Non-alcoholic fatty liver disease is associated with higher levels of objectively measured sedentary behaviour and lower levels of physical activity than matched healthy controls
TL;DR: High levels of sedentary behaviour and low levels of physical activity represent a therapeutic target that may prevent progression of metabolic conditions and weight gain in people with NAFLD and should be considered in clinical care.
Abstract: Background and aims Physical activity is a key determinant of metabolic control and is recommended for people with non-alcoholic fatty liver disease (NAFLD), usually alongside weight loss and dietary change. To date, no studies have reported the relationship between objectively measured sedentary behaviour and physical activity, liver fat and metabolic control in people with NAFLD, limiting the potential to target sedentary behaviour in clinical practice. This study determined the level of sedentary behaviour and physical activity in people with NAFLD, and investigated links between physical activity, liver fat and glucose control. Methods Sedentary behaviour, physical activity and energy expenditure were assessed in 37 adults with NAFLD using a validated multisensor array over 7 days. Liver fat and glucose control were assessed, respectively, by 1 H-MRS and fasting blood samples. Patterns of sedentary behaviour were assessed by power law analyses of the lengths of sedentary bouts fitted from raw sedentary data. An age and sex-matched healthy control group wore the activity monitor for the same time period. Results People with NAFLD spent approximately half an hour extra a day being sedentary (1318±68 vs1289±60 mins/day; p<0.05) and walked 18% fewer steps (8483±2926 vs 10377±3529 steps/ day; p<0.01). As a consequence, active energy expenditure was reduced by 40% (432±258 vs 732±345 kcal/day; p<0.01) and total energy expenditure was lower in NAFLD (2690±440 vs 2901±511 kcal/day; p<0.01). Power law analyses of the lengths of sedentary bouts demonstrated that patients with NAFLD also have a lower number of transitions from being sedentary to active compared with controls (13±0.03 vs15 ±0.03%; p<0.05). Conclusions People with NAFLD spend more time sedentary and undertake less physical activity on a daily basis than healthy controls. High levels of sedentary behaviour and low levels of physical activity represent a therapeutic target that may prevent progression of metabolic conditions and weight gain in people with NAFLD and should be considered in clinical care.
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TL;DR: The large number of patients with NAFLD with potential for progressive liver disease creates challenges for screening, as the diagnosis of NASH necessitates invasive liver biopsy.
Abstract: NAFLD is one of the most important causes of liver disease worldwide and will probably emerge as the leading cause of end-stage liver disease in the coming decades, with the disease affecting both adults and children. The epidemiology and demographic characteristics of NAFLD vary worldwide, usually parallel to the prevalence of obesity, but a substantial proportion of patients are lean. The large number of patients with NAFLD with potential for progressive liver disease creates challenges for screening, as the diagnosis of NASH necessitates invasive liver biopsy. Furthermore, individuals with NAFLD have a high frequency of metabolic comorbidities and could place a growing strain on health-care systems from their need for management. While awaiting the development effective therapies, this disease warrants the attention of primary care physicians, specialists and health policy makers.
3,076 citations
TL;DR: This Review discusses NAFLD-associated HCC, including its epidemiology, key features that promote hepatocarcinogenesis and the management of HCC in patients with obesity and associated metabolic comorbidities, and the challenges and future directions of research.
Abstract: Caloric excess and sedentary lifestyle have led to a global epidemic of obesity and metabolic syndrome. The hepatic consequence of metabolic syndrome and obesity, nonalcoholic fatty liver disease (NAFLD), is estimated to affect up to one-third of the adult population in many developed and developing countries. This spectrum of liver disease ranges from simple steatosis to nonalcoholic steatohepatitis (NASH) and cirrhosis. Owing to the high prevalence of NAFLD, especially in industrialized countries but also worldwide, and the consequent burden of progressive liver disease, there is mounting epidemiological evidence that NAFLD has rapidly become a leading aetiology underlying many cases of hepatocellular carcinoma (HCC). In this Review, we discuss NAFLD-associated HCC, including its epidemiology, the key features of the hepatic NAFLD microenvironment (for instance, adaptive and innate immune responses) that promote hepatocarcinogenesis and the management of HCC in patients with obesity and associated metabolic comorbidities. The challenges and future directions of research will also be discussed, including clinically relevant biomarkers for early detection, treatment stratification and monitoring as well as approaches to therapies for both prevention and treatment in those at risk or presenting with NAFLD-associated HCC.
761 citations
TL;DR: Prolonged sitting time and decreased physical activity level were positively associated with the prevalence of NAFLD in a large sample of middle-aged Koreans, supporting the importance of reducing time spent sitting in addition to promoting physical activity.
153 citations
01 Dec 2019
TL;DR: The evidence behind lifestyle change as a tool to improve hepatic steatosis and liver histology in patients with non-alcoholic fatty liver disease/non- alcoholic steatohepatitis is examined.
