluteal region and face, with excess fat in the neck and abdominal region. Metabolic abnormalities such as hyperlipidaemia and diabetes mellitus frequently coexist, posing these patients to an increased cardiovascular risk. Drug therapy may improve some of these metabolic disturbances, but to date there are no treatments for lipodystrophy with proven benefit.

CASE REPORT

A 42-year-old man with HIV lipodystrophy was started on a standard low caloric diet with <30% of total fat and <10% of saturated fat, together with rosiglitazone 8 mg daily. After five months of treatment, given that lipodystrophic features and dyslipidaemia were still present in our patient, we tried to further improve therapeutic results by eucaloric substitution of medium chain triglycerides for dietary long chain fatty acids. Three months later, a dramatic change in body composition was shown with an increase in lean mass and a decrease in fat mass, together with an improvement in lipid profile.

CONCLUSION

Eucaloric substitution of medium chain triglycerides for dietary long chain fatty acids may produce therapeutic benefits in HIV lipodystrophy.

Adiponectin and resistin in PCOS: a clinical, biochemical and molecular genetic study

BACKGROUND

We conducted a cross-sectional case-control study to evaluate the possible involvement of adiponectin and resistin in the pathogenesis of polycystic ovary syndrome (PCOS).

METHODS

Seventy-six PCOS patients and 40 non-hyperandrogenic women matched for BMI and degree of obesity were included. Serum adiponectin and resistin levels, anthropometrical and hormonal variables, the 45 T-->G and 276 G-->T polymorphisms in the adiponectin gene, and the -420 C-->G variant in the resistin gene, were analysed.

RESULTS

Serum adiponectin concentrations were reduced in PCOS patients compared with controls (P = 0.038) irrespective of the degree of obesity, whereas serum resistin levels were increased in overweight and obese women compared with lean subjects (P = 0.016), irrespective of their PCOS or controls status. The adiponectin and resistin polymorphisms were not associated with PCOS and did not influence serum levels of adiponectin, resistin and other clinical and hormonal variables. In a multiple regression model, the waist-to-hip ratio, free testosterone levels and age, but not insulin resistance, were the major determinants of hypoadiponectinaemia.

CONCLUSIONS

PCOS patients present with hypoadiponectinaemia, in relation with abdominal adiposity and hyperandrogenism. Our present results suggest that hyperandrogenism and abdominal obesity, by reducing the serum levels of the insulin sensitizer adipokine adiponectin, might contribute to the insulin resistance of PCOS.

Effects of thyroid hormones on serum levels of adipokines as studied in patients with differentiated thyroid carcinoma during thyroxine withdrawal

OBJECTIVE

Previous studies addressing the influence of thyroid hormones on serum levels of adipokines yielded conflicting results. We aimed to study the impact of short-term overt hypothyroidism on serum leptin, resistin, and adiponectin levels in an in vivo human model.

DESIGN

Twenty-two women with differentiated thyroid carcinoma were studied the last day of their thyroxine-suppressive treatment, 4-7 days after withdrawal, and the day before whole-body scanning. Evaluations included serum thyroid hormone, leptin, resistin, and adiponectin concentrations, fasting glucose and insulin, lipid profiles, body temperature, body mass index, and total body fat mass.

MAIN OUTCOMES

Thyroid function changed from subclinical or mild hyperthyroidism to normal free thyroxine and triiodothyronine levels, ending in overt hypothyroidism. Thyroxine withdrawal resulted in an increase in serum resistin (p = 0.007) and leptin (p = 0.006) concentrations, whereas adiponectin levels remain unchanged. A significant decrease in body temperature during thyroxine withdrawal was paralleled by a decrease in fasting glucose (p = 0.006) and insulin resistance (p = 0.033), which occurred despite an increase in estimated total body fat mass.

CONCLUSION

Thyroid hormones are important regulators of energy balance and intermediate metabolism, influencing the serum concentrations of leptin and resistin.

The polycystic ovary syndrome associated with morbid obesity may resolve after weight loss induced by bariatric surgery

CONTEXT

The polycystic ovary syndrome (PCOS) is frequently associated with obesity. However, there are very few data about PCOS in morbid obesity, especially with regard to its evolution after bariatric surgery.

