Publications by authors named "T M Greenaway"

55 Publications

PD-L1 expression in papillary thyroid cancer with and without lymphocytic thyroiditis: a cross sectional study.

Pathology 2020 Apr 24;52(3):318-322. Epub 2020 Feb 24.

Australian National University, Medical School, Garran, ACT, Australia; Department of Endocrinology, Canberra Hospital, Garran, ACT, Australia. Electronic address:

The impact of concurrent autoimmune thyroid disease on the tumour microenvironment and disease progression in papillary thyroid cancer (PTC) is not well understood. Studies evaluating the programmed cell death ligand 1 (PD-L1) tumour expression in PTC have shown variable results, and the effect of lymphocytic thyroiditis (LT) on tumour PD-L1 expression has not been adequately assessed. The main aim of this study was to determine expression of PD-L1 in PTC with and without LT. We examined 81 PTC cases; 28.5% of all reviewed PTC had presence of LT. In PTC specimens without LT, tumour PD-L1 expression was significantly lower compared to PD-L1 expression in PTC with LT, 6.9% vs 39.1%, respectively. Expression of PD-L1 did not differ with PTC stage, even when sub-categorised according to the presence and absence of LT. Utility of PD- L1 expression as a prognostic marker in thyroid cancer needs to be interpreted with caution.
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http://dx.doi.org/10.1016/j.pathol.2019.11.007DOI Listing
April 2020

Associations of health literacy with risk factors for diabetic foot disease: a cross-sectional analysis of the Southern Tasmanian Health Literacy and Foot Ulcer Development in Diabetes Mellitus Study.

BMJ Open 2019 07 30;9(7):e025349. Epub 2019 Jul 30.

Menzies Research Institute Tasmania, University of Tasmania, Hobart, Tasmania, Australia.

Objectives: Poor health literacy (HL) is associated with poorer health outcomes in diabetes but little is known about its effects on foot disease. This study was aimed to determine the associations between HL and diabetic foot disease.

Design: This is a cross-sectional analysis of baseline data from a prospective study of foot disease.

Setting: Attendees of the Royal Hobart Hospital's Diabetes outpatient clinics.

Participants: 222 people with type 1 or type 2 diabetes aged >40 years and without a history of foot disease, psychotic disorders or dementia.

Measures: Outcomes were peripheral neuropathy, peripheral arterial disease and foot deformity according to published guidelines. The exposure, HL, was measured using the short form Test of Functional Health Literacy in Adults (S-TOFHLA) and the Health Literacy Questionnaire (HLQ). Covariates included demographic characteristics, medical history, psychological measures and foot care behaviour.

Results: Of 222 participants, 204 had adequate HL. (Mean (SD) S-TOFHLA scores were 31.9 (6.7)), mean(SD) HLQ scores were 134.4 (18.4)). In univariable but not multivariable analyses, higher S-TOFHLA scores were associated with lower overall risk for foot disease (OR 0.96, 95% CI 0.93 to 0.99) and loss of protective sensation (OR 0.95, 95% CI 0.91 to 0.995).

Conclusions: These data provide little support for clinically important impacts of HL on risk factors for diabetic foot disease. However, in the absence of longitudinal data, such effects cannot be ruled out. Longitudinal studies measuring incident foot disease are needed to properly judge the potential for interventions improving HL to reduce the incidence of diabetic foot disease.
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http://dx.doi.org/10.1136/bmjopen-2018-025349DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6677956PMC
July 2019

Are the metabolic benefits of resistance training in type 2 diabetes linked to improvements in adipose tissue microvascular blood flow?

Am J Physiol Endocrinol Metab 2018 12 23;315(6):E1242-E1250. Epub 2018 Oct 23.

Menzies Institute for Medical Research, University of Tasmania , Hobart, Tasmania , Australia.

The microcirculation in adipose tissue is markedly impaired in type 2 diabetes (T2D). Resistance training (RT) often increases muscle mass and promotes a favorable metabolic profile in people with T2D, even in the absence of fat loss. Whether the metabolic benefits of RT in T2D are linked to improvements in adipose tissue microvascular blood flow is unknown. Eighteen sedentary people with T2D (7 women/11 men, 52 ± 7 yr) completed 6 wk of RT. Before and after RT, overnight-fasted participants had blood sampled for clinical chemistries (glucose, insulin, lipids, HbA1c, and proinflammatory markers) and underwent an oral glucose challenge (OGC; 50 g glucose × 2 h) and a DEXA scan to assess body composition. Adipose tissue microvascular blood volume and flow were assessed at rest and 1 h post-OGC using contrast-enhanced ultrasound. RT significantly reduced fasting blood glucose ( P = 0.006), HbA1c ( P = 0.007), 2-h glucose area under the time curve post-OGC ( P = 0.014), and homeostatic model assessment of insulin resistance ( P = 0.005). This was accompanied by a small reduction in total body fat ( P = 0.002), trunk fat ( P = 0.023), and fasting triglyceride levels ( P = 0.029). Lean mass ( P = 0.003), circulating TNF-α ( P = 0.006), and soluble VCAM-1 ( P < 0.001) increased post-RT. There were no significant changes in adipose tissue microvascular blood volume or flow following RT; however those who did have a higher baseline microvascular blood flow post-RT also had lower fasting triglyceride levels ( r = -0.476, P = 0.045). The anthropometric, glycemic, and insulin-sensitizing benefits of 6 wk of RT in people with T2D are not associated with an improvement in adipose tissue microvascular responses; however, there may be an adipose tissue microvascular-linked benefit to fasting triglyceride levels.
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http://dx.doi.org/10.1152/ajpendo.00234.2018DOI Listing
December 2018