Abstract: The development of non-alcoholic fatty liver disease is closely linked to lifestyle factors, namely excessive caloric intake coupled with reduced physical activity and exercise. This review aims to examine the evidence behind lifestyle change as a tool to improve hepatic steatosis and liver histology in patients with non-alcoholic fatty liver disease/non-alcoholic steatohepatitis. Furthermore, potential barriers to adopting lifestyle changes and strategies to overcome these barriers in the clinical setting are discussed.
113 citations
TL;DR: Clinicians should learn to screen and initiate treatment for these extra-hepatic manifestations of NAFLD, in order to provide appropriate multidisciplinary assessments and rigorous surveillance.
Abstract: Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide and its incidence is definitely increasing. NAFLD is a metabolic disease with extensive multi-organ involvement, whose extra-hepatic manifestations include type 2 diabetes mellitus, cardiovascular disease, obstructive sleep apnea, chronic kidney disease, osteoporosis, and polycystic ovarian syndrome. Recently, further evidence has given attention to pathological correlations not strictly related to metabolic disease, also incorporating in this broad spectrum of systemic involvement hypothyroidism, psoriasis, male sexual dysfunction, periodontitis, and urolithiasis. The most common cause of mortality in NAFLD is represented by cardiovascular disease, followed by liver-related complications. Therefore, clinicians should learn to screen and initiate treatment for these extra-hepatic manifestations, in order to provide appropriate multidisciplinary assessments and rigorous surveillance. This review evaluates the current evidence regarding extra-hepatic associations of NAFLD, focusing on the pathogenic hypothesis and the clinical implications.
83 citations
Cites background from "Non-alcoholic fatty liver disease i..."
...Undoubtedly, NAFLD patients commonly exhibited lifestyle habits at risk for low BMD (sedentary behavior and lower levels of physical activity) [129], but evidence identified several pathophysiological mechanisms and possible mediating molecules that may interplay directly in the increasing of bone loss....
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References
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TL;DR: Exercise training reduces HbA1c by an amount that should decrease the risk of diabetic complications, but no significantly greater change in body mass was found when exercise groups were compared with control groups.
Abstract: ContextExercise is widely perceived to be beneficial for glycemic control and
weight loss in patients with type 2 diabetes. However, clinical trials on
the effects of exercise in patients with type 2 diabetes have had small sample
sizes and conflicting results.ObjectiveTo systematically review and quantify the effect of exercise on glycosylated
hemoglobin (HbA1c) and body mass in patients with type 2 diabetes.Data SourcesDatabase searches of MEDLINE, EMBASE, Sport Discuss, Health Star, Dissertation
Abstracts, and the Cochrane Controlled Trials Register for the period up to
and including December 2000. Additional data sources included bibliographies
of textbooks and articles identified by the database searches.Study SelectionWe selected studies that evaluated the effects of exercise interventions
(duration ≥8 weeks) in adults with type 2 diabetes. Fourteen (11 randomized
and 3 nonrandomized) controlled trials were included. Studies that included
drug cointerventions were excluded.Data ExtractionTwo reviewers independently extracted baseline and postintervention
means and SDs for the intervention and control groups. The characteristics
of the exercise interventions and the methodological quality of the trials
were also extracted.Data SynthesisTwelve aerobic training studies (mean [SD], 3.4 [0.9] times/week for
18 [15] weeks) and 2 resistance training studies (mean [SD], 10 [0.7] exercises,
2.5 [0.7] sets, 13 [0.7] repetitions, 2.5 [0.4] times/week for 15 [10] weeks)
were included in the analyses. The weighted mean postintervention HbA1c was lower in the exercise groups compared with the control groups
(7.65% vs 8.31%; weighted mean difference, −0.66%; P<.001). The difference in postintervention body mass between exercise
groups and control groups was not significant (83.02 kg vs 82.48 kg; weighted
mean difference, 0.54; P = .76).ConclusionExercise training reduces HbA1c by an amount that should
decrease the risk of diabetic complications, but no significantly greater
change in body mass was found when exercise groups were compared with control
groups.
1,660 citations
TL;DR: The protective effect of physical activity was strongest in persons at highest risk for NIDDM, defined as those with a high body-mass index, a history of hypertension, or a parental history of diabetes.
Abstract: Background. Physical activity is recommended by physicians to patients with non-insulin-dependent diabetes mellitus (NIDDM), because it increases sensitivity to insulin. Whether physical activity is effective in preventing this disease is not known. Methods. We used questionnaires to examine patterns of physical activity and other personal characteristics in relation to the subsequent development of NIDDM in 5990 male alumni of the University of Pennsylvania. The disease developed in a total of 202 men during 98,524 man-years of follow-up from 1962 to 1976. Results. Leisure-time physical activity, expressed in kilocalories expended per week in walking, stair climbing, and sports, was inversely related to the development of NIDDM. The incidence rates declined as energy expenditure increased from less than 500 kcal to 3500 kcal. For each 500-kcal increment in energy expenditure, the age-adjusted risk of NIDDM was reduced by 6 percent (relative risk, 0.94; 95 percent confidence interval, 0.90 to 0.98). This ...
1,651 citations
TL;DR: The benefits of physical training are discussed, along with recommendations for varying activities, PA-associated blood glucose management, diabetes prevention, gestational diabetes mellitus, and safe and effective practices for PA with diabetes-related complications.
