Exploration of Human Serum Lipoprotein Supramolecular Phospholipids Using Statistical Heterospectroscopy in n-Dimensions (SHY-n): Identification of Potential Cardiovascular Risk Biomarkers Related to SARS-CoV-2 Infection

SARS-CoV-2 infection causes a significant reduction in lipoprotein-bound serum phospholipids give rise to supramolecular phospholipid composite (SPC) signals observed in diffusion and relaxation edited ¹H NMR spectra. To characterize the chemical structural components and compartmental location of SPC and to understand further its possible diagnostic properties, we applied a Statistical HeterospectroscopY in n-dimensions (SHY-n) approach. This involved statistically linking a series of orthogonal measurements made on the same samples, using independent analytical techniques and instruments, to identify the major individual phospholipid components giving rise to the SPC signals. Thus, an integrated model for SARS-CoV-2 positive and control adults is presented that relates three identified diagnostic subregions of the SPC signal envelope (SPC₁, SPC₂, and SPC₃) generated using diffusion and relaxation edited (DIRE) NMR spectroscopy to lipoprotein and lipid measurements obtained by in vitro diagnostic NMR spectroscopy and ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The SPC signals were then correlated sequentially with (a) total phospholipids in lipoprotein subfractions; (b) apolipoproteins B100, A1, and A2 in different lipoproteins and subcompartments; and (c) MS-measured total serum phosphatidylcholines present in the NMR detection range (i.e., PCs: 16.0,18.2; 18.0,18.1; 18.2,18.2; 16.0,18.1; 16.0,20.4; 18.0,18.2; 18.1,18.2), lysophosphatidylcholines (LPCs: 16.0 and 18.2), and sphingomyelin (SM 22.1). The SPC₃/SPC₂ ratio correlated strongly (r = 0.86) with the apolipoprotein B100/A1 ratio, a well-established marker of cardiovascular disease risk that is markedly elevated during acute SARS-CoV-2 infection. These data indicate the considerable potential of using a serum SPC measurement as a metric of cardiovascular risk based on a single NMR experiment. This is of specific interest in relation to understanding the potential for increased cardiovascular risk in COVID-19 patients and risk persistence in post-acute COVID-19 syndrome (PACS).

Testosterone, Diabetes Risk, and Diabetes Prevention in Men

Middle-aged and older men with lower testosterone concentrations are more likely to have or to develop metabolic syndrome and type 2 diabetes. Central adiposity is a risk factor for metabolic syndrome and diabetes and predisposes to lower testosterone concentrations. Conversely, testosterone treatment reduces fat mass and insulin resistance. In a randomized controlled trial of 1007 men with either impaired glucose tolerance or newly diagnosed type 2 diabetes, 2 years of testosterone treatment on a background of lifestyle intervention reduced the risk of type 2 diabetes by 40%; this demonstrates the potential utility for testosterone pharmacotherapy to prevent diabetes in men.

Barriers to prescribing proprotein convertase subtilisin-kexin type 9 inhibitors after coronary revascularisation

BACKGROUND

Guidelines advocate for intensive lipid-lowering in patients with atherosclerotic cardiovascular disease (ASCVD). In May 2020, evolocumab, a proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitor, became government subsidised in Australia for patients with ASCVD requiring further low-density lipoprotein cholesterol (LDL-C) lowering.

AIM

To identify barriers to prescribing PCSK9 inhibitors in hospitalised patients with ASCVD.

METHODS

A retrospective three-month, single-site, observational analysis was conducted in consecutive patients undergoing percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG) surgery. Lipid-lowering therapy prescriptions, including PSCK9 inhibitors, were assessed using electronic medical records, compared against the Australian Pharmaceutical Benefits eligibility criteria, and barriers to PCSK9 inhibitor use identified.

RESULTS

Of 331 patients, 244 (73.7%) underwent PCI and 87 (26.3%) underwent CABG surgery. A lipid profile during or within 8 weeks of admission was measured for 202 (82.8%) patients undergoing PCI and 59 (67.8%) undergoing CABG surgery. In patients taking high-intensity statins on admission (n=109), LDL-C ≥1.4, ≥1.8 and >2.6mmol/L were seen in 64 (58.7%), 44 (40.4%) and 19 (17.4%) respectively. High-intensity statin prescribing at discharge was high (>80%); however, ezetimibe was initiated in zero patients with LDL-C ≥1.4mmol/L. There was variable advice given by clinicians for LDL-C targets. No patients met criteria for subsidised PSCK9 inhibitor therapy, largely due to lack of qualifying lipid levels following combined statin and ezetimibe therapy.

CONCLUSION

Prescribing of non-statin LDL-C-lowering therapies remains low in patients with ASCVD. Under-prescribing of ezetimibe and suboptimal lipid testing rates are barriers to accessing subsidised PCSK9i therapy using current Australian eligibility criteria. This article is protected by copyright. All rights reserved.

