Surveillance MRI is associated with improved survival in patients with primary sclerosing cholangitis.

BACKGROUND: The benefits of regular surveillance imaging for cholangiocarcinoma in patients with primary sclerosing cholangitis (PSC) are unclear. Hence, we aimed to evaluate the impact of regular magnetic resonance cholangiopancreatography (MRCP) on outcomes of patients with PSC in Australia, where the practice of MRCP surveillance is variable. METHODS: The relationship between MRCP surveillance and survival outcomes was assessed in a multicenter, retrospective cohort of patients with PSC from 9 tertiary liver centers in Australia. An inverse probability of treatment weighting approach was used to balance groups across potentially confounding covariates. RESULTS: A total of 298 patients with PSC with 2117 person-years of follow-up were included. Two hundred and twenty patients (73.8%) had undergone MRCP surveillance. Regular surveillance was associated with a 71% reduced risk of death on multivariate weighted Cox analysis (HR: 0.29, 95% CI: 0.14-0.59, p < 0.001) and increased likelihood of having earlier endoscopic retrograde cholangiopancreatography from the date of PSC diagnosis in patients with a dominant stricture (p < 0.001). However, survival posthepatobiliary cancer diagnosis was not significantly different between both groups (p = 0.74). Patients who had surveillance of less than 1 scan a year (n = 41) had comparable survival (HR: 0.46, 95% CI 0.16-1.35, p = 0.16) compared to patients who had surveillance at least yearly (n = 172). CONCLUSIONS: In this multicenter cohort study that employed inverse probability of treatment weighting to minimize selection bias, regular MRCP was associated with improved overall survival in patients with PSC; however, there was no difference in survival after hepatobiliary cancer diagnosis. Further prospective studies are needed to confirm the benefits of regular MRCP and optimal imaging interval in patients with PSC.

Attitudes towards transjugular intrahepatic portosystemic shunt (TIPS) in Australia: a national survey of TIPS centres.

BACKGROUND: Transjugular intrahepatic portosystemic shunt (TIPS) is a minimally invasive therapeutic option to treat the sequelae of portal hypertension. It is unclear whether current international recommendations are reflected in current clinical practice across Australia and the extent of variations in care. This study aimed to address this gap in knowledge and benchmark the current landscape of TIPS services in Australia against international guidelines. METHODS: We designed a 42-item questionnaire according to practice-based recommendations and standards of international guidelines to investigate current landscape of TIPS service across four key domains: (1) service provision, (2) patient selection and indications, (3) best procedure practice, and (4) postoperative care. RESULTS: Gastroenterologist/hepatologists from 23 major liver centres (67.6%) across Australia currently performing TIPS completed the questionnaire. Between 2017 and 2020, there were 456 elective TIPS insertions. Units offering TIPS service had a low median number of TIPS insertions (n=7 per annum). More than half of respondents (56.5%) did not have institutional clinical practice protocols. There was marked variation in practices across institutions in terms of TIPS indications and patient selection. Despite variations, the success rate of elective TIPS was high at 91.7% (79-100%), with 86.6% (29-100%) for rescue TIPS. There was significant variation in postoperative follow-up and care. CONCLUSION: Current TIPS practice in Australia varies significantly across institutions. There is a need for a national consensus clinical practice guidelines to improve access and minimise unwarranted variation. A national registry for TIPS could measure, monitor, and report on quality of clinical care and patient outcomes.

Late-Life Metabolic Dysfunction-Associated Steatotic Liver Disease and its Association With Physical Disability and Dementia.

BACKGROUND: The burden of metabolic dysfunction-associated steatotic liver disease (MASLD) is growing rapidly, including among older adults. The number of older adults is also rising with concomitantly increasing rates of age-related physical and cognitive dysfunction. However, data on whether MASLD affects physical and cognitive function in older adults is limited. As such, we aimed to identify whether prevalent MASLD influences the risk of incident physical disability or dementia in initially healthy older adults. METHODS: A post-hoc analysis of participants from the ASPREE-XT cohort study, which recruited community-dwelling older adults without a history of cardiovascular disease, dementia, or independence-limiting functional impairment. The Fatty Liver Index (to identify MASLD) was calculated in those with complete data. Cox proportional-hazards models were used to investigate the outcomes of dementia and persistent physical disability in participants with MASLD vs those without. RESULTS: Of the 9 097 individuals included (mean age 75.1 ±â€…4.2 years; 45.0% men), 341 (3.7%) developed persistent physical disability and 370 (4.1%) developed dementia over a median follow-up of 6.4 years (IQR 5.3-7.5 years). When adjusting for known contributors including age, gender, education, comorbidity, and functional measures, MASLD was associated with an increased risk of persistent physical disability (HR 1.41 [95% CI: 1.07-1.87]) and reduced risk of incident dementia (HR 0.63 [95% CI: 0.48-0.83]). CONCLUSIONS: Prevalent MASLD is associated with reduced rates of incident dementia but increased risk of persistent physical disability in initially relatively healthy older adults. Understanding the mechanisms underlying these divergent results to allow appropriate risk stratification and counseling is important.

