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	Protein		Energy
	Sodium/salt		Phosphorus and phosphate
	Potassium		Vitamin supplements
	Nutrition in the elderly

Type 2 diabetes mellitus afflicts millions of people world wide. A genetic predisposition, changes in lifestyle, excess food consumption, and a reduction in physical activity all contribute to the development of Type 2 diabetes. And many diabetics develop chronic renal disease, which leads to morbidities needing expensive therapies. So, we need to implement treatment strategies that could change the disease process and prevent the development of complications.

For example, poor glycaemic control and uncontrolled hypertension contribute to macro- and microvascular disease – two major risk factors for cardiovascular disease (CVD), nephropathy, retinopathy and neuropathy. Improving the treatment of hyperglycaemia, hypertension, and hyperlipidaemia should play a role in the prevention of these complications. And dietary management is essential in treating all patients with either Type 1 or Type 2 diabetes.

So, it is important to refer diabetic patients with renal involvement to specialised centres that can provide combined diabetes and renal care and offer access to experienced support staff, including dietitians..

Nutritional management of diabetic patients at risk of chronic kidney disease (CKD) is aimed at metabolic control of diabetes and changing function during all stages of CKD.

The National Kidney Foundation Kidney Disease Outcome Quality Initiative (KDOQI) recently published its Clinical Practise Guidelines for CKD: Evaluation, Classification and Stratification. (1)

(Table: The five stages of CKD.)

These Best Practice Guidelines could also be used to introduce nutritional changes. The following summary of nutrient intake is based on guidelines published to date.

(Table: Recommended nutritional intakes for CKD. )

Protein
A moderate protein restriction may have a positive effect on albumin excretion rate in patients with Type 1 and 2 diabetes (2). Recommendations to reduce the intake of protein further at CKD stage 5 are aiming to control uraemic symptoms, but with the emphasis that at least 50% of protein should be of High Biological Value to maintain nitrogen balance (3). However, patients may unconsciously reduce protein and energy intake and unexplained weight loss caused by changes in appetite could contribute to protein and energy malnutrition (PEM) with an adverse effect on prognosis of patients treated by dialysis.

During dialysis, water-soluble products such as amino acids and albumin are lost. It is recommended that the protein intake be increased by
0.2-0.3g/kg to supplement losses and help prevent PEM.

Energy
Insufficient energy intake during the pre-dialysis phase of treatment can lead to protein catabolism, a negative nitrogen balance, and unplanned weight loss.

The nutritional recommendations for maintaining energy intake for diabetic patients are the same as for non-diabetic patients.

The recommendations are dependent on age and activity. Older and less-active patients can reduce their energy intake to 30kcal/kg/ibw while retaining nitrogen balance. It is also possible to assess energy requirements by calculating Physical Activity Levels (PAL).

PEM is common and must be prevented and prompt action is needed to avert an increase in morbidity and mortality. During the early stages of treatment, however, obese patients should be encouraged to lose weight.

The KDOQI Clinical Practice Guidelines on Managing Dyslipidaemias in CKD recommends specific strategies for treatment during all stages of treatment.

Nutritional recommendations include eating a healthy diet with advice on alcohol consumption, increased physical activity and cessation of smoking (4).

(Table: Classifications of Malnutrition and Obesity Malnutrition (BAPEN))

Sodium/salt
A high sodium intake may be associated with hypertension in the general population. As much as 70 to 80% of salt is obtained from processed foods. The remainder is added during and/or after food preparation. The aim is to reduce the intake of salt to 6g/day, which is a minimum to retain the quality of dietary regimens.

A high sodium intake causes thirst and this is a major problem with anuric or oliguric patients on dialysis and a reduction in salt intake helps the patient to control their Intra-Dialysis Weight Gain (IDWG). However, food contains fluid and patients with a good appetite might gain more then the accepted 2 to 2.5kg between haemodialysis treatments.

Hyperglycaemia is an additional factor in higher IDWG in diabetic patients.