OBJECTIVE

The objective of this study was to evaluate the response of PCOS to the sustained and marked weight loss achieved by bariatric surgery in morbidly obese women.

DESIGN

This was a longitudinal prospective nonrandomized evaluation.

SETTINGS

The study was performed at an academic hospital.

PATIENTS

Thirty-six consecutive premenopausal women submitted to bariatric surgery were screened for PCOS, which was present in 17.

INTERVENTIONS

Bariatric surgery was performed.

MAIN OUTCOME MEASURES

Hyperandrogenism, menstrual function, and insulin resistance were estimated before and at least 6 months after bariatric surgery in 12 patients with PCOS.

RESULTS

Weight loss (41 +/- 9 kg after 12 +/- 5 months) was paralleled by decreases in the hirsutism score (from 9.5 +/- 6.8 to 4.9 +/- 4.2; P = 0.001), total (69 +/- 32 to 42 +/- 19 ng/dl; P < 0.02) and free testosterone (from 1.6 +/- 0.7 to 0.6 +/- 0.3 ng/dl; P < 0.005), androstenedione (from 4.1 +/- 1.5 to 3.0 +/- 0.9 ng/ml; P < 0.02), and dehydroepiandrosterone sulfate (from 2000 +/- 1125 to 1353 +/- 759 ng/ml; P < 0.005); amelioration of insulin resistance estimated by homeostasis model assessment (from 6.0 +/- 3.0 to 1.6 +/- 1.0; P < 0.001); and restoration of regular menstrual cycles and/or ovulation in all patients.

CONCLUSIONS

The PCOS is a frequent finding in women with morbid obesity and may resolve after weight loss induced by bariatric surgery.

The effects of thyroid hormones on circulating markers of cell-mediated immune response, as studied in patients with differentiated thyroid carcinoma before and during thyroxine withdrawal

OBJECTIVE

To address the influence of thyroid hormones on circulating markers of cell-mediated immune response in an in vivo human model.

SUBJECTS AND DESIGN

Twenty-two patients with stage I differentiated thyroid carcinoma were studied on the last day of thyroxine suppressive treatment, 4-7 days after withdrawal, and the day before whole body scanning. Three patients were excluded because of residual disease. Twenty euthyroid individuals served as controls. Serum thyrotrophin and thyroid hormones were measured by an immunometric assay, circulating cytokines by enzyme-linked immuno-sorbent assay and lymphoid populations by flow cytometry.

RESULTS

Thyroid function in patients changed from subclinical or mild hyperthyroidism at the first visit, to a situation of normal circulating levels of free thyroxine and triiodothyronine at the second, ending in a state of overt hypothyroidism. Thyroxine suppressive treatment in patients increased serum interleukin-18 concentrations (IL-18, mean+/-s.d., 280+/-122 vs 183+/-106 pg/ml, F = 3.192, P = 0.029), soluble interleukin-2 receptor levels (sIL-2R, 4368+/-1480 vs 2564+/-846 pg/ml, F = 21.324, P < 0.001), and the percentage of natural killer (NK) cells in peripheral blood (15.9+/-8.6 vs 10.5+/-3.6%, F = 4.977, P = 0.004) compared with controls. After thyroxine withdrawal, serum levels of IL-18, sIL-2R and the percentage of NK cells decreased progressively.

CONCLUSION

Our present results suggest that thyroid hormones modulate the cell-mediated immune response in humans.

REVIEW: Treatment of hypothyroidism with combinations of levothyroxine plus liothyronine

CONTEXT

Combined infusion of levothyroxine plus liothyronine, as opposed to levothyroxine alone, is the only way of restoring the concentrations of circulating TSH, T4, and T3 as well as those of both T4 and T3 in all tissues of thyroidectomized rats. Considering the substantial differences in thyroid hormone secretion, transport, and metabolism between rats and humans, whether or not combined levothyroxine plus liothyronine replacement therapy has advantages over treatment with levothyroxine alone in hypothyroid patients is still questioned.