Enhancing gender equality for women using person-centred care and cultural curiosity.

Socially constructed gender norms influence people's access to, and experience of, healthcare. Gender norms can negatively affect the health of women, men and people with other gender identities, such as transgender or non-binary individuals. Person-centred care and shared decision-making, which are widely recognised as essential aspects of healthcare, could be effective approaches for enhancing gender equality in healthcare for women. However, many women appear to receive suboptimal person-centred care. Additionally, there is a lack of representation of diverse gender identities in research, as well as a lack of awareness of diverse gender identities among nurses and other healthcare professionals. To enhance gender equality in healthcare for women, nurses and nursing students should be encouraged to reflect on their unconscious biases and adopt a stance of cultural curiosity, while organisations need to improve preregistration and post-registration training on equality and diversity.

Metabolic dysfunction-associated steatotic liver disease in older adults is associated with frailty and social disadvantage.

BACKGROUND & AIMS: The burden of metabolic dysfunction-associated steatotic liver disease (MASLD) is growing rapidly, as is the number of older adults globally. However, relatively few studies have been performed evaluating the prevalence and risk factors for MASLD in older adults. As such, we aimed to identify the prevalence of MASLD in older adults, as well as sociodemographic, clinical, functional and biochemical associations. METHODS: The study population included older adults without a history of cardiovascular disease, dementia or independence-limiting functional impairment who had participated in the ASPirin in Reducing Events in the Elderly (ASPREE) randomised trial. MASLD was defined using the Fatty Liver Index (FLI). Associations were identified using Poisson regression with robust variance for FLI ≥ 60 vs FLI < 30. RESULTS: 9097 Australian participants aged ≥70 years had complete biochemical and anthropometric data to identify MASLD. The study population had a mean age of 75.1 ± 4.3 years and was 45.0% male. Almost one-third (33.0%) had prevalent MASLD, and the prevalence decreased with increasing age (adjusted RR [aRR] 0.96, 95% CI: 0.96-0.97). MASLD was also negatively associated with social advantage (aRR 0.94, 95% CI: 0.90-0.99) and exercise tolerance and was positively associated with diabetes mellitus (aRR: 1.22, 95% CI: 1.16-1.29), hypertension (aRR: 1.31, 95% CI: 1.22-1.41), male sex (aRR: 1.66, 95% CI: 1.57-1.74), pre-frailty (aRR: 1.99, 95% CI: 1.82-2.12) and frailty (aRR: 2.36, 95% CI: 2.16-2.56). MASLD and nonalcoholic fatty liver disease (NAFLD) results were 100% concordant. CONCLUSION: This study in a large cohort of relatively healthy community-dwelling older adults shows that MASLD is common, decreases with age and is associated with poorer metabolic health, social disadvantage and frailty.

Global survey of stigma among physicians and patients with nonalcoholic fatty liver disease.

