UPDATE ON DIETARY MANAGEMENT OF OBESITY IN TYPE 2 DIABETES MELLITUS Mary Moloney, European Federation of the Associations of Dietitians

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1 UPDATE ON DIETARY MANAGEMENT OF OBESITY IN TYPE 2 DIABETES MELLITUS Mary Moloney, European Federation of the Associations of Dietitians SUMMARY Diabetes Mellitus (DM) is a metabolic disorder. It is characterised by absolute or relative insulin deficiency, due to defects in insulin secretion that result in chronic hyperglycaemia and profoundly impaired carbohydrate, lipid and protein metabolism (American Diabetes Association ADA, 2008), Scottish Intercollegiate Guidelines Network SIGN- 2001, World Health Organisation (WHO) 2006). Insulin is a hormone that is produced by the β-cells of the pancreas. It facilitates the entry of glucose into body cells (Balanda et al, 2006). Relative or absolute insulin deficiency leads to decreased cellular uptake of glucose and hyperglycaemia. Type 1 diabetes is usually of acute onset and Type 2 diabetes (Type 2 DM) is preceded by a period of months or years of declining β-cell function and insulin resistance (Vinik 2006), which has potentially devastating consequences (King & Rubin 2003) because chronic hyperglycaemia can lead to long-term complications including diabetic retinopathy, neuropathy, nephropathy, cerebral vascular disease, cardiovascular disease and peripheral vascular disease (Ehud Ur 2008, Thomas & Bishop 2007, Stratton et al, 2000) as well as decreased quality of life. For example the risk of cardiovascular disease is ten times higher in diabetics than in the normal population (Retnakaran & Zinman 2008). In the Framingham Heart Study, the presence of diabetes doubled the age adjusted risk for cardiovascular disease in men and tripled it in women (Fox et al 2006). STUDIES HAVE SHOWN THAT REDUCING ENERGY INTAKE AND INCREASING PHYSICAL ACTIVITY IMPROVES GLYCAEMIC CONTROL AND OTHER METABOLIC ABNORMALITIES IN OBESE DIABETICS Diabetes (Types 1 and 2) currently affects 171 million people worldwide. (Wild et al 2004) and it is projected to rise to 380 million by 2025 (Woo 2008). Type 2 DM accounts for about 85% of all cases of DM (Hall & Davies 2008). The prevalence in the South-Asian and Afro-Caribbean populations is rising (Hall & Davies 2008). Overall risk factors for Type 2 DM include central obesity, limited physical activity, increasing age and previous history of gestational diabetes. An estimated 80% to 90% of Type 2 patients are overweight or obese (United Kingdom Prospective Diabetes Study (UKPDS) 1998). In the Nurses Health Study of 84,941 female nurses, overweight and obesity were the most important predictors of Type 2 DM (Hu et al 2001) and in another study by Tuomilehto et al (1992), the risk of all cause mortality, was increased with excess body fat. (Calle et al 2003). Although obese diabetics have greater difficulty in losing weight than their non-diabetic counterparts (Wing et al 1987) weight loss and other lifestyle changes are to be encouraged because they promote good glycaemic control and result in optimal clinical outcomes (Thomas & Bishop 2007). In the Finnish Diabetes Federation study (2003) a modest weight loss of 5% significantly reduced risk factors by 58% over a 4 year period (Uusitupa et al 2003). Optimal glycaemic control is an essential component in the management of diabetes (Imran & Ross 2008). The WHO (1999) issued the gold standard for measuring glycaemic control namely: glycosylated haemoglobin (HbA1c), which reflects glycaemic control over the previous two to three months. The American Diabetes Association (ADA 2008) recommends a self-monitored blood glucose level of 5-7mmol/l pre-prandially and <10mmol/l post-prandially. In the United Kingdom (UK), the National Institute for Health and Clinical Excellence (NICE) published clinical guidelines for the management of Type 2 DM in 2008 and recommended a target of 6.5% for a patient s HbA1c (NICE 2008). An HbA1c > 10% is a marker of poor glycaemic control. In the United Kingdom Prospective Diabetes Study (UKPDS) (1998), a 1.0% (absolute) reduction of mean HbA1c levels was associated with a 37% reduction in microvascular complications, 14% lower rates of myocardial infarction and fewer deaths from diabetes (Stratton 2000). Weight loss has also been shown to improve glycaemic control (Markovic et al, 1998). All Type 2 diabetics should have their nutritional status assessed. The assessment should incorporate the following measurements: Anthropometry - height, weight and BMI (kg/m 2 ) and waist circumference; Biochemical indices- HbA1c level and lipid profile; clinical signs and symptoms; a detailed review of intakes including energy and nutrients; and a profile of usual physical activity. The normal BMI range for adults is kg/m 2 (WHO 2000). The higher the BMI the greater the health risk. Waist circumference (cm) is useful for This article first appeared in March 2009 Published by Sovereign Publications

2 Table 1. Evidence Based Dietary Guidelines (Europe 2004, USA 2008)

