A review of the propriety of thyroid ultrasound referrals and their follow-up burden.

PURPOSE: The overdiagnosis of thyroid nodules and indolent thyroid cancers represents an increasing burden on health services, with thyroid ultrasound (US) imaging often representing the initial entry point into the thyroid nodule diagnostic pathway. The aim of this study was to retrospectively review thyroid US referrals to a single Irish hospital to determine if the stated indications for imaging had been appropriate, to review the results of the scans, and to assess the follow-up required in each case. METHODS: Patient demographics, scan indications, results, and outcomes were retrospectively reviewed for all patients undergoing thyroid ultrasound from 2012 to 2016. Data were analyzed using GraphPad Prism and expressed in mean ± standard deviation. RESULTS: In total, 318 patients (mean age 53 ± 15 years, 85% female) had at least one ultrasound. Most US scans were performed for appropriate indications in order to follow up known thyroid nodular disease and/or malignancy (34.3%), to assess new thyroid goiters or discrete neck lumps (33.3%), and to follow up incidental findings from other imaging modalities (12.6%). However, scans were also requested (in the absence of any palpable goiter or mass) for choking/neck pain/swallowing complaints (12.3%), hypo/hyperthyroidism (6.6%), and miscellaneous reasons (0.6%) that were deemed either potentially or likely inappropriate. Of these scans, approximately half of the identified nodule(s) were deemed unlikely to be related to the stated symptoms, but which subsequently required follow-up imaging ± biopsy. No cases of malignancy were identified. CONCLUSIONS: In our center, a significant percentage of thyroid US scans along with their subsequent follow-up were potentially avoidable.

In women with PCOS, waist circumference is a better surrogate of glucose and lipid metabolism than disease status per se.

OBJECTIVE: Cardiometabolic abnormalities are recognized in polycystic ovary syndrome (PCOS). However, over-emphasis on PCOS as a risk factor potentially results in over-investigation and treatment of some women with and under-recognition of cardiometabolic risk in obese women without PCOS. Our objective was to explore the association between waist circumference (WC) and indices of glucose and lipid metabolism in women with and without PCOS. DESIGN, PATIENTS AND MEASUREMENTS: (i) An exploratory cross-sectional study investigating association of potential cardiometabolic risk markers (PCOS status, anthropometric measures, hsCRP, HOMA-IR, SHBG, testosterone) with indices of glucose (frequently sampled intravenous glucose tolerance test) and lipid metabolism (postprandial studies and lipoprotein particle size) in 61 women with (n = 29) and without (n = 32) PCOS; (ii) a cross-sectional study in 103 PCOS women and 102 BMI-matched controls to explore if between-group differences in indices of lipid and glucose metabolism persist after adjusting for WC. NIH criteria were used for PCOS diagnosis. RESULTS: Study 1: Univariate correlations and stepwise regression modelling identified waist circumference (WC), as a better surrogate than PCOS status, independently predicting multiple variables of glucose and lipid metabolism. Study 2: Fasting insulin and triglyceride, hsCRP and insulin resistance (according to HOMA-IR and SiM [Avignon index]) were greater, while fasting HDL was lower in women with PCOS compared to BMI-matched women without PCOS. None of these differences persisted when a subset of 80 women with PCOS was compared with 80 women without PCOS, pair-matched for WC. CONCLUSION: Some cardiometabolic abnormalities in PCOS are related to central obesity, and following adjustment for WC does not differ from normal subjects. Waist circumference measurement has potential to take precedence over PCOS status as part of the assessment of cardiometabolic risk in reproductive-age women.

The effect of growth hormone replacement on the thyroid axis in patients with hypopituitarism: in vivo and ex vivo studies.