BACKGROUND & AIMS: Patients with fatty liver disease may experience stigma from the disease or comorbidities. In this cross-sectional study, we aimed to understand stigma among patients with nonalcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH) and healthcare providers. METHODS: Members of the Global NASH Council created two surveys about experiences/attitudes toward NAFLD and related diagnostic terms: a 68-item patient and a 41-item provider survey. RESULTS: Surveys were completed by 1,976 patients with NAFLD across 23 countries (51% Middle East/North Africa [MENA], 19% Europe, 17% USA, 8% Southeast Asia, 5% South Asia) and 825 healthcare providers (67% gastroenterologists/hepatologists) across 25 countries (39% MENA, 28% Southeast Asia, 22% USA, 6% South Asia, 3% Europe). Of all patients, 48% ever disclosed having NAFLD/NASH to family/friends; the most commonly used term was "fatty liver" (88% at least sometimes); "metabolic disease" or "MAFLD" were rarely used (never by >84%). Regarding various perceptions of diagnostic terms by patients, there were no substantial differences between "NAFLD", "fatty liver disease (FLD)", "NASH", or "MAFLD". The most popular response was being neither comfortable nor uncomfortable with either term (56%-71%), with slightly greater discomfort with "FLD" among the US and South Asian patients (47-52% uncomfortable). Although 26% of patients reported stigma related to overweight/obesity, only 8% reported a history of stigmatization or discrimination due to NAFLD. Among providers, 38% believed that the term "fatty" was stigmatizing, while 34% believed that "nonalcoholic" was stigmatizing, more commonly in MENA (43%); 42% providers (gastroenterologists/hepatologists 45% vs. 37% other specialties, p = 0.03) believed that the name change to metabolic dysfunction-associated steatotic liver disease (or MASLD) might reduce stigma. Regarding the new nomenclature, the percentage of providers reporting "steatotic liver disease" as stigmatizing was low (14%). CONCLUSIONS: The perception of NAFLD stigma varies among patients, providers, geographic locations and sub-specialties. IMPACT AND IMPLICATIONS: Over the past decades, efforts have been made to change the nomenclature of nonalcoholic fatty liver disease (NAFLD) to better align with its underlying pathogenetic pathways and remove any potential stigma associated with the name. Given the paucity of data related to stigma in NAFLD, we undertook this global comprehensive survey to assess stigma in NAFLD among patients and providers from around the world. We found there is a disconnect between physicians and patients related to stigma and related nomenclature. With this knowledge, educational programs can be developed to better target stigma in NAFLD among all stakeholders and to provide a better opportunity for the new nomenclature to address the issues of stigma.

Broadening and strengthening the health providers caring for patients with chronic hepatitis C may improve continuity of care.

BACKGROUND: Direct-acting antiviral (DAA) therapies for hepatitis C virus infection (HCV) lead to excellent rates of sustained virological response (SVR). However, loss to follow-up (LTFU) for SVR testing remains a challenge. We examine factors associated with LTFU in a real-world setting. METHODS: Adults who received DAA therapy for HCV in one of 26 centers across Australia during 2016-2021 were followed up for 2 years. Data sources included the patient medical records and the national Pharmaceutical and Medicare Benefits Schemes. Linkage to Medicare provided utilization data of other health-care providers and re-treatment with DAAs. LTFU was defined as no clinic attendance for SVR testing by at least 52 weeks after DAA treatment commencement. Multivariable logistic regression assessed factors associated with LTFU. RESULTS: In 3619 patients included in the study (mean age 52.0 years; SD = 10.5), 33.6% had cirrhosis (69.4% Child-Pugh class B/C), and 19.3% had HCV treatment prior to the DAA era. Five hundred and fifteen patients (14.2%) were LTFU. HCV treatment initiation in 2017 or later (adj-OR = 2.82, 95% confidence interval [CI] 2.25-3.54), younger age (adj-OR = 2.63, 95% CI 1.80-3.84), Indigenous identification (adj-OR = 1.99, 95% CI 1.23-3.21), current injection drug use or opioid replacement therapy (adj-OR = 1.66, 95% CI 1.25-2.20), depression treatment (adj-OR = 1.49, 95% CI 1.17-1.90), and male gender (adj-OR = 1.31, 95% CI 1.04-1.66) were associated with LTFU. CONCLUSIONS: These findings stress the importance of strengthening the network of providers caring for patients with HCV. In particular, services targeting vulnerable groups of patients such as First Nations Peoples, youth health, and those with addiction and mental health disorders should be equipped to treat HCV.

Improved Survival Outcomes with Surgical Resection Compared to Ablative Therapy in Early-Stage HCC: A Large, Real-World, Propensity-Matched, Multi-Centre, Australian Cohort Study.

The optimal treatment approach in very-early and early-stage hepatocellular carcinoma (HCC) is not precisely defined, and there is ambiguity in the literature around the comparative efficacy of surgical resection versus ablation as curative therapies for limited disease. We performed this real-world propensity-matched, multi-centre cohort study to assess for differences in survival outcomes between those undergoing resection and those receiving ablation. Patients with Barcelona Clinic Liver Cancer (BCLC) 0/A HCC first diagnosed between 1 January 2016 and 31 December 2020 who received ablation or resection as initial treatment were included in the study. A total of 450 patients were included in the study from 10 major liver centres including two transplant centres. Following propensity score matching using key covariates, 156 patients were available for analysis with 78 in each group. Patients who underwent resection had significantly improved overall survival (log-rank test p = 0.023) and local recurrence-free survival (log rank test p = 0.027) compared to those who received ablation. Based on real-world data, our study supports the use of surgical resection in preference to ablation as first-line curative therapy in appropriately selected BCLC 0/A HCC patients.