Associations of Serum Testosterone and Sex Hormone-Binding Globulin With Incident Cardiovascular Events in Middle-Aged to Older Men

BACKGROUND

The influence of testosterone on risk for cardiovascular events in men is uncertain. Previous observational studies of sex hormones and incident cardiovascular disease in men have reported inconsistent findings, limited by cohort sizes and different selection criteria.

OBJECTIVE

To analyze associations of serum total testosterone and sex hormone-binding globulin (SHBG) with incident cardiovascular events in men.

DESIGN

Cohort study.

SETTING

UK Biobank prospective cohort.

PARTICIPANTS

Community-dwelling men aged 40 to 69 years.

MEASUREMENTS

Testosterone and SHBG were assayed, and free testosterone was calculated. Cox proportional hazards regression was done, with outcomes of incident myocardial infarction (MI), hemorrhagic stroke (HS), ischemic stroke (IS), heart failure (HF), and major adverse cardiovascular events (MACE), adjusted for sociodemographic, lifestyle, and medical factors.

RESULTS

Of 210 700 men followed for 9 years, 8790 (4.2%) had an incident cardiovascular event. After adjustment for key variables, lower total testosterone concentrations (quintile 1 vs. quintile 5) were not associated with incident MI (fully adjusted hazard ratio [HR], 0.89 [95% CI, 0.80 to 1.00]), HS (HR, 0.94 [CI, 0.70 to 1.26]), IS (HR, 0.95 [CI, 0.82 to 1.10]), HF (HR, 1.15 [CI, 0.91 to 1.45]), or MACE (HR, 0.92 [CI, 0.84 to 1.00]). Men with lower calculated free testosterone values had a lower incidence of MACE (HR, 0.90 [CI, 0.84 to 0.97]). Lower SHBG concentrations were associated with higher incidence of MI (HR, 1.23 [CI, 1.09 to 1.38]) and lower incidence of IS (HR, 0.79 [CI, 0.67 to 0.94]) and HF (HR, 0.69 [CI, 0.54 to 0.89]), but not with HS (HR, 0.81 [CI, 0.57 to 1.14]) or MACE (HR, 1.01 [CI, 0.92 to 1.11]).

LIMITATION

Observational study; single baseline measurement of testosterone and SHBG.

CONCLUSION

Men with lower total testosterone concentrations were not at increased risk for MI, stroke, HF, or MACE. Calculated free testosterone may be associated with risk for MACE. Men with lower SHBG concentrations have higher risk for MI but lower risk for IS and HF, with causality to be determined.

PRIMARY FUNDING SOURCE

Western Australian Health Translation Network, Medical Research Future Fund, and Lawley Pharmaceuticals.

Hearing impairment and frailty in later life: The Health in Men Study (HIMS)

OBJECTIVE

To determine if hearing loss is associated with increased risk of frailty in later life.

STUDY DESIGN

Cross-sectional study of a community sample of 4,004 men aged 70 years and above living in the metropolitan region of Perth, Western Australia. Data were retrieved from the Health in Men Study (HIMS) and the Western Australian Data Linkage System (WADLS). Frailty was assessed using the FRAIL scale and the Frailty Index. Hearing loss was defined by self-report or by diagnosis recorded in the WADLS. We also collected demographic, lifestyle and social support information.

MAIN OUTCOME MEASURES

Frailty was assessed using the FRAIL scale and the Frailty Index.

RESULTS

The prevalence of frailty in the sample population was 16.1% and 25.4% when assessed using the FRAIL scale and the Frailty Index respectively. After adjusting for participant demographic, lifestyle and social factors, hearing loss was significantly associated with the prevalence of frailty when diagnosed by either measure (FRAIL scale: odds ratio [OR] 1.59, 95 CI% 1.32 to 1.91; Frailty Index: OR 1.76, 95 CI% 1.50 to 2.05). The proportion of men with hearing loss increased with increasing severity of frailty.

CONCLUSION

Hearing loss is associated with increased prevalence of frailty in older men when assessed using the FRAIL scale and the Frailty Index. Future longitudinal studies using objective measures of hearing will be helpful in determining if this association is likely to be causal.

Attainment of Lipid Targets Following Coronary Artery Bypass Graft Surgery: Can We Do Better?

Objective

Patients undergoing coronary artery bypass graft (CABG) surgery remain at high cardiovascular risk; however, few studies have evaluated lipid management and attainment of lipid targets in these patients. We investigated the proportion of CABG surgery patients who attained low-density lipoprotein cholesterol (LDL-C) and non-high-density lipoprotein cholesterol (HDL-C) targets.

Methods

Data were retrospectively obtained from patients undergoing CABG surgery at an Australian tertiary hospital between February 2015 and August 2020. The most recent lipid profile was recorded (at least 3 weeks post-operatively). We studied patients with electronically available data to ensure accuracy. Target LDL-C was defined as <1.4 (54 mg/dL) and <1.8 mmol/L (70 mg/dL), and target non-HDL-C as <2.2 (85 mg/dL) and <2.6 mmol/L (100 mg/dL), as per the 2019 and 2016 European dyslipidaemia guidelines, respectively.