OBJECTIVE: Alterations in the hypothalamic-pituitary-thyroid axis have been reported following growth hormone (GH) replacement. The aim was to examine the relationship between changes in serum concentration of thyroid hormones and deiodinase activity in subcutaneous adipose tissue, before and after GH replacement. DESIGN: A prospective, observational study of patients receiving GH replacement as part of routine clinical care. PATIENTS: Twenty adult hypopituitary men. MEASUREMENTS: Serum TSH, thyroid hormones - free and total thyroxine (T4) and triiodothyronine (T3) and reverse T3, thyroglobulin and thyroid-binding globulin (TBG) levels were measured before and after GH substitution. Changes in serum hormone levels were compared to the activity of deiodinase isoenzymes (DIO1, DIO2 and DIO3) in subcutaneous adipose tissue. RESULTS: The mean daily dose of growth hormone (GH) was 0·34 ± 0·11 mg (range 0·15-0·5 mg). Following GH replacement, mean free T4 levels declined (-1·09 ± 1·99 pmol/l, P = 0·02). Reverse T3 levels also fell (-3·44 ± 1·42 ng/dl, P = 0·03) and free T3 levels increased significantly (+0·34 ± 0·15 pmol/l, P = 0·03). In subcutaneous fat, DIO2 enzyme activity declined; DIO1 and DIO3 activities remained unchanged following GH substitution. Serum TSH, thyroglobulin and TBG levels were unaltered by GH therapy. CONCLUSIONS: In vitro analysis of subcutaneous adipose tissue from hypopituitary human subjects demonstrates that GH replacement is associated with significant changes in deiodinase isoenzyme activity. However, the observed variation in enzyme activity does not explain the changes in the circulating concentration of thyroid hormones induced by GH replacement. It is possible that deiodinase isoenzymes are differentially regulated by GH in other tissues including liver and muscle.

Obesity and Insulin Resistance Are the Main Determinants of Postprandial Lipoprotein Dysmetabolism in Polycystic Ovary Syndrome.

Postprandial dyslipidaemia may be a plausible mechanism by which polycystic ovary syndrome (PCOS) increases cardiovascular risk. We sought to investigate whether the postprandial glucose and insulin and lipid and lipoprotein responses, including that of apolipoprotein B-48 (apoB-48) containing chylomicrons, to a mixed meal are different in obese PCOS women when compared to obese control subjects and whether differences, if any, are related to obesity, insulin resistance (IR), hyperandrogenaemia, or PCOS status. 26 women with PCOS (age 30.4 ± 1.2 years (mean ± SEM), body mass index (BMI) 36.8 ± 1.5 kg/m(2)) and 26 non-PCOS subjects (age 34.1 ± 0.9 years, BMI 31.5 ± 1.0 kg/m(2)) were studied before and up to 8 hours following a standard mixed meal. AUC-triglyceride (AUC-TG) was higher and AUC-high-density lipoprotein (AUC-HDL) lower in PCOS women. These differences were not apparent when BMI was accounted for. Insulin sensitivity (S I), AUC-apoB-48, and AUC-apolipoprotein B (AUC-apoB) were found to be independent predictors of AUC-TG, accounting for 55% of the variance. Only AUC-insulin remained significantly elevated following adjustment for BMI. Obesity related IR explains postprandial hypertriglyceridaemia and hyperinsulinaemic responses. Management of obesity in premenopausal women with PCOS is likely to reduce their cardiovascular risk burden.

Association between Sleep Disruption and Levels of Lipids in Caucasians with Type 2 Diabetes.

Aim. To investigate the association between sleep quality and duration with lipid and glycaemic control in Caucasian subjects with type 2 diabetes. Methods. Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI) in 114 type 2 diabetes (T2DM) subjects. Comparisons were made between subjects with different sleep quality and sleep duration. Hierarchical multiple regression analyses were used to determine contributors to metabolic parameters. Results. Subjects with poor sleep quality (PQ; PSQI ≥ 6) had higher systolic blood pressure, glycated haemoglobin, urine albumin : creatinine ratio (UAC), total cholesterol (TC), and triglycerides (TG) (P < 0.05 for all) compared to those with good sleep quality (GQ; PSQI ≤ 5). Long sleep duration (LSD) subjects had higher TC and short sleep duration (SSD) subjects had higher TG compared to those with medium sleep duration. Sleep duration and PSQI score were independent predictors of TC and low-density lipoprotein cholesterol (LDL), contributing to 14.0% and 6.1% of the total variance, respectively. Conclusions. In this Caucasian T2DM population, PQ is associated with adverse cardiovascular risk markers, and long and short sleep disruptions have an independent negative impact on lipids. Sleep assessment should be included as part of a diabetes clinic review.

Oxidative stress and inflammation in lean and obese subjects with polycystic ovary syndrome.

OBJECTIVE: To determine whether polycystic ovary syndrome (PCOS) independently influences oxidative stress and inflammation or if the culprit is the comorbidities of obesity and/or insulin resistance common to this condition. STUDY DESIGN: Thirty women with PCOS were matched for age, body mass index and insulin resistance with 30 control subjects. Oxidative stress was examined by measuring the total oxidant status (TOS) and total antioxidant capacity (TAC) by spectrophotometric assay. The inflammatory biomarkers, C-reactive protein, plasminogen activator inhibitor-1, myeloperoxidase, neopterin, and serum amyloid A were measured by ELISA methodologies. RESULTS: Oxidative status was increased in the PCOS subjects relative to their weight-matched controls (TOS: obese PCOS patients vs. obese controls, 42.42 +/- 4.49 vs. 32.57 +/- 1.97, p<0.05; lean PCOS patients vs. lean controls, 33.69 +/- 1.59 vs. 28.69 +/- 1.18 micromol H2O2 Equiv/L, p < 0.05). Furthermore, antioxidant capacity was lower in the lean PCOS group relative to their weight-matched controls (TAC: lean PCOS patients vs. lean controls, 1.10 +/- 0.09 vs. 1.49 +/- 0.03 nmol Trolox Equiv/L, p < 0.05). CONCLUSION: These results suggest that PCOS independently influenced oxidative stress. Overall, the presence of PCOS may increase cardiovascular risk.

Executive function and diabetes mellitus--a stone left unturned?

Diabetes mellitus (DM) is a chronic medical condition that is dependent upon patients self-caring and managing their condition to achieve optimal control. Adherence to medical therapy, making decisions related to lifestyle changes, and self-treating hypoglycaemia for example, require planning and organisational skills that are under the control of a specific domain of cognitive function known as executive function. Executive function has been shown by functional imaging studies such as magnetic resonance imaging to be under the influence of the frontal and prefrontal cortical system. It is now recognised that even in subjects with apparently normal cognition, DM may be associated with impaired executive function (IEF). The exact cause of IEF in DM is still not fully understood. However cerebral microvascular disease and chronic dysglycaemia have been postulated as possible factors contributing to functional neuronal dysfunction leading to IEF. IEF may adversely affect patients' abilities to self-manage their diabetes care, potentially cause worsening glycaemic control and difficulty managing risk factors. Several bedside assessment tools to screen for IEF are currently available and have been shown to correlate with functional status. However, more studies are needed to validate these tests against diabetes self-care assessment tools. Until then, clinicians and healthcare workers managing patients with DM should be aware of the potential for IEF in their patients as specific behaviour and education intervention may be needed to help manage patients with diabetes and IEF.

Hormonal and metabolic effects of polyunsaturated fatty acids in young women with polycystic ovary syndrome: results from a cross-sectional analysis and a randomized, placebo-controlled, crossover trial.

BACKGROUND: Polycystic ovary syndrome (PCOS) is characterized by an adverse metabolic profile. Although dietary changes are advocated, optimal nutritional management remains uncertain. Polyunsaturated fatty acids (PUFAs), particularly long-chain (LC) n-3 (omega-3) PUFAs, improve metabolic health, but their therapeutic potential in PCOS is unknown. OBJECTIVES: We aimed to determine the associations between plasma PUFAs and metabolic and hormonal aspects of PCOS to investigate the efficacy of LC n-3 PUFA supplementation and to support the findings with mechanistic cellular studies. DESIGN: We selected a cross-sectional PCOS cohort (n = 104) and conducted a principal component analysis on plasma fatty acid profiles. Effects of LC n-3 PUFA supplementation on fasting and postprandial metabolic and hormonal markers were determined in PCOS subjects (n = 22) by a randomized, crossover, placebo-controlled intervention. Direct effects of n-6 (omega-6) compared with n-3 PUFAs on steroidogenesis were investigated in primary bovine theca cells. RESULTS: Cross-sectional data showed that a greater plasma n-6 PUFA concentration and n-6:n-3 PUFA ratio were associated with higher circulating androgens and that plasma LC n-3 PUFA status was associated with a less atherogenic lipid profile. LC n-3 PUFA supplementation reduced plasma bioavailable testosterone concentrations (P < 0.05), with the greatest reductions in subjects who exhibited greater reductions in plasma n-6:n-3 PUFA ratios. The treatment of bovine theca cells with n-6 rather than with n-3 PUFAs up-regulated androstenedione secretion (P < 0.05). CONCLUSIONS: Cross-sectional data suggest that PUFAs modulated hormonal and lipid profiles and that supplementation with LC n-3 PUFAs improves androgenic profiles in PCOS. In bovine theca cells, arachidonic acid modulated androstenedione secretion, which suggests an indirect effect of n-3 PUFAs through the displacement of or increased competition with n-6 PUFAs. This trial was registered at clinicaltrials.gov as NCT01189669.