Adherence to a Mediterranean diet may improve serum adiponectin in adults with nonalcoholic fatty liver disease: The MEDINA randomized controlled trial.

Nonalcoholic fatty liver disease (NAFLD) affects approximately 30% of adults worldwide, with chronic low-grade inflammation being a key pathophysiological feature of progression. The Mediterranean diet (MedDiet) is recognized for improving metabolic and hepatic outcomes in people with diabetes and NAFLD, in part, via anti-inflammatory properties. The aim of this study was to determine the effect of an ad libitum MedDiet versus low-fat diet (LFD) on inflammatory markers in adults with NAFLD. It was hypothesized that the MedDiet, and its individual components, would improve inflammation. This multicenter, randomized controlled trial, randomized participants to a MedDiet or LFD intervention for 12 weeks. Primary outcomes included change from baseline to 12 weeks for serum high-sensitivity C-reactive protein, interleukin-6, tumor necrosis factor-α, adiponectin, leptin, and resistin. Forty-two participants (60% female; age 52.3 ± 12.6 years; body mass index, 32.2 ± 6.2 kg/m²) were randomized to the MedDiet (n = 19) or low-fat diet (n = 23). At 12 weeks, the LFD showed a greater decrease in leptin compared with the MedDiet (-1.20 ± 3.9 ng/mL vs 0.64 ± 3.5 ng/mL, P = .010). Adiponectin significantly improved within the MedDiet (13.7 ± 9.2 µg/mL to 17.0 ± 12.5 µg/mL, P = .016), but not within the LFD group. No statistically significant changes were observed for other inflammatory markers following the MedDiet or LFD. Adherence to the MedDiet significantly improved in both study arms, although greater improvements were seen in the MedDiet group. Adiponectin significantly improved following a Mediterranean diet intervention, in the absence of weight loss. The low-fat diet did not elicit improvements in inflammatory markers. High-quality clinical trials appropriately powered to inflammatory markers are required in this population.

Current Therapeutics in Primary Sclerosing Cholangitis.

Primary sclerosing cholangitis (PSC) is an orphan, cholestatic liver disease that is characterized by inflammatory biliary strictures with variable progression to end-stage liver disease. Its pathophysiology is poorly understood. Chronic biliary inflammation is likely driven by immune dysregulation, gut dysbiosis, and environmental exposures resulting in gut-liver crosstalk and bile acid metabolism disturbances. There is no proven medical therapy that alters disease progression in PSC, with the commonly prescribed ursodeoxycholic acid being shown to improve liver biochemistry at low-moderate doses (15-23 mg/kg/day) but not alter transplant-free survival or liver-related outcomes. Liver transplantation is the only option for patients who develop end-stage liver disease or refractory complications of PSC. Immunosuppressive and antifibrotic agents have not proven to be effective, but there is promise for manipulation of the gut microbiome with fecal microbiota transplantation and antibiotics. Bile acid manipulation via alternate synthetic bile acids such as norursodeoxycholic acid, or interaction at a transcriptional level via nuclear receptor agonists and fibrates have shown potential in phase II trials in PSC with several leading to larger phase III trials. In view of the enhanced malignancy risk, statins, and aspirin show potential for reducing the risk of colorectal cancer and cholangiocarcinoma in PSC patients. For patients who develop clinically relevant strictures with cholestatic symptoms and worsening liver function, balloon dilatation is safer compared with biliary stent insertion with equivalent clinical efficacy.

Current understanding and future perspectives on the impact of changing NAFLD to MAFLD on global epidemiology and clinical outcomes.

INTRODUCTION: For the first time in nearly half a century, fatty liver disease has undergone a change in name and definition, from the exclusive term, non-alcoholic fatty liver disease (NAFLD), to the inclusion-based, metabolic-associated fatty liver disease (MAFLD). This has led investigators across the globe to evaluate the impact the nomenclature change has had on the epidemiology and natural history of the disease. METHODS: This systematic review provides a comprehensive overview on how the shift in name and diagnostic criteria has influenced point prevalence in different geographic regions, as well as morbidity and mortality risk, whilst highlighting gaps in the literature that need to be addressed. CONCLUSIONS: MAFLD prevalence is higher than NAFLD prevalence, carries a higher risk of overall mortality, with greater granularity in risk-stratification amongst MAFLD subtypes.

Rotational ThromboElastometry-guided blood component administration versus standard of care in patients with Cirrhosis and coagulopathy undergoing Invasive ProcEdures (RECIPE): study protocol for a randomised controlled trial.

BACKGROUND: Patients with cirrhosis often undergo invasive procedures both for management of complications of their advanced liver disease, including treatment for hepatocellular carcinoma, as well as underlying comorbidities. Despite a current understanding that most patients with cirrhosis are in a rebalanced haemostatic state (despite abnormalities in conventional coagulation tests, namely INR and platelet count), patients with cirrhosis are still often given prophylactic blood components based on these conventional parameters, in an effort to reduce procedure-related bleeding. Viscoelastic tests such as Rotational Thromboelastometry (ROTEM) provide a global measurement of haemostasis and have been shown to predict bleeding risk more accurately than conventional coagulation tests, and better guide blood product transfusion in a number of surgical and trauma-related settings. The aim of this study is to assess the utility of a ROTEM-based algorithm to guide prophylactic blood component delivery in patients with cirrhosis undergoing invasive procedures. We hypothesise that ROTEM-based decision-making will lead to a reduction in pre-procedural blood component usage, particularly fresh frozen plasma (FFP), compared with standard of care, whilst maintaining optimal clinical outcomes. METHODS: This is a multi-centre randomised controlled trial comparing ROTEM-guided prophylactic blood component administration to standard of care in patients with cirrhosis and coagulopathy undergoing invasive procedures. The primary efficacy outcome of the trial is the proportion of procedures requiring prophylactic transfusion, with the primary safety outcome being procedure-related bleeding complications. Secondary outcomes include the amount of blood products (FFP, platelets, cryoprecipitate) transfused, transfusion-related side effects, procedure-related complications other than bleeding, hospital length of stay and survival. DISCUSSION: We anticipate that this project will lead to improved prognostication of patients with cirrhosis, in terms of their peri-procedural bleeding risk. We hope to show that a significant proportion of cirrhotic patients, deemed coagulopathic on the basis of standard coagulation tests such as INR and platelet count, are actually in a haemostatic balance and thus do not require prophylactic blood product, leading to decreased and more efficient blood component use. TRIAL REGISTRATION: RECIPE has been prospectively registered with the Australia and New Zealand Clinical Trials Registry on the 30th April 2019 ( ACTRN12619000644167 ).

Non-alcoholic fatty liver disease prevalence in Australia has risen over 15 years in conjunction with increased prevalence of obesity and reduction in healthy lifestyle.

BACKGROUND AND AIM: Non-alcoholic fatty liver disease (NAFLD) is the most prevalent liver condition globally. The aim of this study was to evaluate the change in age- and sex-standardized prevalence of NAFLD in regional Victoria over a 15-year period and explore the underlying factors associated with differences over time. METHODS: Repeated comparative cross-sectional studies in four towns in regional Victoria, Australia. Individuals randomly selected from households from residential address lists from local government organizations in 2001-2003 (CrossRoads I [CR1]) and 2016-2018 (CrossRoads II [CR2]) with 1040 (99%) and 704 (94%) participants from CR1 and CR2 having complete data for analysis. Primary outcome was change in prevalence estimates of NAFLD (defined by a fatty liver index ≥ 60 in the absence of excess alcohol and viral hepatitis) between 2003 and 2018. RESULTS: Crude prevalence of NAFLD increased from 32.7% to 38.8% (P < 0.01), while age-standardized/sex-standardized prevalence increased from 32.4% to 35.4% (P < 0.01). Concurrently, prevalence of obesity defined by BMI and elevated waist circumference increased 28% and 25%, respectively. Women had a greater increase in the prevalence of NAFLD than men, in parallel with increasing prevalence of obesity. Proportion of participants consuming takeaway food greater than once weekly increased significantly over time. Up to 60% of NAFLD patients require additional tests for assessment of significant fibrosis. CONCLUSIONS: Crude and age-standardized/sex-standardized prevalence of NAFLD have both increased significantly over the last 15 years, particularly among women, in association with a parallel rise in the prevalence of obesity.

The Effect of Aspirin Use on Incident Hepatocellular Carcinoma-An Updated Systematic Review and Meta-Analysis.

An increasing number of observational studies have described an association between aspirin use and a reduced risk of incident hepatocellular carcinoma. We performed this meta-analysis to provide a comprehensive and updated aggregate assessment of the effect of aspirin on HCC incidence. Two independent authors performed a systematic search of the literature, utilising the Medline, Embase, Scopus, and PubMed databases. A total of 16 studies (12 cohort studies, and 4 case-control studies) were selected for inclusion, with a large number of studies excluded, due to an overlapping study population. The pooled analysis of cohort studies involving a total population of approximately 2.5 million subjects, 822,680 aspirin users, and 20,626 HCC cases demonstrated a 30% reduced risk of HCC associated with aspirin use (adjusted HR 0.70, 95%CI 0.60-0.81). There was a similar but non-significant association observed across the case-control studies (adjusted OR 0.60, 95%CI 0.32-1.15, p = 0.13), which involved a total of 1961 HCC cases. In a subgroup meta-analysis of patients with cirrhosis, the relationship between aspirin use and incident HCC diminished to non-significance (adjusted HR 0.96, 95%CI 0.84-1.09). Aspirin use was associated with a statistically significant increase in bleeding events when all relevant studies were pooled together (adjusted HR 1.11, 95%CI 1.02-1.22). Prospectively collected data should be sought, to define the optimal patient group in which aspirin is safe and effective for the chemoprophylaxis of HCC.

Climate-driven phenological shifts in emergence dates of British bees.

Climate change has a diverse range of impacts on wild bees, including their phenology or timing of life history events. Climate-driven phenological shifts can not only impact individuals at species level but also threaten the vital pollination service that wild bees provide to both wild plants and cultivated crops. Despite their involvement in pollination, for most bee species, especially in Great Britain, little is known about phenological shifts. This study makes use of 40 years of presence-only data for 88 species of wild bees to analyse shifts in emergence dates, both over time and in relation to temperature. The analyses reveal widespread advances in emergence dates of British wild bees, at an average rate of 0.40 ± 0.02 days per year since 1980 across all species in the study data set. Temperature is a key driver of this shift, with an average advance of 6.5 ± 0.2 days per 1°C warming. For change in emergence dates both over time and in relation to temperature, there was significant species-specific variation, with 14 species showing significant advances over time and 67 showing significant advances in relation to temperature. Traits did not appear to explain variation in individual species' responses, with overwintering stage, lecty, emergence period and voltinism considered as possible explanatory traits. Pairwise comparisons showed no differences in sensitivity of emergence dates to increasing temperature between trait groups (groups of species which share all four traits) that differed by only one trait. These results highlight not only a direct impact of temperature on the phenology of wild bees themselves but also the species-specific shifts highlight a possible impact on the temporal structure of bee communities and the pollination networks for which the wild bees are so crucial.

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Understanding Solid-State Photochemical Energy Storage in Polymers with Azobenzene Side Groups.

Solar thermal fuel (STF) materials store energy through light-induced changes in the structures of photoactive molecular groups, and the stored energy is released as heat when the system undergoes reconversion to the ground-state structure. Solid-state STF devices could be useful for a range of applications; however, the light-induced structural changes required for energy storage are often limited or prevented by dense molecular packing in condensed phases. Recently, polymers have been proposed as effective solid-state STF platforms, as they can offer the bulk properties of solid materials while retaining the molecular-level free volume and/or mobility to enable local structural changes in photoresponsive groups. Light-induced energy storage and macroscopic heat release have been demonstrated for polymers with photoisomerizable azobenzene side groups. However, the mechanism of energy storage and the link between the polymer structure, energy density and storage duration has not yet been explored in detail. In this work, we present a systematic study of methacrylate- and acrylate-based polymers with azobenzene side groups to establish the mechanism of energy storage and release and the factors affecting energy density and reconversion kinetics. For polymers with directly attached azobenzene side groups, the energy storage properties are in line with previous work on similar systems, and the photoisomerization and reconversion properties of the azobenzene side groups mirror those of molecular azobenzene. However, the inclusion of an alkyl linker between the azobenzene side group and the backbone significantly increases the photoswitching efficiency, giving almost quantitative conversion to the Z isomeric state. The presence of the alkyl linker also reduces the glass transition temperature and leads to faster spontaneous thermal reconversion to the E isomeric form, but in all cases, half-lives of more than 4 days are observed in the solid state, which provides scope for applications requiring daily energy storage-release cycles. The maximum gravimetric energy density observed is 143 J g-1, which represents an increase of up to 44% compared to polymers with directly attached azobenzene moieties.