Results

Follow-up lipid results were available for 484 patients (median post-operative follow-up, 483 days; interquartile range, 177.5–938.75 days). The mean age was 62.7±10.5 years and 387 (80.1%) were male. At discharge, 469 (96.9%) patients were prescribed statins, 425 (90.6%) high-intensity. Ezetimibe was prescribed for 62 (12.8%) patients and a proprotein convertase subtilisin-kexin type 9 inhibitor for 1. LDL-C levels <1.4 and <1.8 mmol/L were attained in 118 (24.4%) and 231 (47.7%) patients, respectively, and non-HDL-C levels <2.2 and <2.6 mmol/L in 140 (28.9%) and 237 (49.0%) patients, respectively.

Conclusion

The use of non-statin lipid-lowering therapies was limited, and many CABG surgery patients did not attain lipid targets despite high-intensity statins. Further studies are required to optimise lipid management in this very high-risk population.

Real-world barriers and safety of initiating sodium-glucose co-transporter 2 inhibitor treatment immediately following an acute cardiac event in people with diabetes

In this real-world study, the main barriers for not initiating SGLT2 inhibitor therapy early after an acute cardiac event are prescribing criteria around glycated haemoglobin and renal function. Initiation of SGLT2 inhibitors near to, or at, hospital discharge following the cardiac event was not associated with 30-day diabetic ketoacidosis readmissions.

Reduction in femoral neck and total hip bone mineral density following hospitalisation for diabetes-related foot ulceration

Management of diabetes-related foot ulceration (DFU) includes pressure offloading resulting in a period of reduced activity. The metabolic effects of this are unknown. This study aims to investigate changes in bone mineral density (BMD) and body composition 12 weeks after hospitalisation for DFU. A longitudinal, prospective, observational study of 22 people hospitalised for DFU was conducted. Total body, lumbar spine, hip and forearm BMD, and total lean and fat mass were measured by dual-energy X-ray absorptiometry (DXA) during and 12 weeks after hospitalisation for DFU. Significant losses in total hip BMD of the ipsilateral limb (- 1.7%, p < 0.001), total hip BMD of the contralateral limb (- 1.4%, p = 0.005), femoral neck BMD of the ipsilateral limb (- 2.8%, p < 0.001) and femoral neck BMD of the contralateral limb (- 2.2%, p = 0.008) were observed after 12 weeks. Lumbar spine and forearm BMD were unchanged. HbA1c improved from 75 mmol/mol (9.2%) to 64 mmol/mol (8.0%) (p = 0.002). No significant changes to lean and fat mass were demonstrated. Total hip and femoral neck BMD decreased bilaterally 12 weeks after hospitalisation for DFU. Future research is required to confirm the persistence and clinical implications of these losses.

Association of Thyroid Dysfunction With Cognitive Function: An Individual Participant Data Analysis

IMPORTANCE

In clinical guidelines, overt and subclinical thyroid dysfunction are mentioned as causal and treatable factors for cognitive decline. However, the scientific literature on these associations shows inconsistent findings.

OBJECTIVE

To assess cross-sectional and longitudinal associations of baseline thyroid dysfunction with cognitive function and dementia.

DESIGN, SETTING, AND PARTICIPANTS

This multicohort individual participant data analysis assessed 114 267 person-years (median, 1.7-11.3 years) of follow-up for cognitive function and 525 222 person-years (median, 3.8-15.3 years) for dementia between 1989 and 2017. Analyses on cognitive function included 21 cohorts comprising 38 144 participants. Analyses on dementia included eight cohorts with a total of 2033 cases with dementia and 44 573 controls. Data analysis was performed from December 2016 to January 2021.

EXPOSURES

Thyroid function was classified as overt hyperthyroidism, subclinical hyperthyroidism, euthyroidism, subclinical hypothyroidism, and overt hypothyroidism based on uniform thyrotropin cutoff values and study-specific free thyroxine values.

MAIN OUTCOMES AND MEASURES

The primary outcome was global cognitive function, mostly measured using the Mini-Mental State Examination. Executive function, memory, and dementia were secondary outcomes. Analyses were first performed at study level using multivariable linear regression and multivariable Cox regression, respectively. The studies were combined with restricted maximum likelihood meta-analysis. To overcome the use of different scales, results were transformed to standardized mean differences. For incident dementia, hazard ratios were calculated.

RESULTS

Among 74 565 total participants, 66 567 (89.3%) participants had normal thyroid function, 577 (0.8%) had overt hyperthyroidism, 2557 (3.4%) had subclinical hyperthyroidism, 4167 (5.6%) had subclinical hypothyroidism, and 697 (0.9%) had overt hypothyroidism. The study-specific median age at baseline varied from 57 to 93 years; 42 847 (57.5%) participants were women. Thyroid dysfunction was not associated with global cognitive function; the largest differences were observed between overt hypothyroidism and euthyroidism-cross-sectionally (-0.06 standardized mean difference in score; 95% CI, -0.20 to 0.08; P = .40) and longitudinally (0.11 standardized mean difference higher decline per year; 95% CI, -0.01 to 0.23; P = .09). No consistent associations were observed between thyroid dysfunction and executive function, memory, or risk of dementia.

CONCLUSIONS AND RELEVANCE

In this individual participant data analysis of more than 74 000 adults, subclinical hypothyroidism and hyperthyroidism were not associated with cognitive function, cognitive decline, or incident dementia. No rigorous conclusions can be drawn regarding the role of overt thyroid dysfunction in risk of dementia. These findings do not support the practice of screening for subclinical thyroid dysfunction in the context of cognitive decline in older adults as recommended in current guidelines.

Associations of Osteocalcin Forms With Metabolic Syndrome and Its Individual Components in Older Men: The Health In Men Study

CONTEXT

The osteoblast-derived polypeptide, osteocalcin (OC), has been associated with lower risk of type 2 diabetes and metabolic syndrome (MetS) in several epidemiological studies. Animal studies have indicated the undercarboxylated form of OC (ucOC) drives its association with metabolic outcomes.

OBJECTIVE

We compared associations of ucOC and carboxylated OC (cOC) with MetS and its components in older men.

METHODS

A cross-sectional analysis of 2575 men aged ≥70 years and older resident in Perth, Western Australia. ucOC was assayed using a hydroxyapatite-binding method, and cOC calculated by subtracting ucOC from total OC. Main outcome measures were MetS and its components.

RESULTS

Both lower serum ucOC and cOC levels, and the proportion of cOC (%cOC) were associated with less favorable metabolic parameters (higher waist circumference, triglyceride, glucose, blood pressure, and lower high-density lipoprotein cholesterol), whereas inverse associations were found with %ucOC. Men in the lowest quintile of ucOC had higher risk of MetS compared to men in the highest quintile (Q1 ≤ 7.7 vs Q5 > 13.8 ng/mL; OR = 2.4; 95% CI, 1.8-3.2). Men in the lowest quintile of cOC had higher risk of MetS compared to those in the highest quintile (≤ 5.8 vs > 13.0 ng/mL; OR = 2.4; 95% CI, 1.8-3.2).

CONCLUSION

Lower concentrations of serum ucOC or cOC were associated with less favorable metabolic parameters and a higher risk of MetS. In contrast, a lower proportion of ucOC was associated with better metabolic parameters and lower MetS risk. Further research is warranted to determine whether ucOC and cOC are suitable biomarkers for cardiometabolic risk in men.

U-Shaped Relationship of Leukocyte Telomere Length With All-Cause and Cancer-Related Mortality in Older Men

BACKGROUND

Telomeres are essential DNA-protein complexes whose attrition results in cellular dysfunction and senescence. Leukocyte telomere length (LTL) correlates with tissue telomere length, representing a biomarker for biological age. However, its predictive value for mortality risk, and for cardiovascular versus cancer deaths, in older adults remains uncertain.

METHOD

We studied 3608 community-dwelling men aged 77.0 ± 3.6 years. Leukocyte telomere length was measured using multiplex quantitative PCR, expressed as amount of telomeric DNA relative to single-copy control gene (T/S ratio). Deaths from any cause, cardiovascular disease (CVD), and cancer were ascertained using data linkage. Curve fitting used restricted cubic splines and Cox regression analyses adjusted for age, cardiometabolic risk factors, and prevalent disease.

RESULTS

There was a U-shaped association of LTL with all-cause mortality. Men with T/S ratio in the middle quartiles had lower mortality (quartiles, Q2 vs Q1, hazard ratio [HR] = 0.86, 95% confidence interval [CI] 0.77-0.97, p = .012; Q3 vs Q1 HR = 0.88, CI 0.79-0.99, p = .032). There was no association of LTL with CVD mortality. There was a U-shaped association of LTL with cancer mortality. Men with LTL in the middle quartiles had lower risk of cancer death (Q2 vs Q1, HR = 0.73, CI 0.59-0.90, p = .004; Q3 vs Q1, HR = 0.75, CI 0.61-0.92, p = .007).

CONCLUSIONS

In older men, both shorter and longer LTL are associated with all-cause mortality. A similar U-shaped association was seen with cancer deaths, with no association found for cardiovascular deaths. Further research is warranted to explore the prognostic utility of LTL in ageing.

Effect of Testosterone Treatment on Bone Microarchitecture and Bone Mineral Density in Men: A 2-Year RCT

CONTEXT

Testosterone treatment increases bone mineral density (BMD) in hypogonadal men. Effects on bone microarchitecture, a determinant of fracture risk, are unknown.

OBJECTIVE

We aimed to determine the effect of testosterone treatment on bone microarchitecture using high resolution-peripheral quantitative computed tomography (HR-pQCT).

METHODS

Men ≥ 50 years of age were recruited from 6 Australian centers and were randomized to receive injectable testosterone undecanoate or placebo over 2 years on the background of a community-based lifestyle program. The primary endpoint was cortical volumetric BMD (vBMD) at the distal tibia, measured using HR-pQCT in 177 men (1 center). Secondary endpoints included other HR-pQCT parameters and bone remodeling markers. Areal BMD (aBMD) was measured by dual-energy x-ray absorptiometry (DXA) in 601 men (5 centers). Using a linear mixed model for repeated measures, the mean adjusted differences (95% CI) at 12 and 24 months between groups are reported as treatment effect.

RESULTS

Over 24 months, testosterone treatment, versus placebo, increased tibial cortical vBMD, 9.33 mg hydroxyapatite (HA)/cm3) (3.96, 14.71), P < 0.001 or 3.1% (1.2, 5.0); radial cortical vBMD, 8.96 mg HA/cm3 (3.30, 14.62), P = 0.005 or 2.9% (1.0, 4.9); total tibial vBMD, 4.16 mg HA/cm3 (2.14, 6.19), P < 0.001 or 1.3% (0.6, 1.9); and total radial vBMD, 4.42 mg HA/cm3 (1.67, 7.16), P = 0.002 or 1.8% (0.4, 2.0). Testosterone also significantly increased cortical area and thickness at both sites. Effects on trabecular architecture were minor. Testosterone reduced bone remodeling markers CTX, -48.1 ng/L [-81.1, -15.1], P < 0.001 and P1NP, -6.8 μg/L[-10.9, -2.7], P < 0.001. Testosterone significantly increased aBMD at the lumbar spine, 0.04 g/cm2 (0.03, 0.05), P < 0.001 and the total hip, 0.01 g/cm2 (0.01, 0.02), P < 0.001.

CONCLUSION

In men ≥ 50 years of age, testosterone treatment for 2 years increased volumetric bone density, predominantly via effects on cortical bone. Implications for fracture risk reduction require further study.

Effects of testosterone treatment, with and without exercise training, on ambulatory blood pressure in middle-aged and older men

CONTEXT

With age, testosterone (T) and physical activity levels often decline in parallel. The effect of combining T treatment and exercise training on ambulatory blood pressure (ABP) is unclear.

OBJECTIVE

To assess T and exercise effects, alone and in combination, on ABP in men aged 50-70 years, waist circumference ≥ 95 cm and low-normal serum T (6-14 nmol/L), without organic hypogonadism.

DESIGN

A 2 × 2 factorial randomised, placebo-controlled study.

INTERVENTION

Randomization to daily transdermal AndroForte5^® (Testosterone 5.0%w/v, 100 mg in 2 ml) cream (T), or matching placebo (P) (double-blind), and to supervised exercise (Ex) or no additional exercise (NEx), for 12 weeks.

RESULTS

Average 24-h systolic blood pressure (SBP) increased with T treatment (testosterone*time, p = .035). Average 24-h SBP increased in T+Ex (T+Ex:+3.0 vs. P+NEx: -3.0 mmHg, p = .026) driven by day-time changes (T+Ex:+3.5 vs. P+NEx: -3.0 mmHg, p = .026). There was an effect of T for 24-h average diastolic blood pressure (DBP, testosterone*time, p = .044) driven by the decrease in P+Ex (P+Ex: -3.9 vs. T+NEx: -0.5 mmHg, p = .015). Night-time DBP was lower with exercise (P+Ex: -4.0 vs. P+NEx: +0.7 mmHg, p = .032). The effect of exercise to lower night-time DBP was not apparent in the presence of T (T+Ex: -0.4 vs. P+NEx: +0.7 mmHg, p > .05). Ex increased average 24-h pulse pressure (PP, exercise*time, p = .022), largely during daytime hours (exercise*time, p = .013).

CONCLUSIONS

There was a main effect of T to increase 24-h SBP, primarily seen when T was combined with Ex. Exercise alone decreased 24-h and night-time DBP; an effect attenuated by T. BP should be carefully assessed and monitored, when prescribing T treatment to middle-aged and older men, especially when combined with exercise training.

Incomplete Systemic Recovery and Metabolic Phenoreversion in Post-Acute-Phase Nonhospitalized COVID-19 Patients: Implications for Assessment of Post-Acute COVID-19 Syndrome