3 determining abdominal fat which is an independent predictor of cardiovascular disease, particularly if values exceed the International Diabetes Federation (2006) recommendations of 94cm in men and 80cm in women (Alberti et al 2006, Reeder et al 1997). The methodology for assessing waist circumference is for the patient to stand arms at side and feet together with the waist unclothed and the abdomen relaxed. The waist is measured at the end of a normal expiration using a non-stretchable tape midway on the mid-axillary line between the lowest rim of the ribcage and the iliac crest, not at the maximum point or at the umbilicus (Aronne 1998, SIGN 1996, Yanovski 1993). For Type 2 diabetics moderate physical activity/exercise of minutes per day with no more than 2 consecutive days without exercise is recommended, because it is associated with improved glycaemic control, decreased insulin resistance, increased cardio-respiratory fitness, improved lipid profiles, better maintenance of weight loss and reduced morbidity and mortality (EASD 2004, ADA 2008, Sigal et al 2008). Recommended forms of exercise include walking, gardening and cycling (Institute of European Food Studies 1998) and swimming, dancing and raking leaves (Sigal et al 2008) Structured counselling by health care professionals on appropriate exercise has been found to be very effective (Wolf et al 2004). Dietary guidelines for patients with diabetes that are based on systematic evidence reviews are available (EASD 2004, ADA 2008). These comprehensive guidelines provide recommendations for energy; macro- and micro- nutrient as well as alcohol intakes and physical activity. Table 1 shows the recommended intakes for macronutrients and alcohol (EASD 2004, ADA 2008). Both reviews recommend that salt intake should be reduced to <6grams per day and if the patient is hypertensive a further reduction may be valuable. A high intake of antioxidant containing foods is also recommended. There is no evidence for antioxidant supplementation in the diet as their long-term safety is unknown and may even be harmful (ADA 2008). The recommendation for fibre intake is 20g per 4.2MJ (EASD 2004) and a consumption of at least 5 portions of fruit and vegetables per day. Diabetic foods should not be encouraged (EASD 2004); however, non-nutritive artificial sweeteners in moderation are permitted when taken within the recommended levels issued (2006) by the United States Food and Drug Administration (FDA) (ADA 2008). The goal of diet therapy for obese Type 2 diabetics is to maintain and improve quality of life, nutritional and physiological wellbeing, reduce weight and prevent and treat acute and longterm complications (Gougeon et al 2008). Dietary counselling is beneficial when it is provided to a small group or on a one to one basis by a dietitian who is also a clinical specialist in diabetes management (Brekke et al 2005, Lemon et al 2004, Franz et al 1995) and who makes it an ongoing interactive and personalised process (British Dietetic Association (BDA) 2003). Nutrition programmes for overweight Type 2 diabetics should be regularly evaluated (Ash et al 2003). The dietitian is the team member who plays the leading role in providing nutritional care for diabetics (ADA 2008). Implementation of nutritional advice provided by the dietitian is challenging for patients (BDA 2003). Indeed, diabetics frequently find dietary manipulation the most difficult part of the overall management of their condition (Humphreys 1997). In order to obtain a realistic assessment the dietitian must be a good listener, supportive, objective, and non-judgemental and a good communicator (Moloney 2000). This client-centred approach considers the history, key elements of the condition, diabetic measurements taken, knowledge and attitudes of each patient (Glasgow et al 1999). Good rapport encourages the patient to disclose more accurately actual intakes of food and fluid including alcohol (Wing 1999). This is important because under-reporting in the overweight is well documented and a hypocaloric diet is often needed (Lissner et al 2000, Poppitt et al 1998). Patients must be empowered with skills to make appropriate choices on the type and portion size of foods which they eat while taking into account overall personal circumstances, physical activity and lifestyle. STUDIES HAVE SHOWN THAT STRUCTURED SELF-MANAGEMENT DIET AND LIFESTYLE EDUCATION PROGRAMMES IMPROVE OUTCOMES AND QUALITY OF LIFE Diabetes self-management education programmes are now being recognised as essential for diabetics who want to achieve successful health-related outcomes (Mensing et al 2007). Studies have shown that effective programmes improve glycaemic control (Gary et al 2003, Norris et al 2002). These programmes improve knowledge, skills and confidence by facilitating patients in making informed decisions regarding self management of their condition. These programmes have been found to be effective in improving outcomes and quality of life of diabetics. They include DESMOND- Diabetes Education and Self Management for Ongoing and Newly Diagnosed- (Cavan & Craddock, 2004) and X-PERT- Diabetes Expert Patient Education versus Routine Treatment (Deakin et al 2006, O Brien et al 2006). These programmes are more successful for diabetics in improving fasting BG levels; HbA1c; lowering systolic blood pressure; lowering weight and improving knowledge on diabetes than one-to-one counselling (Moran 2004). The cost is small in comparison to treating complications which may occur as a result of uncontrolled diabetes (Moran 2004). All educational programmes for Type 2 diabetics should be evaluated to assess costs and benefits. Health is not only the absence of disease and infirmity, but is also the presence of physical, mental, and social wellbeing (WHO 1952). An appreciation of these factors in the lives of diabetics is important, as it affects their overall quality of life. Perceived quality of life can in turn powerfully affect the commitment of patients to actively self-manage their diabetes (Rubin 2000). Significant behavioural and psychosocial challenges including anxiety and depression occur in nearly all aspects of diabetes management and subsequent diabetes control and they must be addressed in treatment. (Delamater et al 2001). The aims in the dietary management of obesity in Type 2 DM are to alleviate the acute symptoms, prevent extremes of glycaemia, reduce the risk of cardiovascular disease and diabetic microvascular complications and maintain quality of life (Thomas and Bishop 2007). For more information please visit:

