Medical nutrition therapy in diabetes
Medical nutrition therapy helps patients better manage their diabetes.
Although type 2 diabetes is preventable, its prevalence and incidence are rapidly increasing in the United States and worldwide.1 Currently, more than 5.4% of adults worldwide have a diagnosis of diabetes, and an estimated 300 million will have diabetes by 2025.2 In 2012, the American Diabetes Association estimated the total cost of diabetes in the United States to be $245 billion, compared with $174 billion in 2007—a 41% increase over this 5-year period. People who have a diagnosis of diabetes spend approximately $13,700 per year on medical expenses, with $7,900 of that going toward diabetes management.3
To reduce medical complications and optimize blood glucose control, medications are only part of the solution. Clinicians and patients must work together to change behaviors that lead to subsequent problems of uncontrolled blood glucose levels.2 With no cure available for diabetes, primary prevention through diet and exercise is important.1
According to Bantle et al4, medical nutrition therapy is a crucial component of glycemic control to help manage existing diabetes and prevent or slow the rate of complications of the disease. Medical nutrition therapy in diabetes is based on an assessment of the patient's nutrition status; it consists of diabetes self-knowledge, individually identified and designed nutrition goals, meal planning that is flexible for the patient and easily implemented, and last, the evaluation of outcomes to ascertain if further changes are needed.5 The Institute of Medicine found that medical nutrition therapy improves clinical outcomes and decreases the cost of managing diabetes.5 The purpose of this review is to examine the literature on the benefits of medical nutrition therapy as part of controlling diabetes and preventing complications, which in turn can reduce the overall costs of diabetes care.
To search specifically for articles on medical nutrition therapy in patients with type 2 diabetes, two databases were used: CINAHL (Cumulative Index of Nursing and Allied Health Literature) and PubMed. The terms used for the CINAHL search were diabetes type 2 interventions and diabetic medical nutrition therapy; for the PubMed search, they were diabetes type 2, interventions, medical nutrition therapy, cost-analysis, and nutrition therapy. MeSH (Medical Subject Headings) terms used were diabetes mellitus type 2 and nutrition therapy. The CINAHL search yielded one relevant article, and the PubMed search 223 articles. The PubMed search was most useful after it had been narrowed to include only randomized controlled trials and systematic reviews; 63 relevant articles were then found based on title and publication date. After a review of information in the abstracts, 11 articles were chosen, and following further narrowing to focus specifically on medical nutrition therapy in diabetes, four studies remained for detailed review.
In a randomized controlled trial, Franz F et al6 focused on the cost-effectiveness of medical nutrition therapy for patients with non-insulin-dependent diabetes. Participants received either medical nutrition therapy based on practice guidelines or basic nutrition therapy. Therapy consisted of three visits with a dietitian. The basic nutrition group met with a dietitian once and collaborated with a physician to formulate a nutrition care plan. The outcome defining cost-effectiveness was the effect of medical nutrition therapy on glucose control, which was determined by measuring the fasting blood sugar and hemoglobin A1C levels after 6 months. As the hemoglobin A1C decreases as a result of dietary restrictions, insulin sensitivity increases; therefore, less medication is needed to control blood glucose. The medical nutrition therapy group had medication cost savings of $31.49 per year, whereas the basic nutrition group had savings of $3.13.6
A randomized controlled trial by Franz MJ et al7 assessed the effects of medical nutrition therapy on patients with a new diagnosis of non-insulin-dependent diabetes. Patients were placed into two groups, with the first receiving medical nutrition therapy and the second receiving only basic nutrition therapy from a dietitian. The main difference between the groups was the intensity of the dietary instruction by the dietitians. The authors tracked glucose control in both groups. The group receiving medical nutrition therapy had significantly better glycemic control than the basic nutrition group. An indirect finding of the study was that patients who had had diabetes for a longer period of time benefited more from intense medical nutrition therapy than did those with newly diagnosed diabetes.7
A clinical trial by Johnson and Valera8 evaluated the use of medical nutrition therapy in primary care for patients with non-insulin-dependent diabetes. The patients had at least three visits with a registered dietitian, and each time they were seen in the office, a random finger stick was done to check the blood sugar. Within 2 weeks, a 41% decrease in the blood sugar level was observed in 14 of 21 patients. At the end of the study, the blood sugar levels were 50% lower in 16 of the 21 patients.8