EVIDENCE ACQUISITION

We conducted a systematic review of all the published controlled studies comparing treatment with levothyroxine alone with combinations of levothyroxine plus liothyronine in hypothyroid patients, identified through the Entrez-PubMed search engine.

EVIDENCE SYNTHESIS

Nine controlled clinical trials were identified that compared treatment with levothyroxine alone and treatment with combinations of levothyroxine plus liothyronine and included a sufficient number of adult hypothyroid patients to yield meaningful results. In only one study did the combined therapy appear to have beneficial effects on the mood, quality of life, and psychometric performance of the patients over levothyroxine alone. These results have not been confirmed by later studies using either T3 substitution protocols or approaches with fixed combinations of levothyroxine plus liothyronine, including those based on the physiological proportion in which T3 and T4 are secreted by the human thyroid. However, in some of these studies the patients preferred levothyroxine plus liothyronine combinations, for reasons not explained by changes in the psychological and psychometric tests employed. Yet patients' preference should be balanced against the possibility of adverse events resulting from the addition of liothyronine to levothyroxine, even in the small doses used in these studies.

CONCLUSIONS

Until clear advantages of levothyroxine plus liothyronine are demonstrated, the administration of levothyroxine alone should remain the treatment of choice for replacement therapy of hypothyroidism.

Polymorphisms in the insulin receptor substrate-1 (IRS-1) gene and the insulin receptor substrate-2 (IRS-2) gene influence glucose homeostasis and body mass index in women with polycystic ovary syndrome and non-hyperandrogenic controls

BACKGROUND

We aimed to evaluate the influence of the Gly972Arg variant of the insulin receptor substrate-1 gene (IRS-1) and the Gly1057Asp variant in IRS-2 on insulin resistance and glucose tolerance in women with polycystic ovary syndrome (PCOS) and healthy controls.

METHODS

Genotypes, allelic frequencies, indexes of insulin resistance, glucose tolerance and hormone profiles were studied in a large sample of Spanish PCOS (n = 103) women compared with a control group (n = 48) of healthy women matched for body mass index.

RESULTS

No differences in genotype or allelic frequencies were found between PCOS patients and healthy controls. When considering control subjects and PCOS patients as a whole, IRS-1 Arg972 carriers also presented with increased fasting insulin (133 +/- 60 versus 95 +/- 67 pmol/l, P = 0.008) and insulin resistance measured by homeostasis model assessment (4.3 +/- 2.1 versus 3.1 +/- 2.4, P = 0.009) compared with subjects homozygous for Gly972 alleles. These differences were even higher when restricting the analysis to PCOS patients. Subjects homozygous for the Gly1057 allele of IRS-2 presented with increased 60 and 90 min oral glucose tolerance test (OGTT) glucose levels compared with carriers of one or two Asp1057 alleles (7.9 +/- 2.1 versus 7.1 +/- 2.1 mmol/l, P = 0.042 and 7.0 +/- 2.1 versus 6.0 +/- 1.8 mmol/l, P = 0.014), and a similar tendency was observed for 120 min OGTT glucose levels.

CONCLUSIONS

The Gly972Arg in IRS-1 and Gly1057Asp in IRS-2 polymorphisms influence glucose homeostasis in premenopausal women, but are not associated with PCOS.

A study of the hexose-6-phosphate dehydrogenase gene R453Q and 11beta-hydroxysteroid dehydrogenase type 1 gene 83557insA polymorphisms in the polycystic ovary syndrome

CONTEXT

The R453Q variant in the hexose-6-phosphate dehydrogenase gene (H6PD) and 83557insA mutations in 11beta-hydroxysteroid dehydrogenase (11betaHSD) type 1 gene (HSD11B1) interact, resulting in cortisone reductase deficiency (CRD), a rare disorder characterized by a polycystic ovary syndrome (PCOS)-like phenotype.

OBJECTIVE

The objective was to study these mutations in PCOS.

DESIGN

The design was a case-control study.

SETTING

The study was conducted in an academic hospital.

PARTICIPANTS

A total of 116 PCOS patients and 76 nonhyperandrogenic controls participated.