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5 41. Scottish Intercollegiate Guidelines Network (SIGN) (2001): Management of Diabetes- a National Clinical Guideline. 42. Scottish Intercollegiate Guidelines Network (1996) Obesity in Scotland: Integrating Prevention with Weight Management. Edinburgh: Royal College of Physicians 43. Sigal R, Kenny G, Oh P, et al (2008): Physical Activity and Diabetes. Canadian Diabetes Association Clinical Practice Expert Committee: Clinical Practice Guidelines for the Prevention and Management of Diabetes in Canada. Can. J. of Diab; 32, Suppl 1. S37-S Stratton IM, Adler AI, Neil HAW, et al (2000): Association of Glycaemia with Macrovascular and Microvascular Complications of Type 2 Diabetes (UKPDS 35): Prospective Observational Study. Br Med J; 321, Thomas B, Bishop J (2007): Diabetes Mellitus. In Manual of Dietetic Practice, Diabetes Mellitus: Oxford: Blackwell Publishing. 46. Tuomilehto J, Knowler WC, Zimmet P (1992): Primary Prevention of Non-Insulin-Dependent Diabetes Mellitus. Diab Metab Rev; 8, United Kingdom Prospective Diabetes Study (1998): Intensive Blood Glucose Control with Sulphonylureas or Insulin Compared with Conventional Treatment and Risk of Complications in Patients with Type 2 Diabetes (UKPDS 33). Lancet; 352, Uusitupa M, Lindi V, Louheranta A, et al for the Finnish Diabetes Prevention Study Group (2003): Long-Term Improvement in Insulin Sensitivity by Changing Lifestyles of People with Impaired Glucose Tolerance; 4-Year Results From the Finnish Diabetes Prevention Study. Diab; 52: Vinik AI (2006): Benefits of Early Initiation of Insulin Therapy to Long-term Goals in Type 2 Diabetes Mellitus. Insulin; 1, Wild S, Roglic G, Anders G, et al (2004): Global Prevalence of Diabetes Estimates for the Year 2000 and Projections for Diab Care; 27, Wing RR (1999): Behavioral Strategies to Improve Long-term Weight Loss and Maintenance. Med Health 82, Wing RR, Marcus MD, Epstein LH, et al (1987): Type 2 Diabetic Subjects Lose Less Weight than their Overweight Nondiabetic Spouses. Diab Care; 10, Wolf AM, Conaway MR, Crowther JQ, et al (2004): Translating Lifestyle Intervention to Practice in Obese Patients with Type 2 Diabetes: Improving Control with Activity and Nutrition (ICAN) study. Diab Care; 27, Woo V (2008): Introduction. Canadian Diabetes Association Clinical Practice Expert Committee, Clinical Practice Guidelines for the Prevention and Management of Diabetes in Canada. Can. J. of Diab; 32, Suppl 1. S1-S4 55. World Health Organisation, (1952). Constitution of the World Health Organization. In World Health Organization: Handbook of Basic Documents. 5th ed. Geneva, Palais des Nations, World Health Organisation, (1999). Diagnosis and Classification of Diabetes Mellitus and its Complications. Report of a WHO Consultation. 57. World Health Organisation, (2000). Obesity: Preventing and Managing the Global Epidemic 58. World Health Organisation, (2006). Definition and Diagnosis of Diabetes Mellitus and Intermediate Hyperglycaemia. 59. Yanovski SZ (1993). A Practical Approach to the Treatment of the Obese Patient. Arch of Fam Med; 3, Organisation and Structure The European Federation of the Associations of Dietitians was established in 1978 in Copenhagen, Denmark. Membership of the Federation is open to the National Associations of Dietitians of all member states of the Council of Europe. The Federation is directed and represented by an Executive Committee. The President and the Member Associations of the Executive Committee are elected at the General Meeting. EFAD represents over 27,000 European dietitians and has recently published a Code of Ethics. EFAD is also actively involved in collaborating with the EU funded DIETS (Dietitians Improving the Education and Training Standards) European Project The Federation has links with other organisations in the field of nutrition and dietetics and with other professionals. EFAD actively participates in a number of European projects including the EU Platform on Diet, Physical Activity and Health The aims of EFAD are to: promote the development of the dietetic profession develop dietetics on a scientific and professional level in the common interest of the member associations facilitate communication between national dietetic associations and other organisations - professional, educational, and governmental encourage a better nutrition situation for the population of the member countries of the Council of Europe. These aims shall be pursued in co-operation within the member associations and with international organisations. 5 Metabolic Disease Review Secretariat@efad.org Web: