Obesity management in liver clinics: What's your style of lifestyle intervention?
Article first published online: 23 MAR 2009
© 2009 The Authors. Journal compilation © 2009 Journal of Gastroenterology and Hepatology Foundation and Blackwell Publishing Asia Pty Ltd
Journal of Gastroenterology and Hepatology
Volume 24, Issue 3, pages 327–328, March 2009
How to Cite
Hickman, I. J. (2009), Obesity management in liver clinics: What's your style of lifestyle intervention?. Journal of Gastroenterology and Hepatology, 24: 327–328. doi: 10.1111/j.1440-1746.2009.05777.x
- Issue published online: 23 MAR 2009
- Article first published online: 23 MAR 2009
- Accepted for publication 3 December 2008.
The consequences of Australia's increasingly sedentary lifestyle, expanding waistline, and worrying apathy towards the quantity and quality of food we consume have reached our Hepatology Clinics with obesity-related liver damage occurring across a wide range of chronic liver diseases. Superimposed cardiovascular risk factors present in obese patients add to the overall mortality risk for patients with liver disease. In overweight patients, calorie restriction in conjunction with increased physical activity can benefit the liver in many ways. Decreased free fatty acid flux from adipose tissue as a result of improved fat metabolism reduces hepatic triglyceride storage. Hepatic free fatty acid uptake can be reduced by up to 30% after substantial weight loss in obese patients.1 Weight loss restores hepatic insulin sensitivity resulting in improved insulin-stimulated suppression of hepatic glucose production.1 Enhancing peripheral insulin sensitivity through weight loss also increases total body glucose disposal, which directly contributes to decreasing hyperglycemia and hyperinsulinemia. Obesity may contribute to inflammatory processes through recruitment of T-lymphocytes and macrophages into adipose tissue.2 A combination of calorie restriction and exercise attenuates this low-grade inflammation by decreasing adipose tissue expression of macrophage-specific markers (CD14, CD68), interleukin (IL)-6, IL-8, and TNF-α (tumour necrosis factor-α) and increases mRNA expression of the anti-inflammatory, insulin-sensitizing adipokine, adiponectin.3 In addition, obese populations report remarkable improvements to physical and mental aspects of quality of life after modest weight reductions, even with the persistence of obesity.4
However, the loudly proclaimed benefits of weight reduction are of no use if patients are unable to achieve and sustain meaningful weight loss. Although a multitude of weight loss methods can be offered to obese patients, including very low-calorie diets and drug therapies, a well-designed structured lifestyle intervention performs well for longer-term weight loss maintenance when compared with these methods.5 The evidence for structured lifestyle intervention as an effective short-term method of improving metabolic dysfunction, cardiovascular risk, and quality of life in the obese is clear, but the literature lacks well-designed, randomized controlled trials that assess the efficacy of weight loss programs for treating the biochemical, metabolic, and histological features of liver disease.
In this issue of the Journal, St George et al. report on the effects of a lifestyle intervention in 152 centrally obese patients with abnormal liver enzymes and metabolic risk factors. They report that modest weight reduction of around 3 kg, achieved through a moderately intensive lifestyle intervention can significantly reduce expression of the constellation of cardiovascular risk factors that define the metabolic syndrome. This study confirms our intuition that successful weight reduction results in similar metabolic responses to those seen in obese populations without diagnosed liver disease. However, the histological data to confirm whether these improvements translate to improvements in fibrosis and slow disease progression are still yet to be seen.
Of particular interest in this study was the innovative approach to study design, which incorporated different methods of service delivery for weight management clinics. The style of lifestyle intervention is critical to its ultimate success and acceptance as a viable treatment alternative for patients with liver disease, and this study informs us about a possible balance between the needs of a lifelong chronic condition and a time-poor health-care system.