Associations of health literacy with diabetic foot outcomes: a systematic review and meta-analysis.

Diabet Med 2018 11 20;35(11):1470-1479. Epub 2018 Jun 20.

Faculty of Health, University of Tasmania, Hobart, Tasmania, Australia.

Background: People with diabetes have low health literacy, but the role of the latter in diabetic foot disease is unclear.

Aim: To determine, through a systematic review and meta-analysis, if health literacy is associated with diabetic foot disease, its risk factors, or foot care.

Methods: We searched PubMed, EMBASE, CINAHL, Web of Science, Scopus and Science Direct. All studies were screened and data extracted by two independent reviewers. Studies in English with valid and reliable measures of health literacy and published tests of association were included. Data were extracted on the associations between the outcomes and health literacy. Meta-analyses were performed using random effects models.

Results: Sixteen articles were included in the systematic review, with 11 in the meta-analysis. In people with inadequate health literacy, the odds of having diabetic foot disease were twice those in people with adequate health literacy, but this was not statistically significant [odds ratio 1.99 (95% CI 0.83, 4.78); two studies in 1278 participants]. There was no statistically significant difference in health literacy levels between people with and without peripheral neuropathy [standardized mean difference -0.14 (95% CI -0.47, 0.18); two studies in 399 participants]. There was no association between health literacy and foot care [correlation coefficient 0.01 (95% CI -0.07, 0.10); seven studies in 1033 participants].

Conclusions: There were insufficient data to exclude associations between health literacy and diabetic foot disease and its risk factors, but health literacy appears unlikely to have a role in foot care. The contribution of low health literacy to diabetic foot disease requires definitive assessment through robust longitudinal studies.
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http://dx.doi.org/10.1111/dme.13694DOI Listing
November 2018

Oral glucose challenge impairs skeletal muscle microvascular blood flow in healthy people.

Am J Physiol Endocrinol Metab 2018 08 15;315(2):E307-E315. Epub 2018 May 15.

Menzies Institute for Medical Research, University of Tasmania , Hobart, Tasmania , Australia.

Skeletal muscle microvascular (capillary) blood flow increases in the postprandial state or during insulin infusion due to dilation of precapillary arterioles to augment glucose disposal. This effect occurs independently of changes in large artery function. However, acute hyperglycemia impairs vascular function, causes insulin to vasoconstrict precapillary arterioles, and causes muscle insulin resistance in vivo. We hypothesized that acute hyperglycemia impairs postprandial muscle microvascular perfusion, without disrupting normal large artery hemodynamics, in healthy humans. Fifteen healthy people (5 F/10 M) underwent an oral glucose challenge (OGC, 50 g glucose) and a mixed-meal challenge (MMC) on two separate occasions (randomized, crossover design). At 1 h, both challenges produced a comparable increase (6-fold) in plasma insulin levels. However, the OGC produced a 1.5-fold higher increase in blood glucose compared with the MMC 1 h postingestion. Forearm muscle microvascular blood volume and flow (contrast-enhanced ultrasound) were increased during the MMC (1.3- and 1.9-fold from baseline, respectively, P < 0.05 for both) but decreased during the OGC (0.7- and 0.6-fold from baseline, respectively, P < 0.05 for both) despite a similar hyperinsulinemia. Both challenges stimulated brachial artery flow (ultrasound) and heart rate to a similar extent, as well as yielding comparable decreases in diastolic blood pressure and total vascular resistance. Systolic blood pressure and aortic stiffness remained unaltered by either challenge. Independently of large artery hemodynamics, hyperglycemia impairs muscle microvascular blood flow, potentially limiting glucose disposal into skeletal muscle. The OGC reduced microvascular blood flow in muscle peripherally and therefore may underestimate the importance of skeletal muscle in postprandial glucose disposal.
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http://dx.doi.org/10.1152/ajpendo.00448.2017DOI Listing
August 2018