Isolated central hypothyroidism: Underlying pathophysiology and relation to antidepressant and antipsychotic medications-A multi-centre South Wales study

OBJECTIVE

Isolated biochemical central hypothyroidism is a presentation we are experiencing more frequently as endocrinologists, with variation in levels of investigation between physicians. We therefore conducted research to investigate the final diagnosis and clinical outcome of patients across multiple hospitals in South Wales with biochemical isolated central hypothyroidism; namely to establish whether this isolated biochemical picture was clinically significant. We also analysed whether there is an association between this biochemical picture and treatment with antidepressant and antipsychotic medications, and how common this is.

DESIGN

We performed a retrospective observational study of patients across nine different hospitals in South Wales. We analysed patients referred to endocrinology at each site over a 6-year period with unexplained isolated biochemical central hypothyroidism.

MATERIALS AND METHODOLOGY

1022 individual patients' thyroid function test results were identified from our biochemical database using our inclusion criteria. After exclusion criteria were applied, 71 patients' results were analysed as to the final pathophysiology of their central hypothyroidism.

RESULT

Of the 71 patients included in the study, none were found to have any clinically significant pathology on pituitary imaging. On reviewing their medications, 46/71 (65%) were found to be taking psychotropic medications.

CONCLUSIONS

Our study strongly suggests isolated central hypothyroidism, in the absence of other pituitary hormone dysfunction or visual field defect, does not require further investigation, saving resources as well as sparing patients unnecessary anxiety. It also strongly supports a relationship between patients taking psychotropic medications and biochemical isolated central hypothyroidism, an association only described in a very limited amount of literature before this, and further supporting our previous single-centre study findings. The mechanism behind this is likely to be the suppression of thyrotropin secretion via antagonism of the dopamine-serotoninergic pathway. In our opinion, patients found to have isolated biochemical central hypothyroidism who are taking psychotropic medications can therefore be regarded to have a recognised cause for this biochemical finding and do not require further radiological investigation.

A series of patients with hospital-acquired diabetic ketoacidosis (HADKA): a descriptive analysis

BACKGROUND

Hospital-acquired diabetic ketoacidosis (HADKA) can complicate hospital admission in people with type 1 diabetes (T1D) and type 2 diabetes (T2D). We aimed to determine the characteristics of such patients and the reasons for HADKA.

METHODS

A retrospective analysis of patients referred to diabetes services with HADKA at Morriston Hospital between January 2016 and January 2022 was undertaken. Patients that were included were admitted without diabetic ketoacidosis (DKA), were aged 18 years and over, and who subsequently developed DKA in hospital.

RESULTS

Twenty-five patients were included with a mean age of 65.2 years; nine (32.0%) were men, 13 (52.0%) had T1D and 12 (48.0%) had T2D. Patients had a mean pre-admission glycated haemoglobin of 84.7 mmol/mol, and 17 (68.0%) were insulin-treated. Most were admitted under medicine (n=14; 56.0%) and the remainder under surgery (n=11; 44.0%). More common reasons for HADKA were erroneous insulin administration (n=9; 36.0%), infection (n=7; 28.0%) and surgery (n=5; 20.0%). Five (20.0%) patients required intensive care admission, and the mean length of hospital stay was 42.6 days (range 2-173). Three (12.0%) patients died during the hospital admission.

CONCLUSION

HADKA was identified in a significant number of patients at our hospital and was associated with significant mortality. Earlier recognition of ketonaemia and associated medication use may prevent HADKA and improve outcomes.

Real-World Clinical Experience of Semaglutide in Secondary Care Diabetes: A Retrospective Observational Study

INTRODUCTION

The glucagon-like peptide-1 receptor analogue (GLP-1RA) semaglutide is associated with improvements in glycaemia and cardiovascular risk factors in clinical trials. The aim of this study was to examine the real-world impact of semaglutide administered by injection in people with type 2 diabetes (T2D) across three secondary care sites in Wales.

METHODS

A retrospective evaluation of 189 patients with T2D initiated on semaglutide between January 2019 and June 2020 with at least one follow-up visit was undertaken.

RESULTS

At baseline, participants had a mean age of 61.1 years, mean glycated haemoglobin (HbA1c) of 77.8 mmol/mol (9.3%) and mean body weight of 101.8 kg. At 6 and 12 months of follow-up, mean HbA1c reductions of 13.3 mmol/mol (1.2%) and 16.4 mmol/mol (1.5%), respectively, were observed, and mean weight loss at 6 months was 3.0 kg (all p < 0.001). At 12 months, there were significant reductions in total cholesterol (0.5 mmol/L) and alanine transaminase (4.8 IU/L). Patients naïve to GLP-1RAs or with higher baseline HbA1c at baseline had greater glycaemic reductions, although clinically significant HbA1c reductions were also observed in those who switched from other GLP-1RAs, whose body mass index was < 35.0 and > 35.0 kg/m² or who had lower baseline HbA1c. Semaglutide was generally well tolerated, although adverse-effects limited use in 18 patients (9.5%).

CONCLUSION

Semaglutide provided clinically and statistically significant reductions in HbA1c, body weight, lipids and liver enzymes.

Dapagliflozin is associated with improved glycaemic control and weight reduction at 44 months of follow-up in a secondary care diabetes clinic in the UK

BACKGROUND AND AIMS

We examined HbA1c and cardiovascular risk factors with a median follow-up of 44 months therapy with dapagliflozin.

METHODS

We undertook a clinical practice evaluation of 101 patients attending our clinic.

RESULTS

Dapagliflozin resulted in a significant reduction in HbA1c 82.6 ± 15.7 v 68.7 ± 17.8 mmol/mol.

CONCLUSION

Dapagliflozin maintains glycaemic control along with sustained improvements in weight and no decline in renal function.

White Matter Microstructure and Cognitive Function in Young Women With Polycystic Ovary Syndrome

CONTEXT

Polycystic ovary syndrome (PCOS) is a disorder characterized by insulin resistance and hyperandrogenism, which leads to an increased risk of type 2 diabetes in later life. Androgens and insulin signaling affect brain function but little is known about brain structure and function in younger adults with PCOS.

OBJECTIVE

To establish whether young women with PCOS display altered white matter microstructure and cognitive function. PATIENTS, INTERVENTIONS, AND MAIN OUTCOME MEASURES: Eighteen individuals with PCOS (age, 31 ± 6 y; body mass index [BMI] 30 ± 6 kg/m(2)) and 18 control subjects (age, 31 ± 7 y; BMI, 29 ± 6 kg/m(2)), matched for age, IQ, and BMI, underwent anthropometric and metabolic evaluation, diffusion tensor MRI, a technique especially sensitive to brain white matter structure, and cognitive assessment. Cognitive scores and white matter diffusion metrics were compared between groups. White matter microstructure was evaluated across the whole white matter skeleton using tract-based spatial statistics. Associations with metabolic indices were also evaluated.

RESULTS

PCOS was associated with a widespread reduction in axial diffusivity (diffusion along the main axis of white matter fibers) and increased tissue volume fraction (the proportion of volume filled by white or grey matter rather than cerebrospinal fluid) in the corpus callosum. Cognitive performance was reduced compared with controls (first principal component, t = 2.9, P = .007), reflecting subtle decrements across a broad range of cognitive tests, despite similar education and premorbid intelligence. In PCOS, there was a reversal of the relationship seen in controls between brain microstructure and both androgens and insulin resistance.

CONCLUSIONS

White matter microstructure is altered, and cognitive performance is compromised, in young adults with PCOS. These alterations in brain structure and function are independent of age, education and BMI. If reversible, these changes represent a potential target for treatment.

Detailed characterisation of circulatory nitric oxide and free radical indices--is there evidence for abnormal cardiovascular homeostasis in young women with polycystic ovary syndrome?

OBJECTIVE

To assess circulating biochemical indices of endothelial function and nitro-oxidative stress in women with polycystic ovary syndrome (PCOS).

DESIGN

Case-control study.

POPULATION

Seventeen women with PCOS and eighteen age- and body mass index-matched healthy volunteers.

METHODS

Nitric oxide (NO) metabolite levels were assessed by chemiluminescence. Electron paramagnetic resonance spectroscopy with spin trapping was used to assess oxidative stress ex vivo and in vitro. Antioxidant capacity was measured using oxygen radical absorbance.

MAIN OUTCOME MEASURES

Biochemical indices of endothelial function, including NO metabolites, lipid-derived radicals and antioxidant capacity.

RESULTS

Plasma NO metabolites were similar in the two groups (nitrite: 257±116 nmol/l [PCOS], 261±135 nmol/l [controls] P=0.93; nitrate: 27±7 μmol/l [PCOS], 26±6 μmol/l [controls] P=0.89). Alkoxyl free radicals (lipid-derived) were detected as the dominant species, but levels were not different between women with PCOS and controls whether measured directly ex vivo (median 7.2 [range 0.17-16.73]e6 arbitrary units [a.u.] and 7.2 [1.7-11.9]e6 a.u., respectively, P=0.57) or when stimulated in vitro to test radical generation capacity (1.23 [0.3-5.62]e7 a.u. and 1.1 [0.48-15.7]e7 a.u. respectively, P=0.71). In regression analysis, visceral fat area was independently associated with in vitro oxidative potential (β=0.6, P=0.002). Total plasma antioxidant capacity (94±30% [PCOS], 79±24% [controls], P=0.09) and plasma hydroperoxides (7.5±4 μmol/l [PCOS], 6.7±5 μmol/l [controls], P=0.21) were not different between groups. However, lipophilic antioxidant capacity was lower in women with PCOS compared with controls (92±32 and 125±48%, respectively, P=0.02).

CONCLUSIONS

Young overweight women with PCOS display a reduced lipophilic antioxidant capacity compared with healthy volunteers, but no change in circulating free radicals or nitro-oxidative stress.

Cutaneous allergy to insulin: could statins and ACE inhibitors play a role? A case report

Insulin allergy is rare. Both statins and angiotensin converting enzyme (ACE) inhibitors may cause local urticarial skin reactions and have been implicated to precipitate local reactions to insulin. We describe a case of a localised urticarial allergic reaction related to insulin use in a patient co-prescribed an ACE inhibitor and statin.

Metastatic haematological malignancy presenting as a sellar mass

A man in his 60s with a history of multiple myeloma diagnosed 6&emsp14;months previously was referred with a diagnosis of a sellar mass. He reported a 3-month history of headaches associated with double vision which appeared to improve with corticosteroid treatment. An MRI scan revealed a 3.7 cm × 3 cm × 2.6 cm sellar mass with erosion into the sphenoid sinus and extending to the right cavernous sinus. Pituitary function tests were normal apart from hypogonadotrophic hypogonadism. A diagnosis of plasmacytoma was considered and so transphenoidal biopsy of the sellar lesion was organised, which revealed sheets of mature appearing plasma cells, staining exclusively for κ-light chain immunoglobulins. He was to be started on chemotherapy for the myeloma and radiotherapy for the plasmacytoma. The patient's clinical course was complicated by community-acquired pneumonia and renal failure resulting in his death a month after the diagnosis of plasmacytoma.