Abstract: Although physical activity (PA) is a key element in the prevention and management of type 2 diabetes, many with this chronic disease do not become or remain regularly active. High-quality studies establishing the importance of exercise and fitness in diabetes were lacking until recently, but it is now well established that participation in regular PA improves blood glucose control and can prevent or delay type 2 diabetes, along with positively affecting lipids, blood pressure, cardiovascular events, mortality, and quality of life. Structured interventions combining PA and modest weight loss have been shown to lower type 2 diabetes risk by up to 58% in high-risk populations. Most benefits of PA on diabetes management are realized through acute and chronic improvements in insulin action, accomplished with both aerobic and resistance training. The benefits of physical training are discussed, along with recommendations for varying activities, PA-associated blood glucose management, diabetes prevention, gestational diabetes mellitus, and safe and effective practices for PA with diabetes-related complications.
1,635 citations
TL;DR: There is an emergence of inactivity physiology studies beginning to raise a new concern with potentially major clinical and public health significance: the average nonexercising person may become even more metabolically unfit in the coming years if they sit too much, thereby limiting the normally high volume of intermittent nonexercise physical activity in everyday life.
Abstract: It is not uncommon for people to spend one-half of their waking day sitting, with relatively idle muscles. The other half of the day includes the often large volume of nonexercise physical activity. Given the increasing pace of technological change in domestic, community, and workplace environments, modern humans may still not have reached the historical pinnacle of physical inactivity, even in cohorts where people already do not perform exercise. Our purpose here is to examine the role of sedentary behaviors, especially sitting, on mortality, cardiovascular disease, type 2 diabetes, metabolic syndrome risk factors, and obesity. Recent observational epidemiological studies strongly suggest that daily sitting time or low nonexercise activity levels may have a significant direct relationship with each of these medical concerns. There is now a need for studies to differentiate between the potentially unique molecular, physiologic, and clinical effects of too much sitting (inactivity physiology) separate from the responses caused by structured exercise (exercise physiology). In theory, this may be in part because nonexercise activity thermogenesis is generally a much greater component of total energy expenditure than exercise or because any type of brief, yet frequent, muscular contraction throughout the day may be necessary to short-circuit unhealthy molecular signals causing metabolic diseases. One of the first series of controlled laboratory studies providing translational evidence for a molecular reason to maintain high levels of daily low-intensity and intermittent activity came from examinations of the cellular regulation of skeletal muscle lipoprotein lipase (LPL) (a protein important for controlling plasma triglyceride catabolism, HDL cholesterol, and other metabolic risk factors). Experimentally reducing normal spontaneous standing and ambulatory time had a much greater effect on LPL regulation than adding vigorous exercise training on top of the normal level of nonexercise activity. Those studies also found that inactivity initiated unique cellular processes that were qualitatively different from the exercise responses. In summary, there is an emergence of inactivity physiology studies. These are beginning to raise a new concern with potentially major clinical and public health significance: the average nonexercising person may become even more metabolically unfit in the coming years if they sit too much, thereby limiting the normally high volume of intermittent nonexercise physical activity in everyday life. Thus, if the inactivity physiology paradigm is proven to be true, the dire concern for the future may rest with growing numbers of people unaware of the potential insidious dangers of sitting too much and who are not taking advantage of the benefits of maintaining nonexercise activity throughout much of the day.
1,577 citations
TL;DR: The long, self-administered IPAQ questionnaire has acceptable validity when assessing levels and patterns of PA in healthy adults and might introduce a source of error in criterion validation studies.
Abstract: IntroductionThe International Physical Activity Questionnaire (IPAQ) was developed to measure health-related physical activity (PA) in populations. The short version of the IPAQ has been tested extensively and is now used in many international studies. The present study aimed to explore the validity characteristics of the long-version IPAQ.Subjects and methodsForty-six voluntary healthy male and female subjects (age, mean±standard deviation: 40.7±10.3 years) participated in the study. PA indicators derived from the long, self-administered IPAQ were compared with data from an activity monitor and a PA log book for concurrent validity, and with aerobic fitness, body mass index (BMI) and percentage body fat for construct validity.ResultsStrong positive relationships were observed between the activity monitor data and the IPAQ data for total PA (ρ = 0.55, P < 0.001) and vigorous PA (ρ = 0.71, P < 0.001), but a weaker relationship for moderate PA (ρ = 0.21, P = 0.051). Calculated MET-h day−1 from the PA log book was significantly correlated with MET-h day−1 from the IPAQ (ρ = 0.67, P < 0.001). A weak correlation was observed between IPAQ data for total PA and both aerobic fitness (ρ = 0.21, P = 0.051) and BMI (ρ = 0.25, P = 0.009). No significant correlation was observed between percentage body fat and IPAQ variables. Bland–Altman analysis suggested that the inability of activity monitors to detect certain types of activities might introduce a source of error in criterion validation studies.ConclusionsThe long, self-administered IPAQ questionnaire has acceptable validity when assessing levels and patterns of PA in healthy adults.
1,461 citations