MAIN OUTCOME MEASURES

Genotype distributions and influence of genotypes on clinical and biochemical variables and, in 28 patients and 12 controls, estimates of 11betaHSD oxoreductase activity were the main outcome measures.

RESULTS

Four controls and five patients presented three of four mutant alleles in H6PD R453Q and HSD11B1 83557insA, which is the genotype observed in some subjects with CRD. Estimates of 11betaHSD oxoreductase activity were measured in six of these nine women, ruling out CRD. Moreover, H6PD R453Q and HSD11B1 83557insA genotypes, either separately or in combination, did not influence 11betaHSD oxoreductase activity. The distribution of H6PD R453Q genotypes (R/R, R/Q, and Q/Q) was different in patients and controls (42% of controls and 63% of PCOS patients were R/R; 53% of controls and 31% of PCOS patients were R/Q; and 5% of controls and 6% of PCOS patients were Q/Q; chi(2) = 9.1; P = 0.011). Patients homozygous for R453 alleles presented with increased cortisol and 17-hydroxyprogesterone levels, compared with carriers of Q453 alleles, but these differences were not observed in controls. On the contrary, HSD11B1 83557insA genotypes were not associated with PCOS and did not influence any phenotypic variable.

CONCLUSIONS

Digenic triallelic genotypes of the H6PD R453Q variant and HSD11B1 83557insA mutation do not always cause CRD. On the contrary, the H6PD R453Q variant is associated with PCOS and might influence its phenotype by influencing adrenal activity.

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

BACKGROUND

Substituting part of the dose of l-thyroxine with small but supraphysiologic doses of liothyronine in hypothyroid patients has yielded conflicting results.

OBJECTIVE

To evaluate combinations of L-thyroxine plus liothyronine in hypothyroid patients that match the proportions present in normal secretions of the human thyroid gland.

DESIGN

Randomized, double-blind, crossover trial.

SETTING

Academic research hospital.

PARTICIPANTS

28 women with overt primary hypothyroidism.

INTERVENTION

Crossover trial comparing treatment with l-thyroxine, 100 microg/d (standard treatment), versus treatment with L-thyroxine, 75 microg/d, plus liothyronine, 5 microg/d (combination treatment), for 8-week periods. All patients also received L-thyroxine, 87.5 microg/d, plus liothyronine, 7.5 microg/d (add-on combination treatment), for a final 8-week add-on period.

MEASUREMENTS

Primary outcomes included serum thyroid hormone levels, results of quality-of-life and psychometric tests, and patients' preference. Multiple biological thyroid hormone end points were studied as secondary outcomes.

RESULTS

Compared with standard treatment, combination treatment led to lower free thyroxine levels (decrease, 3.9 pmol/L [95% CI, 2.5 to 5.3 pmol/L]), slightly higher serum levels of thyroid-stimulating hormone (increase, 0.62 mU/L [CI, 0.01 to 1.23 mU/L]), and unchanged free triiodothyronine levels. No improvement was observed in the other primary and secondary end points after combination treatment, with the exception of the Digit Span Test, in which the mean backward score and the mean total score increased slightly (0.6 digit [CI, 0.1 to 1.0 digit] and 0.8 digit [CI, 0.2 to 1.4 digits], respectively). The add-on combination treatment resulted in overreplacement. Levels of thyroid-stimulating hormone decreased by 0.85 mU/L (CI, 0.27 to 1.43 mU/L) and serum free triiodothyronine levels increased by 0.8 pmol/L (CI, 0.1 to 1.5 pmol/L) compared with standard treatment; 10 patients had levels of thyroid-stimulating hormone that were below the normal range. Twelve patients preferred combination treatment, 6 patients preferred the add-on combination treatment, 2 patients preferred standard treatment, and 6 patients had no preference (P = 0.015).

LIMITATIONS

Treatment with L-thyroxine, 87.5 microg/d, plus liothyronine, 7.5 microg/d, was an add-on regimen and was not randomized.

CONCLUSIONS

Physiologic combinations of L-thyroxine plus liothyronine do not offer any objective advantage over l-thyroxine alone, yet patients prefer combination treatment.