We present a multivariate metabotyping approach to assess the functional recovery of nonhospitalized COVID-19 patients and the possible biochemical sequelae of "Post-Acute COVID-19 Syndrome", colloquially known as long-COVID. Blood samples were taken from patients ca. 3 months after acute COVID-19 infection with further assessment of symptoms at 6 months. Some 57% of the patients had one or more persistent symptoms including respiratory-related symptoms like cough, dyspnea, and rhinorrhea or other nonrespiratory symptoms including chronic fatigue, anosmia, myalgia, or joint pain. Plasma samples were quantitatively analyzed for lipoproteins, glycoproteins, amino acids, biogenic amines, and tryptophan pathway intermediates using Nuclear Magnetic Resonance (NMR) spectroscopy and mass spectrometry. Metabolic data for the follow-up patients (n = 27) were compared with controls (n = 41) and hospitalized severe acute respiratory syndrome SARS-CoV-2 positive patients (n = 18, with multiple time-points). Univariate and multivariate statistics revealed variable patterns of functional recovery with many patients exhibiting residual COVID-19 biomarker signatures. Several parameters were persistently perturbed, e.g., elevated taurine (p = 3.6 × 10-3 versus controls) and reduced glutamine/glutamate ratio (p = 6.95 × 10-8 versus controls), indicative of possible liver and muscle damage and a high energy demand linked to more generalized tissue repair or immune function. Some parameters showed near-complete normalization, e.g., the plasma apolipoprotein B100/A1 ratio was similar to that of healthy controls but significantly lower (p = 4.2 × 10-3) than post-acute COVID-19 patients, reflecting partial reversion of the metabolic phenotype (phenoreversion) toward the healthy metabolic state. Plasma neopterin was normalized in all follow-up patients, indicative of a reduction in the adaptive immune activity that has been previously detected in active SARS-CoV-2 infection. Other systemic inflammatory biomarkers such as GlycA and the kynurenine/tryptophan ratio remained elevated in some, but not all, patients. Correlation analysis, principal component analysis (PCA), and orthogonal-partial least-squares discriminant analysis (O-PLS-DA) showed that the follow-up patients were, as a group, metabolically distinct from controls and partially comapped with the acute-phase patients. Significant systematic metabolic differences between asymptomatic and symptomatic follow-up patients were also observed for multiple metabolites. The overall metabolic variance of the symptomatic patients was significantly greater than that of nonsymptomatic patients for multiple parameters (χ2p = 0.014). Thus, asymptomatic follow-up patients including those with post-acute COVID-19 Syndrome displayed a spectrum of multiple persistent biochemical pathophysiology, suggesting that the metabolic phenotyping approach may be deployed for multisystem functional assessment of individual post-acute COVID-19 patients.

Investigating the effect of an education program on diabetes and lipid lowering medication usage following coronary artery bypass graft surgery

BACKGROUND

Guidelines advocate multifactorial cardiovascular risk management in patients with diabetes and atherosclerotic cardiovascular disease. In hospitalised patients with diabetes following coronary artery bypass graft (CABG) we evaluated the impacts of decision-support algorithms for optimising glycaemia and lipid-lowering. We also assessed the safety of initiating sodium-glucose cotransporter 2 (SGLT2) inhibitors near time of hospital discharge.

METHODS

This was a single-site, pre- and post-intervention analysis of glucose and lipid management in consecutive hospitalised patients with diabetes undergoing CABG surgery. The intervention involved education and decision-support algorithms designed by a multidisciplinary committee to guide cardiac surgery unit clinicians.

RESULTS

A total of 200 patients were included in the study. The pre- and post-intervention groups had similar baseline characteristics (HbA1c 7.9 ± 1.9% versus 8.1 ± 1.8%). Of 4092 blood glucose measurements the incidence of levels between 5 to 10 mmol/L was not different post-intervention (55.5% versus 57.0%, p = 0.441). Fewer endocrinology consultations occurred (59.0% versus 45.0%, p = 0.048) and rates of hypoglycaemia remained low. High-intensity statin was prescribed in >90% pre- and post-intervention although non-statin lipid-lowering agents remained <10% despite patients not achieving LDL-C targets. No 30-day readmissions for diabetic ketoacidosis occurred in patients prescribed SGLT2 inhibitors.

CONCLUSION

The intervention did not improve inpatient glycaemia or increase non-statin lipid-lowering prescriptions in patients with diabetes following CABG surgery but did reduce reliance on specialty input. Initiation of SGLT2 inhibitor therapy near time of hospital discharge was not associated with safety concerns. Alternative interventions or strategies are required to optimise glycaemia and non-statin lipid-lowering therapy prescribing in this setting. This article is protected by copyright. All rights reserved.

Circulating insulin-like growth factor-I, total and free testosterone concentrations and prostate cancer risk in 200 000 men in UK Biobank

