Another potential benefit of diabetes management is prevention of arterial calcification and peripheral artery disease (PAD), common by stage 5 CKD and a predictor of cardiovascular mortality. The positive impact of early intensive diabetes control on PAD is demonstrated in recently published results of a 12-year observational study of 1,398 previous DCCT participants (Diabetes Care. 2007;30:2646). During this follow-up study, called the Epidemiology of Diabetes Interventions and Complications (EDIC) trial, subjects returned to usual care from their health-care providers, with annual examinations including measurement of ankle-to-brachial ratio index (ABI) as a marker for PAD.
The authors note that “in diabetes, a high-pressure ABI due to medial wall arterial calcification and noncompressible vessels may be associated with adverse outcomes, including diabetic kidney disease.” Study results demonstrated that “intensive therapy administered during the DCCT may be protective for peripheral arterial calcification, consistent with the previous coronary calcification findings on this same cohort.”
The latest statement of the American Diabetes Association (ADA), “Nutrition Recommendations and Interventions for Diabetes” (Diabetes Care. 2007;30, Suppl 1:S48-S63), outlines recommendations for how to improve HgA1c that are applicable to patients with CKD. These include:
- “In overweight and obese insulin-resistant individuals, modest weight loss (5-7%) improves insulin resistance.”
- “Physical activity and behavior modification aid weight loss.”
- “High-protein diets are not recommended as a method for weight loss”; and regarding prevention of microvascular complications, “reduction of protein intake (0.8-1.0 gm/kg/day in early CKD, 0.8 gm/kg/day in later pre-dialysis stages) may improve measures of renal function (urine albumin excretion, GFR) and is recommended.” This is slightly more liberal than the KDOQI diabetes guidelines which recommend limiting protein to 0.8 gm/kg/day for all early CKD stages (1-4).
- “Low-carbohydrate diets of <130 gm/day are not recommended.” Instead, “monitor carbohydrates to achieve glycemic control.”
A major point of agreement between the ADA and NKF guidelines is on the importance of early referral for medical nutrition therapy (MNT) by a registered dietitian. With MNT, a Medicare-covered service for CKD patients, timely nutrition intervention may help slow disease progression, improving outcomes. A list of board-certified specialists in renal nutrition can be found at http://www.cdrnet.org/certifications/spec/rstatelist.htm.
Ms. Blair is a renal dietitian working on her doctorate in clinical nutrition at the University of Medicine and Dentistry of New Jersey.