Chronic thyrotropin-suppressive therapy with levothyroxine and short-term overt hypothyroidism after thyroxine withdrawal are associated with undesirable cardiovascular effects in patients with differentiated thyroid carcinoma

To evaluate cardiovascular functionality in patients with thyroid cancer, we have performed echocardiography and ambulatory blood pressure monitoring in 19 women with differentiated thyroid carcinoma during thyroxine withdrawal, at three time points: the last day on TSH-suppressive thyroxine doses (subclinical or mild hyperthyroidism), 4-7 days after withdrawal (normal free thyroxine (FT4) and free triiodothyronine (FT3) levels), and before 131I whole body scanning (overt hypothyroidism). Twenty-one healthy euthyroid women served as controls. When compared with the values at visit 2, when patients had normal serum FT4 and FT3 levels, night-time systolic and mean blood pressure were increased when the patients were mildly hyperthyroid, and night-time systolic, diastolic and mean blood pressure were increased during overt hypothyroidism. The proportion of nondippers (absence of nocturnal decline in blood pressure) was markedly increased compared with healthy controls (7%), when patients were hyper- or hypothyroid (58% and 50% respectively), but not when patients had normal FT4 and FT3 levels (12%). No changes were observed in office blood pressure or in daytime ambulatory blood pressure readings. Diastolic function worsened during thyroxine withdrawal (E and A waves (early and late mitral flow) decreased, and the E/A ratio and the isovolumic relaxation time increased), and cardiac output decreased in parallel with the decrease in heart rate and systolic blood flow. In conclusion, the chronic administration of TSH-suppressive doses of thyroxine and the withdrawal of thyroxine frequently used for the management of differentiated thyroid carcinoma, are associated with undesirable cardiovascular effects.

Weight gain and cardiovascular risk factors during smoking cessation with bupropion or nicotine

Weight gain is frequent after smoking cessation, and may limit patient's will to quit and long-term success. Nicotine and bupropion are effective drugs for smoking withdrawal. However, their influence on weight gain, insulin resistance and other cardiovascular risk factors, as well as possible differences in obese and lean subjects, have not been fully evaluated. We randomised 25 lean and 25 obese smokers to receive either bupropion or nicotine patches. Clinical evaluation and lipid profile were performed at baseline and after treatment. Insulin resistance was also assessed at the end. Weight, BMI, waist-to-hip ratio, and diastolic blood pressure increased (p < 0.005), whereas lipid profile improved (p < 0.001) after smoking cessation independently of obesity at baseline or drug used. Obese patients had higher insulin resistance at the end (p < 0.05) regardless of drug used. Weight gain was inversely related to age (beta= - 0.125, R = 0.38, p = 0.046), and insulin resistance was related to obesity at baseline (beta = 0.85, R = 0.46, p = 0.02). In conclusion, weight gain after smoking cessation is not dependent on obesity or drug taken. A beneficial lipid profile is achieved after quitting smoking with either bupropion or nicotine patch in both obese and lean subjects.

Serum interleukin-18 concentrations are increased in the polycystic ovary syndrome: relationship to insulin resistance and to obesity

Low-grade chronic inflammation is involved in the pathogenesis of the metabolic syndrome and atherosclerosis, and serum levels of inflammatory cytokines are useful cardiovascular risk markers. We have studied serum IL-18 concentrations in women with polycystic ovary syndrome (PCOS), focusing on its relationship with obesity and indexes of insulin resistance. Sixty consecutive women with PCOS and 34 healthy women were recruited. Serum levels of IL-18 and lipid and hormone profiles were measured. The insulin sensitivity index was calculated from glucose and insulin concentrations during an oral glucose tolerance test. Data were submitted to a multivariate general linear model introducing age as a covariate. Serum IL-18 levels were increased in PCOS patients compared with controls (P = 0.031) and in obese women compared with lean women (P = 0.018). No interaction between PCOS and obesity was found, suggesting that the influence of PCOS on serum IL-18 concentrations studied here was not different in lean women compared with obese women and that the influence of obesity on serum IL-18 concentrations was the same in the PCOS and control groups. Serum IL-18 levels correlated, after logarithmic transformation, with body mass index (r = 0.38; P < 0.0002), waist-to-hip ratio (r = 0.33; P < 0.001), and total testosterone levels (r = 0.24; P < 0.02), and inversely with the insulin sensitivity index (r = -0.23; P < 0.03). In conclusion, PCOS and obesity induce an increase in serum IL-18 levels, which are also associated with several indexes of global and visceral adiposity and with insulin resistance.