Insulin-like growth factor-I (IGF-I) and testosterone have been implicated in prostate cancer aetiology. Using data from a large prospective full-cohort with standardised assays and repeat blood measurements, and genetic data from an international consortium, we investigated the associations of circulating IGF-I, sex hormone-binding globulin (SHBG), and total and calculated free testosterone concentrations with prostate cancer incidence and mortality. For prospective analyses, risk was estimated using multivariable-adjusted Cox regression in 199 698 male UK Biobank participants. Hazard ratios (HRs) were corrected for regression dilution bias using repeat hormone measurements from a subsample. Two-sample Mendelian randomisation (MR) analysis of IGF-I and risk used genetic instruments identified from UK Biobank men and genetic outcome data from the PRACTICAL consortium (79 148 cases and 61 106 controls). We used cis- and all (cis and trans) SNP MR approaches. A total of 5402 men were diagnosed with and 295 died from prostate cancer (mean follow-up 6.9 years). Higher circulating IGF-I was associated with elevated prostate cancer diagnosis (HR per 5 nmol/L increment = 1.09, 95% CI 1.05-1.12) and mortality (HR per 5 nmol/L increment = 1.15, 1.02-1.29). MR analyses also supported the role of IGF-I in prostate cancer diagnosis (cis-MR odds ratio per 5 nmol/L increment = 1.34, 1.07-1.68). In observational analyses, higher free testosterone was associated with a higher risk of prostate cancer (HR per 50 pmol/L increment = 1.10, 1.05-1.15). Higher SHBG was associated with a lower risk (HR per 10 nmol/L increment = 0.95, 0.94-0.97), neither was associated with prostate cancer mortality. Total testosterone was not associated with prostate cancer. These findings implicate IGF-I and free testosterone in prostate cancer development and/or progression.

Long-term exposure to outdoor air pollution and risk factors for cardiovascular disease within a cohort of older men in Perth

While there is clear evidence that high levels of pollution are associated with increased all-cause mortality and cardiovascular mortality and morbidity, the biological mechanisms that would explain this association are less understood. We examined the association between long-term exposure to air pollutants and risk factors associated with cardiovascular disease. Air pollutant concentrations were estimated at place of residence for cohort members in the Western Australian Centre for Health and Ageing Health in Men Study. Blood samples and blood pressure measures were taken for a cohort of 4249 men aged 70 years and above between 2001 and 2004. We examined the association between 1-year average pollutant concentrations with blood pressure, cholesterol, triglycerides, C-reactive protein, and total homocysteine. Linear regression analyses were carried out, with adjustment for confounding, as well as an assessment of potential effect modification. The four pollutants examined were fine particulate matter, black carbon (BC), nitrogen dioxide, and nitrogen oxides. We found that a 2.25 μg/m3 higher exposure to fine particulate matter was associated with a 1.1 percent lower high-density cholesterol (95% confidence interval: -2.4 to 0.1) and 4.0 percent higher serum triglycerides (95% confidence interval: 1.5 to 6.6). Effect modification of these associations by diabetes history was apparent. We found no evidence of an association between any of the remaining risk factors or biomarkers with measures of outdoor air pollution. These findings indicate that long-term PM2.5 exposure is associated with elevated serum triglycerides and decreased HDL cholesterol. This requires further investigation to determine the reasons for this association.

Managing inpatient hyperglycaemia and initiating sodium-glucose cotransporter 2 inhibitor therapy in the setting of diabetes and acute coronary syndrome

We previously showed that implementing algorithms for managing diabetes in acute coronary syndrome was associated with improved inpatient glycaemic control and increased sodium-glucose cotransporter 2 (SGLT2) inhibitor prescriptions. The present study performed 1 year later found that inpatient hyperglycaemia had relapsed to pre-intervention rates, although SGLT2 inhibitor prescriptions remained increased. We discuss the challenges of improving inpatient glycaemic control.

Testosterone and exercise: effects on fitness, body composition, and strength in middle-to-older aged men with low-normal serum testosterone levels

As men age, serum testosterone (T) concentrations decrease, as do fitness, strength, and lean mass. Whether testosterone treatment confers additive benefit to reverse these changes when combined with exercise training in middle-to-older aged men remains unclear. We assessed the effects of T treatment and exercise, alone and in combination, on aerobic capacity (V̇o₂peak), body composition, and muscular strength in men 50-70 yr, waist circumference ≥95 cm and low-normal serum T (6-14 nmol·L^-1). Participants (n = 80) were randomized to AndroForte5 (testosterone 5.0% wt/vol, 100 mg/2 mL) cream (T), or matching placebo (P), applied transdermally daily, and supervised center-based exercise (Ex) or no additional exercise (NEx), for 12-wk. Exercise increased V̇o_2peak and strength versus nonexercise (V̇o_2peak: T + Ex: +2.5 mL·kg^-1·min^-1, P + Ex: +3.2 mL·kg^-1·min^-1, P < 0.001; leg press: T + Ex: +31 kg, P + Ex: +24 kg, P = 0.006). T treatment did not affect V̇o_2peak or strength. Exercise decreased total (T + Ex: -1.7, P + Ex: -2.3 kg, P < 0.001) and visceral fat (T + Ex: -0.1 kg, P + Ex: -0.3 kg, P = 0.003), and increased total (T + Ex: +1.4 kg, P + Ex: +0.7 kg, P = 0.008) and arm lean mass (T + Ex: +0.5 kg, P + Ex: +0.3 kg, P = 0.024). T treatment did not affect total or visceral fat, but increased total (T + Ex: +1.4 kg, T + NEx: +0.7 kg, P = 0.015), leg (T + Ex: +0.3 kg, T + NEx: +0.2 kg, P = 0.024), and arm lean mass (T + Ex: +0.5 kg, T + NEx: +0.2 kg, P = 0.046). T + Ex increased arm lean mass (T + Ex: +0.5 kg vs. P + NEx: -0.0 kg, P = 0.001) and leg strength (T + Ex: +31 kg vs. P + NEx: +12 kg, P = 0.032) compared with P + NEx, with no other additive effects. Exercise training was more effective than T treatment in increasing aerobic capacity and decreasing total and visceral fat mass. T treatment at therapeutic doses increased lean mass but conferred limited additional benefit when combined with exercise. Exercise should be evaluated as an antiaging intervention in preference to testosterone treatment in men.NEW & NOTEWORTHY We illustrate that exercise training generates superior outcomes to testosterone treatment for improving aerobic fitness, muscular strength, and total and visceral fat mass in men 50-70 yr with low-normal serum testosterone concentrations. Adding testosterone treatment to exercise did not provide any additive benefit for these variables. Testosterone treatment alone and exercise alone had similar impacts on lean mass. Therefore, men unable to exercise may obtain benefit from testosterone treatment alone to improve lean mass.

U-shaped association of vigorous physical activity with risk of metabolic syndrome in men with low lean mass, and no interaction of physical activity and serum 25-hydroxyvitamin D with metabolic syndrome risk

BACKGROUND

There is uncertainty over how lean mass, physical activity (PA) and 25-hydroxyvitamin D (25-OH-D) status interact on metabolic syndrome (MetS) risk in adults.

AIMS

To test the hypothesis that these factors additively influence MetS risk.

METHODS

Four thousand eight hundred and fifty-eight adults (54.6% female) mean ± SD age 58.0 ± 5.8 years, body mass index 28.1 ± 4.8 kg/m² , resident in Busselton, Western Australia. PA assessed by questionnaire (all/total and vigorous), lean mass using dual energy X-ray absorptiometry (% total body mass), serum 25-OH-D via immunoassay, analysed using multivariable logistic regression.

RESULTS

In men, lower total PA was associated with MetS (no vs >24 h/week odds ratio (OR) = 3.1; ≤8 vs >24 h/week OR = 1.8, both P < 0.001), as was lower lean mass (low vs high OR = 20.4; medium vs high OR = 7.4, both P < 0.001). Men with low lean mass exhibited a U-shaped relationship of vigorous PA with MetS risk (covariate-adjusted: 0 vs 4-8 h/week OR = 2.1, P = 0.037; >12 vs 4-8 h/week OR = 4.3, P = 0.002; interaction P = 0.039). In women, low PA (0 vs >24 h/week OR = 2.1, P = 0.003) and lean mass (low vs high OR = 13.1; medium vs high OR = 7.2, both P < 0.001) were associated with MetS risk. Low 25-OH-D status was associated with MetS in men (low vs high OR = 4.1; medium vs high OR = 2.3, both P < 0.001) and women (OR = 3.5 and 2.1 respectively, both P < 0.001) with no PA interaction.

CONCLUSIONS

Men and women with high lean mass have low risk of MetS regardless of PA. Low lean mass identifies men who may benefit most from increasing PA, with an optimal level associated with lowest risk. 25-OH-D and PA do not interact on MetS risk.

Psychological flexibility is associated with less diabetes distress and lower glycated haemoglobin in adults with type 1 diabetes

BACKGROUND

Diabetes distress, self-efficacy and health literacy are associated with diabetes self-management and health outcomes. Measures of coping styles and their impact on diabetes self-management and diabetes-related distress may add value in identifying those at risk of poorer health outcomes. Current evidence of associations between psychological flexibility/inflexibility and diabetes related health outcomes is limited.

AIMS

To measure associations of psychological flexibility, self-efficacy and health literacy with diabetes distress and HbA1c, in adults with type 1 diabetes.

METHODS

We surveyed 105 adults with type 1 diabetes attending a tertiary diabetes outpatient clinic (mean age 27±7.1 years, 53% men, duration of diabetes 12.6±8.5 years, HbA1c 72±22 mmol/mol, 8.7± 2.0 %, 34% using insulin pumps). We assessed psychological flexibility, self-efficacy, health literacy and diabetes distress. Regression models explored the relative contributions of different factors to diabetes distress and HbA1c.

RESULTS

The majority of health literacy scores were in the low risk range. Those with greater psychological flexibility had higher self-efficacy (r=0.34, p<0.01) and reported less diabetes distress (r=-0.54, p<0.001). In multiple regression analyses, psychological flexibility and self-efficacy accounted for 36% of the variance in distress score (p<0.001). Shorter duration of diabetes (p<0.001) and greater psychological flexibility (p<0.01) correlated with lower HbA_1c . A 10-point (one standard deviation) higher psychological flexibility score corresponded to a 0.5% lower HbA1c.

CONCLUSIONS

Greater psychological flexibility was associated with less diabetes distress and lower HbA1c_. The psychological flexibility construct may inform alternative interventional approaches aiming to improve wellbeing and glycaemic control. This article is protected by copyright. All rights reserved.