Patients in the study were randomized into three groups of 12-week duration, defined as: a moderate-intensity intervention (six consultations occurring every 2 weeks over 12 weeks), a low-intensity intervention (three consults every 2 weeks over 6 weeks, then no follow up for 6 weeks), and a control group (one consult at baseline to explain the nutrition and physical activity goals of the study, but no further follow up). The moderately intensive intervention achieved weight loss of 2.8 ± 3.4 kg, increased physical activity by 124 ± 329 min/week, and decreased caloric intake by a little over 1000 kJ/day. This translated into significant improvements in cardiovascular risk factors, such as decreased fasting serum glucose, insulin, low-density lipoprotein cholesterol and triglyceride levels, decreased diastolic blood pressure and, most notably, a 40% improvement in 2 h insulin levels during an oral glucose tolerance test. While the low-intensity intervention seemed adequate enough to initiate an increase in weekly physical activity, the amount of weight loss was less (1.9 ± 3.7 kg at 12 weeks) and not adequate to induce significant improvements to cardiovascular risk factors compared with controls. These results suggest that a minimum threshold of weight loss is necessary to manipulate features of the metabolic syndrome, and that a minimum threshold of professional contact is necessary in order to achieve this extent of weight loss.
St George et al. provided face-to-face consultations to deliver the individualized lifestyle counseling for both low- and moderate-intensity groups. The impressively low dropout rate (3.9% for moderate intensity, 5.3% for low intensity) indicates that face-to-face consultations are well received by obese patients seeking treatment. Retention in obesity treatment programs is associated with more successful weight reduction, and a greater number of treatment visits correlate positively with more extensive weight loss.6 However, with the extraordinary numbers of people expected to need access to weight management services over the coming decades, it is vital that the style of service delivery embraces new technologies to reduce the human resource burden of regular face-to-face contact, while still engaging with the patient during the initial stage of the intervention. Group therapy is one way to reduce the drain on resources. However, obesity interventions need to innovate service delivery to maintain social relevance and can include interactive web-based engagement, podcast and vodcast educational sessions, online and community social networking links, and practical skill developments such as cooking classes and exercise sessions. These novel aspects of service delivery need to be developed urgently to complement existing services so as to lessen the resource burden of the more traditional forms of face-to-face contact that the patients so clearly appreciate.
The multidisciplinary consultations in this study involved dietitians and exercise physiologists who used a combination of behavioral theories to individually tailor the intervention. Use of cognitive behavioral theories as the basis of program development is essential for successful weight loss.7,8 The pediatric obesity literature has seen a switch from individual behavior therapy (e.g. child education or mother education alone) to family- and/or society-based interventions that show far greater success.9,10 Creating an intervention that initiates social support and family involvement can have a ‘ripple effect’ whereby weight loss treatment for the patient has a positive effect on spouses and children within the same household.11 Conversely, a lack of encouragement or involvement from family or friends can have a serious sabotaging effect on the food choices and physical activity of obese patients, especially those from lower socioeconomic backgrounds.12 The change to family-based intervention for obesity management may be just as important for our adult populations. Further, integrating psychologists with expertise in family counseling into the multidisciplinary team may help us develop and implement appropriate strategies to engage social support systems, thereby bolstering effects at reducing the dependence of clients on ongoing, face-to-face consultations with health professionals.
A strength of the study by St George et al. is the inclusion of the control group; this highlights what could happen if we continue with treatment styles of the past. Simply providing patients with information about lifestyle change without structured support resulted in 70% of control patients returning after 12 weeks at either the same weight or heavier than baseline; less than 10% experienced what could be considered a clinically substantial weight loss of at least 4% of bodyweight. The inclusion of the control group also reiterates the caution necessary when using liver enzymes as a surrogate marker of disease activity. All groups improved alanine aminotransferase, aspartate aminotransferase, γ-glutamyltransferase, and serum ferritin after 12 weeks, including the control group, in which a mean increase in waist circumference of nearly 1.5 cm was evident.
Although the study by St George et al. lacks histological data to confirm whether these metabolic and biochemical improvements translate to reductions in liver fibrosis and disease progression, the results clearly demonstrate that a lifestyle intervention with continuing professional contact can improve metabolic function and decrease cardiovascular risk factors in patients with liver disease. Further, they indicate that a minimum amount of weight loss, at least 3 kg, is necessary before these changes are achieved. It is therefore important that we reflect on our own style of lifestyle intervention to ensure our patients can successfully achieve this necessary amount of weight loss. Establishing a long-term, follow-up plan to promote maintenance of weight loss achieved will be a vital extension of this work. The future of lifestyle interventions as a suitable treatment option for the vast numbers of patients who will need them requires an investment in training those health professionals who will be needed to specialize in this field of lifestyle medicine, a long-term retention of patients in structured follow-up programs, an embrace of new technologies for cost-effective, ‘virtual’ service delivery, and engagement with social support systems so we can avoid the long-term dependence on clinical follow up that we currently endure.