Quality of life and psychometric functionality in patients with differentiated thyroid carcinoma

We studied the psychological performance and the quality of life in patients with differentiated thyroid carcinoma, either during treatment with chronic suppressive doses of levothyroxine, or during the withdrawal of levothyroxine needed to perform whole-body scanning with radioactive iodine, with those of appropriate healthy controls. Eighteen women with differentiated thyroid carcinoma and 18 euthyroid age-matched healthy women were recruited. Patients were studied the day before levothyroxine withdrawal (when in chronic mild or subclinical hyperthyroidism), 4-7 days later (when most patients had normal serum free thyroxine and free triiodothyronine levels), and the day before scanning (when in profound hypothyroidism). Controls were studied at one time point. When compared with controls, patients presented with impairment of several indexes during chronic suppressive levothyroxine therapy (total score, emotional, sleep, energy and social of the Nottingham Health Profile; mental health, general health and social function of the SF-36, and total score on Wais Digit Span; P<0.05 for all comparisons). Also, quality of life indexes (19 of 21 scores), cognitive tests (6 of 12 scores), and affective and physical symptoms visual mental scales (18 of 19) worsened during profound hypothyroidism (P<0.05 for all comparisons). Quality of life and cognitive performance were almost comparable with those of euthyroid controls when most patients had normal free thyroxine and triiodothyronine levels. In conclusion, quality of life and psychometric functionality in patients with differentiated thyroid carcinoma is not only affected by withdrawal of levothyroxine but also by long-term treatment with supraphysiological doses of levothyroxine.

Obesity, and not insulin resistance, is the major determinant of serum inflammatory cardiovascular risk markers in pre-menopausal women

AIMS/HYPOTHESIS

Increased serum inflammatory markers have been found in obesity and insulin-resistant states, and could play a causative role in insulin resistance, atherosclerosis and cardiovascular disease. The polycystic ovary syndrome represents a human model of insulin resistance because both lean and obese polycystic ovary syndrome patients are insulin-resistant compared with non-hyperandrogenic women. We evaluated whether obesity, insulin resistance, or both, are related to the increased concentrations of inflammatory markers in pre-menopausal women.

METHODS

We compared 35 patients with polycystic ovary syndrome and 28 healthy women, paired for BMI, prevalence of obesity and smoking. Measurements included serum inflammatory markers, BMI, waist-to-hip ratio, blood pressure, serum glucose, insulin, lipid and hormone concentrations, and insulin sensitivity index.

RESULTS

The insulin sensitivity index was reduced in polycystic ovary syndrome patients compared with controls. However, no differences were observed between both groups in C-reactive protein, interleukin 6, tumour necrosis factor-alpha, soluble type 2 tumour necrosis factor receptor, and soluble intercellular cell adhesion molecule-1. When considering patients and controls as a whole, C-reactive protein and interleukin 6, were increased in obese subjects compared with lean women. Inverse correlations existed between insulin sensitivity index and C-reactive protein, interleukin 6, tumour necrosis factor-alpha, soluble type 2 tumour necrosis factor receptor, and soluble intercellular cell adhesion molecule-1. Only the weak correlation with C-reactive protein persisted after controlling for BMI.

CONCLUSION/INTERPRETATION

Obesity, and not insulin resistance, is the major determinant of serum inflammatory cardiovascular risk markers in pre-menopausal women.

Deletion of the long arm of the Y chromosome in an adolescent with short stature and hypogonadism

We describe a patient with short stature more than that expected for non-treated congenital adrenal hyperplasia due to nonclassic 21-hydroxylase deficiency with deletions in the long arm of the Y chromosome including the CGY gene and the AZF subregions.